Electrical isolation of the left atrial appendage increases the risk of ischemic stroke and transient ischemic attack regardless of postisolation flow velocity

Electrical isolation of the left atrial appendage (LAA) is associated with a lower rate of atrial fibrillation (AF) recurrence in patients undergoing radiofrequency catheter ablation. However, LAA isolation can significantly impair LAA contractility.This study was performed to evaluate whether electrical isolation of the LAA is associated with an increased risk of ischemic stroke or transient ischemic attack (TIA).Consecutive patients with AF undergoing radiofrequency catheter ablation at Korea University Medical Center Anam Hospital were analyzed.Of 2352 patients, 39 (1.7%) had LAA isolation. Patients with LAA isolation had a significantly higher rate of ischemic stroke or TIA than did those without LAA isolation (log-rank, P < .001; hazard ratio 23.6; P < .001). There were significant differences in the baseline characteristics of the 2 groups, including type of AF (34 [87.2%] and 911 [39.4%] patients with and without LAA isolation had nonparoxysmal AF, respectively). After multivariate adjustment, LAA isolation was found to be a significant risk factor for ischemic stroke or TIA (adjusted hazard ratio 11.3; P < .001). Propensity score-matched analysis also revealed an increased risk of ischemic stroke or TIA in patients with LAA isolation compared with those without LAA isolation (log-rank, P = .001). The LAA flow velocity of post-LAA isolation status was not significantly different between patients who did and did not experience ischemic stroke or TIA (30.3 ± 17.7 cm/s vs 33.9 ± 17.9 cm/s; P = .608).A significantly increased risk of ischemic stroke or TIA was observed in patients with electrical isolation of the LAA. In addition, postisolation LAA flow velocity is not a reliable marker to predict future ischemic events.