Sex Differences in Patients Presenting With ST-Segment Elevation Myocardial Infarction and Nonobstructive Coronary Arteries.

Abstract

Background: Sex differences in ST-segment elevation myocardial infarction (STEMI) due to obstructive coronary artery disease (CAD) are well-established, but limited research exists on sex differences in STEMI patients with nonobstructive coronary arteries (MINOCA) and MINOCA mimickers.

Methods: We analyzed 8560 consecutive STEMI patients, enrolled in the Midwest STEMI Consortium from 2003 to 2020. Patients with non-obstructive CAD were classified into MINOCA (defined as < 50% coronary artery stenosis and confirmed or suspected coronary artery plaque disruption, epicardial coronary spasm, or coronary embolism/thrombosis) and MINOCA mimickers (takotsubo cardiomyopathy, myocarditis, or non-ischemic cardiomyopathy). The primary outcome was 5-year all-cause mortality.

Results: Of the 8560 patients, 409 (4.8%) had non-obstructive CAD, including 120 (1.4%) MINOCA and 289 (3.4%) MINOCA mimickers. Females were more likely to have MINOCA and MINOCA mimickers (49.2% and 56.4%, respectively). There were no significant sex differences in in-hospital or 5-year mortality in MINOCA, but females with MINOCA mimickers had higher unadjusted 5-year mortality (HR 2.90, 95% CI 1.53-5.53). After adjusting for age and comorbidities, the long-term mortality risk was similar between sexes (adjusted HR 1.16, 95% CI: 0.61-2.24). Females with obstructive CAD had higher 5-year mortality in unadjusted models (HR 1.66, 95% CI 1.48, 1.86), but the difference was not significant after adjustment (adjusted HR 1.1, 95% CI: 0.98-1.24).

Conclusions: Our findings highlight important sex-based differences in the prevalence, treatment, and long-term outcomes of STEMI patients with MINOCA, MINOCA mimickers, and obstructive CAD. Despite clinical disparities, mortality risks were similar across sexes after adjusting for comorbidities.