Differential systemic inflammatory responses after TAVI: The role of self versus balloon expandable devices.

OBJECTIVE: Transcatheter aortic valve implantation (TAVI) provokes early injury response, represented in part by dynamic changes in the inflammatory markers. The association of self-expanding valves (SEVs) and balloon-expandable valves (BEVs) with the consequent inflammatory response remains uncertain.
MATERIALS AND METHODS: Patients with severe symptomatic aortic stenosis who underwent transfemoral TAVI: SEVs or BEVs, from January 2010 to December 2019 were enrolled. Whole white blood cells (WBC) and subpopulation dynamics as well the neutrophil to lymphocyte ratio (NLR) were evaluated.
RESULTS: Three-hundred seventy consecutive patients (mean age 81.75 ± 6.8 years, 199 women's) were enrolled. In the entire population, significant kinetic changes in the WBC response (p <0.0001) between admission and first 24 hours post procedure, with a significant increase in total WBC (7.46 ± 2.26 to 10.08 ± 3.55) and absolute neutrophil count (4.97 ± 2.06 to 8.19 ± 3.43), NL ratio (3.72 ± 2.8 to 9.76 ± 7.29), and a meaningful decrease in absolute lymphocytes count (1.67 ± 1.1 to 1.1 ± 0.76). When compared between the types of valves, SEVs were associated with a more pronounced inflammatory response than BEVs, with total WBC (10.44 ± 3.86 vs. 9.45 ± 3.19) neutrophils (8.56 ± 3.75 vs. 7.55 ± 3.06) with p 0.016 and 0.012 respectively.
CONCLUSION: This is the first description of a differential inflammatory response between the two leading delivery systems. SEV appears to trigger a more robust inflammatory response as compared to BEV. Clinical studies are warranted to assess the long term effect of our findings.

Introduction

Previous studies have reported that developing a systemic inflammatory response syndrome (SIRS) after transcatheter valve implantation (TAVI) is associated with poor prognosis [1-7]. In recent years, much effort has gone into improving existing prognostic models for risk stratification of patients undergoing TAVI. The neutrophil to lymphocyte ratio (NLR) is a well described prognostic marker in cardiovascular medicine [8-11]. There is no clinical data comparing the impact of self-expandable valves (SEV) and balloon-expandable valves (BEV), the two leading implantation systems on NLR. The objective of our study was to investigate the differences among these two systems with respect to the value and kinetic behavior of white blood cells (WBC) and their subsets after TAVI and compare the short-term outcomes of these procedures.

As inflammation triggers a series of biological processes that could potentially promote the long term viability of the valves, it is important to study differences in the pro-inflammatory behavior of different valves and associate those with long term durability and outcome.

Materials and methods

Study participants and TAVI procedure

We retrospectively included patients with severe symptomatic aortic stenosis who underwent trans-femoral TAVI in our center between January 2010 and December 2019. This study approved by the local Helsinki committee, Kaplan Medical Center, confirmation number 0091-20-KMC. The data used was completely anonymized, de-identified, and aggregated before access and analysis.

We excluded patients who did not have repeated blood tests and those with periprocedural death (up to 72 hours after TAVI). The type and size of the valves were at the discretion of the local heart team after they assembled, and a decision was made according to the patient’s anatomical and clinical characteristics. Patients treated with BEV were implanted with either Sapien, Sapien XT, or S3 (Edwards Lifesciences, Irvine, California) valves. Patients treated with SEV were implanted with either Corevalve, Evolute-Pro, or Evolute-R (Medtronic, Inc., Minneapolis, Minnesota) valves. The small number of subjects treated with other valves was also excluded from the analysis. Trans-femoral vascular access and closure was performed using the percutaneous approach with the safety wire technique and the Prostar XL (Abbott Vascular, Redwood City, California) vascular closure device. The procedure duration was calculated as "skin to skin", i.e. time 0 was the opening of the arterial blood pressure from the accessory support access and the final time was represented by the closure of this accessory support access. Since then, we also used local anesthesia with conscious sedation as a first-line approach. All patients received unfractionated heparin to maintain a minimum active clotting time >250 seconds after the insertion of the femoral sheet. Protamine (1 mg for each 100 U of heparin, maximal dose 50 mg) was administrated at the time of vascular closure if needed. The use of prophylactic antibiotics during the procedure or hospital stay was routinely avoided. Aspirin was recommended before TAVI. Dual-antiplatelet treatment with aspirin 100 mg and clopidogrel 75 mg was started the day before the procedure and followed thereafter for six months, except for patients requiring chronic oral anticoagulation.

Blood samples, inflammatory markers and definition criteria for events

Baseline characteristics, procedural data, and clinical outcomes were collected. Blood samples were obtained using a 21G sterile syringe without stasis. Laboratory analyses were performed before the procedure, during the patient’s postprocedural intensive care unit stay on a daily basis, and at the physician’s discretion in the cardiology ward, and were retrospectively collected. Neutrophil-Lymphocyte Ratio (NLR) was calculated using this formula: [NLR = absolute neutrophils count/absolute lymphocytes count]. The definition of the patients’ baseline characteristic risk factors included the corresponding diagnosis in the medical records together with the chronic use of anti-hypertensive, glycemic control and lipid lowering drugs, respectively. Coronary artery disease (CAD), atrial fibrillation, peripheral arterial disease and strokes, were based on the medical records and confirmed by complementary clinical tools, such as angiograms in CAD. All the outcome definitions were strictly determined according the Valve Academic Research Consortium 2 Criteria (VARC-2). Standard follow-up included 30-day and six-month visits after hospital discharge. This follow-up was performed on site.

Statistical analysis

Data are presented as means ± standard deviations. Continuous variables between the various study groups were tested for normality by a Shapiro- Wilk test and when an abnormal distribution was found, a Mann- Whitney test was performed. When the distribution was normal, a t-test was used. Pearson’s chi-square test was performed for categorical variables when appropriate. Main effect estimates are presented with their 95% confidence interval.

We divided the patients into two groups according to the TAVI expandable system. One group was patients receiving SEV and the other were patients receiving BEV. Repeated measures analysis of variance was used to determine any significant differences between variability over time between SEV and BEV. The Kaplan-Meier method was used for cumulative survival analysis after six months. To compare the survival between patients that received SEV TAVI and patient that received BEV TAVI, a log-rank test was used when appropriate. A value of P<0.05 was defined as statistically significant. Analyses were performed using IBM Statistical Package for the Social Sciences (SPSS) version 23.0 (IBM Corp., Armonk, NY).

Results

Patients’ and procedural characteristics

During the ten years study period, 370 consecutive patients were enrolled. The study flowchart is shown in Fig 1. Only 22 patients were excluded. The analyzed population included 348 patients (57.2% female, mean age 81.7 ± 6.8 years) with severe, symptomatic aortic stenosis (mean transaortic pressure gradient 45.0 ± 13.9 mmHg), and high or prohibitive operative risk (STS score of 8.01 ± 1.5). Baseline and procedural characteristics of the study population according to types of expandable systems are summarized in Table 1.

Fig 1

Study flowchart of patients from 2010 to 2019.

A total of 370 patients were treated with TAVI. After excluding 22 patients, a total of 348 patients were finally included in the analysis.

Table 1

Patients’ and procedural characteristics.

