Impact of dense “smoke” detected on transesophageal echocardiography on stroke risk in patients with atrial fibrillation undergoing catheter ablation

Background: Spontaneous echocardiographic contrast (”smoke”) within the left atrial cavity on transesophageal echocardiography (TEE) suggests low blood flow velocities in the heart that may lead to thromboembolic (TE) events. Objective: The purpose of this study was to evaluate the risk of TE events in the periprocedural period and at long-term follow-up in atrial fibrillation (AF) patients having dense smoke on preprocedural TEE. Methods: A total of 2511 patients undergoing AF ablation were included in this analysis. They were classified as group 1 (dense smoke detected on TEE at baseline; n = 234) and group 2 (no smoke on baseline TEE; n = 2277). Patients were followed up for TE events, which included both stroke and transient ischemic attacks (TIAs). In order to attenuate the observed imbalance in baseline covariates between the study groups, a propensity score matching technique was used (covariates were age, sex, AF type, diabetes, and CHADS ₂ VASc score). Results: In the periprocedural period, no TE events were reported in group 1 and 3 events (0.13%) were reported in group 2. At follow-up of 6.62 ± 2.01 years, 6 (2.6%) TE complications (2 TIA, 4 stroke) occurred in group 1 and 16 (0.70%) TE complications (6 TIA, 10 stroke) in group 2 (P =.004). In the propensity-matched population, 6 (2.56%) TE complications occurred in group 1 and 1 (0.2%) in group 2 (P =.007). Conclusion: In our study population, the presence of dense left atrial smoke did not show any correlation with periprocedural TE events in patients undergoing catheter ablation with uninterrupted anticoagulation. However, significant association was observed with late stroke/TIA, irrespective of CHA ₂ DS ₂ -VASc score.