Sex-Dependent Differences in Predictive Value of the C2HEST Score in Subjects with COVID-19-A Secondary Analysis of the COLOS Study.

Background: Since the outbreak of the COVID-19 pandemic, a growing number of evidence suggests that COVID-19 presents sex-dependent differences in clinical course and outcomes. Nevertheless, there is still an unmet need to stratify the risk for poor outcome at the beginning of hospitalization. Since individual C2HEST components are similar COVID-19 mortality risk factors, we evaluated sex-related predictive value of the score. Material and
Methods: A total of 2183 medical records of consecutive patients hospitalized due to confirmed SARS-CoV-2 infections were analyzed. Subjects were assigned to one of two of the study arms (male vs. female) and afterward allocated to different stratum based on the C2HEST score result. The measured outcomes included: in-hospital-mortality, three-month- and six-month-all-cause-mortality and in-hospital non-fatal adverse clinical events.
Results: The C2HEST score predicted the mortality with better sensitivity in female population regarding the short- and mid-term. Among secondary outcomes, C2HEST-score revealed predictive value in both genders for pneumonia, myocardial injury, myocardial infarction, acute heart failure, cardiogenic shock, and acute kidney injury. Additionally in the male cohort, the C2HEST value predicted acute liver dysfunction and all-cause bleeding, whereas in the female arm-stroke/TIA and SIRS.
Conclusion: In the present study, we demonstrated the better C2HEST-score predictive value for mortality in women and illustrated sex-dependent differences predicting non-fatal secondary outcomes.

1. Introduction

Since the outbreak in 2019 in China of the coronavirus disease (COVID-19), the pandemic has revealed an unprecedented impact on the global health care system, with over 450 million confirmed cases resulting in approximately 6 million of deaths reported worldwide [1]. From the initial phase of the pandemic, a growing number of evidence [2] suggests that COVID-19 presents significant sex-dependent differences in clinical course and mortality.

The clinical manifestation of COVID-19 remains unpredictable and varies from asymptomatic to severe or lethal [3,4,5]. Hence, there is an urgent need to introduce a simple and fast triage tool to clinical practice aimed at supporting the decision-making process for the clinicians in terms of appropriate management and optimized use of limited resources.

The C2HEST score was originally designed [6] to predict the potential development of atrial fibrillation (AF) in the general population. Lately, a growing body of evidence has appeared, illustrating that the C2HEST score can predict poor outcomes of patients in severe clinical conditions. Our previous study demonstrated the usefulness of the C2HEST-score in predicting the adverse COVID-19-outcomes in hospitalized subjects with type 2 diabetes mellitus. Since male sex is postulated to be an independent risk factor of an unfavorable COVID-19 outcome, we aimed to assess the sex-dependent predictive value of the C2HEST-score.

2. Materials and Methods

2.1. Study Design and Population

The study population consisted of 2183 consecutive patients with confirmed by reverse transcription-polymerase chain reaction (RT-PCR) infection of SARS-CoV-2 admitted to the Medical University COVID-19 Center. All subjects were hospitalized between February 2020 and June 2021. The study protocol has been approved by the Institutional Review Board and Ethics Committee at the Wroclaw Medical University, Wroclaw, Poland (No: KB-444/2021). All medical data were fully anonymized and retrospectively analyzed. Due to the character of the study protocol written informed consent from participants was not required. Subjects were assigned to one of two of the study arms male vs. female. Subsequently, all patients were assigned into one C2HEST score stratum. The C2HEST score value was calculated depending on originally proposed variables; coronary artery disease (CAD) (1 point), chronic obstructive pulmonary disease (COPD) (1 point), hypertension (1 point), elderly (age ≥ 75 years, 2 points), systolic heart failure (HF) (2 points), and thyroid disease (1 point). Based on the calculated score subjects were allocated to one of three stratum -low-risk 0 or 1 point, medium-risk 2 or 3 points, and high-risk 4 and more points.

2.2. Follow-Up and Outcomes

The primary clinical outcome was an in-hospital, three-month-, and six-month-all-cause mortality. Other clinical outcomes focused on in-hospital: end of hospitalization other than death (discharge, deterioration or recovery with subsequent transfer to another hospital) advanced mechanical ventilation support, shock, multiple organ dysfunction syndrome (MODS), systemic inflammatory response syndrome (SIRS), sepsis. Also, other clinical features were collected symptomatic bleeding, pneumonia, pulmonary embolism, acute heart failure, myocardial injury, stroke, acute kidney injury, acute liver dysfunction.

2.3. Statistical Analysis

Statisticians with experience in medical academic research performed the analyses to this manuscript. The R language version 4.0.4 with additional packages-pROC and time-ROC [7], survival [8], coin [9], and odds ratio was used for the purpose of data analysis [10] A level of 0.05 was set as significance value.

Descriptive data regarding categorical variables are shown as numbers and percentages, whereas for numerical variables as mean with standard deviation, range (minimum-maximum) along with the number of non-missing values. The omnibus and chi-square tests were performed for categorical variables which exceeded five expected cases in each group. The Fisher exact test was performed for subjects with fewer cell counts. The Welch’s ANOVA was set up for continuous variables in order to adjust for unequal variances between the risk-strata and sample size large sufficient for appropriateness of asymptotic results. For continuous variables, the Games-Howell’s variant of Tukey correction was performed as a part of a post-hoc analysis. On the other hand, for categorical variables, the post-hoc test was analogous to the omnibus test. However, it was performed in subgroups with a Bonferroni correction. Due to a fact that the in-hospital mortality along with the all-cause mortality were available as right-censored data, the time-dependent ROC analysis with inverse probability of censoring weighting (IPCW) was used to estimate them. The time-dependent area under the curve (AUC) was used to assess the C2HEST score and additionally a confirmation of differences in survival curves among risk strata was obtained by a Log-rank test. Proportional hazard assumption was verified using the Grambsch-Therneau test. During analysis of the hazard ratio (HR) in the C2HEST score, its components, as well as risk strata, a Cox proportional hazard model was used. Dichotomic nature of secondary outcomes resulted in the use of a logistic regression model during their analysis. In order to assess predictive capability, the classical receiver operating characteristic (ROC) analysis with an AUC measure was performed. Odds ratio (OR) was presented as a size effect for the influence of the C2HEST score, its components and risk strata.

3. Results

3.1. Baseline Demographical and Clinical Features of the Studied Population

The study population was composed of 2183 subjects at mean age 60.1 ±18.8 [17-100] A total of 1101 women at mean age 59.3 ± 21.1 [17-100] were enrolled to this study, who were subsequently assigned to the low-risk n = 682 subjects, medium-risk n = 284 patients, and high-risk n = 135 C2HEST strata, respectively. Simultaneously, a total of 1082 males at mean age of 60.8 ± 16.1 [17-99], were assigned to the low-risk (n = 735), medium-risk (n = 208) and high-risk(n = 139). The baseline clinical data of both study cohorts is presented in Table 1. In both cohorts, higher C2HEST risk was related to a higher number of comorbidities and more advanced age.

Table 1

Baseline demographics and clinical characteristics.

VariablesUnits	Low Risk[0–1]		Medium[2–3]		High Risk[≥4]		OMNIBUSp-Value		p Valuefor Post-Hoc Analysis
	FemalesN = 682	MalesN = 735	FemalesN = 284	MalesN = 208	FemalesN = 135	MalesN = 139	Females	Males	Females	Males
Demographics
Age, yearsmean ± SD/min-max	47.8 ± 17.117–74	54.2 ± 14.017–74	76.7 ± 12.029–100	74.0 ± 1.237–99	81.0 ± 8.747–100	76.2 ± 9.438–92	<0.0001	<0.0001	0.0 a,b 0.0001 c	0.0 a<0.0001 b0.115 c
Age ≥ 65 yearsn/n(%)	165(24.2)	211(28.7)	247(87.0)	172(82.7)	129(95.6)	123(88.5)	<0.0001	<0.0001	<0.0001 a,b 0.0339 c	<0.0001 a,b0.5515 c
BMI, kg/m2mean ± SD/min-max/N	28.3 ±5.317.1–45.7199	28.2 ± 4.815.4–49.4198	30.1 ±5.918.6–47.848	28.3 ±5.220.9–46.742	27.1 ±6.716.4–45.817	28.0 ± 5.617.3–48.250	0.1255	0.9609	N/A	N/A
Co-morbidities
Hypertensionn/n(%)	179(26.2)	236(32.1)	213(75.0)	144(69.2)	126(93.3)	123(88.5)	<0.0001	<0.0001	<0.0001 a,b,c	<0.0001 a,b 0.0002 c
Dyslipidaemian/n(%)/N	74(59.2)125	138(57.3)241	37(44.6)83	32(39.0)82	29(48.3)60	17(29.8)57	0.0932	0.00011	N/A	0.0191 a0.001 b1.0 c
Atrial fibrilation/fluttern/n(%)	14(2.1)	35(4.8)	60(21.1)	46(22.1)	65(48.1)	70(50.4)	<0.0001	<0.0001	<0.0001 a,b,c	<0.0001 a,b,c
Previous coronary revascularisationn/n(%)	0(0.0)	6(0.8)	9(3.2)	28(13.5)	35(25.9)	76(54.7)	<0.0001	<0.0001	<0.0001 a,b,c	<0.0001 a,b,c
Previous myocardial infarctionn/n(%)	1(0.1)	10(1.4)	18(6.3)	45(21.6)	37(27.4)	80(57.6)	<0.0001	<0.0001	<0.0001 a,b,c	<0.0001 a,b,c
Heart failuren/n(%)	0(0.0)	0(0.0)	20(7.0)	33(15.9)	91(67.4)	111(79.9)	<0.0001	<0.0001	<0.0001 a,b,c	<0.0001 a,b,c
Moderate/severe valvular heart disease or previous valve heart surgeryn/n(%)	7(1.0)	6(0.8)	14(4.9)	18(8.7)	26(19.3)	25(18.0)	<0.0001	<0.0001	0.0012 a <0.0001 b,c	<0.0001 a,b 0.0467 c
Peripheral artery diseasen/n(%)	7(1.0)	19(2.6)	14(4.9)	17(8.2)	11(8.1)	32(23.0)	<0.0001	<0.0001	0.0012 a<0.0001 b0.5813 c	0.0014 a <0.0001 b 0.0006 c
Previous stroke/TIAn/n(%)	17(2.5)	30(4.1)	33(11.6)	26(12.5)	24(17.8)	34(24.5)	<0.0001	<0.0001	<0.0001 a,b0.3522 c	<0.0001 a,b 0.0183 c
Chronic kidney diseasen/n(%)	33(4.8)	37(5.0)	26(9.2)	44(21.2)	39(28.9)	52(37.4)	<0.0001	<0.0001	0.0486 a <0.0001 b,c	<0.0001 a,b 0.0042 c
Haemodialysisn/n(%)	11(1.6)	8(1.1)	5(1.8)	15(7.2)	8(5.9)	11(7.9)	0.01467	<0.0001	1.0 a0.0204 b0.0963 c	<0.0001 a,b1.0 c
Asthman/n(%)	32(4.7)	22(3.0)	17(6.0)	3(1.4)	7(5.2)	4(2.9)	0.7053	0.4996	N/A	N/A
COPDn/n(%)	1(0.1)	5(0.7)	9(3.2)	16(7.7)	16(11.9)	28(20.1)	<0.0001	<0.0001	0.0003 a <0.0001 b 0.0041 c	<0.0001 a,b 0.0035 c
Hypothyroidismn/n(%)	65(9.5)	11(1.5)	56(19.7)	12(5.8)	52(38.5)	12(8.6)	<0.0001	<0.0001	<0.0001 a,b 0.0002 c	0.004 a<0.0001 b1.0 c
Hyperthyroidismn/n(%)	3(0.4)	1(0.1)	7(2.5)	3(1.4)	3(2.2)	4(2.9)	0.0083	0.0009	0.0272 a0.1807 b1.0 c	0.1065 a0.0081 b1.0 c