	Overall (N = 348)	Balloon expandable valve (N = 120)	Self-expandable valve (N = 228)	p value
Clinical Characteristic
Age, years	81.75 ± 6.85	81.92 ± 6.28	81.66 ± 7.14	0.744
Women (%)	199 (57.2%)	67 (55.8%)	132 (57.9%)	0.798
Body mass index, kg/m2	28.20 ± 5.14	28.44 ± 5.17	28.07 ± 5.13	0.522
Hypertension (%)	321 (92.2%)	113 (94.2%)	208 (91.2%)	0.445
Diabetes (%)	144 (41.5%)	51 (42.5%)	93 (41.0%)	0.872
Dyslipidemia (%)	262 (75.3%)	91 (75.8%)	171 (75.0%)	0.968
Smoker (%)	33 (9.5%)	11 (9.2%)	22 (9.7%)	1
Atrial Fibrillation (%)	100 (29.1%)	36 (30.0%)	64 (28.6%)	0.878
Coronary artery disease (%)	138 (39.9%)	40 (33.6%)	98 (43.2%)	0.108
Peripheral artery disease (%)	44 (12.7%)	15 (12.6%)	29 (12.8%)	1
Previous myocardial infarction(%)	33 (9.5%)	6 (5.0%)	27 (11.9%)	0.059
Previous stroke (%)	28 (8.0%)	5 (4.2%)	23 (10.1%)	0.085
Previous pacemaker (%)	43 (12.4%)	14 (11.8%)	29 (12.7%)	0.933
CABG (%)	16 (7.3%)	7 (9.6%)	9 (6.1%)	0.511
STS Score	8.01 ± 1.5	8.04 ± 1.45	7.95 ± 1.62	0.617
Medications
Aspirin (%)	221(63.5%)	74(61.6%)	147(64.4%)	0.720
P2Y12 inhibitors (%)	93(26.7%)	23(19.1%)	70(30.7%)	0.281
DAPT therapy (%)	55 (15.8%)	18(15.0%)	37 (16.2%)	0.890
Statin (%)	254 (72.9%)	84 (70.0%)	170 (74.5%)	0.621
Glucophage (%)	114 (32.7%)	40 (33.3%)	74 (32.4%)	0.848
Insulin (%)	88 (25.2%)	25 (20.8%)	63 (27.6%)	0.504
Steroids (%)	33 (9.4%)	9 (7.5%)	24 (10.9%)	0.162
Anticoagulant (%)	84 (24.1%)	30 (25.0%)	54 (23.6%)	0.696
ACE-I / ARBs (%)	293 (84.1%)	95 (79.1%)	198 (86.8%)	0.732
Beta Blockers (%)	198 (56.8%)	74 (61.6%)	124 (54.3%)	0.663
Echocardiography
LVEF (%)	52.8 ± 9.8	52.5 ± 10.1	53.5 ± 9.3	0.408
Septum thickness (mm)	13.55 ± 2.04	13.45 ± 2.03	13.6 ± 2.06	0.501
Aortic valve area (cm2)	0.69 ± 0.16	0.71 ± 0.15	0.67 ± 0.15	0.393
Aortic valve gradient (mm Hg)	45.0 ± 13.9	45.6 ± 15.1	44.0 ± 11.6	0.704
Blood count
WBC (K/uL)	7.51 ± 2.35	7.50 ± 2.15	7.51 ± 2.46	0.951
Absolute Neutrophils (K/uL)	5.03 ± 2.16	5.02 ± 1.86	5.04 ± 2.30	0.91
Absolute Lymphocytes (K/uL)	1.66 ± 1.06	1.61 ± 0.69	1.68 ± 1.22	0.575
NLR	3.78 ± 2.82	3.82 ± 2.62	3.76 ± 2.93	0.844
Procedure details
Contrast volume (ml)	134.79 ± 59.84	129.67 ± 57.54	137.48 ± 60.96	0.25
Time (minutes)	93.19 ± 32.83	92.86 ± 31.84	93.36 ± 33.40	0.895

Values are mean ± SD or n (%).

ACE-I = Angiotensin Converting Enzyme Inhibitor; ARBs = Angiotensin Receptor Blockers; CABG = coronary artery bypass; STS = Society of Thoracic Surgeons; LVEF = left ventricle ejection fraction; WBC = white blood cells; NLR = Neutrophils to Lymphocytes Ratio.

There were no significant differences between the two group types at baseline and no differences in procedural characteristics.

Inflammatory markers dynamics

Baseline total WBC, absolute cell counts of neutrophils, monocytes and lymphocytes, and neutrophil to lymphocytes ratio (NL Ratio) and their dynamic changes after TAVI for the total study population are summarized in Table 2. In the entire population, we noticed that there were significant kinetic changes in the WBC response (p value <0.0001) between admission, 24 hours and 72 hours post procedure, with significant increases in WBC, neutrophils absolute, monocytes absolute, NL ratio, and significant decreases in absolute lymphocyte count.

Table 2

Dynamic changes of WBC and their subpopulation after TAVI.

	Admission	24h	72h	6 Month	p1	p2	p3
WBC (K/uL)	7.46 ± 2.26	10.08 ± 3.55	9 ± 2.91	7.47 ± 2.38	<0.0001	<0.0001	1.000
Absolute Neutrophils (K/uL)	4.97 ± 2.06	8.19 ± 3.43	6.73 ± 2.79	4.89 ± 2.04	<0.0001	<0.0001	1.000
Absolute Lymphocytes (K/uL)	1.67 ± 1.1	1.1 ± 0.76	1.29 ± 0.59	1.76 ± 1.09	<0.0001	<0.0001	1.000
Absolute Monocytes (K/uL)	0.55 ± 0.24	0.65 ± 0.44	0.74 ± 0.37	0.33 ± 0.92	0.004	<0.0001	0.715
NLR	3.72 ± 2.8	9.76 ± 7.29	6.52 ± 4.66	3.36 ± 2.23	<0.0001	<0.0001	1.000

Values are mean ± SD.

p1 = Comparison of pre-procedural values with those at 24h.

p2 = Comparison of pre-procedural values with those at 72h.

p3 = Comparison of pre-procedural values with those at 6 months.

WBC = white blood cells; NLR = Neutrophils to Lymphocytes Ratio.

Fig 2 shows the dynamic changes of white blood cells and its differential subsets with time, in the first 72 hours post-procedure. There is a significant increase in inflammatory markers including total WBC, neutrophils, monocytes and NL ratio.

Fig 2

Dynamic changes of leukocytes and its components after TAVI, (A) dynamic changes in total WBC with time, (B) dynamic changes in Neutrophils with time, (C) dynamic changes of lymphocytes with time, (D) dynamic changes of NL ratio with time, (E) dynamic changes of monocytes with time.

LYMP. abs = Absolute Lymphocytes (K/uL); NEUT. abs = Absolute Neutrophils (K/uL); MONO. abs = Absolute monocytes (K/uL); WBC = White Blood Cells (K/uL); NLR = Neutrophils to Lymphocytes Ratio.

When comparing between the two valve systems as shown in Fig 3, SEVs were associated with a more pronounced inflammatory response than BEVs, with total WBC 10.44 ± 3.86 vs. 9.45 ± 3.19 neutrophils 8.56 ± 3.75 vs. 7.55 ± 3.06 with p value 0.016 and 0.012 respectively. The Kaplan-Meier survival curve at the ten-year follow up is shown in Fig 4. During the ten-year study period, we found no significant differences between the two types of expandable systems (p value 0.949).

Fig 3

Difference in two types of expandable system for leukocytes and its components after TAVI, (A) difference in total WBC with time, (B) difference in Neutrophils with time, (C) difference in lymphocytes with time, (D) difference in NL ratio with time.

SEV = Self Expandable Valve; BEV = Balloon Expandable Valve; LYMP. abs = Absolute Lymphocytes (K/uL); NEUT. abs = Absolute Neutrophils (K/uL); WBC = White Blood Cells (K/uL); NLR = Neutrophils to Lymphocytes Ratio.

Fig 4

Kaplan Meir curve based on all cause mortality for patients underwent TAVI, showing no difference in survival between the two TAVI types during ten years follow up.

SEV = Self Expandable Valve; BEV = Balloon Expandable Valve.

The variables that may be related to an increase in inflammatory markers after TAVI are presented in Table 3. In the variable analysis, the duration of the procedure and the amount of contrast used were related to a heightened inflammatory response with a p value < 0.01. Septum thickness at baseline (13.55 ± 2.04) was associated with a higher risk for inflammatory response post-procedure with a significant p value.

Table 3

Variable analysis of factors that may influence inflammatory markers at 24 hours post TAVI ┼.

