BACKGROUND: The LAmbre occluder, available in two versions, allows for selective coverage of the pulmonary ridge (PR) during left atrial appendage closure (LAAC). This study evaluated the effects of PR coverage on imaging and clinical outcomes in patients undergoing LAAC. METHODS: Imaging data and clinical events were retrospectively analyzed for patients with nonvalvular atrial fibrillation who successfully underwent LAAC using the LAmbre device at the First Affiliated Hospital of Wenzhou Medical University between October 2018 and May 2022. The primary composite endpoint was thromboembolic (TE) events and DRT. RESULTS: In total, 259 patients were evaluated using transesophageal echocardiography (TEE) at a median interval of 52 days (short-term) and 385 days (long-term). Patients were divided into a PR-covered group (n=109) and a PR-uncovered group (n=150). PR-uncovered patients showed a trend toward higher DRT incidence (8/150 vs 1/109, P=0.056, log-rank test). The primary composite endpoint of TE events and DRT was significantly lower in the PR-covered group (14.0% vs 6.4%, P=0.046, log-rank test). Any peri-device leak (PDL) was more frequent in the PR-covered group during both short-term (45.9% vs 28.7%, P=0.004) and long-term follow-up (49.5% vs 25.3%, P<
0.001), but no differences was found in significant PDLs (>
3mm). PR coverage was identified as an independent predictor of long-term any PDL (odds ratio 3.19, 95% confidence interval 1.64-6.18, P<
0.001). CONCLUSIONS: PR coverage during LAAC with the LAmbre device was associated with a reduced risk of the primary composite endpoint of TE events and DRT, albeit with an increased incidence of nonsignificant PDL (≤3mm).