Background: Myocardial Infarction (MI) with Non-Obstructive Coronary Arteries (MINOCA) accounts above 6 % of patients presenting with acute MI (AMI) and it’s known to be more prevalent in females. Differences in terms of clinical features and prognosis in MINOCA patients according to gender have been poorly understood.
Purpose: To evaluate clinical and prognostic differences between male and female patients with MINOCA.
Methods: We included all consecutive patients with AMI undergoing coronary angiography between 2016 and 2020 in our multicentric Registry. We considered as MINOCA all patients fulfilling the European Society of Cardiology diagnostic criteria. We analyzed the baseline clinical characteristics of MINOCA patients by dividing the population according to gender. We performed a multivariate logistic regression analysis including all AMI patients to determine independent predictors of MINOCA at admission. We considered the composite endpoint (MACE) of death, re AMI, stroke and heart failure at follow-up (FU, mean of 36 ± 14.8 months). Outcomes were evaluated also using Kaplan-Meier survival curves.
Results: Among 289 patients affected by MINOCA, 191 were female (66%). Males were more frequently smokers (56.1% vs 33.9 %, p=0.001) while females were older (68.9± 13.1 vs 58.4±14.5 years, p=0.0001), more affected by hypertension (69.3% vs 55.1%, p=0.017) and dyslipidemia (65.6% vs 49%, p=0.005), more frequently on beta-blockers (39% vs 20%, p=0.002) and statins (33% vs 19%, p=0.015) and had a lower degree of coronary stenosis (9.1% vs 15.5%, p=0.019) than males. During follow-up, females had more MACE (33% vs 19.3%, p=0.015), also shown at Kaplan Meier curves (χ2 = 5.997, p=0.014). Finally, multivariate analysis revealed that age is an independent predictor of MINOCA (HR 1.04, CI 1.01-2.07, p=0.006), rather than sex, diabetes, and hypertension.
Conclusions: In our MINOCA population, females had a higher incidence of MACE than males: this could reflect the different pathogenesis of myocardial damage in our subgroups. Statins and estrogens have a well-known protective role towards the progression of atherosclerosis, but they have less impact on other causes of MINOCA more frequent in females.