Sex- and age-related differences in outcomes of patients with acute myocardial infarction: MINOCA vs. MIOCA

AIMS: The aim of the study is to evaluate the impact of sex on acute myocardial infarction (AMI) patients' clinical presentation and outcomes, comparing those with non-obstructive and obstructive coronary arteries (MINOCA vs. MIOCA). METHODS AND RESULTS: We enrolled 2455 patients with AMI undergoing coronary angiography from January 2017 to September 2021. Patients were divided according to the type of AMI and sex: male (n = 1593) and female (n = 607) in MIOCA and male (n = 87) and female (n = 168) in MINOCA. Each cohort was further stratified based on age (≤/> 70 years). The primary endpoint (MAE) was a composite of all-cause death, recurrent AMI, and hospitalization for heart failure (HF) at follow-up. Secondary outcomes included all-cause and cardiovascular death, recurrent AMI, HF re-hospitalization, and stroke. MINOCA patients were more likely to be females compared with MIOCA ones (P < 0.001). The median follow-up was 28 (15-41) months. The unadjusted incidence of MAE was significantly higher in females compared with males, both in MINOCA [45 (26.8%) vs. 12 (13.8%); P = 0.018] and MIOCA cohorts [203 (33.4%) vs. 428 (26.9%); P = 0.002]. Age was an independent predictor of MAE in both cohorts. Among MINOCA patients, females ≤70 years old had a higher incidence of MAE [18 (23.7%) vs. 4 (5.9%); P = 0.003] compared with male peers, mainly driven by a higher rate of re-hospitalization for HF (P = 0.045) and recurrence of AMI (P = 0.006). Only in this sub-group of MINOCA patients, female sex was an independent predictor of MAE (hazard ratio = 3.09; 95% confidence interval: 1.02-9.59; P = 0.040). MINOCA females ≤70 years old had worse outcomes than MIOCA female peers. CONCLUSION: MINOCA females ≤70 years old had a significantly higher incidence of MAE, compared with males and MIOCA female peers, likely due to the different pathophysiology of the ischaemic event. TRIAL REGISTRATION: Data were part of the ongoing observational study 'AMIPE: Acute Myocardial Infarction, Prognostic and Therapeutic Evaluation' (ClinicalTrials.gov Identifier: NCT03883711).