Stroke Risk in Patients With Atrial Fibrillation Undergoing Electrical Isolation of the Left Atrial Appendage.

Background: Loss of contractility leading to stasis of blood flow following left atrial appendage electrical isolation (LAAEI) could lead to thrombus formation.

Objectives: This study evaluated the incidence of thromboembolic events (TE) in post-LAAEI cases "on" and "off" oral anticoagulation (OAC).

Methods: A total of 1,854 consecutive post-LAAEI patients with follow-up transesophageal echocardiography (TEE) performed in sinus rhythm at 6 months to assess left atrial appendage (LAA) function were included in this analysis.

Results: The TEE at 6 months revealed preserved LAA velocity, contractility, and consistent A waves in 336 (18%) and abnormal parameters in the remaining 1,518 patients. In the post-ablation period, all 336 patients with preserved LAA function were off OAC. At long-term follow-up, patients with normal LAA function did not experience any stroke events. Of the 1,518 patients with abnormal LAA contractility, 1,086 remained on OAC, and the incidence of stroke/transient ischemic attack (TIA) in this population was 18 of 1,086 (1.7%), whereas the number of TE events in the off-OAC patients (n = 432) was 72 (16.7%); p < 0.001. Of the 90 patients with stroke, 84 received left atrial appendage occlusion (LAAO) devices. At median 12.4 months (interquartile range: 9.8 to 15.3 months) of device implantation, 2 (2.4%) patients were on OAC because of high stroke risk or personal preference, whereas 81 patients discontinued OAC after LAAO device implantation without any TE events.

Conclusions: LAAEI is associated with a significant risk of stroke that can be effectively reduced by optimal uninterrupted OAC or LAAO devices.