The Comparing of Short Clinical Cardiovascular Outcomes with Wraparound and Nonwraparound Left Anterior Descending Artery in Patients with Anterior ST-Segment Elevation Myocardial Infarction.

BACKGROUND: The relation between left anterior descending artery (LAD) anatomy and clinical outcomes in patients with anterior ST-segment elevation myocardial infarction (STEMI) has not been fully investigated. The aim of this study was to determine the frequency and severity of short-term cardiovascular outcomes in patients with Anterior ST-Segment Elevation Myocardial Infarction (STEMI) undergoing primary percutaneous intervention (PCI), based on wraparound and non-wraparound left anterior descending artery (LAD).
METHODS: In a cross-sectional study, 126 patients with anterior STEMI who were admitted to Shahid Chamran Hospital in Isfahan during 2020 were studied. Patients were evaluated for anatomical features of LAD coronary artery and clinical outcomes determined and compared based on wraparound LAD and non-wraparound LAD during hospitalization and up to one month after PCI.
RESULTS: The prevalence of wraparound LAD in the studied patients was 73% and left ventricular systolic dysfunction in admission was greater and more severe in patients with wraparound LADs compared with those with non-wraparound. Severe LV systolic dysfunction in the wraparound and non-wraparound groups was 39.6% and 8.8%, respectively (P < 0.001). Also, the frequency of arrhythmias in the wraparound group (21.7%) was higher than the non-wraparound group (5.9%) (P = 0.037).
CONCLUSION: The patients with anterior STEMI and wraparound LAD have a worse clinical outcome and more severe left ventricular systolic dysfunction. Therefore, it seems that the study of the anatomical condition of the LAD artery at the time of angiography is of great importance in the way of observation and care, and treatment of patients. Copyright:

INTRODUCTION

Acute myocardial infarction (AMI) is the most common cause of mortality in developed countries. Patients with anterior ST-segment elevation myocardial infarction (STEMI) are at higher risk for clinical complications because it affects more of the myocardium.[1] Left anterior descending artery (LAD) obstruction is one of the strongest factors in infarct size.[2]

Wraparound LAD is defined by the arrival of LAD at the apex and supplying the apical inferior aspect of the heart.[34] It supplies more of the myocardium than the non-wraparound where the LAD terminates before or at the apex.[5] Although the overall infarct size was similar in the two groups in the INFUSE-AMI study, the infarct size was not the same in different regions. In wraparound LAD, larger areas of infarction were observed in the inner apical and apicoseptal.

The relation between the LAD artery anatomy and the clinical implications in anterior STEMI patients has not been fully investigated.[5] Larger infarct size and left ventricular apical remodeling are the most important mechanisms that have been suggested as a mechanism of worse cardiovascular outcomes in patients with anterior STEMI and wrapprand LAD compared with non-wraparound.[6]

Some of the studies have shown that dysrhythmia, acute moral thrombosis, and reduced ejection fraction were more common in patients with wraparound LAD. Also, in the 6-year follow-up of these patients, major cardiovascular events (death, stroke, and stent thrombosis) were higher in the LAD wraparound group.[7] Beppu et al. has shown that left ventricular apex akinesia or dyskinesia after anterior STEMI causes stasis, responsible for thrombosis.[8] Also, left ventricular moral thrombosis, which is more common in wraparound LAD patients than non-wraparound patients, has caused a higher prevalence of stroke in these patients.[9] In the INFUSE-AMI study, the wraparound LAD group was associated with a larger apical infarction size that resulted in worse one-year outcomes. Inferior STEMI occurs in the following setting: distal LAD occlusion with a wraparound LAD, wraparound LAD only, or only distal LAD occlusion because the electrical vector of inferior leads during anterior STEMI would be affected by multiple factors.[7]

At the same time, despite the high prevalence of myocardial infarction in our country and the high clinical complications in anterior STEMI patients and wraparound LAD's role in the development of these complications, a comprehensive study has not been conducted in our country in this field. Therefore, the aim of this study was to determine the frequency of short-term cardiovascular events in anterior STEMI patients undergoing primary angioplasty, based on wraparound and non- wraparound LAD, to reduce adverse clinical outcomes with more accurate observation and faster complications diagnose to increase the patients quality of life.

MATERIALS AND METHODS

This study is a cross-sectional study that was performed between January 2020 and May 2020 in Shahid Chamran Hospital in Isfahan, Iran. The study's target population was patients with Anterior STEMI in the electrocardiogram (ECG) undergoing primary PCI.

Inclusion criteria included: PCI less than 48 hours from the onset of chest pain, no previous known LV systolic dysfunction, and patient consent to participate in the study. Also, the patient's death before echocardiography, lack of PCI for the patient, and patient dissatisfaction and cooperation in performing echocardiography and angiography were considered as exclusion criteria.

