A Nomogram for Predicting Residual Mitral Regurgitation in Patients With Obstructive Hypertrohpic Cardiomyopathy...

Residual mitral regurgitation (MR) after septal myectomy increases the risk of further mitral interventions. This study aimed to identify predictors of residual MR (grade ≥ 2+) following transapical beating-heart septal myectomy (TA-BSM) in hypertrophic obstructive cardiomyopathy (HOCM) patients and to develop a predictive nomogram.

We prospectively enrolled 200 HOCM patients undergoing TA-BSM from April 2023 to March 2024, all with resting or provoked left ventricular outflow tract gradient ≥ 50 mmHg and MR ≥ 2+. Preoperative clinical and echocardiographic MV parameters were analysed. Predictors were identified via univariate and multivariate logistic regression. A nomogram was constructed and evaluated for discrimination, calibration, and clinical utility.

Before discharge, 128 (64%) patients had no or mild residual MR, 65 (32.5%) moderate, and 7 (3.5%) moderate-to-severe MR. Independent predictors included atrial fibrillation, leaflet thickening ≥ 5 mm, annular calcification, annular anterior-posterior diameter, and annular height. The nomogram demonstrated good discrimination (area under curve (AUC) 0.879; 95% confidence interval [CI], 0.817-0.940), with favourable calibration and clinical utility.

Atrial fibrillation, leaflet thickening, annular calcification, annular anterior-posterior diameter, and annular height are independent predictors of residual MR after TA-BSM. The nomogram demonstrated robust predictive performance following internal validation.