		WBC		Abs. Neutrophils		Abs. Lymphocytes		NLR
		(mean ± SD)	p value	(mean ± SD)	p value	(mean ± SD)	p value	(mean ± SD)	p value
Total		10.101 ± 3.671		8.216 ± 3.559		1.095 ± 0.729		9.855 ± 7.534
Baseline characteristics
Gender	Women	10.151 ± 3.798	0.795	8.282 ± 3.713	0.568	1.144 ± 0.863	0.273	9.811 ± 7.873	0.838
	Men	10.033 ± 3.504		8.125 ± 3.35		1.029 ± 0.491		9.913 ± 7.081
Age*, years		0.024	0.652	0.012	0.823	-0.014	0.8	0.035	0.518
Body mass index*, kg/m2		0.101	0.062	0.077	0.152	0.127	0.018	-0.004	0.937
Hypertension	no	10.266 ± 4.814	0.791	8.578 ± 4.657	0.576	0.946 ± 0.434	0.258	10.682 ± 6.417	0.593
	yes	10.086 ± 3.567		8.184 ± 3.458		1.107 ± 0.747		9.785 ± 7.625
Diabetes	no	10.111 ± 3.705	0.877	8.323 ± 3.65	0.459	1.055 ± 0.681	0.315	10.237 ± 7.833	0.474
	yes	10.095 ± 3.645		8.073 ± 3.443		1.148 ± 0.792		9.354 ± 7.098
Dyslipidemia	no	10.253 ± 3.479	0.77	8.446 ± 3.272	0.449	1.021 ± 0.452	0.684	9.796 ± 5.786	0.875
	yes	10.05 ± 3.736		8.139 ± 3.65		1.118 ± 0.798		9.874 ± 8.034
Smoker	no	10.077 ± 3.706	0.909	8.202 ± 3.605	0.974	1.09 ± 0.741	0.915	9.879 ± 7.628	0.698
	yes	10.332 ± 3.42		8.381 ± 3.175		1.134 ± 0.623		9.75 ± 6.761
Atrial Fibrillation	no	10.172 ± 3.682	0.643	8.294 ± 3.545	0.565	1.081 ± 0.659	0.949	9.823 ± 7.281	0.915
	yes	9.952 ± 3.684		8.034 ± 3.627		1.14 ± 0.887		9.837 ± 8.163
Coronary artery disease	no	10.312 ± 3.968	0.215	8.363 ± 3.868	0.38	1.142 ± 0.856	0.309	10.112 ± 8.58	0.343
	yes	9.768 ± 3.145		7.983 ± 3.011		1.018 ± 0.474		9.496 ± 5.637
Peripheral artery disease	no	10.125 ± 3.689	0.911	8.232 ± 3.586	0.956	1.1 ± 0.756	0.59	9.895 ± 7.643	0.842
	yes	10.041 ± 3.63		8.192 ± 3.457		1.063 ± 0.532		9.709 ± 6.974
Previous myocardial infarction	no	10.173 ± 3.726	0.446	8.275 ± 3.629	0.507	1.104 ± 0.755	0.46	9.962 ± 7.748	0.467
	yes	9.647 ± 2.857		7.834 ± 2.647		1.024 ± 0.402		8.987 ± 5.151
Previous stroke	no	10.098 ± 3.668	0.945	8.21 ± 3.555	0.918	1.095 ± 0.745	0.785	9.906 ± 7.654	0.649
	yes	10.132 ± 3.764		8.275 ± 3.661		1.085 ± 0.508		9.27 ± 6.08
Previous pacemaker	no	10.112 ± 3.746	0.992	8.209 ± 3.619	0.84	1.109 ± 0.75	0.288	9.632 ± 7.253	0.163
	yes	10.09 ± 3.138		8.319 ± 3.151		0.997 ± 0.562		11.472 ± 9.286
CABG	no	9.913 ± 3.533	0.305	8.025 ± 3.435	0.359	1.119 ± 0.703	0.387	9.31 ± 7.272	0.966
	yes	8.977 ± 3.062		7.215 ± 2.79		0.963 ± 0.479		9.23 ± 5.84
STS Score*		0.134	0.423	0.312	0.52	0.114	0.81	0.135	0.518
Baselines Echo
LVEF (%) *		0.1	0.065	0.008	0.139	0.106	0.048	0.015	0.799
AVA (cm2) *		-0.023	0.689	-0.03	0.602	0.074	0.201	-0.025	0.656
AV Gradient mean (mm Hg) *		0.036	0.698	0	0.999	0.108	0.236	-0.014	0.881
LVEDD (mm) *		-0.024	0.664	-0.014	0.798	-0.051	0.346	0.047	0.389
Septum thickness (mm) *		0.118	0.029	0.108	0.045	0.001	0.985	0.08	0.14
MR-Pre	other	10.020 ± 3.443	0.598	8.064 ± 3.292	0.33	1.116 ± 0.522	0.537	9.019 ± 6.098	0.019
	moderate to severe	10.233 ± 3.991		8.445 ± 3.907		1.066 ± 0.946		11.057 ± 9.072
Procedure related
TAVI types	SEV	10.442 ± 3.859	0.016	8.564 ± 3.751	0.012	1.068 ± 0.514	0.353	10.096 ± 7.463	0.411
	BEV	9.451 ± 3.197		7.552 ± 3.068		1.145 ± 1.02		9.396 ± 7.676
Contrast volume (ml)*		0.192	<0.001	0.209	<0.001	-0.068	0.205	0.22	<0.001
Time (minutes)*		0.204	<0.001	0.243	<0.001	-0.172	<0.001	0.33	<0.001
Post dilatation	no	10.129 ± 3.684	0.785	8.214 ± 3.573	0.926	1.115 ± 0.769	0.156	9.702 ± 7.365	0.28
	yes	9.95 ± 3.681		8.208 ± 3.567		0.996 ± 0.515		10.643 ± 8.373
Post TAVI Echo
AV Gradient (mm Hg) *		0.058	0.305	0.073	0.195	-0.004	0.947	0.037	0.512
AI Post (moderate)*		0.012	0.865	0.017	0.812	-0.132	0.06	-0.017	0.81

┼ Data are presents as means ± standard deviations. Continues variables between the various study groups were tested for normality by Shapiro- Wilk test and when abnormal distribution was found Mann- Whitney test was performed, when the distribution was normal t—test was used.

* Correlation between two Continues variables was tested by Pearson Correlation.

TAVI = transcatheter valve implantation; CABG = coronary artery bypass; STS = Society of Thoracic Surgeons; LVEF = left ventricle ejection fraction; AVA = aortic valve area; AV = aortic valve; LVEDD = left ventricular end diastolic diameter; MR = Mitral Regurgitation; SEV = self-expandable valve; BEV = balloon expandable valve; AI = aortic insufficiency; WBC = white blood cells; Abs = absolute; NLR = Neutrophils to Lymphocytes Ratio.

Inflammatory response according the valve delivery system

We found a positive significant association between the types of the expandable system and inflammatory markers, with SEV implantation predicting an elevated inflammatory response as also demonstrated in Fig 3.

Clinical outcomes

The thirty-day clinical outcomes according to the Valve Academic Research Consortium-2 criteria are summarized in Table 4. An increase in WBC post-TAVI was associated with higher rates of major bleeding, arrhythmia and mortality at 30 days (Table 5).

Table 4

Association of inflammatory markers at 24 hours and thirty days outcome in patient underwent TAVI ┼.

