Sex differences in treatment and outcomes amongst myocardial infarction patients presenting with and without obstructive coronary arteries: a prospective multicentre study

AIMS: Women have an increased prevalence of myocardial infarction (MI) with non-obstructive coronary arteries (MINOCA). Whether sex differences exist in the outcomes of patients with MI and obstructive coronary arteries (MIOCA) vs. MINOCA remains unclear. We describe sex-based differences in diagnosis, treatment, and clinical outcomes of patients with MINOCA vs. MIOCA. METHODS AND RESULTS: A large-scale cohort study of patients with ST/non-ST elevation MI undergoing coronary angiography (01/2015–12/2019). Patient demographics, diagnosis, prescribed discharge medications, in-hospital complications, and follow-up data were prospectively collected. A total of 13 202 participants were included (males 68.2% and females 31.8%). 10.9% were diagnosed with MINOCA. Median follow-up was 4.62 years. Females (44.8%) were as commonly diagnosed with MINOCA as males (55.2%), unlike the male preponderance in MIOCA (male, 69.8%; female, 30.2%). Less secondary prevention medications were prescribed at discharge for MINOCA than MIOCA. There was no difference in mortality risk between MINOCA and MIOCA [in-hospital: adjusted odds ratio (OR) 1.32, 95% confidence interval (CI) 0.74–2.35, P = 0.350; long term: adjusted hazard ratio (HR) 1.03, 95% CI 0.81–1.31, P = 0.813]. MINOCA patients had reduced mortality at long-term follow-up if prescribed secondary prevention medications (aHR 0.64, 95% CI 0.47–0.87, P = 0.004). Females diagnosed with MIOCA had greater odds of in-hospital and 1-year mortality than males (aOR 1.50, 95% CI 1.09–2.07, P = 0.014; aHR 1.18, 95% CI 1.01–1.38, P = 0.048). CONCLUSION: MINOCA patients have similar mortality rates as MIOCA patients. MINOCA patients were less likely than those with MIOCA to be discharged with guideline-recommended secondary prevention therapy; however, those with MINOCA who received secondary prevention survived longer. Females with MIOCA experienced higher mortality rates vs. males.