Abstract 4143918: Differences in Outcomes in Spontaneous Coronary Artery Dissection vs. Type 1 Myocardial Infarction

Background: Spontaneous coronary artery dissection (SCAD) is a non-iatrogenic dissection in the epicardial coronary arteries, not related to trauma or atherosclerosis. In SCAD, myocardial injury occurs due to luminal obstruction following intimal disruption or intramural hematoma. We aimed to determine the differences in outcomes associated with SCAD compared to Type 1 myocardial infarction (MI) in the Aurora Health Care community. Methods: A retrospective, matched cohort, multicenter community study was carried out on adult patients aged >18 years admitted to all Aurora Hospitals from January 2012 to December 2022. A total of 57 patients were diagnosed with SCAD during that period. The SCAD and Type 1 MI groups were matched by age and gender at a 1:5 ratio using a propensity score-based matching. Outcomes between the SCAD and Type 1 MI groups were compared using chi-squared tests or Fisher’s exact tests, and t-tests or nonparametric equivalents (Wilcoxon), and a time-to-event analysis. Results: SCAD patients who underwent conservative therapy were 87.7%. There were no significant differences in in-hospital outcomes between SCAD and Type 1 MI in measures such as cardiogenic shock, mortality rate, sudden cardiac death, ischemic stroke, hospital length of stay, and arrhythmias (AF, atrial flutter, supraventricular tachycardia, and ventricular fibrillation). In the long term, SCAD patients required less repeat coronary catheterization (7% vs. 24.6%, p=0.003) and PCI (1.8% vs. 11.2%, p=0.027) compared to the Type 1 MI group. Type 1 MI patients had a higher incidence of AF, atrial flutter, death, readmissions for heart failure, and diastolic and systolic function in the long term, but this was not statistically significant. Type 1 MI patients required loop diuretics in the long term (24.6% vs 10.5%, p 0.02). Conclusion: Type 1 MI patients exhibited poorer long-term prognoses characterized by a higher risk of heart failure, which likely increased the necessity for diuretics. Additionally, Type 1 MI patients showed a higher need for repeat coronary catheterization and PCI. Although SCAD and Type 1 MI present similarly as acute coronary syndrome, it is important to understand the differences in outcomes as the management of these two populations differ.