Safety and efficacy of early anticoagulation drug regimens after WATCHMAN left atrial appendage closure: three-month data from the EWOLUTION prospective, multicentre, monitored international WATCHMAN LAA closure registry.

Aims While LAA closure has recently been incorporated into both European and US guidelines for stroke prevention, uncertainties regarding post-procedural drug therapy so far limit its adoption. The aim of this analysis is to compare real-world outcome data stratified for the post-procedural drug regimen employed. Methods and results One thousand and five patients were implanted with a WATCHMAN device in the prospective EWOLUTION study at 47 centres; 73.5% of the patients were deemed contraindicated for long-term OAC therapy. Here we report on three-month data including the first follow-up TOE exam for 94% of the study population. Following LAA closure, patients received DAPT, VKA, NOAC, single antiplatelet or no therapy (60.3%, 15.4%, 10.9%, 7% and 6.5%, respectively). Device thrombus (2.6%), stroke (0.4%) and major bleeding SAE (2.6%) rates were low overall and did not vary by post-implantation medication strategy. Patients on NOAC had the lowest bleeding rate, without an increase in device thrombus or stroke rates. Conclusions LAA closure with the WATCHMAN device is feasible in patients with a relative or absolute contraindication to oral anticoagulation. Neither DAPT nor NOAC therapy leads to a significant increase in device thrombus, stroke or bleeding compared to the standard VKA regimen. Numerically, NOAC therapy had the lowest event rate.