Impact of Left Atrial Appendage Closure on LAA Thrombus Formation and Thromboembolism After LAA Isolation

This study sought to evaluate the safety and effectiveness of electrical isolation of the left atrial appendage (LAAEI) as well as the status of left atrial appendage closure (LAAC) in these patients. Catheter-based LAAEI is increasingly performed for treatment of symptomatic atrial fibrillation and pulmonary vein isolation nonresponders. Previous studies indicate an increased incidence of thromboembolic events after LAAEI despite effective oral anticoagulation. Interventional LAAC may prevent cardioembolic events after LAAEI but data regarding safety, feasibility, and efficacy of LAAC in this clinical setting are scarce. Consecutive patients who underwent LAAEI at 2 German tertiary care hospitals were analyzed. A total of 270 patients underwent LAAEI by radiofrequency ablation in 255 (94.4%), cryoballoon ablation in 12 (4.4%), and by a combination of both techniques in 3 cases (1.1%). Stroke or transient ischemic attack occurred in 24 of 244 (9.8%) individuals with available follow-up. LAA thrombus formation was found in 53 patients (19.6%). A total of 150 patients underwent LAAC after LAAEI. No LAA thrombus was documented in any patient who underwent LAAC. Of the patients who underwent LAAEI, 67.6% were in sinus rhythm after a mean of 682.7 ± 61.7 days. LAA flow after LAAEI but not arrhythmia recurrence was identified as an independent predictor of stroke and/or transient ischemic attack or LAA thrombus (p < 0.0001). Sinus rhythm was documented in about two-third of patients undergoing LAAEI as treatment of therapy refractory atrial arrhythmias. LAAC potentially prevents LAA thrombus formation and thromboembolism.