		WBC		Abs. Neutrophils		Abs. Lymphocytes		NLR
		(mean ± SD)	p value	(mean ± SD)	p value	(mean ± SD)	p value	(mean ± SD)	p value
Total		10.1 ± 3.671		8.216 ± 3.559		1.095 ± 0.729		9.855 ± 7.534
30 days mortality	NO	9.997 ± 3.544	0.008	8.11 ± 3.427	0.005	1.098 ± 0.734	0.609	9.69 ± 7.39	0.014
	YES	14.503 ± 6.082		12.686±5.974		0.925 ± 0.433		16.857 ± 10.423
Bleeding	NO	9.979 ± 3.541	0.093	8.098 ± 3.424	0.072	1.082 ± 0.634	0.469	9.587 ± 7.111	0.005
	YES	11.485 ± 4.778		9.552 ± 4.716		1.231 ± 1.434		12.917 ± 11.016
Major vascular complication	NO	9.982 ± 3.537	0.098	8.115 ± 3.452	0.18	1.107 ± 0.749	0.85	9.545 ± 7.099	0.067
	YES	11.46 ± 4.605		9.369 ± 4.367		1.007 ± 0.539		12.872 ± 10.566
Stroke	NO	10.067 ± 3.526	0.705	8.171 ± 3.405	0.74	1.1 ± 0.734	0.098	9.697 ± 7.058	0.608
	YES	10.541 ± 6.07		8.985 ± 6.071		0.891 ± 0.496		13.483 ± 14.152
MI	NO	10.081 ± 3.665	0.419	8.192 ± 3.545	0.448	1.094 ± 0.732	0.511	9.78 ± 7.274	0.844
	YES	11.442 ± 4.241		9.778 ± 4.584		1.152 ± 0.556		14.99 ± 19.13
AKI	NO	10.046 ± 3.624	0.527	8.165 ± 3.509	0.573	1.086 ± 0.729	0.365	9.728 ± 6.903	0.525
	YES	11.044 ± 4.402		9.086 ± 4.342		1.242 ± 0.727		12.053 ± 14.844
Arrhythmia	NO	10.02 ± 3.762	0.375	8.07 ± 3.599	0.151	1.15 ± 0.815	0.023	9.205 ± 6.696	0.017
	YES	10.291 ± 3.453		8.561 ± 3.452		0.963 ± 0.44		11.401 ± 9.077

┼ Data are presents as means ± standard deviations. Continues variables between the various study groups were tested for normality by Shapiro- Wilk test and when abnormal distribution was found Mann- Whitney test was performed, when the distribution was normal t—test was used

AKI = acute kidney injury; Abs = absolute; NLR = Neutrophils to Lymphocytes Ratio; WBC = white blood cells.

Table 5

Thirty-days outcomes of patients after TAVI, SEV vs. BEV ┼.

Variable	Total	SEV	BEV	p Value
	(n = 348)	(n = 228)	(n = 120)
30 days mortality	8 (2.3%)	7 (3.1%)	1 (0.8%)	0.271
Bleeding	28 (8.0%)	19 (8.3%)	9 (7.5%)	0.786
Major vascular complication	33 (9.5%)	22 (9.6%)	11 (9.2%)	0.884
Stroke	16 (4.6%)	11 (4.8%)	5 (4.2%)	0.774
Myocardial infarction	5 (1.4%)	4 (1.8%)	1 (0.8%)	0.663
Acute Kidney Injury	19 (5.5%)	14 (6.1%)	5 (4.2%)	0.441
Arrhythmia	103 (29.6%)	71 (31.3%)	32 (26.7%)	0.385

┼ Categorical and Nominal variables were reported by prevalence and percentages and were analyzed by pearson’s chi-square (χ2) test and Fisher’s Exact Test.

Discussion

We observed an acute increase in leukocytes and their subpopulations, and consequently, increased NLR after TAVI. This response was also found to be associated with a worse 30 days outcome. SEV is associated with more leukocytosis, more lymphopenia and a higher NLR.

SIRS has been described in different cardiovascular scenarios such as acute coronary syndromes, heart failure and interventional procedures, including TAVI. In this last setting, a comprehensive understanding of the underlying biological responses to the prosthesis is essential to corroborate with potential future complications. These triggers comprise of three main pathogenic pathways leading to SIRS’ clinical manifestations: activation of leucocytes and other inflammatory components, endothelial injury, and myocardial/pericardial injury.

In this work, we studied different inflammatory markers that may potentially affect clinical outcome. We found that there is a more than an 80% increase in total leukocyte count, neutrophil count and a decrease in lymphocyte count, in the first 72 hours post TAVI in our study population. Post-TAVI, 47% of the patients had total WBC and an absolute neutrophils counts of more than 11 K/uL and 8, 11 K/uL, respectively. As recently described by Baratchi et al. [12] monocytes have a pivotal role in the chronic process and contribute to aortic stenosis development. We found a significant rise in the monocytes count in the acute phase, but we did not measure their activated function. This limits the possible interpretations.

The neutrophil to lymphocyte ratio (NLR) has been proposed as an accurate prognostic marker of a systemic inflammatory response in previous studies [8-11]. In our study, 57% of the study population had an NLR of more than nine which is considered moderate to high stress and a robust inflammatory marker.

Neutrophils mediate some of the inflammatory responses to acute injury by numerous biochemical mechanisms, resulting in further tissue damage. These include the release of arachidonic acid metabolites and platelet-aggravating factors, cytotoxic oxygen–derived free radicals [13], myeloperoxidase [14], elastase [15], various hydrolytic enzymes such as acid phosphatases [16], etc. The relative lymphopenia observed post TAVI can be explained by the endogenous cortisol segregation response to the procedure’s stress [17].

Our results are in agreement with those obtained by Condado, et al. [18], who reported that an elevated NLR is associated with the occurrence of composite adverse outcomes at 30 days in patients undergoing balloon expandable TAVI. We extended this observation to SEV as well as BEV systems comparatively.

Our findings suggesting a link between post TAVI peri-nflammatory response and poorer 30 days outcome is similar to a previous study by Schwietz T, et al. [3]. They describe that the occurrence of SIRS in the first 48 hours post-procedure is associated with impaired prognosis following TAVI, but they included both transfemoral and transapical access routes while our findings related only to the femoral approach. The transapical approach is associated with significantly more organ trauma and consequent inflammatory response that could have clouded the results. Despite the statistically significant differences between the two types of valves at 24 hours post-procedure, this is not reflected in the survival rate. This is similar to other clinical situations where laboratory significant changes are seen without a clinical translation. Similarly, thrombocytopenia after TAVI is a universal and virtually inevitable phenomenon in more than 90% of the patients [19]. However, a clinical impact is only found when there is an extreme thrombocyte count drop. In our present study, we did not discriminate according to the inflammatory response intensity and the clinical outcomes, which probably can shed light this finding.

The procedure risk score assessment is a dynamic process, it will change according the clinical evolution. We propose to add our findings, as they are inexpensive to do, to the well-established and known pre-TAVI procedure scores, such as CAPRI. We have demonstrated that a simple, routine test WBC count and its differential is a potentially valuable screening tool for risk stratification of patients who undergo TAVI. The association between unfavorable 30 day outcomes of deaths, bleeding and vascular access complications, according to the VARC-2 definition, highlights that the more complex procedures provoke major inflammatory responses. Therefore, less favorable outcomes or inherently, a major inflammatory response predisposes the patient to unfavorable clinical events related to the existing milieu. The addition of NLR to the TAVI risk score improved the predictability of MACE after TAVI. This cost-effective routine test can possibly guide or even justify upcoming anti-inflammatory therapies in patients with severe aortic stenosis post TAVI if a cause and effect relationship is firmly established between inflammation and poorer outcome.

To the best of our knowledge, we are the first to describe a difference between the two leading TAVI valve systems that impose different mechanical stresses on the vessel wall and have different cusp origins. SEV is associated with a higher pro-inflammatory response as compared with the BEV system. The underlying explanation can be ascribed to the differences in the delivery systems. BEV’s frame is comprised of cobalt chromium, and the leaflet component is based on bovine tissue whereas the SEV is made of a nitinol scaffold and the cusps-leaflet component is porcine pericardial tissue. Adverse responses to xenogeneic pericardium-based valves might be prevented by tissue decellularization, ideally removing all cells and preserving the original extracellular matrix. A comparative assessment of acellular pericardia from different species is still lacking, as opposed to the commonly implanted glutaraldehyde (GA) preserved native tissues. Submitting native tissues to a decellularization process causes different effects on these tissues in terms of their histological, immunohistochemical, biochemical, and ultrastructural properties, as well as their denaturation, biomechanical, and cytocompatibility profiles [20]. Additionally, the decellularization process can degrade matrix components, which result in loss of extracellular matrix integrity [21]. The resultant tissue deterioration can lead to degenerative structural graft failure [21]. A major concern with porcine-derived materials is the presence of residual cells, DNA, and the alpha-Gal epitope after the decellularization process. These issues justify the ongoing efforts to achieve a reliable and safe tissue-engineered heart valve (TEHV).

