SIMPLAAFY study of the WATCHMAN FLX™ Pro Left Atrial Appendage Closure Device meets primary endpoints
Boston Scientific reports positive six-month results from the SIMPLAAFY trial, showing simplified post-procedure drug regimens for the WATCHMAN FLX Pro device are as effective as standard dual therapy with lower bleeding risks.
Boston Scientific announced positive six-month primary endpoint results from the SIMPLAAFY randomized controlled trial of the WATCHMAN FLX Pro Left Atrial Appendage Closure Device. The study evaluated two single-drug regimens— aspirin alone or reduced-dose non-vitamin K antagonist oral anticoagulant (NOAC) followed by aspirin—as alternatives to dual anti-platelet therapy (DAPT) after device implantation in patients with non-valvular atrial fibrillation. Both regimens met non-inferiority criteria compared to DAPT, supporting the potential to simplify post-procedure care.
The trial randomized 1,857 patients across 86 U.S. clinical sites to either aspirin alone for the duration of the trial or reduced-dose NOAC for three months followed by aspirin, or a DAPT regimen of aspirin and clopidogrel for six months followed by aspirin. At six months, ischemic stroke rates were equivalent across groups at 0.7%, while patients on simplified regimens experienced less bleeding compared to those on DAPT.
Imaging at 45 days showed the lowest rate of device-related thrombus in patients on reduced-dose NOAC compared to DAPT, with rates of 0.9% versus 3.4% (P=0.01). The findings were presented as a late-breaking clinical trial at TCT 2026 and simultaneously published in JAMA, highlighting the clinical and practical benefits of simplified post-implant drug regimens.
The WATCHMAN FLX Pro device, approved by the U.S. FDA in 2023, includes HEMOCOAT Technology designed to promote faster, more controlled healing. Dr. Saibal Kar, study co-chair, noted the results could meaningfully simplify post-procedure care and reduce medication burden for patients following implantation of the device.