Clinical characteristics and predictors of adverse cardiovascular events from the australia-new zealand spontaneous coronary artery dissection (ANZ-SCAD) registry

Abstract Background Spontaneous coronary artery dissection (SCAD) is an increasingly recognised cause of acute coronary syndrome (ACS), predominantly affecting women. Our understanding of SCAD remains incomplete with limited prospective data on determinants of major adverse cardiovascular events (MACE). Purpose We aimed to describe the clinical characteristics of patients with SCAD from a large, multicentre SCAD registry. We aimed to identify the predictors of MACE (defined as the composite of all-cause death, non-fatal myocardial infarction, stroke, heart failure, and revascularisation). Methods Observational, multi-centre prospective and retrospective cohort study recruiting patients with SCAD from 23 hospitals in Australia and New Zealand. Patients aged=>18 years with SCAD and an ACS were eligible for inclusion. Prospectively recruited patients gave their informed consent with a waiver of consent for retrospectively recruited patients. All invasive coronary angiography imaging was adjudicated by an independent core laboratory to confirm the diagnosis of SCAD. Cox proportional hazard analysis was used to evaluate the association between MACE and SCAD recurrence with predefined clinical variables. Results From a total 487 patients recruited, 423 (132 prospective and 291 retrospective) patients with SCAD confirmed on core laboratory review were included for analysis. Mean age was 52.4±10.7 years, 89.7% were female and 73.1% were Caucasian. Percutaneous coronary intervention (PCI) was performed in 10.6% of patients. On discharge, 64% of conservatively managed patients were on dual antiplatelet therapy (DAPT). At 15 (interquartile range 5-36) months median follow-up, the accumulated MACE rate was 6.6%. On multivariate analysis, percutaneous coronary intervention (PCI) was associated with a higher risk of MACE [hazard ratio (HR) 3.50, 95% confidence interval (CI) 1.56-7.89, p=0.002], while discharge on at least one antiplatelet medication was associated with a lower risk of MACE (HR 0.13, 95% CI, 0.05-0.36, p<0.001). In patients managed conservatively (n=353), discharge on at least one antiplatelet medication (n=337) was associated with lower MACE (HR 0.27, 95% CI 0.1-0.73, p=0.01), with no difference between single and dual antiplatelet therapy (DAPT) (p=0.74). In patients managed conservatively and on DAPT (n=226), aspirin and clopidogrel was associated with a lower risk of MACE (HR 0.31, 95% CI 0.10-0.93, p=0.038) compared with DAPT consisting of aspirin and ticagrelor (HR 3.25, 95%CI 1.07-9.85 p=0.038) on multivariate analysis. Conclusion Patients with SCAD are at significant risk of MACE. In conservatively managed patients treated with DAPT, aspirin and clopidogrel was independently associated with a lower risk of MACE than aspirin and ticagrelor