509 RECURRENCE OF ACUTE MYOCARDIAL INFARCTION AFTER MINOCA: INSIGHTS FROM A MULTICENTRE NATIONAL REGISTRY

Abstract

Abstract Background Myocardial infarction with non-obstructed coronary arteries (MINOCA) is an increasingly recognized condition with challenging management. Prognosis of this patients could be of concern, in particular for those who experienced recurrent acute myocardial infarction (re-AMI). Moreover, there are limited data on characteristics of re-AMI among MINOCA patients. Methods In this retrospective multicentre cohort study involving seven Hub Hospitals across Italy we enrolled consecutive patients 18 years and older discharged with diagnosis of MINOCA according to the IV universal definition of myocardial infarction who experienced hospitalization for re-AMI during follow-up. Results A total of 54 patients were included (mean age 66±13). Compared to MINOCA patients without re-AMI (n=695), on first angiography MINOCA patients with re-AMI showed less frequently angiographically normal coronaries (37 versus 53%, p=0,032) and had higher prevalence of atherosclerosis involving 3 vessels or left main stem (17% versus 8%, p=0,049). Twenty four patients (44%) with re-AMI underwent a new coronary angiography and 25% had normal coronary arteries, 12% had mild luminal irregularities (<30%), 21% had moderate coronary atherosclerosis (30-49%), and 42% showed obstructive coronary atherosclerosis (≥50%). Among patients undergoing new angiography, only 4% had LDL cholesterol under 55 mg/dL, atherosclerosis progression was observed in 11 (46%), 38% received revascularization and 33% experienced a new cardiovascular event (death, AMI, heart failure, stroke) at subsequent follow-up. Conclusions In the present study near one out of two patients with re-AMI after MINOCA showed angiographic atherosclerosis progression requiring revascularization in the majority of cases. These patients rarely presented with recommended LDL cholesterol levels and are at risk for further cardiovascular events, indicating a possible underestimation of cardiovascular risk in this population.