Left atrial appendage thrombi relate to easily accessible clinical parameters in patients undergoing atrial fibrillation transcatheter ablation: A multicenter study

Background: Transesophageal echocardiography (TEE) is routinely performed before atrial fibrillation (AF) transcatheter ablation to exclude the presence of left atrial (LA) or LA appendage (LAA) thrombi. The aim of the study is to evaluate if easily accessible clinical parameters may relate to the presence of LA or LAA thrombi to identify patients who could potentially avoid TEE. Methods and results: Between January 2012 and September 2014, data from 1539 consecutive patients undergoing TEE, as a work-up before AF transcatheter ablation, in six large volume centers were collected. Baseline clinical features, CHA2DS2-VASc score, transthoracic echocardiography and presence of thrombi at TEE were recorded. Exclusion criteria were valvular, hypertrophic or dilated cardiomyopathy, previous heart surgery or an ejection fraction ≤35%. Mean age was 59.6±10.4years, 1215 (78.9%) were males; 951 (62.9%) presented in sinus rhythm (SR) on admission, 324 (21.1%) had undergone at least one previous ablation and 900 (58.5%) had CHA2DS2-VASc score 0-1. Thrombi were encountered in 12 patients (0.8%). SR at TEE independently related to the absence of thrombi (OR 5.15, 95% CI 1.38-19.02, p =0.015); in addition to this, no patient with a CHA2DS2-VASc score 0-1 and SR on admission presented thrombi at TEE (specificity 100%, p =0.011). Conclusion: In a selected population of patients referred for AF ablation, LA/LAA thrombi prevalence is low. No patients in SR with CHA2DS2-VASc score 0-1 presented LAA thrombi at TEE, identifying a significant subset of patients who could potentially safely be spared from pre-procedural TEE.