Impact of gender-related differences in outcomes in acute myocardial infarction: non-obstructive coronary arteries versus obstructive coronary arteries

Abstract Background Myocardial Infarction with Non-Obstructive Coronary Arteries (MINOCA) represents 6-10% of acute myocardial infarction (AMI) and is more prevalent in females. The impact of gender on the outcomes of MINOCA patients has been poorly understood. Purpose To evaluate the impact of gender on the prognosis of MINOCA. Methods We enrolled 2455 patients with AMI undergoing coronary angiography from January 2016 to June 2021. Patients were divided according to type of AMI and gender: male (n=1593) and female (n=607) in AMI with obstructive coronary arteries (MIOCA); male (n=87) and female (n=168) in MINOCA. Each cohort was further stratified based on age (<=/> 70 years). The primary endpoint was a composite of all-cause death, recurrent AMI, and hospitalization for heart failure (MACE) at 5-year follow-up. Secondary outcomes included: all-cause and cardiovascular death, recurrent AMI, HF re-hospitalization and stroke. Results MINOCA patients were more likely to be females compared to MIOCA ones (p<0.001). The incidence of MACEs was significantly higher in females compared to males, both in MINOCA (p=0.018) and MIOCA cohorts (p=0.002). Age was an independent predictor of MACEs in both cohorts. No difference in outcomes was found comparing females to males >70 years, in both MINOCA and MIOCA. MINOCA females <70 years old had a higher incidence of MACEs (p=0.003), mainly driven by a higher prevalence of re-hospitalization for HF (p=0.045) and recurrence of AMI (p=0.006). Only in this sub-group of MINOCA patients, female gender was an independent predictor of MACEs (HR=3.09; 95%CI: 1.02-9.59; p=0.040). MINOCA females <70 years old had worse outcomes than MIOCA peers. Conclusion MINOCA females <70 years old had a significantly higher incidence of MACEs, compared to males and MIOCA peers, likely due to the different pathophysiology of the ischemic event.Survival curves in MINOCA and MIOCASurvival curves stratified for age