Left atrial appendage occlusion (LAAO) has emerged as an alternative to anticoagulation for atrial fibrillation patients with contraindications or unsuitable for long-term oral anticoagulants. However, the performance of LAAO among East Asians is to be investigated. In the current study, we aimed to document the real-world procedural success rate and configurations, major adverse event rates, and antithrombotic medication regimens peri- and post-LAAO.

 A total of 3,096 consecutive patients from 39 Chinese centers undergoing LAAO between was prospectively enrolled between 1^st April 2019 and 31^st October 2020. The main outcomes were device, technical, or procedural success, peri-procedural complications, and major adverse events of death, stroke, systemic embolism, procedural complications, and bleeding events at 30-days post-procedure. All events were adjudicated by an independent clinical event committee (CEC). Unadjusted and multivariable-adjusted logistic regression analyses were performed to assess the peri-procedural techniques in thirty-day adverse events.

Enrolled participants had a high risk of stroke (CHA₂DS₂-VASc:4.0±1.8), a moderate-to-high risk of bleeding (HAS-BLED score:2.4±1.2). The number of procedures performed under local anesthesia was 1,287 (41.6%), while 493 (15.9%) used only fluoroscopy guidance. In 41.9% of cases, LAAO implantation was combined with radiofrequency ablation or cryoablation for atrial fibrillation. Device and procedural success were achieved respectively in 99.5% (3,082/3,096) and 97.9% (3,032/3,096) of cases. At 30-day follow-up, the rate of the composite endpoint of death, stroke, and systemic embolism was 0.52% (95%CI:0.32-0.84), and any life-threatening/major bleeding 1.23% (95%CI:0.90-1.68). The types of anesthesia (general/local), intra-procedural imaging (transesophageal echocardiography/fluoroscopy/intracardiac echocardiography), or whether a combined ablation procedure was performed or not, had no significant impact on the procedural success or 30-day adverse events. Procedural success was significantly higher (98.2% versus 96.5%, OR_adjusted:1.97, 95%CI:1.01-3.53, P=0.023) and life-threatening or major bleeding significantly lower (2.5% versus 1.0%, OR_adjusted: 0.42, 95%CI:0.21-0.87, P=0.019) in centers performing ≥40 versus <40 cases annually.

In Chinese centers, patients with a high risk of stroke and moderate-to-high risk of bleeding who underwent implantation of a WATCHMAN LAAO device had high rates of procedural success and low rates of short-term ischemic and bleeding events.