Prognostic impact of spontaneous coronary artery dissection in young female patients with acute myocardial infarction: A report from the Angina Pectoris-Myocardial Infarction Multicenter Investigators in Japan

Background We sought to compare the prognosis of patients with spontaneous coronary artery dissection (SCAD) and atherosclerosis as the cause of acute myocardial infarction (AMI), especially in young females. Methods and results A total of 20,195 patients with AMI at 20 institutions between 2000 and 2013 were retrospectively studied. Major adverse cardiac event (MACE: Cardiac death, AMI or urgent revascularization) was the endpoint. The overall prevalence of SCAD was 0.31% (n = 63; female, 94%). SCAD developed following emotional stress in 29% of patients. Revascularization was performed in 56% (35 of 63 patients), and SCAD recurrence developed in the originally involved vessel in 6 of 35 patients with revascularization, compared to none among 28 patients after conservative therapy (p = 0.002). We compared the clinical characteristics of young female AMI patients aged ≤ 50 years in the SCAD (n = 45) and no-SCAD groups (atherosclerotic AMI, n = 55). During a median follow-up of 50 months, SCAD recurred in 27% of patients, of which 42% was in the first 30 days. Kaplan-Meier analysis showed a significantly higher incidence of MACE in the SCAD group compared to the no-SCAD group (hazard ratio, 6.91; 95% confidence interval, 2.5 to 24.3; p < 0.001), although the rate of successful percutaneous coronary intervention for SCAD was as high as 92%. Conclusions Young female patients with SCAD represent a high-risk subgroup of patients with AMI and require close follow-up.