The influence of severe mitral regurgitation on major adverse cardiac and cerebrovascular events after myocardial infarction in 1-year follow-up: Data from PL-ACS registry

Background: Mitral regurgitation (MR) is frequently observed in patients with myocardial infarction (MI). However, the incidence of severe MR in the contemporary population is unknown. Aims: The study evaluates the prevalence and prognostic impact of severe MR in the contemporary population of patients with ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI). Methods: The study group consisted of 8062 patients enrolled in the Polish Registry of Acute Coronary Syndromes (PL-ACS) in the years 2017–2019. Only the patients with full echocardiography performed during the index hospitalization were eligible. The primary composite outcome was 12-month major adverse cardiac and cerebrovascular events (MACCE) (death, non-fatal myocardial infarction, stroke, and heart failure [HF] hospitalization) compared between patients with and without severe MR. Results: 5561 NSTEMI patients and 2501 STEMI patients were enrolled in the study. Severe MR occurred in 66 (1.19%) NSTEMI patients and 30 (1.19%) STEMI patients. Multivariable regression models demonstrated that severe MR is an independent risk factor for all-cause death in 12-month follow-up (odds ratio [OR], 1.839; 95% confidence interval [CI], 1.012–3.343; P = 0.046) in all MI patients. Patients with NSTEMI and severe MR had higher mortality (22.7% vs. 7.1%), HF rehospitalization rate (39.4% vs. 12.9%), and MACCE occurrence (54.5% vs. 29.3%). Severe MR was associated with higher mortality (20% vs. 6%) and higher HF rehospitalization rate (30% vs. 9.8%), stroke (10% vs. 0.8%), and MACCE rates (50% vs. 23.1%) in STEMI patients. Conclusions: Severe MR is associated with higher mortality and MACCE occurrence in patients with MI in 12-month follow-up. Severe MR is an independent risk factor for all-cause death.