- Question
- Is percutaneous left atrial appendage closure with a device (Watchman FLX) noninferior to non-vitamin K antagonist oral anticoagulants (NOACs) for preventing cardiovascular and embolic events in patients with atrial fibrillation who are candidates for anticoagulation, with less bleeding?
- Design
- Prospective, international, ongoing, 1:1 randomized trial with single-blind masking, enrolling 3000 patients. The primary efficacy end point was tested for noninferiority (margin of 4.8 percentage points) after 3 years of follow-up; the primary safety end point was tested for superiority. Funded by Boston Scientific.
- Population
- Patients with nonvalvular atrial fibrillation who were suitable candidates for anticoagulation. Mean age was 71.7±7.5 years, 31.9% were women, and the mean CHA2DS2-VASc score was 3.5±1.3.
- Intervention
- Percutaneous left atrial appendage closure with the Watchman FLX device (device group, 1499 patients).
- Control
- Therapy with a non-vitamin K antagonist oral anticoagulant (NOAC) (anticoagulation group, 1501 patients).
- Primary outcome
- Efficacy: composite of death from cardiovascular causes, stroke, or systemic embolism at 3 years, tested for noninferiority. Safety: non-procedure-related bleeding, tested for superiority.
- Results
- A primary efficacy event occurred in 81 patients in the device group (Kaplan-Meier estimate 5.7%) and in 65 in the anticoagulation group (4.8%); difference 0.9 percentage points (95% CI, −0.8 to 2.6; P<0.001 for noninferiority). Non-procedure-related bleeding occurred in 154 patients (10.9%) with the device vs 260 (19.0%) with NOAC (HR 0.55; 95% CI, 0.45 to 0.67; P<0.001 for superiority).
- Safety
- Non-procedure-related bleeding was significantly lower with left atrial appendage closure than with anticoagulation (10.9% vs 19.0%).
- Conclusion
- Among patients with atrial fibrillation who were candidates for anticoagulation, device-based left atrial appendage closure was noninferior to NOAC therapy for the composite of cardiovascular death, stroke, or systemic embolism and superior for non-procedure-related bleeding at 3 years.
- Why it matters
- It provides evidence that left atrial appendage closure may be considered an alternative to long-term anticoagulation even in patients who can take anticoagulants, rather than only in those unsuitable for them.
Card generated automatically with AI from the abstract of the original publication and the trial registry; every figure was checked against those sources. It may contain errors: verify the data at the source before using it for clinical decisions.
Generated on October 14, 2026