Continuous variables are presented as: mean ± SD, range (minimum–maximum) and number of non-missing values. Categorized variables are presented as: a number with a percentage. Information about the numbers with valid values is provided in the left column. Abbreviations: N, valid measurements; n, number of patients with parameter above cut-off point; SD, standard deviation; BMI, body mass index; TIA, transient ischemic attack; COPD, chronic obstructive pulmonary disease; OMNIBUS, analysis of variance; N/A, non-applicable; a low risk vs. medium risk, b low risk vs. high risk, c medium risk vs. high risk. Red color text = statistically significant values.

Data regarding the relationship between the C2HEST score result and treatment applied before hospitalization is shown in the Table 2. In the both cohorts along with increased C2HEST score, we observed an increasing prevalence drug commonly used in cardiovascular disorders such as angiotensin-converting-enzyme inhibitors (ACEI), mineralocorticoid receptor antagonists (MRA), b-blockers, calcium channel blockers, diuretics, statins, vitamin K antagonists (VKA), novel oral anticoagulants (NOAC), acetylsalicylic acid, P2Y12 inhibitor, metformin, and insulin.

Table 2

Baseline characteristics of the study cohort-treatment applied before hospitalization.

VariablesUnits	Low Risk[0–1]		Medium[2–3]		High Risk[≥4]		OMNIBUSp-Value		p Valuefor Post-Hoc Analysis
	FemalesN = 682	MalesN = 735	FemalesN = 284	MalesN = 208	FemalesN = 135	MalesN = 139	Females	Males	Females	Males
Treatment applied before hospitalization
ACEIn/n(%)	47(6.9)	69(9.4)	57(20.1)	63(30.3)	54(40.0)	62(44.6)	<0.0001	<0.0001	<0.0001 a,b,c	<0.0001 a,b 0.0273 c
ARBn/n(%)	33(4.8)	43(5.9)	26(9.2)	12(5.8)	14(10.4)	16(11.5)	0.0087	0.0413	0.04855 a0.0611 b1.0 c	1.0 a0.0724 b0.2546 c
MRAn/n(%)	3(0.4)	15(2.0)	13(4.6)	20(9.6)	20(14.8)	29(20.9)	<0.0001	<0.0001	<0.0001 a,b 0.0021 c	<0.0001 a,b 0.0158 c
β-blockern/n(%)	78(11.4)	119(16.2)	102(35.9)	77(37.0)	76(56.3)	81(58.3)	<0.0001	<0.0001	<0.0001 a,b 0.0004 c	<0.0001 a,b 0.0005 c
Calcium channel blocker dihydropiridinesn/n(%)	37(5.4)	66(9.0)	48(16.9)	36(17.3)	34(25.2)	40(28.8)	<0.0001	<0.0001	<0.0001 a,b0.1863 c	0.003 a <0.0001 b 0.0493 c
α-adrenergic blockern/n(%)	10(1.5)	35(4.8)	6(2.1)	28(13.5)	8(5.9)	31(22.3)	0.0113	<0.0001	1.0 a0.0137 b0.2272 c	<0.0001 a,b0.1358 c
Amiodaronen/n(%)	1(0.1)	0(0.0)	1(0.4)	1(0.5)	0(0.0)	1(0.7)	0.6165	0.1027	N/A	N/A
Thiazide or thiazide-like diureticn/n(%)	29(4.3)	39(5.3)	36(12.7)	11(5.3)	16(11.9)	19(13.7)	<0.0001	0.0008	<0.0001 a0.0026 b1 c	1.0 a0.0017 b0.0345 c
Loop diureticn/n(%)	13(1.9)	26(3.5)	25(8.8)	40(19.2)	33(24.4)	48(34.5)	<0.0001	<0.0001	<0.0001 a,b,c	<0.0001 a,b 0.0061 c
Statinn/n(%)	40(5.9)	63(8.6)	56(19.7)	65(31.3)	49(36.3)	77(55.4)	<0.0001	<0.0001	<0.0001 a,b 0.0012 c	<0.0001 a, b, c
Acetylsalicylic acidn/n(%)	35(5.1)	46(6.3)	44(15.5)	51(24.5)	33(24.4)	49(35.3)	<0.0001	<0.0001	<0.0001 a,b0.1137 c	<0.0001 a,b0.1234 c
The second antiplatelet drugn/n(%)	1(0.1)	6(0.8)	5(1.8)	5(2.4)	4(3.0)	18(12.9)	0.0009	<0.0001	0.0292 a0.0094 b1.0 c	0.2154 a<0.0001 b0.0007 c
LMWHn/n(%)	32(4.7)	42(5.7)	23(8.1)	18(8.7)	11(8.1)	15(10.8)	0.0674	0.0535	N/A	N/A
VKAn/n(%)	4(0.6)	6(0.8)	6(2.1)	8(3.8)	10(7.4)	13(9.4)	<0.0001	<0.0001	0.2172 a<0.0001 b0.038 c	0.0129 a<0.0001 b0.1213 c
NOACn/n(%)	6(0.9)	12(1.6)	22(7.7)	15(7.2)	23(17.0)	29(20.9)	<0.0001	<0.0001	<0.0001 a,b 0.0207 c	0.0002 a <0.0001 b 0.001 c
Insulinn/n(%)	23(3.4)	39(5.3)	14(4.9)	15(7.2)	22(16.3)	18(12.9)	<0.0001	0.0038	1.0 a<0.0001 b0.0007 c	1.0 a0.0047 b0.3296 c
Metforminn/n(%)	40(5.9)	64(8.7)	35(12.3)	32(15.4)	22(16.3)	29(20.9)	<0.0001	<0.0001	0.0031 a0.0002 b1.0 c	0.022 a0.0001 b0.7261 c
SGLT2 inhibitorn/n(%)	4(0.6)	7(1.0)	4(1.4)	3(1.4)	3(2.2)	6(4.3)	0.12658	0.018	N/A	1.0 a0.0286 b0.4938 c
Oral antidiabetics other than SGLT2 inhibitor and metforminn/n(%)	10(1.5)	17(2.3)	20(7.0)	14(6.7)	11(8.1)	17(12.2)	<0.0001	<0.0001	<0.0001 a,b1.0 c	0.01 a<0.0001 b0.3507 c
Proton pump inhibitorn/n(%)	31(4.5)	58(7.9)	39(13.7)	36(17.3)	37(27.4)	49(35.3)	<0.0001	<0.0001	<0.0001 a,b 0.0034 c	0.0003 a <0.0001 b 0.0007 c
Oral corticosteroidn/n(%)	31(4.5)	31(4.2)	17(6.0)	7(3.4)	5(3.7)	1(0.7)	0.5164	0.125	N/A	N/A
Immuno-suppressionother than oral corticosteroidn/n(%)	24(3.5)	25(3.4)	12(4.2)	10(4.8)	2(1.5)	0(0.0)	0.3606	0.0185	N/A	1.0 a0.0686 b0.0209 c

Categorized variables are presented as: a number with a percentage. Information about the numbers with valid values is provided in the left column. Abbreviations: N, valid measurements; n, number of patients with parameter above the cut-off point; ACEI, angiotensin-converting-enzyme inhibitors; ARBs, angiotensin receptor blockers; MRAs, mineralocorticoid receptor antagonists; LMWH, low molecular weight heparin; VKA, vitamin K antagonists; NOAC, novel oral anticoagulants; SGLT2 inhibitors, sodium glucose co-transporter-2 inhibitors; OMNIBUS, analysis of variance; N/A, non-applicable; a low risk vs. medium risk, b low risk vs. high risk, c medium risk vs. high risk. Red color text = statistically significant values.

Table 3 shows the sex-specific baseline characteristics of patient-reported symptoms, and vital signs during the hospital admission in the studied cohort. The female but not male cohort, had significant differences between the C2HEST strata regarding the prevalence of cough, smell dysfunction, body temperature, and systolic blood pressure, which were decreasing as the score raised. Opposite findings were observed regarding dyspnoea, heart rate, and the diastolic blood pressure.

Table 3

Patient-reported symptoms, vital signs and abnormalities measured during physical examination at hospital admission in the studied cohort.

