Prediction of Left Atrial Appendage Dysfunction by Atrial Strain Imaging in Patients with Rheumatic Mitral Stenosis in Sinus Rhythm
In severe rheumatic mitral stenosis with sinus rhythm, left atrial appendage (LAA) dysfunction increases thromboembolic risk, yet clinical guidelines provide no recommendations, and its assessment via transesophageal echocardiography is not feasible for routine or repeated use. This study assessed whether left atrial (LA) strain imaging could noninvasively predict LAA contractile dysfunction. We prospectively enrolled 138 patients with severe rheumatic MS in sinus rhythm who underwent transthoracic and transesophageal echocardiography. LAA inactivity was defined as LAA emptying velocity <25 cm/s. LA reservoir (LASr), conduit, and contractile strain were quantified using speckle-tracking echocardiography. Multivariable logistic regression and receiver-operating characteristic (ROC) analyses were performed to evaluate predictors of LAA inactivity. LAA inactivity was observed in 108 patients (78.2%), and LAA thrombus was detected in 8 patients (5.8%)—all in sinus rhythm. In multivariate analysis, LASr was the strongest independent predictor of LAA inactivity (OR 0.61 per 1% increase; 95% CI: 0.50–0.75; p < 0.0001). LASr yielded an AUC of 0.950 (95% CI: 0.911-0.989), with a threshold of ≤22.95% showing a sensitivity of 93.5%, and specificity of 90% for predicting LAA inactivity. Impaired LA strain identified patients with elevated fibrinogen, D-dimer, and the presence of LAA thrombus. LA strain imaging provides a robust noninvasive predictor of LAA dysfunction in severe rheumatic MS patients in sinus rhythm. These findings support the potential clinical utility of LA strain in improving risk stratification and guiding anticoagulation decisions in this under-recognized high-risk population.