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.