|Year : 2020 | Volume
| Issue : 2 | Page : 85-88
A single-center study of the profile of spontaneous coronary artery dissection in acute coronary syndrome patients
Harsha Basappa, Sachin T Rao, KS Sadananda, Srinidhi Hegde, CN Manjunath
Department of Cardiology, Sri Jayadeva Institute of Cardiovascular Sciences and Research, Mysuru, Karnataka, India
|Date of Submission||23-Apr-2020|
|Date of Decision||15-May-2020|
|Date of Acceptance||02-Jun-2020|
|Date of Web Publication||25-Sep-2020|
Dr. Sachin T Rao
Department of Cardiology, Sri Jayadeva Institute of Cardiovascular Sciences and Research, Mysuru, - 570 016, Karnataka
Source of Support: None, Conflict of Interest: None
Background: Spontaneous coronary artery dissection (SCAD) is rarely encountered as a primary cause of acute coronary syndrome (ACS). There is a paucity of studies involving SCAD, especially in the Indian population. Aims: We aim to study the clinical and angiographic characteristics and in-hospital outcomes of ACS patients whose angiogram incidentally shows SCAD as the cause of ACS and the management strategies opted. Methods: This is a prospective and retrospective observational study. All coronary angiograms of patients with ACS, either ST-segment elevation myocardial infarction (STEMI) or unstable angina non-STEMI, underwent within 72 h of admission, were analyzed and those patients with Saw classification Type I SCAD were included in the study. Clinical and angiographic characteristics, in-hospital outcomes, and management strategies of patients with SCAD were recorded. Results: Of the total 70 cases with SCAD included in the study, 66 (94.28%) were male. Smoking was the most common risk factor seen in 22 (31.4%) cases. STEMI was the most common presentation seen in 44 (62.8%) subjects. Single-vessel involvement was seen in 67 (95.7%) patients. Significant stenosis, i. e., >70% luminal narrowing was seen in 40 (57.1%) patients. Root cause analysis (RCA) is the most common artery to be involved with 35 (50%) cases. Majority of the cases, i.e., 60 (85.7%) cases had thrombolysis in myocardial infarction 3 flow. The majority was managed conservatively. Percutaneous transluminal coronary angioplasty (PTCA) was done successfully in 18.5% of patients. Conclusion: Indian subjects, as observed in this study, differ significantly in their profile compared to the Western population. Indian subjects are predominantly middle-aged males with a significant proportion having traditional risk factors, and they tolerate thrombolysis better, success rates of PTCA are much higher, RCA is the most commonly involved artery as opposed to left anterior descending in Western population and more than half of the patients have atherosclerotic disease involving other arteries.
Keywords: Acute coronary syndromes, spontaneous coronary artery dissection, ST-segment elevation myocardial infarction
|How to cite this article:|
Basappa H, Rao ST, Sadananda K S, Hegde S, Manjunath C N. A single-center study of the profile of spontaneous coronary artery dissection in acute coronary syndrome patients. J Indian coll cardiol 2020;10:85-8
|How to cite this URL:|
Basappa H, Rao ST, Sadananda K S, Hegde S, Manjunath C N. A single-center study of the profile of spontaneous coronary artery dissection in acute coronary syndrome patients. J Indian coll cardiol [serial online] 2020 [cited 2020 Oct 21];10:85-8. Available from: https://www.joicc.org/text.asp?2020/10/2/85/296121
| Introduction|| |
Spontaneous coronary artery dissection (SCAD) is defined as an epicardial coronary artery dissection that is not associated with atherosclerosis or trauma and not iatrogenic. SCAD is rarely detected as a cause of acute coronary syndrome (ACS). The predominant mechanism of myocardial injury occurring as a result of SCAD is coronary artery obstruction caused by the formation of an intramural hematoma (IMH) or intimal disruption rather than atherosclerotic plaque rupture or intraluminal thrombus. Currently, the diagnosis of SCAD relies on angiographic visualization of a radiolucent intimal flap. SCAD is graded according to the National Heart Lung and Blood Institute classification system, developed by the Coronary Artery Registry  as Types A-F based on angiographic visualization. Improvement in coronary imaging techniques such as intravascular ultrasound (IVUS) and optical coherence tomography (OCT) has added to the diagnosis. Precipitating stressors that result in a Valsalva-like increase in thoracoabdominal pressure or that raise catecholamines can increase cardiocirculatory shear stress, which can trigger SCAD, especially in patients with underlying predisposing arteriopathies. There is a wide spectrum of clinical presentations and the severity of SCAD. Almost all patients with SCAD present with ACS and elevation of cardiac enzymes.
Therapeutic options include medical therapy, percutaneous coronary interventions (PCIs), and bypass surgery. There are not many studies involving the clinical profile, in-hospital outcomes, management, and follow-up of patients. Recent studies show differing characteristics of SCAD patients in the Asian population, compared to Western subjects. We aim to study the clinical and angiographic characteristics and in-hospital outcomes of ACS patients whose angiogram incidentally shows SCAD as the cause of ACS and the management strategies opted.
| Methods|| |
This is a prospective and retrospective observational study. The database of cardiac catheterization laboratory in a single tertiary care cardiac center, SJICSR, Mysore, was reviewed to identify ACS patients with SCAD in angiograms.
