The Canadian WATCHMAN Registry for Percutaneous Left Atrial Appendage Closure

Background: Access to left atrial appendage closure (LAAC) in Canada is limited, due to funding restrictions. This work aimed to assess Canadian clinical practice on patient selection, postprocedural antithrombotic therapy, and safety and/or efficacy with WATCHMAN device implantation.Methods: Seven Canadian centres implanting the WATCHMAN device participated in this prospective multicentre, observational registry. All procedures were done under general anesthesia with transesophageal echocardiography guidance. Patients were prospectively followed for 2years. The long-term stroke rate was compared with the expected rate based on the CHA2DS2-VASc score.Results: A total of 272 patients who underwent LAAC with the WATCHMAN device between December 2013 and August 2019 (mean age: 75.4 years [standard deviation {SD}: 8.75]; male, 63.2%; CHA2DS2-VASc score: 4.35 [SD: 1.64]; HAS-BLED score: 3.55 [SD: 0.94]) were included. Most patients (90.4%) had prior history of bleeding (major, 80.5%; minor, 21.7%). The WATCHMAN device was successfully implanted in 269 patients (98.9%), with a few procedure related complications, including 5 pericardial effusions requiring drainage (1.8%), and 1 death (0.4%; 22 days post-LAAC from respiratory failure). Post-LAAC antithrombotic therapy included dual anti platelet therapy in 70.6%, single antiplatelet therapy in 18.4%, and oral anticoagulation in 13.6%. During the follow-up period (mean: 709.7 days [SD: 467.2]), an 81.4% reduction of the ischemic stroke rate occurred, based on the expected rate from the CHA2DS2-VASc score (6.0% expected vs 1.1% observed). Device-related thrombus was detected in 1.8%.Conclusions: The majority of Canadian patients who underwent LAAC had oral anticoagulation contraindication due to prior bleeding, and most were safely treated with antiplatelet therapy post-LAAC, with a low device-related thrombus incidence. Long-term follow-up demonstrated that LAAC achieved a significant reduction in ischemic stroke rate.