Endothelial injury and foreign body placement lead to the activation of platelets at the implant site with recruitment of circulating leukocytes. The ultimate biocompatibility of a device will be influenced by both inflammation and coagulation. Studies have found that the adsorption of fibrinogen and platelet activation to nitinol surfaces is dependent on the surface chemical composition and topography. Specifically, titanium content enhances the adsorption of fibrinogen [22, 23]. With respect to metal ion delivery, studies have shown that cobalt-chromium and stainless-steel alloys tend to release less nickel than nitinol in Hank’s solution when the surface finishing processes are similar [24]. These observations may explain the differences that we observed with regard to the differential inflammatory response to the two valvular systems.

One key to a successful TAVI procedure is the safe anchoring of the prosthesis and the alignment to the patient’s anatomy. The TAVI valve prosthesis anchoring mechanism relies entirely on oversizing that provokes different degrees of pressure and consequently subjacent tissue injury. Therefore, a radial force exists between the surrounding anatomy and the prosthesis. The influence of the delivery system and mechanical anchoring forces is the most remarkable difference between these valves. The BEV tissue injury surface is less than that of SEV due to BEV’s "ring" design and the "sleeve" shape which has more contact surface than SEV. Furthermore, the nitinol shape memory behavior of the SEV continues to expand after implantation. Thus, the apparently increased tissue stress imposed by the SEV system could account for the heightened inflammatory response as compared to the BEV system.

The use of iodinated contrast agents has also been proposed as another possible etiologic factor for the enhanced systemic inflammatory response. Their chemical properties, immunoallergic reactions, and genetic predispositions, are some of the possible explanations to understand this relationship. We presume that the association between the inflammation, procedure duration and amount of contrast agents are all surrogates of the complexity of the procedure more than a mechanistic cause. Some confounders, such as the peri-procedure use of anti-inflammatory drugs, including steroids in iodine contrast allergy mitigation was minimal and with a similar rate in the two groups, thus there is no bias.

We recognize certain limitations of this study. Being a single-center retrospective observational study is in itself a partial limitation. However, methodologically, the fact that only one team performed the procedure allowed for treatment uniformity to be maintained. Additionally, our sample size, although large, was not robust and therefore did not allow for sufficient power to detect overall mortality event rates.

In conclusion, to the best of our knowledge, this is the first report that found major differences in the early post-procedural inflammatory responses to TAVI, with SEV being associated with a heightened response as compared with BEV. These observations should be further pursued in larger studies as it may have a potentially detrimental effect on the long-term durability of these biological valves.

28 Apr 2021

PONE-D-21-04417

Differential systemic inflammatory responses after TAVI: The role of self versus balloon expandable devices

PLOS ONE

Dear Dr. Blatt,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Your manuscript has been carefully evaluated by four external reviewers and the editorial team as a Regular Article. In its present form the manuscript is not acceptable for publication.

Although all reviewers and editors found that this manuscript has merit and addresses a significant clinical problem, the reviewers raise some important questions. These comments include direct comparison in short-term SIRS between SEV and BEV (reviewer#1), other inflammatory markers (reviewers #2 and #3), medications (reviewer#2), and more detailed discussion based on the authors’ findings and metal differences between SEV and BEV (reviewers #1, #3 and #4).

The authors should address all comments that the reviewers raised. In addition to the reviewers' comments, there are several issues that the authors should address.

1)Survival rates are similar between patients with SEV and BEV, suggesting the minimum impact of TAVI-induced inflammatory response on the survival. Relevance of increased WBC and neutrophils only 24 hours post procedure should be provided. At a minimum, discuss the relevance more in detail.

2)Describe the selection process for BEV and SEV.

3)Provide information on medications including statins, other lipid lowering drugs, and anti-diabetic drugs.

4)Consider potential confounders, including medications.

5)Provide more detailed methods, including determination of study size and definition of diagnosis (hypertension, diabetes, dyslipidemia, smoker, atrial fibrillation, coronary artery disease, etc) and all outcomes (bleeding, major vascular complication, stroke, myocardial infarction, AKI, and arrhythmia).

6)Describe the time point when inflammatory markers (blood samples) were obtained post TAVI; 24 hr 72 hr or 6 months, in Table 3.

7)Explain the data on table 3 and 4 more in detail with the method of statistical analysis in the main text and table legend.

8)Describe the method of statistical analysis in Figure 3.

9)Unites are missing in a lot of data. Provide.

10)Number at risk should be provided in Figure 4.

11)Provide more detailed figure legends. Also, add figure 4 legend.

Please submit your revised manuscript by Jun 11 2021 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.

A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.

An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Michinari Nakamura, MD

Academic Editor

PLOS ONE

Journal Requirements:

When submitting your revision, we need you to address these additional requirements.

Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at

https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and

https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf

Please provide additional details regarding participant consent. In the Methods section, please ensure that you have specified (1) whether consent was informed and (2) what type you obtained (for instance, written or verbal). If your study included minors, state whether you obtained consent from parents or guardians. If the need for consent was waived by the ethics committee, please include this information.

Please include your tables as part of your main manuscript and remove the individual files. Please note that supplementary tables (should remain/ be uploaded) as separate "supporting information" files

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: No

Reviewer #2: Partly

Reviewer #3: Yes

Reviewer #4: Partly

**********

2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: No

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: Yes

**********

3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: No

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: Yes

**********

4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: Yes

**********

5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: In their manuscript titled “Differential systemic inflammatory response after TAVI: The role of self versus balloon expandable devices”, authors tried to compare SIRS between SEV and BEV. The conclusion revealed (1) SEV trigger more SIRS than BEV groups and (2) the short term effect may be associated with long term valvular durability. However, the whole tables did not show any comparison between SEV and BEV, except table 1 (demography). The remaining table just manifested total patients result. Reader may more interest in comparison of WBC, absolute neutrophils, absolute, lymphocytes, postop complication, and short-term result between SEV and BEV groups. Although authors mentioned the difference between two groups in Figure 3, there is no comparative result to enhance the effect of SIRS between two groups, such as postop complication, short-term result. These comparative results should be listed in tables so that matched their title “SEV vs BEV”. Second, short-term result was shown on table 4 and longer result was on Figure 4 (KM curve). The big problem is table 4 is calculated from total number but figure 4 statistics is from separated group. So, I am not sure the authors can conclude “the short-term effect may be associated with long term result”. Furthermore, there isn’t any postop valve evaluation result in this article. This conclusion didn’t make sense.

As authors’ mention, any implant will induce SIRS in patients. So, if authors just show total patients’ data in WBC, neutrophil, lymphocyte, N/L ratio change after TAVI without separated groups’ comparison, it is very usual and predictable result. Many aortic stent graft paper also discuss about effect of metal material and SIRS because stent graft material is very similar to TAVI’s valve support structure, especially in metal material. So, this article should classify the total patients and focus on cobalt chromium (BEV) and nitinol (SEV) comparison. Try to discuss “different” metal material to cause “different” prognosis by “different” SIRS results and statistics.

Generally speaking, this title didn’t match their result and this result (total patients) is also not special. Study of different metal material induce SIRS is frequently published in the patients who receiving aortic stent graft procedure. Please classify to two groups by BEV and SEV groups more detail. Analyze individual pre-, post- inflammation index, perioperative parameter, postoperative complication, short-term follow-up, and valvular durability so that authors can conclude “The role of self versus balloon expandable devices”

Reviewer #2: 1. The study presents the results of original research.

Yes

2. Results reported have not been published elsewhere.

To my knowledge after a brief research the results have von been published yet.

3. Experiments, statistics, and other analyses are performed to a high technical standard and are described in sufficient detail.