VariablesUnits	Low Risk[0–1]		Medium[2–3]		High Risk[≥4]		OMNIBUSp Value		p Value for Post-Hoc Analysis
	FemalesN = 682	MalesN = 735	FemalesN = 284	MalesN = 208	FemalesN = 135	MalesN = 139	Females	Males	Females	Males
Patient-reported symptoms
Coughn/n(%)	219(32.1)	236(32.1)	71(25.0)	53(25.5)	27(20.0)	42(30.2)	0.0047	0.1859	0.102 a0.0208 b0.9427 c	n/A
Dyspnoean/n(%)	244(35.8)	325(44.2)	110(38.7)	96(46.2)	63(46.7)	83(59.7)	0.0551	0.0035	N/A	1.0 a0.0033 b0.0538 c
Chest painn/n(%)	49(7.2)	53(7.2)	18(6.3)	16(7.7)	11(8.1)	16(11.5)	0.7855	0.2237	N/A	N/A
Smell dysfunctionn/n(%)	26(3.8)	35(4.8)	3(1.1)	7(3.4)	0(0.0)	5(3.6)	0.0039	0.6142	0.0656 a0.0414 b1.0 c	N/A
Diarrhoean/n(%)	37(5.4)	38(5.2)	22(7.7)	11(5.3)	11(8.1)	8(5.8)	0.2667	0.9606	N/A	N/A
Nausea/Vomitingn/n(%)	36(5.3)	21(2.9)	18(6.3)	9(4.3)	11(8.1)	3(2.2)	0.4065	0.4662	N/A	N/A
Measured vital signs
Body temperature, °Cmean ± SD/min-max/N	37.1 ± 0.835.0–40.5416	37.1 ± 0.934.4–40.0393	36.9 ± 0.935.8–40.0131	36.9 ± 1.035.0–40.0104	36.8 ± 0.935.2–40.063	37.1 ± 0.835.5–40.078	0.0456	0.3888	0.3 a0.07 b0.588 c	N/A
Heart rate, beats/minute mean ± SD/min-max/N	85.9 ± 14.648–150490	86.9 ± 16.548–160555	84.6 ± 17.250–160217	83.5 ± 15.552–140170	87.4 ± 21.336–170116	82.3 ± 15.858–140124	0.4159	0.0035	N/A	0.045 a0.012 b0.773 c
Respiratory rate breaths/minutemean ± SD/min-max/N	17.9 ± 5.912–50107	18.9 ± 5.712–5097	17.8 ± 3.812–3134	19.6 ± 6.712–4534	19.0 ± 4.112–2922	19.6 ± 7.612–5024	0.5185	0.8014	N/A	N/A
Systolic blood pressure mmHgmean ± SD/min-max/N	128.6 ± 21.374–240488	132.6 ± 21.160–220552	133.2 ± 24.250–210216	135.6 ± 26.750–270169	135.6 ± 25.570–210117	133.5 ± 24.085–200127	0.004	0.4149	0.042 a0.018 b0.687 c	N/A
Diastolic blood pressure, mmHgmean ± SD/min-max/N	77.4 ± 12.540–150487	79.5 ± 12.740–130550	77.1 ± 13.740–157214	79.3 ± 13.545–150166	7.5 ± 15.540–143117	75.1 ± 15.240–120127	0.8167	0.0091	N/A	0.986 a0.007 b0.034 c
SpO2 on room air, % (FiO2 = 21%)mean ± SD/min-max/N	94.4 ± 5.956–100421	91.1 ± 7.948–99393	90.8 ± 8.550–100160	88.2 ± 10.950–99121	91.2 ± 6.964–9984	89.2 ± 9.950–9983	<0.0001	0.0102	<0.0001 a0.0003 b0.934 c	0.018 a0.205 b0.79 c
Abnormalities detected during physical examination
Craclesn/n(%)	62(9.1)	92(12.5)	47(16.5)	52(25.0)	30(22.2)	36(25.9)	<0.0001	<0.0001	0.0038 a<0.0001 b0.6164 c	<0.0001 a0.0002 b1.0 c
Wheezingn/n(%)	32(4.7)	62(8.4)	23(8.1)	33(15.9)	32(23.7)	37(26.6)	<0.0001	<0.0001	0.1611 a<0.0001 b,c	0.0078 a<0.0001 b0.0628 c
Pulmonarycongestionn/n(%)	70(10.3)	114(15.5)	51(18.0)	54(26.0)	37(27.4)	41(29.5)	<0.0001	<0.0001	0.0044 a<0.0001 b0.1096 c	0.0022 a0.0004 b1.0 c

Categorized variables are presented as: a number with a percentage. Continuous variables are presented as: mean ± SD, range (minimum -maximum) and number of non-missing values. Information about the numbers with valid values is provided in the left column. Abbreviations: N, valid measurements; n, number of patients with parameter above the cut-off point; SD, standard deviation. OMNIBUS, analysis of variance; N/A, non-applicable, a low risk vs. medium risk, b low risk vs. high risk, c medium risk vs. high risk. Red color text = statistically significant values.

The detailed characteristics of the laboratory parameters measured during the hospitalisation in the study cohort were pooled in Table 4 and Table 5.

Table 4

Patient initial and on discharge laboratory assay in the studied cohort after C2HEST risk stratification.

