Real-world Safety and Efficacy of WATCHMAN LAA Closure at One Year in Patients on Dual Antiplatelet Therapy: Results of the DAPT Subgroup from the EWOLUTION All-comers Study

Aims: The study aimed to confirm the efficacy and safety of WATCHMAN LAA closure in atrial fibrillation patients unsuitable for oral anticoagulation.

Methods And Results: The EWOLUTION registry prospectively collects all clinical data on 1,005 European patients implanted with a WATCHMAN device. Following the procedure, 605 patients (60.2%) received dual antiplatelet therapy according to the local standard; DAPT was discontinued in 85% of patients within one year. CHA2DS2-VASc and HAS-BLED scores were 4.61.6 and 2.41.2, respectively. The periprocedural SAE rate was 3.3% (2.0% major adverse cardiac events), mostly resolving without sequelae. Device embolisation or pericardial effusion occurred in one (0.2%) and two (0.3%) patients, respectively. TEE (median 62 days post implant, IQR: 47-97) confirmed effective sealing (no leak >5 mm) in 99.2% of patients. Device thrombus was present in 22 patients (4.0%), one patient developed a stroke. One-year mortality in the DAPT group was 9.6% (N=58) reflecting the advanced age and comorbidities in this population. The ischaemic stroke rate at one year was 1.4% (expected based on CHA2DS2-VASc: 7.5%), none fatal. The major bleeding rate was 2.5%, or 2.1% excluding periprocedural events (expected rate on VKA based on HAS-BLED: 5.1%).

Conclusions: LAA closure with the WATCHMAN device followed by DAPT therapy in a high-risk patient population is safe. At one year, the intervention is associated with a substantial risk reduction regarding ischaemic stroke and major bleeding compared to the expected rate based on CHA2DS2-VASc and HAS-BLED scores.