Abstract 13596: The Prognostic Impact of Spontaneous Coronary Artery Dissection in Younger Female Patients with Acute Myocardial Infarction; Report from Angina Pectoris-Myocardial Infarction Multicenter Investigations in Japan

Abstract

Introduction: Spontaneous coronary artery dissection (SCAD) is an unusual cause of acute myocardial infarction (AMI). It is postulated that the patients with SCAD have good clinical prognosis because they have few coronary risk factors (CRF). However, a recent report studying the US patients with SCAD aged 18~78 years suggested that the rate of recurrence was higher than we expected. In the present study, we therefore have focused on prognostic impact of SCAD on younger female populations. Methods: A total of 16,233 AMI patients registered by 10 institutes from 1991 to 2012 were retrospectively studied. The definition of SCAD was based on the presence of medial dissection or intramural hematoma that was recognized by angiography before any catheter intervention. Results: There were 27 patients diagnosed as SCAD (male/female 1/26, age 45±9 [SD] years). The overall prevalence of SCAD was 0.17% of AMI patients. SCAD developed after physical or emotional stress in 11 patients (40.7%). The left anterior descending artery was involved in 17 patients (62.9%), among whom 4 patients had multi-vessel SCAD (14.8%). Recurrences of SCAD were shown in 9 patients (33.3%). In 4 of 9, recurrence was seen in previously unaffected coronary arteries. In young population of AMI patients (age <50), we compared clinical parameters of SCAD (n=21) with those of Non-SCAD groups (atherosclerotic, n=35). In SCAD group, the number of CRF was significantly lower than in Non-SCAD groups (SCAD, 1.0+/-0.8 vs Non-SCAD, 2.2+/-1.1, P<0.0001). In Kaplan-Meier analysis, younger female AMI patients with SCAD showed significantly higher rate of cardiac event (death, AMI and heart failure) in comparison with those without SCAD (SCAD, 11/21 vs Non-SCAD, 4/34; P=0.0002) during a median follow-up of 1557 (1-8172) days. Conclusions: The present multicenter study demonstrated that younger female AMI patients with SCAD, characterized as minimum accumulation of CRF, seem to be prone to cardiac events.