Objective:  LA thrombus in Rheumatic Heart Disease -Mitral Stenosis cannot be explained only with the slowdown of blood flow and stasis in the left atrium associated with rheumatic mitral valve stenosis (RMVS)  ;  seen in around 20% of these  with only valvular obstruction. The dilated LA can cause blood stasis, creating an environment where blood clots (thrombi) are more likely to form, particularly in the left atrial appendage (LAA) and the main LA chamber. ( 1, 2 ) This study is done with the objective to examine relationship between presence of LA thrombus in Rheumatic mitral stenosis and left atrial AP diameter.

METHODS: The study included 85 (Eighty five) paients who presented to the Department of Cardiology, NEIGRIHMS, Shillong with Rheumatic heart disease Mitral stenosis . All patients were   evaluated using transthoracic and transesophageal echocardiography was divided into 2 groups: those with and without LA thrombus. In addition to echocardiographic and biochemical parameters, platelet count , lymphocyte count and their ratio was compared between the groups

LA AP diameter was compared between the groups. Student’s t-test, Mann–Whitney U test ;  Sensitivity, specificity and positive predictive value was estimated for Left atrial AP diameter in comparison to TOE for presence or absence of thrombus. ROC curve analysis was done.

RESULTS : The mean left atrial AP diameter in the study population was 43.03  ± 5.09 mm . The mean left atrial AP diameter in patients with LA clot was 49.47±04.65   and in patients without LA clot was 40.64 ± 2.61 mm. In the LA thrombus group mean left atrial AP diameter was found to be higher with statistical significance(  P< 0.001)[ CI : 47.459- 51.48 ; CI: 39.97-41.30) . ROC curve analysis showed that the optimal LA AP diameter cut off value  for predicting LA thrombus was 45.68 mm , with a sensitivity of 78.4% and specificity of 69.8% (AUC = 0.809, 95% CI: 0.77–0.86)    

CONCLUSION: Left atrial AP diameter is a easily available tool to predict left atrial thrombus in patients with RHD mitral stenosis . LA AP diameter can be a better predictor for LA thrombus in RHD MS.