Prediction of left atrial appendage dysfunction by atrial strain imaging in patients with rheumatic mitral stenosis in sinus rhythm.

AIMS: In severe rheumatic mitral stenosis (MS) with sinus rhythm, left atrial appendage (LAA) dysfunction increases thromboembolic risk, yet clinical guidelines provide no recommendations, and its assessment via transoesophageal echocardiography is not feasible for routine or repeated use. This study assessed whether left atrial (LA) strain imaging could non-invasively predict LAA contractile dysfunction. METHODS AND RESULTS: We prospectively enrolled 138 patients with severe rheumatic MS in sinus rhythm who underwent transthoracic and transoesophageal echocardiography. Left atrial appendage inactivity was defined as LAA emptying velocity < 25 cm/s. Left atrial reservoir strain (LASr), conduit, and contractile strain were quantified using speckle-tracking echocardiography. Multivariable logistic regression and receiver operating characteristic analyses were performed to evaluate predictors of LAA inactivity. Left atrial appendage inactivity was observed in 108 patients (78.2%), and LAA thrombus was detected in eight patients (5.8%)-all in sinus rhythm. In multivariate analysis, LASr was the strongest independent predictor of LAA inactivity [odds ratio: 0.61 per 1% increase; 95% confidence interval (CI): 0.50-0.75; P < 0.0001]. Left atrial reservoir strain yielded an area under the ROC curve 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. CONCLUSION: Left atrial strain imaging provides a robust non-invasive 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.