Youssef, Amal

Background: Spontaneous coronary artery dissection (SCAD) is increasingly recognized as a cause of acute coronary syndrome, particularly in young to middle-aged women. While most presentations are associated with preserved left ventricular ejection fraction (LVEF), a subset of patients present with acute systolic dysfunction. The characteristics of patients who recover their LVEF are not clearly defined. Methods: We retrospectively analyzed 495 patients with angiographically confirmed SCAD treated at three Mayo Clinic sites (Arizona, Rochester, and Florida) from 1994 to 2023. Patients with a prior history of myocardial infarction, coronary artery disease, and congenital heart disease were excluded. Baseline LVEF at SCAD presentation was categorized into <35%, 35–39%, 40–49%, and ≥50%. Follow-up LVEF was assessed by echocardiography performed between 30 days and 1 year post-SCAD. The primary outcome was improvement in LVEF to ≥50% at follow-up. Results: A total of 495 SCAD patients were included. At presentation, 26% had reduced LVEF: 6% had LVEF <35%, 5% had LVEF between 35–39%, and 15% had LVEF between 40–49%. Patients who did not normalize their EF at follow-up were slightly younger (45 vs. 48 years, p=0.04), were more likely to have had an in-hospital cardiac arrest (13% vs. 4%, p=0.01), required mechanical circulatory support during their care, and had SCAD involving the left main artery (11% vs. 2%, p=0.01). Predictors of EF normalization included SCAD which involved the obtuse marginals (15% vs. 4%, p<0.05). The group with the lowest EF at presentation had the highest probability of persistent EF <50% at follow-up (32% for those with LVEF <35%) while patients who had normal EF at presentation had a 6% chance of having EF <50% at follow-up (Figure 1). Conclusions: Our study shows that the majority of SCAD patients have normal EF at presentation. 80% of those with reduced EF at presentation will normalize at follow-up. Predictors of low EF at follow-up included dissection involving the left main artery, lower EF at SCAD presentation, in-hospital arrest and use of mechanical circulatory support.