Yes. The data derive from a fairly large patient cohort. Performed statistical analyses seem appropriate and are described detailed

4. Conclusions are presented in an appropriate fashion and are supported by the data.

Even though the drawn Conclusions are presented well, further analyses are needed to support them. For instance no data on use of antibiotic treatments are provided. Even though especially the NLR has been shown to be a prognostic marker in cardiovascular diseases other markers of inflammation such as C - reactive protein or procalcitonin should have been taken into consideration since the authors state themselves, that SIRS is triggered among others by “activation of leucocytes and other inflammatory components”. In order to sustainable support the message more data analyses are needed.

In the discussion the passage on leaflet components spares any support by the data and remains hypothetical. The authors should discuss the fact that procedure duration impacted inflammatory response. Furthermore, the authors do not at all discuss their findings on survival.

5. The article is presented in an intelligible fashion and is written in standard English.

The manuscript is well written.

6. The research meets all applicable standards for the ethics of experimentation and research integrity.

Since the results are derived from retrospective collected data, so from my point of view no ethic problems apply.

7. The article adheres to appropriate reporting guidelines and community standards for data availability.

Yes

Reviewer #3: Khadija et al. investigated inflammatory changes that occur after transcatheter aortic valve implantation (TAVI) in 370 patients. The authors investigated the white blood cell counts before and after the procedure (24 hours), as well as the neutrophil and lymphocyte count and their ratio. The main finding is that inflammation is increased in all patients but significantly more in of self-expanding valves compared to and balloon-expandable valves. The authors discuss several potential reasons for this but do not prevent data potentially explaining this difference.

Overall this is a focused, concise and well written paper. The data are well presented.

One of the issues is that the authors should discuss that this is not a randomized trial. For this reason there remains the caveat that there is some bias in the selection of the patients.

Do the authors have monocyte data as well? There was a recent paper in Circulation (Baratchi et al. 2000) showing that monocytes are activated before TAVI and this activation is reduced after TAVI. This finding would be of interest to be discussed in the context of the authors’ current findings.

The authors should also discuss potential clinical consequences of their findings.

Reviewer #4: In this manuscript, Khadija and colleagues retrospectively investigated the kinetic of white blood cell differential counts at different time points after TAVI to compare the pro-inflammatory and prognostic impact of self-expandable and balloon expandable valves in 348 patients undergoing transcatheter aortic valve implantation (TAVI) for severe aortic stenosis. Routine laboratory records of total leukocyte, neutrophil and lymphocyte counts, and the neutrophil-lymphocyte were analyzed prior to TAVI, post-TAVI, 24 hrs, 72 hrs, and 6 months post-TAVI.

There was a significant postprocedural increase in WBS, neutrophil counts and NLR, accompanied by significant decrease in total lymphocyte counts at 24 hours and at 72 hours, followed by normalization of parameters at 6 months after TAVI. Whereas self-expandable valves were associated with more pronounced neutrophilia, there were no significant differences in 10-year patients’ survival between the both types of expandable systems. Although the dynamic changes of WBS and neutrophils after TAVI marked by a significant increase of neutrophil counts and lymphocytic drops (and the increased NL ratio, accordingly) 24 hours after TAVI are per se not particularly surprising and have been already described previously (as already cited in the current manuscript), the actual differences between the both leading TAVI delivery systems are interesting. The authors spend a great deal of the discussion dealing with the possible pathophysiological explanations for differential inflammatory response between SEVs and BEVs. This is a very learned discussion. Overall, this study is well performed and presented. I have following comments for authors' consideration.

1. I do not agree with or do not understand the authors’ discussion statement: “The addition of NLR to the TAVI risk score improved the predictability of MACE after TAVI.” What ‘TAVI risk score’ are the authors referring to? Do the authors present such data or do they refer to any published data (please include a reference if so)? Do the authors postulate that their results outline the feasibility of leukocyte counts or NLR as a novel additive tool for improved post-procedural patient assessment? Can authors prove e.g. improvement of the AUC of the ROC curve after addition of NLR to known scores (such as STS)? The authors should clarify these issues, add new analyses supporting their statements, or tone down the above sentence.

2. Why was pre-TAVI septal hypertrophy associated with a higher risk of postprocedural neutrophilia? Possible explanation? Did patients with thicker interventricular septum have possibly higher WBS/neutrophil counts at baseline – before TAVI (being indicative for pre-existing low-grade inflammation, likely associated with IVS hypertrophy/remodeling) when compared with non-hypertrophic pts? Significant basal septal hypertrophy bears the risk of maldeployment of the TAVI valve. So the presence of LVH (or septal hypertrophy) may influence the choice of TAVI delivery system. Did the patients with IV hypertrophy receive SEVs more frequently? Might the presence of LV/septal hypertrophy have biased the results while predisposing for more pronounced neutrophil mobilization (and being possibly independent on the valve type)? Please clarify/discuss.

3. Please explain/shortly discuss the association between the VARC-2-defined 30-day outcomes and WBC elevation? Why was leukocytosis associated with increasing bleeding rates? Did the bleeding events occurred within the first 24 hours after TAVI being possibly partially causative for WBS increase (inflammation is knowingly associated with bleeding events as related to stress, hematoma organization etc.). Was there any association between delivery system (SEVs vs. BEVs) and 30-day complications according to VARC-2 criteria?

**********

6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: No

Reviewer #3: No

Reviewer #4: No

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

Submitted filename: review opinion.docx

Click here for additional data file.

18 Jul 2021

Emily Chenette, Editor-in-Chief

Sara Fuentes Pérez, Senior Editor

PLoS ONE, Cardiovascular and Public Health

Dear Profs. Chenette and Fuentes Pérez,

Thank you for reconsidering our revised manuscript. We have made significant efforts to meet the reviewers' valuable comments.

Attached is a point-by-point letter addressing the comments and the changes made accordingly.

We are submitting (uploading) the revised new manuscript version and deleting the previous file. The new sentences have been placed as described in this letter below. The sentences in bold type are the updated changes.

We hope you will find the current version and the changes made, worthy of publication in the PLoS ONE Open Journal.

Detailed answers to the editor and referees comments:

1) Survival rates are similar between patients with SEV and BEV, suggesting the minimum impact of TAVI-induced inflammatory response on the survival. Relevance of increased WBC and neutrophils only 24 hours post procedure should be provided. At a minimum, discuss the relevance more in detail.

Despite the statistically significant differences between the two types of valves at 24 hours post-procedure, this is not reflected in the survival rate. This is similar to other clinical situations where laboratory significant changes are seen without a clinical translation. Similarly, thrombocytopenia after TAVI is a universal and virtually inevitable phenomenon in more than 90% of the patients. However, a clinical impact is only found when there is an extreme thrombocyte count drop. In our present study, we did not discriminate according to the inflammatory response intensity and the clinical outcomes , which probably can shed light this finding.

(These sentences were added to the main manuscript, Discussion section)

2) Describe the selection process for BEV and SEV.

The type and size of the valves were at the discretion of the local heart team after they assembled, and a decision was made according to the patient’s anatomical and clinical characteristics.

(This sentence was added to the main manuscript, Methods section)

3) Provide information on medications including statins, other lipid lowering drugs, and anti-diabetic drugs.

See new Table 1. We added the drug history for each patient which includes antiplatelet, anticoagulant, lipid-lowering agents, steroids, and medications for diabetes and hypertension.

4) Consider potential confounders, including medications.

Some confounders, such as the peri-procedure use of anti-inflammatory drugs, including steroids in iodine contrast allergy mitigation was minimal and with a similar rate in the two groups, thus there is no bias.

(This sentence was added to the main manuscript, Discussion section)

5) Provide more detailed methods, including determination of study size and definition of diagnosis (hypertension, diabetes, dyslipidemia, smoker, atrial fibrillation, coronary artery disease, etc) and all outcomes (bleeding, major vascular complication, stroke, myocardial infarction, AKI, and arrhythmia).

We performed a retrospective study, including all the patients that underwent TAVI in a 10-year period. Therefore, this is not an event rate driven study.

