Abstract Body (Do not enter title and authors here): Background: Current literature provides limited evidence regarding myocardial infarction with non-obstructive coronary arteries (MINOCA) characteristics, cardiac function evolution, and long-term mortality. We evaluated long-term cardiac function changes and mortality outcomes in MINOCA patients.
Methods: We analyzed data from a prospective multicenter registry of heart failure post-first-time STEMI patients (June 2016- June 2024). Baseline characteristics, treatment patterns, ejection fraction (EF) during hospitalization and at 90-day follow-up, and long-term mortality were compared between MINOCA and obstructive MI patients. Adjusted Cox regression assessed 3-year mortality risk.
Results: Among 2,704 first-time STEMI patients, the mean age was 62±12 years, and 15% were female. MINOCA occurred in 138 patients (5.1%). The median (IQR) follow-up time was 5.62 (4.08, 6.41) years. Compared to obstructive MI patients, MINOCA patients were more likely to be female with diabetes, less likely to have hypertension, presented with higher heart rates but lower peak troponin and LDL-C levels, yet significantly higher brain natriuretic peptide (BNP) and C-reactive protein (CRP) levels. MINOCA patients received less antiplatelet therapy and beta-blockers but more diuretics. Serial echocardiography showed that MINOCA patients were more likely to develop heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF) during hospitalization, with less EF recovery (EF increase>=10%) at 90-day follow-up. At 3-year follow-up, MINOCA patients had higher all-cause mortality (5.8% vs 2.3%, p=0.019). After adjusting for confounders, the 3-year mortality hazard ratio was 2.6-fold higher in MINOCA (95% CI 1.25-5.53) and 3.08-fold higher in elderly patients >65 years (95% CI 1.39-6.84). BNP and LVEF during hospitalization were the independent risk factors for the increased 3-year mortality for MINOCA.
Conclusion: In this multicenter cohort of first-time STEMI patients, MINOCA was associated with significantly higher long-term mortality compared to obstructive MI, with increased heart failure risk and less EF recovery during 90-day follow-up with less guideline-directed medical therapy. Risk stratification and individualized post-MI care should be prioritized in this unique subgroup. Evidence-based guidelines for MINOCA clinical management are urgently needed.