SIMPLAAFY: WATCHMAN FLX Pro Left Atrial Appendage Closure Device With Alternative Post-Implant Monotherapy

doi:10.1001/jama.2026.21361

SIMPLAAFY

Patient / Population Intervention / Exposition Comparaison Critère de jugement

In patients with non-valvular atrial fibrillation after successful left atrial appendage closure, aspirin alone or a reduced-dose NOAC followed by aspirin was non-inferior for 6-month death, stroke, systemic embolism or major bleeding compared with 6 months of dual antiplatelet therapy.

N

1 857patients

Schéma

Multicentre (86 US sites), single-blind randomised non-inferiority trial after WATCHMAN FLX Pro implantation (Boston Scientific). Two test arms, aspirin alone and 3 months of reduced-dose NOAC followed by aspirin, each against 6 months of DAPT followed by aspirin

Critère

All-cause death, stroke, systemic embolism or ISTH major bleeding at 6 months, each test arm against DAPT

RésultatThe primary outcome occurred in 31 patients (5.1%) with a reduced-dose NOAC vs 41 (6.9%) with DAPT (risk ratio 0.75, 95% CI 0.48-1.18; risk difference -1.7 percentage points, 97.5% upper bound 1.2) and in 20 (3.3%) with aspirin alone vs 6.9% with DAPT (risk ratio 0.49, 95% CI 0.29-0.82; risk difference -3.5 percentage points, 97.5% upper bound -0.8). Both monotherapy strategies met non-inferiority criteria (P < .001 for non-inferiority for both). Major bleeding was 4.5% with DAPT, 2.7% with reduced-dose NOACs and 1.7% with aspirin alone. Clinically relevant non-major bleeding was 8.7%, 4.8% and 3.8%, respectively. Device-related thrombus at 45 days was observed in 3.4%, 0.9% and 2.7%, respectively.

Reddy VY, Saliba WI, et al. JAMA. 2026; published online 2 November. 10.1001/jama.2026.21361

Discussion et critique

In a large randomised trial, both a reduced-dose NOAC and aspirin alone were non-inferior to DAPT for the 6-month composite of death, stroke, systemic embolism or major bleeding after uncomplicated left atrial appendage closure. Follow-up is only 6 months, and the trial was open label, with investigators, staff and participants aware of treatment assignment, although events were adjudicated by an independent committee. Bleeding and device-related thrombus were exploratory outcomes without multiplicity adjustment, so the apparent differences between arms there should not be read as confirmed. The abstract does not state the non-inferiority margin, and the result applies only to patients with a successful, uncomplicated implant.