Original Title: Bleeding Outcomes After Left Atrial Appendage Closure Compared With Long-Term Warfarin A Pooled, Patient-Level Analysis of the WATCHMAN Randomized Trial Experience. Reference: Matthew J. Price et al. J Am Coll Cardiol Intv. 2015. Online before print.

The aim of this trial was to compare the relative risk of major bleeding after left atrial appendage closure vs. long term warfarin treatment.

Left atrial appendage closure is an alternative to chronic anticoagulation to prevent thromboembolisms in patients with atrial fibrillation.

This analysis included two randomized studies that had assessed the WATCHMAN device (Boston Scientific, Natick, Massachusetts) to close the left atrial appendage vs. long term warfarin.

A total 1114 patients were included, with a median follow up of 3.1 years. The overall major bleeding rate at the end of follow up was similar in both groups (3.5 events vs. 3.6 events per 100 patients/year; RR 0.96, 95% CI 0.66 to 1.40; p = 0.84).

The left atrial appendage closure significantly reduces bleeding after seven days post randomization (1.8 events vs. 3.6 events per 100 patients/year; RR 0.49, 95% CI 0.32 to 0.75; p = 0.001), which is even more notable after six months (1.0 events vs. 3.5 events per 100 patients/year; RR 0.28, 95% CI 0.16 to 0.49; p < 0.001) when patients assigned to the left atrial appendage closure discontinue anticoagulation and antiplatelet medication.

This reduction in bleeding was consistent across all patient subgroups.

Conclusion
There were no differences in global bleeding rate between patients assigned to left atrial appendage closure compared to patients receiving warfarin over a 3 year period.

However, the left atrial appendage closure reduces bleeding only after the periprocedural period and particularly after six months, when adjunctive anticoagulation and antiplatelets are discontinued.