Abstract 13449: Myocardial Infarction With Non-Obstructive vs Obstructive Coronary Arteries Among Patients With Acute Coronary Syndrome at a Large Safety-Net Hospital

Abstract

Introduction: Myocardial infarction with non-obstructive coronary arteries (MINOCA) has been increasingly recognized. The differences between MINOCA and obstructive coronary artery disease (OCAD) patients have not been studied in lower socioeconomic status populations. Methods: The records of all patients undergoing angiography for ACS at a large Dallas County safety-net hospital from January 2018 to January 2020 were reviewed and categorized as MINOCA or OCAD. Results: During the study period, 592 cases of acute coronary syndrome (ACS) were identified; 10.8% (n=64) were MINOCA. OCAD patients had higher peak pre-angiography troponin compared with MINOCA patients (2498 vs 335 ng/L, p<0.001). MINOCA patients were younger compared with OCAD patients (56 vs 60 y, p=0.01), while MINOCA men were younger than MINOCA women (53 vs 61 y, p=0.009). A higher proportion of MINOCA patients were Black, compared with OCAD (Figure 1). MINOCA patients had a lower prevalence of dyslipidemia and diabetes mellitus but there were no differences in the prevalence of smoking, hypertension, family history of premature CAD, current dialysis or heart failure between the groups. There were no differences in statin, aspirin, beta blocker or calcium channel blocker prescription at presentation between MINOCA and OCAD patients, regardless of sex. The majority of MINOCA patients (75%) did not have a definitive etiology of their ACS event by discharge. Conclusions: In this analysis of ACS patients presenting to a large safety-net hospital, MINOCA was common and MINOCA patients had many traditional risk factors. Men presented with MINOCA more commonly than has been seen in other studies. More Black patients presenting with ACS had MINOCA vs OCAD, likely reflecting the higher rates of left ventricular hypertrophy and diabetes in these patients. Lack of a definitive diagnosis for most MINOCA patients may reflect unfamiliarity with the diagnostic workup of MINOCA patients.