FREQUENCY OF LEFT ATRIAL THROMBUS IN PATIENT WITH MITRAL STENOSIS AND SINUS RHYTHM ON TRANSESOPHAGEAL ECHOCARDIOGRAPHY SCHEDULED FOR PERCUTANEOUS TRANS MITRAL COMMISSUROTOMY

Background: Mitral stenosis remains a significant complication of rheumatic heart disease, particularly in low- and middle-income countries. Left atrial thrombus is a recognized complication in these patients, traditionally linked to atrial fibrillation. However, emerging evidence suggests that thrombus formation can also occur in those maintaining sinus rhythm, posing a risk for thromboembolic complications. The reported prevalence of left atrial thrombus in patients with sinus rhythm varies widely across studies. Understanding its frequency in this subset of patients is crucial for preoperative risk assessment and management strategies. Objective: To determine the frequency of left atrial thrombus in patients with mitral stenosis and sinus rhythm undergoing transesophageal echocardiography before percutaneous trans-mitral commissurotomy. Methods: A cross-sectional study was conducted at the National Institute of Cardiovascular Diseases (NICVD), Karachi, over six months. A total of 185 patients diagnosed with mitral stenosis and sinus rhythm, aged 18 to 70 years, were included. Transesophageal echocardiography was performed to assess the presence of left atrial thrombus. Data were analyzed using SPSS version 26, with stratification applied to control for effect modifiers. Chi-square or Fisher’s exact test was used to assess associations, with a p-value ≤ 0.05 considered statistically significant. Results: The mean age of the participants was 45.0 ± 10.1 years, with 58.4% males and 41.6% females. The mean duration of mitral stenosis was 73.0 ± 23.7 months. Hypertension was present in 51.4%, diabetes mellitus in 28.1%, and smoking history in 28.1%. Left atrial thrombus was detected in 11.4% of patients on transesophageal echocardiography. Conclusion: Left atrial thrombus was observed in a considerable proportion of patients with mitral stenosis despite maintaining sinus rhythm. This highlights the need for careful preoperative evaluation, as thrombus presence has significant implications for procedural safety. Transesophageal echocardiography should be an essential part of the risk stratification process before percutaneous trans-mitral commissurotomy to optimize patient outcomes.