A predictive model for new-onset mitral regurgitation in ACS patients

Ischemic Mitral Regurgitation (IMR) is a well-established predictor of adverse outcomes following myocardial infarction (MI). Early identification of patients at risk for new-onset mitral regurgitation (MR) after acute coronary syndrome (ACS) could improve long-term risk stratification and guide targeted interventions. We aimed to develop and validate a clinical prediction model for new-onset MR in ACS patients during follow-up. In this retrospective cohort study, 1,024 ACS patients were included. Patients without MR at discharge (N = 556) were further analyzed. Clinical, laboratory, electrocardiographic (ECG), angiographic, and echocardiographic data were analyzed. Multivariable Cox regression was used to identify predictors of new-onset MR. A nomogram was developed and validated using the receiver-operating characteristic curve (ROC) and the calibration curve. Among 556 ACS patients without MR at discharge, 108 (19.4%) developed new-onset MR during a median follow-up duration of 12 months. Multivariable analysis identified six independent predictors: female sex (HR 2.988, 95% CI 1.774–5.031), higher peak CK-MB max (HR 1.003 per U/L, 95% CI 1.001–1.004), prolonged QRS duration (HR 1.017 per ms, 95% CI 1.006–1.028), right coronary artery involvement (HR 1.572, 95% CI 1.041–2.375), lack of revascularization (HR 4.356, 95% CI 1.456–13.037), and larger left ventricle diameter (HR 1.055 per mm, 95% CI 1.012–1.099) (all P < 0.05). The prediction model showed good discrimination (concordance index (C-index) 0.754, 95%CI 0.705–0.802) and calibration. A novel clinical model incorporating female sex, myocardial injury markers (CK-MB), ECG parameters (QRS duration), right coronary disease, left ventricular remodeling, and revascularization status effectively predicted new-onset MR post-ACS.