Data collection was carried out from the database available. Both prospective and retrospective analysis of data from August 2018 to February 2020 was done. All available hospital records, including coronary angiograms, were analyzed. Patients were contacted through telephone and asked for outpatient department reviews to get further details when needed. All patients with ACS either ST-segment elevation myocardial infarction (STEMI) or unstable angina non-STEMI (NSTEMI), undergoing coronary angiography within 72 h of admission were included in the study. All angiograms were independently reviewed by three experienced board-certified interventional cardiologists. As IVUS/OCT are not employed in the study, only Saw classification Type I (evident arterial wall stain) SCAD, which refers the pathognomonic angiographic appearance of SCAD with contrast dye staining of the arterial wall with multiple radiolucent lumens were included in the study to avoid confusion. All patients were analyzed for demographic data, risk/precipitating factors, clinical profile, other angiographic parameters, and treatment options employed.
Descriptive statistical analysis has been carried out in the present study, expressed as frequency, percentage, mean, and standard deviation.
| Results|| |
A total of 70 cases with SCAD were identified during the study period and included as subjects in the study. [Table 1] describes the demographic and risk factors profile of the enrolled patients.
The mean age of the study patients was 53.48 ± 11.2 years, majority of them, i.e., 22 (31%) were in the age group of 41–50 years. Female cases were older compared to male subjects. One striking feature of this study was that 66 (94.28%) study subjects were males. The common risk factors noted in the study subjects were smoking seen in 22 (31.4%) cases followed by hypertension in 28.5% and diabetes in 25.7%.
[Table 2] shows the clinical presentation and baseline angiographic characteristics. STEMI was the most common presentation seen in 44 cases, of which 20 (45%) were thrombolyzed with streptokinase. Hence, an overall 20 (28.5%) patients included in the study underwent thrombolysis. SCAD in infarct-related artery was seen in 28 (63.6%) out of 40 STEMI cases. Single-vessel involvement was seen in 67 (95.7%) patients. Only 3 out of 70 (4.28%) had two-vessel SCAD. RCA is the most common artery to be involved with 35 (50%) cases, followed by LAD involved in 26 (37.1%) cases. One patient had SCAD in the left main vessel without any flow limitation. Thrombus was visible in 10 (14.2%) patients. Significant stenosis, i.e., >70% luminal narrowing was seen in 40 (57.1%) patients. More than half of patients had coexisting lesions in other vessels. Three patients were known cases of CAD who had undergone PTCA previously, currently presenting with ACS, and two had ISR in the nondissected artery, with only one having ISR of the dissected artery.
|Table 2: Clinical presentation and baseline angiographic characteristics|
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[Table 3] shows the characteristics of vessels involved in SCAD and the distribution pattern. Mid segments of LAD and RCA were the most common sites to be involved, followed by their proximal segments. The longest disease involving most of the vessels was more commonly seen in RCA. Eight cases of RCA had all three segments involved. No segmental preference was seen in left circumflex (LCX). The proximal part was the most common segment involved in Major OM.
|Table 3: Vessels and their segments involved in spontaneous coronary artery dissection|
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[Table 4] shows that the majority of the cases, i. e., 60 (85.7%) cases had TIMI 3 flow. Total occlusion of the artery was seen in two patients and on opening was found to have SCAD.
|Table 4: Thrombolysis in myocardial infarction flow in spontaneous coronary artery dissection artery|
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The majority was managed conservatively, as shown in [Table 5]. PTCA was possible in 18.5% of patients. PTCA was unsuccessful in one patient, as the wire could not be crossed across the lesion. Ten percent of the patients underwent coronary artery bypass grafting (CABG). No mortality was recorded in patients who underwent intervention.
One patient had a total occlusion of the artery while undergoing PTCA and had to be shifted to CABG.
| Discussion|| |
This is one of the largest studies on SCAD. There is a paucity of data from the South Asian Population regarding SCAD. This study aims to throw light on the SCAD in a single center in South India. The true prevalence of SCAD is difficult to ascertain as it is often under-diagnosed and have varying presentations from mild chest pains to sudden cardiac death. In patients presenting with ACS, SCAD is noted to occur in 3%–4%. In a study by Saw et al., all cases of SCAD presented with troponin-positive ACS, with 26% presenting with ST-elevation myocardial infarction (MI), and 3.6% with ventricular arrhythmia. Two older studies showed a higher proportion presenting with ST-elevation MI (80%–84%), whereas non-S-T elevation MI was 8%–16%, and 4% presented with unstable angina., In this study, STEMI constituted 62.85% of the patients.