Parameter Time of Assessment	Units	Low Risk[0–1]		Medium[2–3]		High Risk[≥4]		p-ValueOMNIBUS		p-Value for Post-Hoc Analysis
		Females	Males	Females	Males	Females	Males	Females	Males	Females	Males
Morphology
Leucocytesn/n(%)/NOn admission	>12 × 103/µL	85(13.8)615	116(16.9)686	52(18.8)277	32(15.8)203	23(17.7)130	29(212)137	0.3085	0.3279	N/A	N/A
	4–12× 103/µL	467(75.9)615	504(73.5)686	198(71.5)277	147(72.4)203	91(70.0)130	100(73.0)137
	<4 × 103/µL	63(10.2)615	66(9.6)686	27(9.7)277	24(11.8)203	16(12.3)130	8(5.8)137
On discharge	>12 × 103/µL	81(13.2)615	119(17.3)686	55(19.9)277	48(23.6)203	36(27.7)130	28(20.4)137	0.0008	0.0028	0.0971 a0.0006 b0.5375 c	0.002 a1.0 b0.1331 c
	4–12× 103/µL	487(79.2)615	530 (77.3)686	205(74.0)277	132(65.0)203	85(65.4)130	103(75.2)137
	<4 × 103/µL	47(7.6)615	37(5.4)686	17(6.1)277	23(11.3)203	9(6.9)130	6(4.4)137
Haemoglobinn/n(%)/NOn admission	<12 g/dL females <13 g/dL males anaemia	172(28.0)615	173(25.2)686	91(32.9)277	104(51.2)203	63(48.5)130	84(61.3)137	<0.0001	<0.0001	0.4836 a<0.0001 b0.0106 c	<0.0001a,b0.2546 c
On discharge		266(43.3)615	244(35.6)686	122(44.0)277	136(67.0)203	79(60.8)130	92(67.2)137	0.0011	<0.0001	1.0 a0.0012 b0.0071 c	<0.0001 a,b1.0 c
Plateletsmean ± SD/min-max/N On admission	×103/µL	244.8 ± 115.74.0–1356615	227.4 ± 101.00.0–746.0686	244.9 ± 115.841.0–740.0277	209.8 ± 108.33.0–730.0203	236.9 ± 98.78.0–537.0130	198.9 ± 83.615.0–578.0137	0.7077	0.001	N/A	0.099 a0.002 b0.548 c
On discharge		267.7 ± 122.92.0–929.0614	273.6 ± 133.06.0–1101.0685	259.6 ± 117.127.0–694.0277	225.7 ± 124.33.0–606.0203	225.6 ± 102.34.0–592.0130	203.3 ± 92.315.0–472.0137	0.0003	<0.0001	0.614 a0.0002 b0.009 c	<0.0001 a,b0.139 c
Acid -base balance in the arterial blood gas
PHmean ± SD/min-max/NOn admission		7.42 ± 0.087.19–7.5848	7.43 ± 0.097.04–7.5773	7.43 ± 0.077.24–7.5337	7.43 ± 0.077.10–7.5451	7.39 ± 0.087.09–7.5232	7.42 ± 0.077.28–7.5435	0.2287	0.8496	N/A	N/A
On discharge		7.43 ± 0.077.22–7.5448	7.42 ± 0.097.06–7.5473	7.43 ± 0.067.27–7.5337	7.42 ± 0.097.01–7.5551	7.44 ± 0,067.26–7.5632	7.40 ± 0.067.25–7.5235	0.8782	0.5746	N/A	N/A
PaO2mean ± SD/min-max/NOn admission	mmHg	75.3 ± 33.012.8–207.048	70.2 ± 22.823.5–136.073	80.7 ± 54.228.3–286.037	73.2 ± 42.528.6–298.051	70.7 ± 25.732.8–134.032	70.5 ± 41.423.7–222.035	0.562	0.9031	N/A	N/A
On discharge		74.8 ± 27.712.8–207..048	75.7 ± 26.023.5–165.073	81.9 ± 55.023.3–286.037	74.6 ± 43.528.6–298.051	69.5 ± 27.628.5–134.032	63.6 ± 20.528.5–129.035	0.4499	0.0316	N/A	0.985 a0.028 b0.268 c
PaCO2mean ± SD/min-max/NOn admission	mmHg	38.3 ± 8.220.2–58.048	37.8 ± 11.525.7–82.473	37.2 ± 9.326.9–79.437	36.3 ± 9.620.9–67.051	38.6 ± 13.625.0–88,432	38.7 ± 8.019.7–61.035	0.8084	0.4415	N/A	N/A
On discharge		38.3 ± 8.420.2–62.248	38.5 ± 10.724.1–75.573	38.5 ± 10.027.8–84.437	37.5 ± 11.720.9–88.451	37.4 ± 11.525.0–88.432	39.9 ± 8.726.8–67.835	0.9071	0.5398	N/A	N/A
HCO3 standardmean ± SD/min-max/NOn admission	mmol/L	25.0 ± 3.712.5–32.947	24.9 ± 3.812.1–32.873	24.9 ± 4.416.9–39.536	24.0 ± 4.014.3–32.449	23.4 ± 4.613.5–32.332	24.8 ± 4.517.5–38.635	0.2666	0.4967	N/A	N/A
On discharge		25.3 ± 3.412.5–35.747	24.8 ± 4.012.1–33.673	25.7 ± 4.816.9–40.336	25.0 ± 6.113.7–51.749	25.1 ± 4.317.4–35.832	24.7 ± 3.719.4–36.735	0.8862	0.9539	N/A	N/A
BEmean ± SD/min-max/NOn admission	mmol/L	0.63 ± 5.06[−]15.7–5.916	1.12 ± 4.67[−]9.1–10.525	2.96 ± 4.72[−]3.3–15.717	0.88 ± 5.59[−]12.5–9.726	[−]0.1 ± 4.75[−]7.4–7.97	2.92 ± 5.21[−]3.3–14.617	0.2745	0.4315	N/A	N/A
On discharge		1.21 ± 5.91[−]15.7–11.916	0.46 ± 5.21[−]11.0–8.325	3.54 ± 4.99[−]3.3–17.117	1.62 ± 6.58[−]14.7–11.826	0.91 ± 4.58[−]7.4–7.97	1.65 ± 5.0[−]5.3–13.217	0.363	0.6978	N/A	N/A
Lactatesmean ± SD/min-max/NOn admission	mmol/L	2.0 ± 0.80.6–4.338	2.7 ± 1.91.1–12.867	2.0 ± 1.00.6–5.732	2.0 ± 0.70.5–3.847	2.9 ± 2.10.8–12.031	2.1 ± 1.40.6–5.730	0.1027	0.0291	N/A	0.02 a0.199 b0.913 c
On discharge		2.1 ± 0.80.7–4.938	2.7 ± 1.91.0–12.867	2.0 ± 0.90.6–5.732	2.2 ± 1.10.5–6.447	2.6 ± 1.30.8–6.031	2.2 ± 1.10.8–4.330	0.0544	0.239	N/A	N/A
Electrolytes, inflammatory and iron biomarkers
Namean ± SD/min-max/NOn admission	mmol/L	138.3 ± 3.8106.0−155.0605	138.2 ± 4.8109.0−159.0683	137.7 ± 7.6101.0−175.0272	137.7 ± 6.1105.0−158.0203	138.3 ± 7.7108.0−174.0130	137.6 ± 5.9112.0−158.0137	0.4803	0.3745	N/A	N/A
On discharge		138.9 ± 3.7113.0−167.0605	139.3 ± 4.8109.0−175.0683	139.0 ± 7.4101.0−172.0272	139.4 ± 7.2105.0−165.0203	140.7 ± 7.1124.0−172.0130	139.8 ± 6.3120.0–157.0137	0.0179	0.6389	0.977 a0.013 b0.062 c	N/A
Kmean ± SD/min-max/NOn admission	mmol/L	3.99 ± 0.542.33–6.5609	4.13 ± 0.612.0–7.5684	4.06 ± 0.72.42 ± 5.9275	4.25 ± 0.692.4–7.0202	4.14 ± 0.742.53–6.6130	4.43 ± 0.873.0–8.7137	0.0403	0.0002	0.325 a0.059 b0.479 c	0.072 a0.0005 b0.1 c
On discharge		4.13 ± 0.562.47–7.4609	4.33 ± 0.62.0–6.9684	4.26 ± 0.752.28–6.32275	4.5 ± 0.772.4–7.0202	4.36 ± 0.692.53–6.5130	4.51 ± 0.692.76–6.64137	0.0004	0.0011	0.033 a0.002 b0.373 c	0.015 a,b0.983 c
CRPmean ± SD/min-max/NOn admission	mg/L	60.49 ± 72.410.13−531.58597	90.54 ± 91.630.32−496.98677	74.25 ± 84.610.4−538.55275	95.36 ± 88.060.29–487.38202	64.75 ± 72.930.4–344.95130	87.45 ± 87.370.4–390.94137	0.0674	0.69258	N/A	N/A
On discharge		36.85 ± 64.50.13–494.73597	58.33± 88.960.25–496.98677	62.6 ± 89.560.22–538.55275	86.23± 99.390.46–447.61202	63.78± 80.70.4–431.9130	83.42± 90.910.42–390.94137	<0.0001	0.0001	<0.0001 a0.001 b0.99 c	0.001 a0.01 b0.961 c
Procalcitoninmean ± SD/min-max/NOn admission	ng/mL	0.33 ± 1.550.01–24.95404	1.24 ± 5.790.01–61.28514	2.0 ± 15.130.01–196.04188	1.62 ± 6.60.01–72.61156	1.36 ± 6.460.01–60.7798	1.59 ± 5.810.01–49.83113	0.0993	0.7214	N/A	N/A
On discharge		0.57 ± 3.260.01–41.32404	1.16 ± 6.140.01–75.16514	0.86 ± 3.620.01–30.67188	2.49 ± 8.440.01–81.09156	1.11 ± 6.170.01–60.7798	1.19 ± 3.680.01–27.61113	0.5044	0.1807	N/A	N/A
IL-6mean ± SD/min-max/NOn admission	pg/mL	85.5 ± 660.22.0–9099.0192	45.2 ± 98.72.0–1000.0288	34.3 ± 52.72.0–398.084	55.9 ± 75.32.0–499.059	55.2 ± 94.12.0–421.038	69.2 ± 97.82.0–369.040	0.2692	0.2811	N/A	N/A
On discharge		90.3 ± 672.02.0–9099.0192	42.0 ± 111.02.0–1000.0288	28.5 ± 53.52.0–398.084	56.5 ± 94.32.0–499.059	67.6 ± 170.42.0–1000.038	82.3 ± 150.62.0–804.040	0.1877	0.1939	N/A	N/A
D-dimermean ± SD/min-max/NOn admission	µg/mL	2.60 ± 8.390.15–-118.32444	4.63 ± 14.460.18–132.82558	5.40 ± 12.570.2–107.65206	7.84 ± 20.750.23–127.24167	3.78 ± 11.480.24–107.54100	7.01 ± 21.410.22–128.0103	0.0133	0.1192	0.011 a0.596 b0.501 c	N/A
On discharge		3.17 ± 11.990.15–128.0444	3.25 ± 9.630.21–115.13558	4.38 ± 8.280.21–74.28206	7.2 ± 17.510.23–106.02167	3.65 ± 11.230.21–107.54100	3.72 ± 6.90.22–46.72103	0.3287	0.0215	N/A	0.016 a0.821 b0.059 c
INRmean ± SD/min-max/NOn admission		1.07 ± 0.20.82–3.6580	1.19 ± 0.630.83–15.2647	1.25 ± 0.690.87–7.8257	1.27 ± 0.440.89–4.37188	1.58 ± 1.750.9–18.74127	1.99 ± 2.980.89–21.1124	<0.0001	0.0031	0.0002 a0.005 b0.112 c	0.136 a0.01 b0.023 c
On discharge		1.1 ± 0.40.82–9.2580	1.17 ± 0.330.87–6.82647	1.2 ± 0.80.88–13.1257	1.32 ± 0.70.92–7.85188	1.4 ± 0.80.9–8.0127	1.53 ± 1.880.87–21.1124	0.0003	0.0019	0.048 a0.001 b0.251 c	0.011 a0.082 b0.452 c
APTTn/n(%)/NOn admission	>60 s	61.1561	223.5630	31.2247	42.2184	64.8124	54.2120	0.0243	0.5704	1.0 a0.0337 b0.1964 c	N/A
On discharge		142.5561	325.1630	31.2247	52.7184	43.2124	86.7120	0.3472	0.2518	N/A	N/A
Fibrinogenmean ± SD/min-max/NOn admission	g/dL	4.69 ± 1.530.35–9.04153	5.11 ± 2.140.44–10.0132	4.34 ± 1.40.35–6.7229	4.93 ± 2.00.37–9.252	3.62 ± 1.061.78–5.5124	5.31 ± 1.712.54–9.129	0.0004	0.6765	0.441 a0.0003 b0.096 c	N/A
On discharge		4.58 ± 1.80.44–10.0153	4.95 ± 2.130.6–10.0132	5.01 ± 2.110.35–9.429	4.98 ± 2.30.37–11.352	3.84 ± 1.211.53–5.7524	5.71 ± 2.072.2–9.0429	0.0184	0.2055	0.561 a0.037 b0.04 c	N/A

Continuous variables are presented as: mean ± SD. range (minimum -maximum) and number of non-missing values. Categorized variables are presented as: a number with a percentage. Information about the numbers with valid values is provided in the left column. Abbreviations: N, valid measurements; n, number of patients with parameter above cut-off point; SD, standard deviation. OMNIBUS, analysis of variance; N/A, non-applicable, a low risk vs. medium risk, b low risk vs. high risk, c medium risk vs. high risk. Red text—statistically significant values.

Table 5

Patient initial and on discharge laboratory assay in the studied cohort after C2HEST risk stratification.

