BackgroundResearch on the impact of angiographically detected residual trabeculation after left atrial appendage closure (LAAC) is limited.ObjectivesTo investigate the incidence, characteristics, and clinical implications of angiographically detected residual trabeculation after LAAC using the WATCHMAN device.MethodsWe analyzed 1350 consecutive patients with atrial fibrillation undergoing LAAC using the WATCHMAN device from the OCEAN‐LAAC registry, which is a prospective ongoing, multicenter Japanese registry. The inclusion criteria comprised patients who successfully underwent LAAC and whose presence or absence of residual trabeculation can be confirmed using a contrast medium. The clinical outcomes were compared between patients with and without angiographically detected residual trabeculation.ResultsResidual trabeculation was angiographically detected in 5.6% (75/1350 patients). At the procedure, the proportion of peri‐device leak (PDL) was significantly higher in the residual trabeculation group than in the non‐residual trabeculation group (20% vs. 5.1%, p < 0.001). However, the PDL and device‐related thrombosis at 45 days and 1 year were comparable between the two groups (37% vs. 23%, p = 0.24; 28% vs. 31%, p = 0.84; 2.1% vs. 1.4%, p = 0.50; 6.9% vs. 6.0%, p = 0.69, respectively). The 3‐year cumulative incidence of ischemic stroke, all cardiovascular death, and all‐cause death were comparable between the two groups (5.7% vs. 5.5%, log‐rank p = 0.96; 7.7% vs. 8.9%, log‐rank p = 0.34, 31.4% vs. 22.3%, log‐rank p = 0.71, respectively).ConclusionThe angiographically detected residual trabeculation rate was 5.6%, and this population had a significantly higher prevalence of PDL at the procedure. However, the presence of residual trabeculation did not contribute to PDL or device‐related thrombosis at follow‐up or affect the clinical outcomes.
