Comparison of contrast enhanced 64-slice computed tomography and transesophageal echocardiography in detection of left atrial thrombus in patients with atrial fibrillation

Background and objective Recent advances in multi-slice computed tomography (MSCT) have allowed an improved analysis of left atrial (LA) and left atrial appendage (LAA) anatomy prior to catheter ablation of atrial fibrillation (AF). However, data regarding the ability of MSCT to identify LA/LAA thrombus are limited. This prospective study compared the efficacy of 64-slice contrast-enhanced computed tomography (64CCT) with transesophageal echocardiography (TEE) of the heart in the identification of LA/LAA thrombus. Materials and methods One- hundred and seventy consecutive patients scheduled for first-time catheter ablation of paroxysmal (n=120) or persistent (n=50) AF were enrolled for study. Each patient underwent non-gated 64CCT and TEE of the heart for exclusion of LA/LAA thrombus prior to ablation procedure. Results Fourteen cases (8.2%) of LA/LAA thrombi were interpreted by 64CCT (ten false-positive, four true positive), whereas 11 actual thrombi (6.5%) were detected by TEE (seven false- negative by 64CCT) in the same population. Maximal dimension of TEE identified thrombi did not differ between the false- negative by 64CCT group and the true-positive group (17 +/- 6 vs. 18 +/- 5 mm P=0.677). Results indicated 64CCT sensitivity=36.4%, specificity= 93.7%, positive predictive value=28.6%, and negative predictive value=95.5% in the detection of LA/LAA thrombus. The Kappa value in evaluating the agreement between 64CCT and TEE for detection of LA/LAA thrombus was 0.267. Conclusion Compared to gold standard TEE, 64CCT was shown to be less reliable in the detection of LA/LAA thrombus prior to catheter ablation in patients with AF.