Parameter Time of Assessment	Units	Low Risk[0–1]		Medium[2–3]		High Risk[≥4]		p-ValueOMNIBUS		p-Value for Post-Hoc Analysis
		Females	Males	Females	Males	Females	Males	Females	Males	Females	Males
Biochemistry
Glucosemean ± SD/min-max/NOn admission	mg/dL	128.1 ± 67.061.0–671.0425	139.3 ± 79.528.0–933.0638	144.1 ± 74.954.0–662.0257	160.5 ± 110.347.0–1026.0192	149.1 ± 86.570–685120	152.0 ± 109.437.0–1064.0126	0.0035	0.0315	0.014 a0.039 b0.849 c	0.038 a0.433 b0.779 c
On discharge		119.0 ± 56.037.0–595.0425	127.3 ± 78.850.0–1444.0638	136.4 ± 75.354.0–596.0257	150.7 ± 92.247.0–578.0192	144.8 ± 90.414.0–685.0120	143.5 ± 63.137.0–406.0126	0.0003	0.0012	0.004 a0.01 b0.653 c	0.005 a0.033 b0.688 c
Glycated hemoglobin (HbA1c)mean ± SD/min-max/NOn admission	%	7.1 ± 1.94.2–12.247	7.9 ± 2.54.9–14.980	7.9 ± 2.74.9–16.639	7.2 ± 1.44.8–12.236	7.2 ± 1.75.1–11.433	7.4 ± 1.95.1–13.728	0.3182	0.1497	N/A	N/A
On discharge		7.0 ± 1.84.2–12.247	7.8 ± 2,44.9–14.980	7.9 ± 2.74.9–16.839	7.1 ± 1.44.7–12.236	7.2 ± 1.75.1–11.433	7.4 ± 1.95.1–13.728	0.2299	0.1563	N/A	N/A
Ureamean ± SD/min-max/NOn admission	mg/dL	36.3 ± 35.17.0–301.0481	47.6 ± 35.85.0–307.0664	60.2 ± 50.68.0–353.0256	69.9 ± 47.515.0–271.0199	69.5 ± 48.912.0–336.0124	84.4 ± 57.117.0–369.0133	<0.0001	<0.0001	<0.0001a,b0.197 c	<0.0001a,b 0.042 c
On discharge		35.5 ± 29.67.0–231.0481	44.9 ± 32.95.0–307.0664	59.0 ± 48.210.0–353.0256	75.6 ± 59.812.0–396.0199	66.9 ± 41.715.0–204.0124	88.9 ± 58.621.0–342.0133	<0.0001	<0.0001	<0.0001a,b0.236 c	<0.0001a,b0.11 c
Creatininemean ± SD/min-max/NOn admission	mg/dL	1.0 ± 0.990.34–11.99533	1.26 ± 1.30.26–14.87683	1.22 ± 0.970.48–9.56275	1.76 ± 1.60.58–12.66203	1.58 ± 1.270.44–8.46130	2.02 ± 1.810.49–11.3137	<0.0001	<0.0001	0.008 a < 0.0001 b 0.012 c	0.0002 a< 0.0001 b0.369 c
On discharge		0.96 ± 0.860.34–9.11533	1.16 ± 1.180.26–14.87683	1.16 ± 0.920.45–9.06275	1.81 ± 1.720.43–12.35 203	1.42 ± 1.210.43–7.66130	1.89 ± 1.580.43–9.27137	<0.0001	<0.0001	0.009 a0.0002 b0.084 c	<0.0001a,b0.877 c
eGFRmean ± SD/min-max/NOn admission	mL/min/1.73 m2	84.6 ± 32.10.0–207.0531	85.3 ± 35.93.0–433.0680	60.8 ± 25.04.0–136.0275	63.7 ± 33.14.0–149.0203	49.7 ± 26.45.0–145.0130	55.3 ± 32.05.0–180.0137	<0.0001	<0.0001	0.0 a < 0.0001 b 0.0002 c	0.0 a 0.0 b 0.054 c
On discharge		86.6 ± 32.10.0–207.0531	91.5 ± 36.53.0–433.0680	65.0 ± 26.64.0–148.0275	66.0 ± 36.14.0–208,0203	58.2 ± 30.35.0–147.0130	58.6 ± 35.76.0–209.0137	<0.0001	<0.0001	0.0 a< 0.0001 b0.076 c	<0.0001a,b0.147 c
Total proteinmean ± SD/min-max/NOn admission	g/L	6.1 ± 0.83.9–8.2145	6.1 ± 0.83.5–8.1186	5.8 ± 0.83.6–8.278	6.0 ± 1.04.2–9.574	5.7 ± 0.93.3–8.162	5.7 ± 0.93.4–8.261	0.0235	0.0555	0.148 a0.033 b0.741 c	N/A
On discharge		6.0 ± 0.93.9–8.2145	6.0 ± 0.93.0–8.1186	5.7 ± 0.93.7–8.278	5.9 ± 0.94.3–9.174	5.5 ± 1.03.3–8.162	5.7 ± 0.93.4–7.861	0.0012	0.0162	0.049 a0.002 b0.388 c	0.799 a0.012 b0.158 c
Albuminmean ± SD/min-max/NOn admission	g/L	3.1 ± 0.61.6–4.6152	3.2 ± 0.61.5–5.1222	3.0 ± 0.51.1–4.378	3.2 ± 0.62.1–4.482	2.9 ± 0.60.7–3.762	3.1 ± 0.61.5–4.967	0.0134	0.3087	0.287 a0.011 b0.307 c	N/A
On discharge		3.1 ± 0.61.1–4.6152	3.0 ± 0.70.4–5.1222	3.0 ± 0.51.9–4.278	3.1 ± 0.61.7–4,482	2.8 ± 0.51.4–3.762	2.8 ± 0.70.9–4..567	0.005	0.0549	0.64 a0.004 b0.277 c	N/A
ASTmean ± SD/min-max/NOn admission =	IU/L	56.8 ± 139.76.0–2405.0384	62.7 ± 89.45.0–1261.0499	72.7 ± 343.68.0–4776193	58.8 ± 49.57.0–323.0154	113.5 ± 450.88.0–3866.0104	60.2 ± 101.810.0–731.0107	0.3869	0.7844	N/A	N/A
On discharge		123.4 ± 1244.410.0–23,896.0384	68.3 ± 255.15.0–3761.0499	43.3 ± 46.58.0–380.0193	107.5 ± 537.611.0–6591.0154	148.9 ± 702.48.0–6088.0104	97.4 ± 402.47.0–4019.0107	0.1438	0.5525	N/A	N/A
ALTmean ± SD/min-max/NOn admission	IU/L	47.0 ± 87.75.0–1411.0435	61.4 ± 96.44.0–1278.0537	52.2 ± 251.25.0–3700.0219	45.0 ± 43.24.0–270.0172	57.1 ± 183.65.0–1361.0112	46.7 ± 88.26.0–612.0113	0.8212	0.0081	N/A	0.006 a0.256 b0.98 c
On discharge		65.5 ± 265.46.0–5163.0435	74.3 ± 105.04.0–1217.0537	38.5 ± 46.15.0–449.0219	65.1 ± 124.77.0–1247.0172	74.4 ± 308.85.0–2985.0112	71.4 ± 207.39.0–1570.0113	0.0624	0.6835	N/A	N/A
Bilirubinmean ± SD/min-max/NOn admission	mg/dL	0.78 ± 1.680.1–19.1363	0.88 ± 1.240.1–15.1489	0.85 ± 0.880.2–9.2195	0.80 ± 0.490.2–3.1157	0.77 ± 0.510.1–4.2100	0.98 ± 0.840.3–6.6103	0.5771	0.1292	N/A	N/A
On discharge		0.77 ± 1.650.1–19.0363	0.95 ± 1.910.1–25.9489	0.95 ± 2.550.2–35.3195	0.76 ± 0.470.2–3.1157	0.78 ± 0.670.3–6.1100	1.06 ± 1.330.2–12.8103	0.6611	0.0224	N/A	0.123 a0.754 b0.08 c
LDHmean ± SD/min-max/NOn admission	U/L	404.5 ± 478.550.0–7100.0328	448.6 ± 282.2120.0–3194.0448	368.2 ± 189.844.0–1357.0156	418.9 ± 212.9134.0–1172.0130	468.1 ± 1015.371.0–9505.083	416.9 ± 269.7113.0–1863.086	0.3576	0.3427	N/A	N/A
On discharge		387.2 ± 739.350.0–11,227.0328	389.2 ± 396.293.0–6577.0448	340.3 ± 167.344.0–1357.0156	407.1 ± 243.5112.0–1584.0130	474.0 ± 1028.1106.0–9505.083	388.8 ± 215.497.0–1260.086	0.292	0.7848	N/A	N/A
Cardiacbiomarkers
BNPmean ± SD/min-max/N On admission	pg/mL	152.5 ± 241.11.7–1130.854	254.1 ± 763.71.7–6924.2107	455.4 ± 872.410.1–4890.650	433.3 ± 747.23.0–3153.250	711.7 ± 995.622.3–4993.056	1432.8 ± 2864.55.9–13,368.442	<0.0001	0.0206	0.054 a0.0004 b0.338 c	0.35 a0.031 b0.082 c
On discharge		177.7 ± 308.15.3–1877.054	239.8 ± 753.11.7–6924.2107	536.1 ± 1562.610.1–10,622.850	396.2 ± 697.63.0–3153.250	592.3 ± 769.122.3–3729.856	1389.2 ± 2735.411.9–13,368.442	0.0008	0.0206	0.257 a0.001 b0.971 c	0.412 a0.027 b0.067 c
NT-proBNPmean ± SD/min-max/NOn admission	ng/mL	1467.1± 3250.718.7–16,551.762	2126.5± 9426.712.0–70,000.0110	6608.9± 12,708.749.6–70,000.054	10,323.4 ± 16,141.418.2–70,000.055	14,888.1 ± 18,982.5119.6–70,000.043	13,522.6 ± 19,276.7343.7–70,000.055	<0.0001	<0.0001	0.015 a 0.0001 b 0.043 c	0.002 a0.0003 b0.614 c
On discharge		1694.0 ± 5047.828.5–35,000.062	1893.4 ± 7660.612.0–70,000.0110	7852.3 ± 15,159.049.6–70,000.054	10,661.5 ± 16,202.218.2–70,000.055	13,084.8 ± 17,275.9119.6–69,519.743	13,265.6 ± 17,873.3391.3–70,000.055	<0.0001	<0.0001	0.016 a0.0003 b0.267 c	0.0009 a<0.0001 b0.703 c
Troponin I,mean ± SD/min-max/NOn admission	ng/mL	53.1 ± 211.10.0–1994.8263	189.6 ± 1015.91.3–11,758.2415	658.5 ± 7215.31.9–94,365.5171	3044.2 ± 15,485.91.0–125,592.6134	988.4 ± 3316.83.3–21,022.994	542.0 ± 1724.64.8–14,128.897	0.015	0.0185	0.517 a0.02 b0.867 c	0.087 a0.133 b0.156 c
On discharge		105.7 ± 873.10.2–12,391.6263	124.0 ± 797.80.8–11,758.2415	692.7 ± 7243.61.9–94,365.5171	3359.3 ± 18,244.20.8–174,652.6134	838.2 ± 3666.21.8–29.828.394	493.1 ± 1504.84.8–12,657.297	0.0977	0.0095	N/A	0.104 a0.055 b0.17 c
n/n(%)/N = F: >46.8 ng/mLM: >102.6 ng/mL	>3-fold upper range	4617.5263	6716.1415	5129.8171	4735.1134	4952.194	3839.297	<0.0001	<0.0001	0.0113 a <0.0001b 0.0017 c	<0.0001a,b1.0 c
LDL-cholesterolmean ± SD/min-max/NOn admission	mg/dL	106.8 ± 64.86.0–510.085	96.2 ± 40.527.0–242.0147	93.9 ± 39.723.0–199.069	79.4 ± 40.617.0–230.060	83.3 ± 44.214.0–187.049	64.2 ± 37.66.0–210.039	0.0498	<0.0001	0.283 a0.038 b0.381 c	0.022 a<0.0001 b0.142 c
HDL-cholesterolmean ± SD/min-max/NOn admission	mg/dL	43.9 ± 17.92.0–120.086	37.7 ± 14.510.0–101.0150	44.5 ± 16.712.0–110.069	35.2 ± 11.97.0–66.060	39.8 ± 17.58.0–79.048	34.0 ± 10.317.0–61.038	0.303979	0.154387	N/A	N/A
Triglyceridesmean ± SD/min-max/NOn admission	mg/dL	189.4 ± 154.540.0–1100.0122	173.7 ± 105.144.0–664.0237	141.0 ± 94.548.0–595.083	148.0 ± 98.850.0–550.081	133.4 ± 56.746.0–282.060	124.8 ± 66.951.0–413.056	0.0022	0.0001	0.016 a0.001 b0.817 c	0.117 a<0.0001 b0.232 c
Hormones
25-hydroxy-vitamin Dmean ± SD/min-max/NOn admission	ng/mL	27.4 ± 21.83.5–146.199	23.4 ± 15.03.5–126.4206	26.1 ± 17.23.5–77.763	22.9 ± 15.45.1–75.645	22.4 ± 16.83.5–63.536	14.5 ± 9.63.5–39.125	0.3738	0.0006	N/A	0.974 a0.0006 b0.018 c
TSHmean ± SD/min-max/NOn admission	mIU/L	1.55 ± 2.00.01–18.6186	1.2 ± 1.060.0–6.33255	1.72 ± 2.980.01–28.81137	1.31 ± 1.390.01–8.2895	2.74 ±5.040.0–38.2485	1.43 ± 1.250.0–6.3662	0.1063	0.3834	N/A	N/A