Anterior STEMI was diagnosed based on ST-segment elevation at least 1 mm in leads V1-V6.

The required sample size for the study using the sample size formula for prevalence studies with 95% confidence level, the prevalence of wraparound LAD in anterior ST-Elevation MI patients which is estimated to be 0.57%[4] and 0.1 error rate was estimated 95. But in order to increase the level of reliability and study capacity, all eligible patients who were 126 during the year Esfand 1397-Tir1398 were included in the study.

Patients with anterior STEMI who were diagnosed based on ECG and symptoms were included in the study and initially, their demographic and clinical information was recorded in the data collection form. After PCI, by examining the angiographic views and reviewing the relevant videos, the condition of the LAD artery was evaluated in terms of wraparound and non-wraparound. Wraparound is cases in which the LAD artery reaches the apex and supplies blood to the apical and inferior parts of the heart, but in the wraparound, the LAD artery terminates before the apex or in the apex and supplies fewer areas than the wraparound.[5]

All patients underwent echocardiography before PCI and cardiac ejection fraction (EF) was determined in them and according to the non decrease in EF of patients divided into four groups: severe (EF <30), moderate (30≤ EF <44), mild (45< EF <54), and normal (EF ≥55).

Patients were evaluated for the occurrence of ventricular and nonventricular arrhythmias, stroke, and the site of infarction (anterior and anterior/inferior) from the time of admission and during hospitalization, and the site of infarction was registered. After PCI and discharge from the hospital, all patients were followed up within a month and were examined for readmission, recurrence of myocardial infarction and stroke, and other short-term complications and mortality.

Data collected from patients were finally entered into SPSS software version 21 (Manufactured by IBM Corporation, USA) and analyzed by Chi-square, Mann–Whitney, and t-test.

RESULTS

In this study, 126 patients with anterior STEMI with a mean age of 60.74 ± 12.1 years were studied, of whom 103 (81.7%) were male. In the angiographic view, LAD status was wraparound in 92 patients (73%) and non-wraparound in 34 patients (27%). The wraparound LAD group had a higher mean age, but the LAD status did not differ significantly by sex (P = 0.35).

Among 126 patients under study, 75 (59.5%) had single-vessel involvement, 33 (26.2%) had two-vessel involvement and 18 patients (14.3%) had three-vessel involvement, but the number of vessels involved according to anatomical condition LAD artery was not significantly different (P = 0.24).

Thirteen patients (10.3%) had rehospitalization, of which 11 (84.6%) were due to heart disease. Also, there was no significant difference in rehospitalization rate and the cause of hospitalization according to the feature of the LAD artery [Table 1].

Table 1

Demographic and clinical characteristics based on wraparound and nonwraparound left anterior descending artery

Variables	LAD status		P
	Wraparound (n=92)	Nonrapparound (n=34)
Mean±SD age (year)	62.1±12.35	57.09±10.57	0.08
Gender
Male	77 (83.7)	26 (76.5)	0.35
Female	15 (16.3)	8 (23.5)
Vessels involvement
One	62 (56.3)	23 (67.6)	0.24
Two	24 (26.1)	9 (26.5)
Three	16 (17.4)	2 (5.9)
Rehospitalization
Cardiac	6 (75)	5 (100)	0.49
Other reasons	2 (25)	0

LAD: Left anterior descending artery, SD: Standard deviation

According to the results of the study, wraparound LAD patients had a higher degree of LV systolic dysfunction, so that in this group, 39.6% suffered from severe LV systolic dysfunction. However, in the non-wraparound LAD group, severe LV systolic dysfunction was observed in 8.8% of patients. In contrast, in the wraparound LAD group, cases of mild LV systolic dysfunction were higher and in general, the severity of LV systolic dysfunction was significantly different between the two groups (P < 0.001).

The incidence of mortality was 8.7% in the wraparound group and 5.9% in the non-wraparound group, but no significant difference was seen between the two groups (P = 0.73).

The frequency of arrhythmia in the wraparound group (21.7%) was higher than the non-wraparound group (5.9%) (P = 0.037). The onset of arrhythmia was in 12 patients (54.5%) before PCI and in 10 patients (45.5%) after PCI. Also, arrhythmia was ventricular in 18 patients (81.8%) and non-ventricular in 4 patients (18.2%), but the time and type of arrhythmia were not significantly different according to the anatomy of the LAD artery.

The site of myocardial infarction in ECG was in 78 patients (61.9%) anterior, 47 (37.3%) anterior-inferior, and in 1 patient (0.8%) inferior. The incidence of ST-segment elevation in the two groups wraparound and non-wraparound, was significantly different so that the incidence of ST-segment elevation in the anterior and inferior in ECG was 47.8% in the wraparound LAD group and 8.8% in the non-wraparound LAD group. The difference between the two groups was quite significant (P < 0.001).

