Predictors of Major Adverse Cardiovascular Events: First Report From the Australian-New Zealand Spontaneous Coronary Artery Dissection (ANZ-SCAD) Registry

Introduction: Spontaneous coronary artery dissection is an increasingly recognised cause of acute coronary syndrome (ACS). There are limited data assessing independent predictors of major adverse cardiovascular events (MACE) following SCAD. 

Aim: To describe the clinical characteristics of people with SCAD and to determine predictors of MACE and SCAD recurrence. 

Method: Multicentre, prospective and retrospective cohort study involving 23 Australian and New Zealand sites. Patients >=18 years with an ACS secondary to SCAD confirmed on core laboratory adjudication were included. Multivariate Cox proportional hazard models were used. 

Results: From 507 patients, n=440 (137 prospective, 303 retrospective) had confirmed SCAD; mean age 52.4±10.7 years, 89.8% female. MACE and SCAD recurrence occurred in 8.3% and 3.2%, respectively at median 15-month follow-up. Risk factors for MACE included anticoagulation use on discharge [adjusted hazard ratio (aHR) 4.8, 95% confidence interval (CI) 1-11.8, p=<0.001], history of AF (aHR 7.6, 95%CI 1.7–32.9, p=0.007) and the presence of fibromuscular dysplasia [(FMD), aHR 2.7, 95%CI 1.2–6.2, p=0.02). Anticoagulation (aHR 7.3, 95% 2.4–22.3, p<0.01), FMD (aHR 5.2, 95% CI 1.8–14.9, p=0.002), history of stroke (aHR 5.5, 95%CI 1.2–24.2, p=0.02), and dual antiplatelet treatment with aspirin and ticagrelor (aHR 2.2, 95% CI 1.1–4.6, p=0.03), but not aspirin and clopidogrel, were associated with SCAD recurrence. 

Conclusion: The risk of MACE was five-fold higher in patients on anticoagulation and three-fold higher in patients with FMD. SCAD recurrence comprised a large proportion of overall MACE. Dual-antiplatelet therapy combining ticagrelor and aspirin was associated with a higher risk of SCAD recurrence.