Continuous variables are presented as: mean ± SD. range (minimum -maximum) and number of non-missing values. Categorized variables are presented as: a number with a percentage. Information about the numbers with valid values is provided in the left column. Abbreviations: N, valid measurements; n, number of patients with parameter above cut-off point; SD, standard deviation. OMNIBUS, analysis of variance; N/A, non-applicable, a low risk vs. medium risk, b low risk vs. high risk, c medium risk vs. high risk. Red text = statistically significant values.

Both genders revealed significant differences between the C2HEST strata and complete blood count parameters along with ion parameters. Noteworthy, no significant differences between strata in terms of initial inflammatory markers (procalcitonin, IL-6, CRP) along with acid-base balance parameters were noted.

The parameters of kidney function, including urea, creatinine, eGFR maintained significantly worse in the high-risk C2HEST stratum for both genders, however baseline serum concentration of protein and albumin was significantly lower only in females with higher C2HEST score value. In both study cohorts we observed increasing level of cardiac injury markers including troponin T and NT-pro-BNP levels in patientsallocated higher-risk group depending on their C2HEST score value. Surprisingly, lipid disorders (level of LDL and triglycerides) noticed at the time of admission were less severe subjects from high-risk stratum in both study cohorts.

3.2. Specific Treatment Applied during Hospitalization

Differences in applied treatment during hospitalization between the C2HEST group among genders are highlighted in Table 6. Women in the higher C2HEST stratum were prone to receive convalescent plasma. We did not observe any differences among the male cohort. In both study arms, we observed changes in the prevalence of antibiotic application. Subjects from the high-risk stratum more often received this type of therapy.

Table 6

Treatment applied during hospitalization.

Variables, Units	Low Risk[0–1]		Medium[2–3]		High Risk[≥4]		p-ValueOMNIBUS		p Value for Post-Hoc Analysis
	FemalesN = 682	MalesN = 735	FemalesN = 384	MalesN = 208	FemalesN = 135	MalesN = 139	Females	Males	Females	Males
Applied treatment and procedures
Systemic corticosteroidn/n(%)	299(43.8)	409(55.6)	127(44.7)	119(57.2)	64(47.4)	78(56.1)	0.7456	0.9222	N/A	N/A
Convalescentplasman/n(%)	54(7.9)	113(15.4)	12(4.2)	29(13.9)	15(11.1)	16(11.5)	0.0274	0.4749	0.1599 a0.8816 b0.0406 c	N/A
Tocilizumabn/n(%)	11(1.6)	11(1.5)	0(0.0)	2(1.0)	1(0.7)	0(0.0)	0.054	0.4308	N/A	N/A
Remdesivirn/n(%)	83(12.2)	153(20.8)	37(13.0)	35(16.8)	12(8.9)	23(16.5)	0.4627	0.2822	N/A	N/A
Antibioticn/n(%)	338(49.6)	408(55.5)	157(55.3)	146(70.2)	88(65.2)	103(74.1)	0.0026	<0.0001	0.3633 a 0.0038 b 0.2079 c	0.0006 a 0.0002 b1.0 c

Continuous variables are presented as: mean ± SD, range (minimum–maximum) and number of non-missing values. Categorized variables are presented as: a number with a percentage. Information about the numbers with valid values is provided in the left column. Abbreviations: N, valid measurements; n, number of patients with parameter above cut-off point; SD, standard deviation; OMNIBUS, analysis of variance; N/A, non-applicable; a low risk vs. medium risk, b low risk vs. high risk, c medium risk vs. high risk. Red text = statistically significant values.

The assignment to specific C2HEST stratum score correlated with the type of respiratory support applied during the hospitalization. Additionally, in the male cohort, it correlated with the prevalence of coronary revascularization procedures during index hospitalization along with the need for the catecholamine’s administration (Table 7).

Table 7

Applied treatment and procedures.

Variables	Low Risk[0–1]		Medium[2–3]		High Risk[≥4]		p ValueOMNIBUS		p Value for Post-Hoc Analysis
	FemalesN = 681	MalesN = 734	FemalesN= 284	MalesN = 207	FemalesN = 135	MalesN = 139	Females	Males	Females	Males
Applied treatment and procedures
The most advanced respiratory support applied during the hospitalisationno oxygenn/n(%)	409(60.1)	332(45.2)	140(49.3)	62(30.0)	50(37.0)	39(28.1)	<0.0001	<0.0001	0.001a <0.0001 b 0.0114 c	0.0001 a0.0007b1.0 c
low flow oxygen supportn/n(%)	199(29.2)	252(34.3)	103(36.3)	85(41.1)	65(48.1)	59(42.4)
high flow nasal cannulanon-invasive ventilationn/n(%)	26(3.8)	56(7.6)	24(8.5)	28(13.5)	17(12.6)	22(15.8)
invasive ventilationn/n(%)	47(6.9)	94(12.8)	17(6.0)	32(15.5)	3(2.2)	19(13.7)
Oxygenation parameters from the period of qualification for advanced respiratory support:SpO2, %mean ± SD/(min-max/N	92.2 ± 6.8(59–100)221	88.8 ± 8.6(50–100)189	87.0 ± 11.0(55–99)64	86.0 ± 8.4(60–99)69	86.2 ± 9.3(59–98)40	85.1 ± 10.5(60–99)48	<0.0001	0.0159	0.002 a0.0008 b0.908 c	0.057 a0.072 b0.87 c
Therapy with catecholaminesn/n(%)/N	39(5.7)682	92(12.5)735	14(4.9)	31(14.9)208	9(6.7)	33(23.7)	0.7614	0.0025	N/A	1.0 a0.0026 b0.1576 c
Coronary revascularisation or/and an indication for coronary revascularisation,n/n(%)/N	1(0.1)682	7(1.0)735	3(1.1)	8(3.8)208	1(0.7)	6(4.3)	0.0795	0.0021	N/A	0.0225 a0.0286 b1.0 c
Haemodialysisn/n(%)/N	15(2.2)682	31(4.2)735	2(0.7)	11(0.7)208	4(3.0)	8(5.8)	0.1486	0.6417	N/A	N/A

Continuous variables are presented as: mean ± SD, range (minimum–maximum) and number of non-missing values. Categorized variables are presented as: a number with a percentage. Information about the numbers with valid values is provided in the left column. Abbreviations: N, valid measurements; n, number of patients with parameter above cut-off point; SD, standard deviation; OMNIBUS, analysis of variance;N/A, non-applicable; a low risk vs. medium risk, b low risk vs. high risk, c medium risk vs. high risk. Red text = statistically significant values.

3.3. Association C2HEST Score with Results and Mortality

In the female cohort, the in-hospital and three-month andsix-month mortality rates were the highest in high-risk C2HEST stratum reaching 31.9%, 48.1%, and 61.4%. Noteworthy, mortality rates in the medium-risk stratum were significantly higher than in low-risk. All data regarding short and long-term mortality were presented in Table 8. Similarly, in the males’ cohort in-hospital, three-month and six-month mortality was also highest in the high-risk C2HEST stratum and come to 38.8%, 59.0%, and 68.8%. Also, in this study arm differences between all C2HEST groups were statistically significant.

Table 8

Total and in-hospital all-cause mortality in the C2HEST risk strata in males’ and females’ cohort.

Variables	Low Risk[0–1]		Medium[2–3]		High Risk[≥4]		p ValueOMNIBUS		p Value for Post-Hoc Analysis
	FemalesN = 682	MalesN = 735	FemalesN = 284	MalesN = 208	FemalesN = 135	MalesN = 139	Females	Males	Females	Males
All-cause mortality rate
In-hospital mortalityn/n(%)	36(5.3)	83(11.3)	50(17.6)	60(28.8)	43(31.9)	54(38.8)	<0.0001	<0.0001	<0.0001 a,b 0.0048 c	<0.0001 a,b0.2029 c
3-month mortalityn/n(%)	68(10.0)	134(18.2)	95(33.5)	103(49.5)	65(48.1)	82(59.0)	<0.0001	<0.0001	<0.0001 a,b 0.016 c	<0.0001 a,b0.3134 c
6-month mortalityn/n(%/)/N	72(17.3)415	142(31.4)452	104(49.3)211	104(60.1)173	70 (61.4)114	86(68.8)125	<0.0001	<0.0001	<0.0001 a,b0.1454 c	<0.0001 a,b0.4696 c
Hospitalization
Duration of hospitalization daysmean ± SD/(min-max)	10.4 ±12.7(1–131)	12.4 ± 14.4(1–130)	12.1 ± 11.9(1–68)	14.6 ± 15.6(1–124)	18.3 ±17.5(1–87)	13.9 ± 13.9(1–121)	<0.0001	0.1386	0.128 a <0.0001 b 0.0007 c	NA
End of hospitalisation deathn/n(%)	36(5.3)	83(11.3)	50(17.6)	60(28.8)	43(31.9)	54(38.8)	<0.0001	<0.0001	<0.0001 a,b 0.0143 c	<0.0001 a,b0.3663 c
discharge to home–full recovery	515(75.5)	478(65.0)	141(49.6)	79(38.0)	57(42.2)	46(33.1)
transfer to another hospital –worsening)	60(8.8)	79(10.7)	59(20.8)	38(18.3)	17(12.6)	27(19.4)
transfer to another hospital –in recovery	71(10.4)	95(12.9)	34(12.0)	31(14.9)	18(13.3)	12(8.6)

Continuous variables are presented as: mean ± SD, range (minimum–maximum) and number of non-missing values. Categorized variables are presented as: a number with a percentage. Information about the numbers with valid values is provided in the left column. Abbreviations: N, valid measurements; n, number of patients with parameter above cut-off point; SD, standard deviation; OMNIBUS, analysis of variance; N/A, non-applicable; a low risk vs. medium risk, b low risk vs. high risk, c medium risk vs. high risk. Red text = statistically significant values.

