Early Canadian Multicenter Experience With WATCHMAN for Percutaneous Left Atrial Appendage Closure

There are limited data with WATCHMAN (Boston Scientific Corporation, Natick, MA, USA) for left atrial appendage (LAA) closure in patients with nonvalvular atrial fibrillation (AF) and contraindications to anticoagulation. The purpose of this study was to evaluate the safety and efficacy of WATCHMAN in our early Canadian experience.

We report our pooled consecutive series of patients who underwent WATCHMAN implantation at four major Canadian centers. Indications for LAA closure were CHADS₂ ≥ 1 or CHA₂ DS₂ -VASc ≥ 2, and contraindication/intolerance to or failure on anticoagulation. Follow-up imaging was typically performed 1-6 months postprocedure.

One hundred and six patients underwent LAA closure with WATCHMAN from May 2013 to October 2015. The mean age was 74.8 ± 7.7, mean CHADS₂ score was 2.8 ± 1.2, CHA₂ DS₂ -VASc score was 4.3 ± 1.5, and HASBLED score was 3.2 ± 1.2. Permanent AF was present in 67.9% and paroxysmal AF in 32.1%. Indications for LAA closure were prior bleeding 89.6% (87 major bleeding and 8 minor bleeding), 9.4% were deemed high risk for bleeding, and 0.9% with recurrent strokes on warfarin. Procedural success was 97.2% (103 of 106), with one device embolization (snared percutaneously), one implant failure due to inadequate LAA depth, and one cardiac perforation requiring surgical repair before WATCHMAN implantation. The composite major safety event-rate was 1.9% (1 death and 1 device embolization). Mean hospital stay was 1.8 ± 4.7 days. Antithrombotic therapy postimplant included dual antiplatelet therapy in 76 of 103 (73.8%). Mean follow-up was 210 ± 182 days; there were two transient ischemic attacks, with estimated 66% reduction in thromboembolic events relative to CHADS₂ predicted risk.

In our early Canadian experience, WATCHMAN for LAA closure in patients contraindicated to anticoagulation appeared safe and effective.