Left Atrial Function in Rheumatic Mitral Stenosis Patients: Addressing Prognostic Insights Beyond Atrial Fibrillation Prediction

Rheumatic mitral stenosis (MS) frequently leads to impaired left atrial (LA) function due to pressure overload, highlighting underlying atrial pathology. Two-dimensional speckle tracking echocardiography (2D-STE) offers early detection of LA dysfunction, potentially improving risk assessment in MS patients. This study aimed to evaluate the predictive value of LA function assessed by 2D-STE for clinical outcomes in MS patients. Between 2011 and 2021, MS patients underwent LA function assessment using 2D-STE, focusing on the reservoir phase (LASr). Atrial fibrillation (AF) development constituted the primary outcome, with death or valve replacement as secondary. Conditional inference trees were employed for analysis, validated through sample splitting. The study included 493 MS patients (mean valve area 1.1 ± 0.4 cm2, 84% female). At baseline, 166 patients (34%) had AF, with 62 patients (19%) developing AF during follow-up. LASr emerged as the primary predictor for new-onset AF, with a threshold of 17.9%. Over a mean 3.8-year follow-up, 125 patients (25%) underwent mitral valve replacement, and 32 patients (6.5%) died. Decision tree analysis identified key predictors such as age, LASr, severity of tricuspid regurgitation (TR), net atrioventricular compliance (Cn), and early percutaneous mitral valvuloplasty, especially in patients aged ≤ 49 years, where LASr, with a threshold of 12.8%, significantly predicted adverse outcomes. LASr emerged as a significant predictor of cardiovascular events in this MS cohort, validated through decision tree analysis. Patients were stratified into low or high-risk categories for adverse outcomes, taking into account LASr, age, TR severity, and Cn.