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

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

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.

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.

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