The average age at diagnosis in different series ranges from 45 to 55-year-old. In this study, the mean age of subjects was 53.48 years, which correlated with previous studies.
Previous studies vastly from Western literature showed that the vast majority of patients of SCAD are women with a low prevalence of risk factors. The conventional teaching is that SCAD occurred predominantly in young women. In a case series by Saw et al., the average age was 52.1 ± 9.2 years, and 58% were actually aged 50 years or older. In a study by Bastante et al., the mean age for females was 44 years. This is in strong contrast with our findings. In our study, males constituted 94.28% of subjects. Another study done in south India by Basavanna et al. also had similar findings, with 93.8% of subjects being males. In a study by Sanjai et al., 87.5% of subjects were males. So, we would like to state that there is a strong predisposition of males toward SCAD in the Indian subcontinent, in contrast to the Western population, which predominantly has female dominance. However, some Indian studies have data where females outnumbered males. In a study by Madhavan and Narayanapillai, 78.8% of the subjects were Females.
In the current study, traditional risk factors such as diabetes mellitus, hypertension, and smoking are seen in approximately one-third of patients. This is in contradistinction with previous reports, where in the absence of traditional cardiovascular risk factors was considered to raise the suspicion of SCAD.
In our study, RCA was the most commonly involved artery, followed by LAD and LCX. This is another contrasting finding. Previous studies showed that the left anterior descending coronary artery is the most frequently involved vessel. In another Indian study by Sanjai et al., LAD and the RCA shared an equal proportion of 38.9%.
Hayes et al. showed that 10%–20% of patients present with multivessel involvement. In our study, two-vessel involvement was seen in 4.28% of patients.
Thrombolytic therapy should be avoided in SCAD, as reports of clinical deterioration due to extension of dissection and IMH are documented., In the retrospective review by Shamloo et al., of 87 SCAD patients who received thrombolysis, 60% had clinical deterioration requiring rescue PCI or CABG. In this study, >28% of cases were thrombolyzed with streptokinase before being taken for coronary angiography. Out of 20 cases, thrombolyzed only two cases required rescue PTCA due to failed thrombolysis. The rest of the 18 cases did well on thrombolysis. Our findings suggest that most of the SCAD patients tolerate thrombolysis reasonably well.
Previous studies noted that SCAD involves the mid to distal LAD artery in the majority of the cases, and the proximal LAD and the left main coronary artery in pregnancy-related SCAD patients. In this study, midsegments of LAD and RCA were the most common sites to be involved, followed by proximal segments.
Revascularization should always be considered in patients with high-risk anatomy (i.e., left main), those hemodynamically unstable, and those with ongoing ischemia., In the present study, >70% of patients were advised conservative optimal medical management.
Observational studies have shown that coronary interventions in these patients are associated with poorer results and an increased risk of complications as compared to atherosclerotic lesions. Technical failure, including the presence of residual dissection, may occur in up to 50% of patients., Long-term durability with PCI is only ~ 30%. Similarly, in the study by Tweet et al., among 43 SCAD patients who underwent PCI, technical success was achieved in only 65%. There is a strong contrast in the present study for this observation. In our study, PTCA failure was seen in only 1 patient out of 14 patients taken for PTCA. This patient, an elderly male with a long segment dissection in LAD, had closure of LAD while attempting PTCA and as the wire could not be crossed, it was taken for emergency CABG. PTCA was successfully completed without complications in the rest of the 13 cases. Possible explanations for higher success rates in our study are: Preferred approach being femoral over radial, for interventions and higher proportion of cases where stiff & hydrophilic coronary guidewires were being used. The femoral route may guarantee a more stable catheter sitting, thus avoiding iatrogenic dissections. In an Indian study by Sanjai et al., high rate of procedural success of 87.5% was documented.
However, emergency coronary artery bypass grafting may be required in 10% of patients undergoing coronary interventions. In this study, CABG was required in 10% of patients. CABG was offered due to either involvement of left main or multi-vessel atherosclerotic disease.
Evidence on the value of dual antiplatelet therapy in patients not treated with coronary interventions is lacking. We followed dual antiplatelet for 1 year as applicable for atherosclerotic ACS, as the majority of patients were of similar clinical profiles.
| Conclusion|| |
There are many differences noted in SCAD patients presenting in ACS in the Indian subcontinent as compared to the Western population. Comparative contrasting findings in Indian subjects as observed in this study are that subjects are predominantly middle-aged males with a significant proportion having traditional risk factors, tolerate thrombolysis better, success rates of PTCA are much higher, RCA is the most commonly involved artery as opposed to LAD in western population, and more than half of patients have the atherosclerotic disease in other arteries. Well-designed, large, nation-wide, prospective studies are required to address major gaps in knowledge on this unique condition in the Indian subcontinent and to ascertain these contrasting features.
Limitations of the study
This was a single-center study with a limited number of patients. We run a small risk of misinterpreting a partially reanalyzed thrombus as SCAD, as intracoronary imaging techniques were not employed in our patients.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]