The definition of the patients’ baseline characteristic risk factors included the corresponding diagnosis in the medical records together with the chronic use of anti-hypertensive, glycemic control and lipid lowering drugs, respectively. Coronary artery disease (CAD), atrial fibrillation, peripheral arterial disease and strokes, were based on the medical records and confirmed by complementary clinical tools, such as angiograms in CAD. All the outcome definitions were strictly determined according the Valve Academic Research Consortium 2 Criteria (VARC-2).

(This sentence was added to the main manuscript, Methods section)

6) Describe the time point when inflammatory markers (blood samples) were obtained post TAVI; 24 hr 72 hr or 6 months, in Table 3

See the corrected new Table 3. We considered inflammatory markers at 24 hours.

7) Explain the data on table 3 and 4 more in detail with the method of statistical analysis in the main text and table legend

We added the two groups of (yes) and (no) for each variable and we did the comparison.

Data are presented as means ± standard deviations. Continuous variables between the various study groups were tested for normality by a Shapiro- Wilk test and when an abnormal distribution was found, a Mann- Whitney test was performed. When the distribution was normal, a t-test was used.

(This sentence was added to the main manuscript, Methods section and the table legends were changed)

8) Describe the method of statistical analysis in Figure 3.

Repeated measures analysis of variance were used to determine any significant differences between variability over time between SEV and BEV.

(This sentence was added to the main manuscript, Methods section)

9) Unites are missing in a lot of data. Provide.

We inserted all missing units.

10) Number at risk should be provided in Figure 4

This parameter was added to the new Figure 4.

11) Provide more detailed figure legends. Also, add figure 4 legend.

All Tables and Figures legends were changed

Detailed answers to all the referee comments:

Reviewer #1:

1. In Materials and Methods, “We excluded patients……….those with periprocedural death (up to 72 hours after TAVI)”, why you choose 72 hours as your exclusion criteria but not 24 hours? 48 hours? 96 hours or even one month?? Could you offer any reference???

We excluded these kind of patients due to the lack of blood samples and follow-up.

2. This paper discussed about inflammation response after TAVI. Although their TAVI protocol mentioned about Aspirin 100mg before procedure and dual-antiplatelet with Aspirin after that, some patients may use Aspirin, anti-platelet agent, or statin for their long-term underlying disease before procedure. Those medication can inhibit different inflammatory pathway level. So, please list patient medication in the demography and compare whether it is significant difference between two groups. Medication may affect postoperative SIRS result.

We added in Table 1 the patients’ chronic medication list and the use of steroids in iodine allergic patients just before the procedure. Also, we added in the Discussion section, a reference to the drugs (see point 4 above).

3. How do authors select BEV or SEV methods for the patient treatment?? Is there any criteria?

See point 2 above.

4. In table 3, it is very disorganized. Author may try to identify which factors (variables) may influence inflammatory markers after TAVI. However, they should organize these variables by different statistics methods. Some variables are continuous but some are categoric. If X and Y (inflammation markers) are continuous variables, please use linear regression and organize as one table. Some X belongs to categoric (hypertension, DM, TAVI type…….), authors may consider to classify inflammation markers (Y variables) to binary variable by certain cut point and use univariate logistic regression to make another table. In this manuscript, if authors can prove TAVI type (SEV and BEV, categoric variables) is one factor for influence of inflammation markers (have been classified to binary variables), that will be very significant finding and match this manuscript’s title. Anyway, separate to two tables by different statistics methods may be easier for reader understanding.

According to the reviewer’s comments, we clarified and consequently changed this table format.

5. In table 3 again, if contrast volume and time may be the factors to influence inflammatory markers, TAVI type should be evaluated with the two factors together by multivariate logistic regression to make sure whether TAVI type (SEV and BEV) is associated with inflammatory marker changes.

The study focused on the inflammatory response. We have done a multivariable analysis for these items, but we considered them to be not relevant to this article.

6. In discussion, it may have to be re-written because manuscript result can’t support authors’ conclusion enough. Most of discussion sentences were written or quoted by other paper result. I will suggest author reorganize whole article after recalculating convincible tables and figures so that authors can say something to correspond their title.

As a result of all the major changes requested by the editors and four rewrites, the article was significantly changed, mainly in the discussion section. We wrote an original paper that included ideas and conclusions from the literature to support or refute our hypothesis which is findings based.

Reviewer #2:

1. For instance no data on use of antibiotic treatments are provided

The use of prophylactic antibiotics before or after TAVI procedure is not routinely recommended (Gomes B, Periprocedural antibiotic treatment in transvascular aortic valve replacement. J Interv Cardiol. 2018 Dec;31(6):885-890). To clarify this point, we added a sentence to the Methods section of this manuscript:

The use of prophylactic antibiotics during the procedure or hospital stay was routinely avoided.

2. ” other markers of inflammation such as C - reactive protein or procalcitonin should have been taken into consideration”.

The CRP values measured in 62 patients was 3.2 ± 4.2 mg/L at baseline and 9.8 ± 8.1 mg/L 24 hours after the procedure (p < 0.001). These values were obtained in a minority of the patients and were not performed in all the timeline sequences (at admission, after 24, 48, 72 hours, and at 6 months). We did not do any procalcitonin assays. Therefore, we did not include this data in the manuscript. If the reviewer or editors insist, we can add this point in the study limitations paragraph.

3. In the discussion the passage on leaflet components spares any support by the data and remains hypothetical

According our findings, the inflammatory response quantified by neutrophils, lymphocytes and N/L ratio, is greater for SEV compared to BEV. The differences in the materials for the components, design and deployment system can hypothetically explain this significant finding.

Reviewer #3:

1. Do the authors have monocyte data as well?

All the monocyte behavior are given as neutrophils and lymphocytes. As you can see in Table 2 and Figure 2, included in the new article version, the findings are amazing as the other components described in the manuscript. We have not given any explanations for this finding because monocytes are not part of the SIRS response and we did not perform an assessment of their activation status, a crucial point when analyzing their possible pathophysiological role.

As recently described by Baratchi et al., Circulation. 2020;142:1092–1105, monocytes have a pivotal role in the chronic process and contribute to aortic stenosis development. We found a significant rise in the monocytes count in the acute phase, but we did not measure their activated function. This limits the possible interpretations.

(This sentence was added to the main manuscript, Discussion section)

Reviewer #4:

1. I do not agree with or do not understand the authors’ discussion statement: “The addition of NLR to the TAVI risk score improved the predictability of MACE after TAVI.” What ‘TAVI risk score’ are the authors referring to?

We agree that including our findings in the weighting of existing TAVI scores such as the French CAPRI, American TAVR or UK scores, was not explained enough.

The procedure risk score assessment is a dynamic process, it will change according the clinical evolution. We propose to add our findings, as they are inexpensive to do, to the well-established and known pre-TAVI procedure scores, such as CAPRI.

(This sentence was added to the main manuscript, Discussion section)

2. Why was pre-TAVI septal hypertrophy associated with a higher risk of postprocedural neutrophilia? Possible explanation?

This finding is interesting and relatively surprising. One hypothetically explanation can be based on the hemodynamics and shear stress in the setting of a severe aortic stenosis. Because the scope of the present study focuses on inflammation response, we did not develop this finding.

3. Please explain/shortly discuss the association between the VARC-2-defined 30-day outcomes and WBC elevation? Why was leukocytosis associated with increasing bleeding rates?

The association between unfavorable 30 day outcomes of deaths, bleeding and vascular access complications, according to the VARC-2 definition, highlights that the more complex procedures provoke major inflammatory responses. Therefore, less favorable outcomes or inherently, a major inflammatory response predisposes the patient to unfavorable clinical events related to the existing milieu.

(This sentence was added to the main manuscript, Discussion section)

Submitted filename: Response to Reviewers FR.docx

Click here for additional data file.

27 Sep 2021

PONE-D-21-04417R1Differential systemic inflammatory responses after TAVI: The role of self versus balloon expandable devicesPLOS ONE

Dear Dr. Blatt,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

The reviewers commented favorably on your manuscript, but had some worthwhile suggestions. The authors should address the remaining issues. Suggestions are all good ones and very constructive, which can be addressed by discussion as study limitations.

