Risk stratification of patients with left atrial appendage thrombus prior to catheter ablation of atrial fibrillation: An approach towards an individualized use of transesophageal echocardiography

Introduction The need for transesophageal echocardiography (TEE) before catheter ablation of atrial fibrillation (CA‐AF) is still being questioned. The aim of this study is to analyze patients’ (patients) risk factors of left atrial appendage thrombus (LAAT) prior to CA‐AF in daily clinical practice, according to oral anticoagulation (OAC) strategies recommended by current guidelines. Methods and results All patients scheduled for CA‐AF from 01/2015 to 12/2016 in our center were included and either treated with NOACs (novel‐OAC; paused 24‐hours preablation) or continuous vitamin K antagonists (INR 2.0–3.0). All patients received a preprocedural TEE at the day of ablation. Two groups were defined: (1) patients without LAAT, (2) patients with LAAT. The incidence of LAAT was 0.78% (13 of 1,658 patients). No LAAT was detected in patients with a CHA2DS2‐VASc score of ≤1 (n = 640 patients) irrespective of the underlying AF type. Independent predictors for LAAT are: higher CHA2DS2‐VASc scores (odds ratio [OR] 1.54, 95%‐confidence interval [CI]: 1.07–2.23, P = 0.0019), a history of nonparoxysmal AF (OR 7.96, 95%‐CI: 1.52–146.64, P = 0.049), hypertrophic cardiomyopathy (HCM; OR 9.63, 95% CI: 1.36–43.05, P = 0.007), and a left ventricular ejection fraction (LVEF) < 30% (OR 8.32, 95% CI: 1.18–36.29, P = 0.011). The type of OAC was not predictive (P = 0.70). Conclusions The incidence of LAAT in patients scheduled for CA‐AF is low. Therefore, periprocedural OAC strategies recommended by current guidelines seem feasible. Preprocedural TEE may be dispensed in patients with a CHA2DS2‐VASc score ≤1. However, a CHA2DS2‐VASc score ≥2, reduced LVEF, HCM, or history of nonparoxysmal AF are independently associated with an increased risk for LAAT.