Acute coronary syndrome with non-obstructive coronary arteries (ACS-NOCA in patients with hypertrophic cardiomyopathy

Abstract

Abstract Background Previous case reports have described myocardial ischemia and/or infarction in hypertrophic cardiomyopathy (HCM); however, prevalence and prognosis are little known. Thus, our study aimed to determine the prevalence and prognosis of acute coronary syndrome with non-obstructive coronary artery (ACS-NOCA) in patients with hypertrophic cardiomyopathy (HCM). Methods We prospectively enrolled 200 consecutive HCM patients (mean age 66±16 years, 42% males) from 2002 to 2013 attending a tertiary referral center, King Chulalongkorn Memorial Hospital, Thailand. The median follow-up time was 13 years. ACS-NOCA was diagnosed by a clinical syndrome of acute myocardial ischemia or MI with <50% angiographically luminal stenosis in the major epicardial coronary branch by coronary angiogram. Results Of 200 HCM patients, 28 patients (14% of overall patients, 51% of patients with ACS) had ACS-NOCA, and 18 patients (9% of overall patients, 86% of patients with acute MI) had myocardial infarction with nonobstructive coronary artery (MINOCA) as initial clinical presentations. Of the 28 patients, 4 (14%) were STEMI, 14 (50%) were NSTEMI and 10 (36%) were UA. ACS-NOCA group had more frequent ventricular tachycardia and lower resting left ventricular (LV) outflow tract gradients than no ACS-NOCA group (p<0.05). The ACS-NOCA group tended to have a lower rate of HCM-related death compared with the no ACS-NOCA group and the significant coronary artery disease (CAD) group (p-log-rank = 0.0018). As shown in Figure 1. Conclusions ACS-NOCA is not an uncommon initial presentation (prevalence rate 9–14%) in patients with HCM. More than half of HCM patients presenting with ACS were found to have NOCA. ACS-NOCA was not associated with an increased mortality, but had a more favorable prognosis. Funding Acknowledgement Type of funding sources: None. Figure 1