In the abstract, limitation regarding a lack of long-term effect on inflammation and outcomes should be added, such as “long-term effect needs to be investigated” or “clinical studies are warranted to assess the long term effect”. The conclusion in the abstract, “this short term effect may be associated with long term valvular durability” is not supported by your data and should be deleted.

The sentence, “an increase in WBC … was associated with higher rates of major …” (result section (clinical outcomes)) and the sentence, “this response was also found to be associated with a worse 30 days outcome”(Discussion (first paragraph)) should be de-emphasized since there is no difference or tendency in 30-day outcome (table 5).

Small sample number should be included in the limitation.

Please submit your revised manuscript by Nov 11 2021 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.

A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.

An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Michinari Nakamura, MD

Academic Editor

PLOS ONE

Journal Requirements:

Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice.

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: (No Response)

Reviewer #3: All comments have been addressed

Reviewer #4: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: No

Reviewer #3: Yes

Reviewer #4: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: No

Reviewer #3: Yes

Reviewer #4: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #3: Yes

Reviewer #4: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #3: Yes

Reviewer #4: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: In their manuscript titled “Differential systemic inflammatory response after TAVI: The role of self versus balloon expandable devices”, authors tried to compare SIRS between SEV and BEV. In the revised version, author still didn’t respond several reviewer’s question accurately. Although the most critical group outcome have been shown (table 5), it didn’t reveal any significant different between SEV and BEV. Hence, it means 24 hr inflammation response difference (Table 3 and Figure 3) can’t affect the outcome between SEV and BEV according to Figure 4 and Table 5. This paper just can say authors found higher inflammatory response in SEV but can’t arbitrarily conclude this difference is associated postoperative outcome, either short-term or long-term. In other words, operator may not worry about postoperative care even higher inflammation response in SEV was found clinically because the outcome is similar to BEV.

Meanwhile, author used a lot of previous paper to explain higher inflammation response may get poor result in discussion. However, these previous evidences can’t correspond and echo this paper because SEV and BEV didn’t show significant difference in postoperative outcome in current data (Table 5). The better discussion for the result of this paper is about why higher inflammation response was found in SEV instead of outcome comparison. In current revised discussion, author mentioned about the material difference between SEV and BEV, including metal part and bovine valve decellularization. They should list more factors may affect inflammation response, such as fibrinogen level, D-dimer level, nitinol concentration and so on. That will be more reasonable to the topic of this paper.

The question as below:

1. In table 2 and table 3, authors listed 24hr WBC, neutrophil, lymphocyte, and NLR. However, the values are a little different (ex: WBC 10.08±3.55 in table 2 vs 10.101±3.671). Do they calculate from the same groups???

2. In discussion: “Our results are in agreement……..which probably can shed light this finding” may be deleted.

Although authors want to focus on the inflammation response, they described too many outcome-related sentence in the discussion. Please remove these sentence and match original result to avoid readers confusion.

3. In discussion, “To the best of our knowledge…….heightened inflammatory response as compared to the BEV system” is good and reasonable to paper result. If author can list the table compare with nitinol concentration, D-dimer, fibrinogen…..so on between SEV and BEV, these biochemistry data will be more convincible and can more focus on inflammation response. That will be the real first report.

4. How do authors select BEV or SEV methods for the patient treatment??? Authors didn’t answer directly. The selection bias may associate post-inflammation response. Please describe and clarity.

5. Contrast and surgical time are very significant difference after 24hr postoperatively to preoperatively. Contrast amount and prolonged surgical time may induce cytokine secretion. Please compare with contrast and surgical time between SEV and BEV. It may explain the inflammation response different between groups.

6. What about prior aortic valve replacement surgery between SEV and BEV (valve-in-surgical valve)??

7. How many valves were used (rescued) during surgery if the first deployed valve was malfunctional (valve-in-valve)??

8. What about reintervention rate between two groups (valve-in-valve)??

Reviewer #3: The authors have addressed my previous comments. Overall the manuscript has now been successfully improved towards a ultimate exclusive of platelets. The discussion has also been improved. The text overall would need a proper English nurse.

Reviewer #4: Overall, the authors have improved the paper and the manuscript has been suitably revised. I have no further specific comments.

**********

7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #3: No

Reviewer #4: Yes: Dr. Jedrzej Hoffmann, MD

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

Submitted filename: review opinion 2.docx

Click here for additional data file.

6 Oct 2021

Detailed answers to the editor comments:

1) In the abstract, limitation regarding a lack of long-term effect on inflammation and outcomes should be added, such as “long-term effect needs to be investigated” or “clinical studies are warranted to assess the long term effect”.

This sentence was added to the abstract, Conclusion section.

2) The conclusion in the abstract, “this short term effect may be associated with long term valvular durability” is not supported by your data and should be deleted.

This sentence was deleted.

3) The sentence, “an increase in WBC … was associated with higher rates of major …” (result section (clinical outcomes) and the sentence, “this response was also found to be associated with a worse 30 days outcome” (Discussion (first paragraph) should be de-emphasized since there is no difference or tendency in 30-day outcome (table 5).

The order of the sentence in the Discussion section, first paragraph, was inadequate and lead to confusion. Findings from table 4 and 5 wrote intercalates, provoke confusion. Now, we order in a more clear version.

4) Small sample number should be included in the limitation.

We added a paragraph to describe the study limitations, including sample size.

Detailed answers to the reviewer #1 comments:

1. In table 2 and table 3, authors listed 24hr WBC, neutrophil, lymphocyte, and NLR. However, the values are a little different (ex: WBC 10.08±3.55 in table 2 vs 10.101±3.671). Do they calculate from the same groups???

The minuscular differences in the blood cell count related to the drop down of two patients excluded in table 3 because lack of 6 month follow-up lab values.

2. In discussion: “Our results are in agreement……..which probably can shed light this finding” may be deleted.

This extended paragraph analyzed the core of our study integrated with the current published bibliography in the field. We see a legitimate discussion to include in the article.

3. In discussion, “To the best of our knowledge…….heightened inflammatory response as compared to the BEV system” is good and reasonable to paper result. If author can list the table compare with nitinol concentration, D-dimer, fibrinogen…..so on between SEV and BEV, these biochemistry data will be more convincible and can more focus on inflammation response. That will be the real first report.

We have limited values of these propose parameters. Nitinol concentration was values were not measured at all.

4. How do authors select BEV or SEV methods for the patient treatment??? Authors didn’t answer directly. The selection bias may associate post-inflammation response. Please describe and clarity.

This requires was answered previously.

5. Contrast and surgical time are very significant difference after 24hr postoperatively to preoperatively. Contrast amount and prolonged surgical time may induce cytokine secretion. Please compare with contrast and surgical time between SEV and BEV. It may explain the inflammation response different between groups.

In table 1 we demonstrated non-significant differences in the injected contrast material and procedural time between SEV and BEV.

6. What about prior aortic valve replacement surgery between SEV and BEV (valve-in-surgical valve)??

We performed V-in-V in a few number of patients, 7 in total.

7. How many valves were used (rescued) during surgery if the first deployed valve was malfunctional (valve-in-valve)??

Rescue additional valve implantation migration related was performed in a small number of patients, 6 in total.

8. What about re-intervention rate between two groups (valve-in-valve)??

Again, the patient needed re-intervention after TAVI is very small.

Submitted filename: Cover letter_Response V3 FR.docx

Click here for additional data file.

11 Oct 2021

Differential systemic inflammatory responses after TAVI: The role of self versus balloon expandable devices

PONE-D-21-04417R2

Dear Dr. Blatt,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org.

If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org.

Kind regards,

Michinari Nakamura, MD

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments:

14 Oct 2021

PONE-D-21-04417R2

Differential systemic inflammatory responses after TAVI: The role of self versus balloon expandable devices

Dear Dr. Blatt:

I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department.

If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org.

If we can help with anything else, please email us at plosone@plos.org.

Thank you for submitting your work to PLOS ONE and supporting open access.

Kind regards,

PLOS ONE Editorial Office Staff

on behalf of

Dr. Michinari Nakamura

Academic Editor

PLOS ONE