3.4. The All-Cause Mortality Discriminatory Performance of the C2HEST Score

The time dependent receiver operating characteristic (ROC) analysis in both study cohorts revealed that the C2HEST scale is more sensitive in the female cohort (Figure 1). The C2HEST predicting AUC in women vs. man cohorts were higher at all calculated periods. Following the 1-month AUC = 72.5 vs. 70.3% 3-month AUC = 74.6 vs. 71.3%, six-month AUC = 73.8 vs. 68.4 %. All of the data were calculated for all-cause death without competing risk Figure 2 present ROC analysis in the male population. Figure 3 presented the time-dependent AUC for the C2HEST score in predicting the all-cause deaths in both cohort, slightly higher AUC value was observed in the female arm. The survival curves for the C2HEST stratum in both study cohorts were estimated using Kaplan-Meier functions. The p value for Log-rank test was <0.0001 (Figure 4). We have observed differences in estimated survival probability in both study cohorts. Practically, starting from admission time, the females were more likely to survive the COVID-19. Estimated six-month survival probability for high-risk subjects reached 0.5 in the female cohort, while for the male subject was below 0.4. Similarly, in medium-risk-stratum for women the survival probability was above 0.6 when compared to 0.5 in men. Additionally, the low-risk subjects in the female cohort maintained at the level of more than 0.9 for the whole observation period while in men reached 0.8, respectively.

Figure 1

The time dependent receiver operating characteristic (ROC) for all-cause mortality in female cohort.

Figure 2

The time dependent receiver operating characteristic (ROC) for all-cause mortality in male cohort.

Figure 3

Time-dependent ROC analysis for the C2HEST predictive abilities of all cause death in both study cohorts.

Figure 4

The survival curves for the C2HEST stratum in both study cohorts estimated by Kaplan-Meier function.

Subsequently, two Cox models were analyzed to assess the effect of the C2HEST score stratification on COVID-19 mortality. The overall model takes an uncategorized value of the C2HEST score, and it met the hazard proportional assumption in both study cohorts. An additional point in the C2HEST score resulted in increased the total-death intensity approximately in 42.8% in female subjects (HR 1.428, 95% CI 1.349–1.513 p < 0.0001) and respectively in male population 40.0% (HR 1.400, 95% CI 1.331–1.474 p < 0.0001). Furthermore, considering the categorized model, the change from the low to the medium category in the female population increased death expectation 4.267 times, and respectively; 3.289 times for males. Subsequently, transfer between the low-risk stratum to high-risk stratum raised all-cause death intensity 6.52 (female) and 4.476(male) times. The data are shown in Table 9 and Table 10.

Table 9

The total all-cause-death hazard Ratios for C2HEST risk stratification in female cohort.

Total Death
	HR	95%CI	p Value
Overall	1.428	1.349–1.513	<0.0001
Risk strata
Low risk vs. Medium risk	4.267	3.170–5.732	<0.0001
Low risk vs. High risk	6.524	4.714–9.031	<0.0001

Red text—statistically significant values.

Table 10

The total all-cause-death Hazard Ratios for C2HEST risk stratification in male cohort.

Total Death
	HR	95%CI	p Value
Overall	1.400	1.331–1.474	<0.0001
Risk strata
Low risk vs. Medium risk	3.289	2.559–4.227	<0.0001
Low risk vs.High risk	4.476	3.438–5.827	<0.0001

Red text = statistically significant values.

The associations of individual C2HEST score components with mortality in both study cohorts are presented in Table 11 and Table 12. The highest prognostic value for all-cause- death in both study groups was noticed for age (in women 2.750 vs. 3.059 in men, respectively). Interestingly, coronary artery disease was associated with higher HR for death only in men, whereas the COPD and hypertension only in woman.

Table 11

Associations of individual C2HEST score components with mortality in female cohort.

	Component	HR	CI Min.	CI Max.	p Value
All-causemortality	Coronaryarterydisease	1.133	0.743	1.728	0.5627
	COPD	2.083	1.299	3.532	0.0064
	Age > 75	2.750	2.088	3.6216	<0.0001
	Thyroiddisease	0.784	0.566	1.105	0.1649
	Hypertension	1.881	1.394	2.537	<0.0001
	HfrEF	1.584	1.134	2.212	0.007

Abbreviations: COPD chronic obstructive pulmonary disease; HfrEF, heart failure with reduce ejection fraction. Red text = statistically significant values.

Table 12

Associations of individual C2HEST score components with mortality in male cohort.

	Component	HR	CI Min.	CI Max.	p Value
All-causemortality	Coronaryarterydisease	1.568	1.180	2.084	0.0019
	COPD	1.182	0.786	1.615	0.4227
	Age > 75	3.0541	2.411	3.869	<0.0001
	Thyroiddisease	1.126	0.688	1.842	0.6378
	Hypertension	1.200	0.952	1.513	0.1233
	HfrEF	1.415	1.055	1.899	0.0206

Abbreviations: COPD, chronic obstructive pulmonary disease; HfrEF, heart failure with reduce ejection fraction. Red text = statistically significant values.

Additionally, we verified whether the original cut-off values for particular C2HEST score risk (the low/medium/high-risk categories for 0–1/2–3/≥4 points, respectively) is potentially the best possible stratification system. Regarding the difference in Kaplan-Meier survival curves, all of the possible C2HEST intervals were analyzed in both study cohorts, and for each, we calculated the log-rank statistics (Table 13 and Table 14). The highest value of log-rank test statistics, presenting the best cut-off point for high (h) and medium (m) strata was obtained for the original C2HEST-score risk strata in the female population (m2 and h4, respectively). On the other hand, in male cohort the highest value of the Log-rank corresponded with m2 and h5, which reflects the following strata: 0–1 low, 2–4 medium, 5–8 high.

Table 13

The log-rank statistics for matching the C2HEST risk strata for in-hospital mortality in female cohort.

	H2	h3	h4	h5	h6	h7	h8
m1	164.317	148.669	142.661	121.294	105.396	105.533	10.259
m2		158.373	166.213	158.483	155.603	155.940	12.436
m3			122.464	116.484	116.367	116.190	10.699
m4				79.813	86.505	82.846	8.919
m5					45.423	40.946	6.156
m6						3.820	1.793
m7							0.139

Abbreviations: m, medium; h, high. Red text = statistically significant values.

Table 14

The Log-rank statistics for matching the C2HEST risk strata for in-hospital mortality in male cohort.

	H2	h3	h4	h5	h6	h7	h8
m1	152.361	134.106	118.904	112.785	98.649	84.149	8.929
m2		152.619	154.813	159.181	155.352	149.997	12.183
m3			116.694	121.473	118.900	115.004	10.673
m4				84.079	82.389	79.865	8.909
m5					58.586	58.244	7.628
m6						32.326	5.686
m7							2.769

Abbreviations: m, medium; h, high. Red text = statistically significant values.

3.5. Relationship of C2HEST Score with Non-Fatal Outcomes

Clinical non-fatal events in the C2HEST risk strata in both study arms are presented in Table 15. In both study cohorts, the subjects assigned to the C2HEST high-risk stratum were characterized by greater prevalence of pneumonia, acute kidney injury, and cardiovascular disorders during hospitalization. This observation regards myocardial injury, myocardial infarction, acute heart failure, and cardiogenic shock. Additional, female subjects with higher C2HEST values were more prone to subject a new episode of stroke/transient ischemic attack (TIA), and systemic inflammatory response syndrome (SIRS) during hospitalization. On the other hand, a high C2HEST score in the male subpopulation was associated with a higher probability of shock, acute liver dysfunction, and bleeding occurrence.

Table 15

Clinical non-fatal events in the C2HEST risk strata in both study arms.