The incidence of myocardial infarction in one month follow-up between the two groups of wraparound (2.2%) and non-wraparound (5.9%) was not significantly different (P = 0.29). Also, the incidence of stroke in the two groups of wraparound (1.1%) and non-wraparound (2.9%) was not significantly different (P = 0.47) [Table 2].

Table 2

Frequency distribution of thrombosis severity and incidence of complications according to left anterior descending artery status

Variables	LAD status		P
	Wraparound (n=92)	Nonrapparound (n=34)
EF drop
Sever	36 (39.6)	3 (8.8)	<0.001
moderate	50 (54.9)	21 (61.8)
Mild or normal	5 (5.5)	10 (29.4)
Outcome
Mortality	8 (8.7)	2 (5.9)	0.73
Arrhythmia	20 (21.7)	2 (5.9)	0.037
Kind of arrhythmia
Ventricular	16 (80)	2 (100)	0.99
Supra ventricular	4 (20)	0
Time of arrhythmia
Before PCI	10 (50)	2 (100)	0.48
After PCI	10 (50)	0
Site of infarction
Anterior	48 (52.5)	30 (88.2)	<0.001
Anterior and inferior	44 (47.8)	4 (11.8)
Main outcome
MI	2 (2.2)	2 (5.9)	0.29
Stroke	1 (1.1)	1 (2.9)	0.47

LAD: Left anterior descending artery, EF: Ejection fraction, PCI: Percutaneous coronary intervention

DISCUSSION

Some previous studies have shown that the anatomical features of the LAD artery play a role in the prognosis of patients with anterior STEMI, and patients with a wraparound LAD have a worse prognosis and greater infarction size, but so far, no unit theory has been provided in this regard. Therefore, this study was performed to determine the frequency of short-term cardiovascular events in anterior STEMI patients undergoing angioplasty, based on wraparound LAD and non-wraparound LAD.

Our study's findings showed that the complications of STEMI were more severe in patients with wraparound LAD status so that the severity of LV systolic dysfunction in these patients was higher than the non-wraparound LAD group. The results of several studies, including those of Antoni et al.,[1] Brener et al.,[10] and Kandzari,[6] have shown that patients with LAD lesions have worse clinical outcomes, especially in the reduction of EF compared to lesions of other arteries.[1610] In the study of Bozbeyoğlu et al., patients with wraparound LAD pattern had a worse clinical outcome.[11]

In our study, the prevalence of wraparound LAD was 73%, which is similar to the results of Perlmutt's study, which estimated the prevalence of wraparound 77.7%,[3] and Brener's et al. study, which achieved a prevalence of 76%[7] but is different from Ilia et al. that 57% reported.[4]

The findings of our study showed that the incidence of ST-segment elevation in both anterior and inferior in ECG was significantly higher in the wraparound group.

In two studies by Karha and Elsman, anterior myocardial infarction in patients with proximal LAD lesions had worse short-term clinical outcomes.[1213] In the study by Brener et al., patients with proximal LAD lesions had worse clinical outcomes than mid-part LAD lesions. In this study, it was shown that in patients with wraparound LAD, the lesions at the proximal of LAD are less than non-wraparound and it was concluded that wraparound LAD has an essential role in clinical outcomes due to less remodeling.[7]

One-month follow-up of patients showed that the incidence of arrhythmia in wraparound LAD patients was higher than that of the non-wraparound LAD group, but the frequency of other complications, including mortality, stroke, and myocardial infarction, was not significantly different between the two groups. A number of previous studies have shown that dysrhythmia, acute moral thrombosis, and decreased EF were more common in patients with wraparound LAD.[7] In a 3-year follow-up, major cardiovascular events (death, stroke, and stent thrombosis) were observed in the group with wraparound LAD was higher 8. In a study by Beppu et al., it was shown that Akinsky or left ventricular apex dyskinesia after anterior STEMI caused stasis, which is responsible for thrombosis.[8]

Also, in previous studies, left ventricular moral thrombosis is more common in LAD wraparound patients than in non-wraparound patients, leading to a higher prevalence of stroke in these patients.[9] When in anterior STEMI, wraparound LAD is found more precise monitoring is recommended for left ventricular moral thrombosis and LV remodeling, as well as short-term and long-term complications.

CONCLUSION

The findings of our study showed that patients with STEMI whose LAD artery is in wraparound feature have a worse clinical condition and the decrease in cardiac ejection fraction is greater and more severe. Therefore, it seems that the study of the anatomical condition of the LAD artery at the time of angiography is of great importance in the way of care and treatment of patients. At the same time, due to the limitations of this study, including the small sample size, it is suggested that more studies be done in this field.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.