Delayed endothelialization of watchman device identified with cardiac CT

Background Left atrial appendage (LAA) closure with the Watchman device is increasingly used in patients with nonvalvular atrial fibrillation for stroke prevention. Though clinical trials have shown a similar combined risk of ischemic and hemorrhagic stroke, there is an increased risk of ischemic stroke in patients with a Watchman device compared with anticoagulation. Some ischemic strokes are related to a device‐related thrombus (DRT), which may be attributable to delayed endothelialization of exposed fabric and metal. Methods and Results Patients undergoing Watchman LAA occlusion between January 2016 and June 2018 were enrolled in a prospective registry. From this cohort, 46 patients who had both transesophageal echocardiogram (TEE) and computed tomography (CT) at 45 days follow‐up were selected for this study. The degree of LAA occlusion and type of leak were assessed by CT and TEE. TEE identified no patients with a significant (>5 mm) peri‐device leak, 27 (58.6%) with nonsignificant peri‐device leak (