Variables	Low Risk[0,1]		Medium[2,3]		High Risk[≥4]		p-ValueOMNIBUS		p-Value for Post-Hoc Analysis
	FemalesN = 682	MalesN = 735	FemalesN= 284	MalesN = 208	FemalesN = 135	MalesN = 139	Females	Males	Females	Males
Shockn/n(%)	34(5.0)	74(10.1)	15(5.3)	31(14.9)	11(8.1)	22(15.8)	0.3314	0.0443	N/A	0.2006 a0.1958 b1.0 c
Hypovolemic shockn/n(%)	9(1.3)	13(1.8)	4(1.4)	3(1.4)	5(3.7)	1(0.7)	0.1362	0.811	N/A	N/A
Cardiogenic shockn/n(%)	2(0.3)	5(0.7)	1(0.4)	10(4.8)	5(3.7)	9(6.5)	0.0018	<0.0001	1.0 a0.0055 b0.0439 c	0.0007 a0.0002 b1.0 c
Septic shockn/n(%)	26(3.8)	62(8.4)	12(4.2)	18(8.7)	4(3.0)	18(12.9)	0.8198	0.2296	N/A	N/A
Venous thromboembolic diseasen/n(%)	30(4.4)	53(7.2)	18(6.3)	12(5.8)	8(5.9)	7(5.0)	0.4093	0.5447	N/A	N/A
Pulmonary embolismn/n(%)	24(3.5)	44(6.0)	15(5.3)	11(5.3)	8(5.9)	5(3.6)	0.5516	0.8214	N/A	N/A
Myocardial infarctionn/n(%)	2 (0.3)	6(0.8)	3(1.1)	7(3.4)	3(2.2)	5(3.6)	0.0251	0.0038	0.464 a0.1026 b1.0 c	0.035 a0.0586 b1.0 c
Myocardial injury, 3x,n/n(%)/N	46(17.5)263	67(16.1)415	51(29.8)171	47(35.1)134	49(52.1)94	38(39.2)97	<0.0001	<0.0001	0.0114 a <0.0001 b 0.0017 c	<0.0001 a,b1.0 c
Acute heart failuren/n(%)	5(0.7)	3(0.4)	8(2.8)	14(6.7)	24(17.8)	22(15.8)	<0.0001	<0.0001	0.0777 a<0.0001 b,c	<0.0001 a,b 0.0329 c
Stroke/TIAn/n(%)	4(0.6)	14(1.9)	12(4.2)	7(3.4)	4(3.0)	3(2.2)	0.0002	0.4167	0.0006 a0.0872 b1.0 c	N/A
Pneumonian/n(%)	268(39.3)	414(56.3)	164(57.4)	141(67.8)	88(65.2)	98(70.5)	<0.0001	0.0004	<0.0001 a, b0.5343 c	0.0117 a0.0076 b1.0 c
Complete respiratory failuren/n(%)/N	23(47.9)48	34(46.6)73	16(43.2)37	30(58.8)51	20(62.5)32	23(65.7)35	0.2528	0.1348	N/A	N/A
SIRSn/n(%)/N	53(8.2)647	89(12.6)705	22(7.8)283	20(9.7)206	21(15.7)134	15(10.8)139	0.0158	0.4818	1.0 a0.0343 b0.0636 c	N/A
Sepsisn/n(%)/N	3(1.0)288	6(2.1)288	3(2.9)104	4(5.1)79	3(5.3)57	4(5.9)68	0.053	0.1334	N/A	N/A
Acute kidney injuryn/n(%)	37(5.4)	73(9.9)	30(10.6)	37(17.8)	28(20.7)	31(22.3)	<0.0001	<0.0001	0.0193 a <0.0001 b 0.0229 c	0.0083 a0.0002 b1.0 c
Acute liver dysfunctionn/n(%)/N	11(1.9)592	19(2.9)664	12(4.5)268	10(5.1)197	5(4.0)126	9(7.1)127	0.0619	0.0458	N/A	0.5214 a0.0936 b1.0 c
Multiple organ dysfunction syndromen/n(%)	7(1.0)	14(1.9)	3(1.1)	5(2.4)	4(3.0)	4(2.9)	0.1674	0.6162	N/A	N/A
Bleedingsn/n(%)	27(4.0)	37(5.0)	13(4.6)	12(5.8)	9(6.7)	16(11.5)	0.3758	0.0128	N/A	1.0 a0.0184 b0.2545 c

Continuous variables are presented as: mean ± SD range (minimum-maximum) and number of non-missing values. Categorized variables are presented as: a number with a percentage. Abbreviations: N, valid measurements; n, number of patients with parameter above cut-off point; SD, standard deviation; OMNIBUS, analysis of variance; TIA, transient ischemic attack; SIRS, systemic inflammatory response syndrome; N/A, non-applicable; a low risk vs. medium risk, b low risk vs. high risk, c medium risk vs. high risk. Red color text = statistically significant values.

Additionally, the overall odds ratio for the discriminatory performance of the C2HEST score on the clinical non-fatal events was summarized in Figure 5 (female) and Figure 6 (male). Noteworthy, the highest predictive of C2HEST score value in the female cohort was achieved for, acute heart failure (ORoverall = 2.180, 95%CI 1.778–2.724, p = 0.0034). Similar findings were observed in the male cohort -the highest value was observed for acute heart failure (ORoverall = 1.861, 95%CI 1.574–2.229, p < 0.0001).

Figure 5

The overall odds ratio for the discriminatory performance of the C2HEST score on the clinical non-fatal events in female cohort. Abbreviations: MODS, multiple organ dysfunction syndrome; TIA, transient ischemic attack; SIRS, systemic inflammatory response syndrome. Significance code: * <0.05; ** <0.01; *** <0.001; **** <0.0001.

Figure 6

The overall odds ratio for the discriminatory performance of the C2HEST score on the clinical non-fatal events in female cohort. Abbreviations: MODS, multiple organ dysfunction syndrome; TIA, transient ischemic attack; SIRS, systemic inflammatory response syndrome. Significance code: * <0.05; ** <0.01; *** <0.001; **** <0.0001.

4. Discussion

Several studies demonstrated [11] no significant differences regarding the susceptibility to the SARS-CoV-2 infection between biological genders. Nevertheless, male gender is an independent risk factor for the poor outcome of COVID-19 including higher severity and fatality rates [12]. Various biological factors may play a role in sex-dependent different responses to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Biological sex affects the initial phase of infection mainly by sex-based differences in the expression of the ACE2 receptor responsible for the entry of the SARS-CoV-2 into the cells [13]. Sex differences affect also an immune response to viral infection. Females tend to have a lower potency to develop an uncontrolled inflammatory response process [14] with coexisting decreased viral load during the infection. The physiological mechanism of this process is multifactorial [15,16] and includes the sex-specific transcriptional regulatory network, various gen variants especially connected with chromosome X, epigenetic modifications, transcription factors, and sex steroids. Noteworthy, different social, behavioral, and comorbid factors are also postulated [17] to worsen the prognosis in men.

The previously observed sex-dependent dichotomy in the COVID-19 mortality was also confirmed in our study. For all of the three C2HEST strata, greater fatality rate in the male cohort compared to the female one was noted. Independently, we confirmed the previously reported usefulness of the C2HEST score in predicting the adverse COVID-19 outcomes, including the mortality in both genders. However, despite lower mortality observed in women, the ROC analysis revealed that the C2HEST-score is a more sensitive tool in women regarding the short- and mid-term (up to 6 month-) mortality (for 1-month the AUC = 72.5 vs. 70.3%and for 6-month AUC = 73.8 vs. 68.4 % in men, respectively). Gender is often considered among the variables defining the probability of a severe clinical outcome of infection.

Analysis of individual C2HEST score variables in both cohorts revealed differences between gender in features significantly affecting mortality. Beyond age and previously diagnosed heart failure common for both sexes, in the female group, only hypertension and COPD reached statistical significance. On the other hand, in the male cohort such observation was made for coronary artery disease. Although the pathophysiology underlying severe COVID-19 course remains not fully understood, it can be hypothesized that endothelial dysfunction induced by hypertension [18] might abolish the initial favorable female immune response [14] to SARS-CoV-2 infection. Moreover, the endothelial dysfunction promotes microvascular thrombi and pro-thrombotic state associated with respiratory failure and fatal outcome in COVID-19 [19]. On the other hand, the increased mortality rate of COVID-19 male patients with CAD is probably related to the presence of multiple comorbidities [20] or direct myocardial injury connected with enhanced platelet activation induced by SARS-CoV-2 infection [21].

It is noteworthy that, besides observed in both genders significant differences in mortality between the C2HEST strata, a similar relationship was noticed in the prevalence of pneumonia and cardiovascular non-fatal secondary outcomes (myocardial infarction, myocardial injury, acute heart failure, cardiogenic shock, and acute kidney failure). Our study revealed that in the male cohort alongside with higher C2HEST stratum, a greater rate of acute liver injury (ALI), bleedings and shock was present. This observation supports the previously described relationships between male gender and liver impairment in COVID subjects [22]. Although the mechanism of liver injury in SARS-CoV-2 infection remains unclear, a combination of direct viral inclusion of hepatocytes, as well as the result of uncontrolled immune, may be responsible for the damage, which interestingly, have also been associated with poor outcomes in COVID patients [23].

Furthermore, some data [5,24] suggests that individuals with gastrointestinal problems particularly those with earlier stages of liver impairment are more prone to develop severe COVID-19 disease with advanced respiratory failure. Concerning epidemiological data a higher prevalence of liver disorders [25] with coexisting higher susceptibility for endothelial dysfunction [26,27] may be important factors affecting outcomes in the male population.

It is possible that acute liver injury in the male cohort may be also partially responsible for the higher rate of bleedings as a result of coagulation systems disorders (mild elevations of INR, activated partial thromboplastin time (APTT), and thrombin time (TT)) observed in patients with ALI in course of COVID-19 [23,28]. Initial higher level of INR in males high-risk C2HEST score stratum seems to support this thesis. Although the principal clinical manifestation of severe COVID-19 is a respiratory failure with a coexisting uncontrolled immune reaction, subjects with COVID-19 show a high incidence of thromboembolic events [29], particularly in fatal cases [30], however antithrombotic treatment prior to COVID-19 infection is unlikely to have a protective effect [31]. Bleeding complications in subjects with COVID-19 give rise to justifiable concerns [32,33] and should always be considered before applying anticoagulation in patients with SARS-CoV-2 infection. Therefore several predictive scores [34] focused on identifying patients at increased risk for major bleeding have been recently proposed. Results of our study suggest that the C2HEST score might be also useful in the identification of the “high-risk for bleeding” subpopulations. However, subsequent studies are needed to define predictive value of the C2HEST score in terms of bleedings.

Limitations

We have observed several limitations of this study including the retrospective, single-center, character. These factors could affect the validity of our conclusions. Additionally, the study population was homogeneous and consisted of hospitalized patients and not involved ambulatory subjects. Furthermore, all hospitalizations were carried out in the face of limited resources (global COVID-19 pandemic) probably these extraordinary circumstances could partially affect the clinical outcomes.

5. Conclusions

To the best of our knowledge, this study is the first demonstration of the sex-dependent differences in the predictive value of the C2HEST score in subjects admitted to hospital due to SARS-CoV-2 infection. This simple risk score evaluated during the hospital admission could predict adverse outcomes in both including in-hospital and six-month-mortality and other clinical events such as acute kidney injury, myocardial injury acute heart failure, myocardial infarction, and cardiogenic shock. Additionally in the male cohort, it well correlated with acute liver injury and prevalence of all kinds of bleeding. The simplicity of this scale allows assuming that C2HEST-score might become a useful triage tool for risk stratification in both genders with COVID-19.