Active WATCHMAN trials
CHAMPION-AF clinical trial
With over 500,000 patients implanted with the WATCHMAN platform, CHAMPION-AF extends Boston Scientific’s LAAC leadership by evaluating the WATCHMAN FLX LAAC Implant as a safe and effective first-line option versus non-vitamin K antagonist oral anticoagulants (NOACs) to reduce stroke risk.*
SIMPLAAFY clinical trial
SIMPLAAFY is a randomized controlled trial that will evaluate two monotherapy regimens vs. dual anti-platelet therapy (DAPT) after implant with the WATCHMAN FLX™ Pro Device in patients with atrial fibrillation (AFib). SIMPLAAFY will assess whether a less intensive drug regimen may help mitigate post-implant bleeding risk and provide other viable options for post-implant treatment.
Clinical trial results
OPTION clinical trial
The OPTION clinical trial is the first randomized head-to-head study comparing LAAC to OAC (95% DOACs) after cardiac ablation to determine if LAAC with the WATCHMAN FLX Implant is a reasonable alternative in patients after AFib ablation.1
PINNACLE FLX clinical study
The PINNACLE FLX US IDE Trial2 was designed to establish the Procedural Safety and LAA Closure Efficacy with the WATCHMAN FLX LAAC Implant.
SURPASS Pro real-world data
Early outcomes with the WATCHMAN FLX Pro Device from the SURPASS Pro NCDR LAAO Registry reaffirm the proven performance of the WATCHMAN FLX platform by continuing to demonstrate a best-in-class safety profile and industry-leading seal along with high procedural success in routine clinical practice.3
SURPASS real-world data
The SURPASS one-year outcomes analysis of the National Cardiovascular Data Registry (NCDR) Left Atrial Appendage Occlusion (LAAO) Registry™ now includes the largest number of commercial WATCHMAN FLX Device patients to date (97,185 patients implanted between August 2020 and September 2022). These data continue to support the best-in-class safety profile and long-term efficacy of the WATCHMAN FLX Device.4
First three-year data from NCDR-LAAO Registry
The NCDR-LAAO Registry analysis is a review of the first three years and over 38,000 WATCHMAN Implants.5 This analysis, The NCDR Left Atrial Appendage Occlusion (LAAO) Registry™: Review of the First 3 Years, was presented by Dr. James Freeman on March 29, 2020 at the ACC 2.0/WCC Virtual Experience. This analysis demonstrates that major in-hospital adverse event rates were in-line with those reported in the pivotal WATCHMAN Implant trials.
Long-term patient-level meta-analysis
Five-year results from patient-level meta-analyses of the totality of data available on the WATCHMAN Device, by Reddy, et al, has been published in the Journal of American College of Cardiology (JACC).6
The clinical studies in this publication includes five-year outcomes of PREVAIL, combined with the five-year outcomes of PROTECT-AF, and demonstrated that LAAC with WATCHMAN provided stroke reduction in non-valvular atrial fibrillation (NVAF) comparable to warfarin with additional reductions in major bleeding and mortality.
CAP 2 registry
The Continued Access to PREVAIL (CAP2) registry is a multi-center prospective non-randomized study allowing continued access to the WATCHMAN Device, following the PREVAIL trial, during regulatory review of the pre-market application for the WATCHMAN Implant.7
The primary objective of the CAP2 registry was to collect additional safety and effectiveness data on WATCHMAN in patients with NVAF who are deemed by their physicians to be suitable for warfarin therapy.
Initial commercial experience data
Post-FDA approval, initial U.S. clinical experience with WATCHMAN for stroke prevention in AFib evaluates the acute procedural performance and complication rates for all WATCHMAN cases performed in the U.S. since FDA approval.8
The authors concluded that despite a large fraction of previously inexperienced operators, the procedural success in the real-world post-FDA approval experience of WATCHMAN was high and the complication rates were low.
PREVAIL clinical trial
The goal of the PREVAIL trial was to assess the safety and efficacy of LAAC for stroke risk reduction in patients with NVAF compared with long-term warfarin therapy.9
The authors concluded that LAA occlusion was non-inferior to warfarin for ischemic stroke risk reduction or SE >7 days’ post-procedure. Although non-inferiority was not achieved for overall efficacy, event rates were low and numerically comparable in both arms. Procedural safety was significantly improved.
This trial provided additional data that LAA occlusion is a reasonable alternative to warfarin therapy for stroke risk reduction in patients with NVAF who do not have an absolute contraindication to short-term warfarin therapy.
CAP registry
The Continued Access to PROTECT AF (CAP) registry was a multi-center prospective non-randomized study allowing continued access to the WATCHMAN Device, following the PROTECT AF trial, during regulatory review of the pre-market application for the WATCHMAN Implant.7
The primary objective of the CAP registry was to collect additional safety and effectiveness data on WATCHMAN in subjects with NVAF who are deemed by their physicians to be suitable for warfarin therapy.
PROTECT AF clinical trial
The multicenter PROTECT AF study was conducted to determine whether percutaneous LAAC with a filter device (WATCHMAN) was non-inferior to warfarin for stroke risk reduction in atrial fibrillation.10
In the Journal of the American Medical Association article (4-year results), the authors concluded that after 3.8 years of follow-up among patients with NVAF at elevated risk for stroke, percutaneous LAAC met criteria for both non-inferiority and superiority, compared with warfarin, for preventing the combined outcome of stroke, systemic embolism, and cardiovascular death, as well as superiority for cardiovascular and all-cause mortality.
Pilot study
Meta-analyses confirmed that in cases of left atrial thrombus in non-rheumatic AFib patients, approximately 90% of them are in the LAA. This study assessed the feasibility of implanting a device in the LAA in patients with AFib to prevent thromboembolic stroke.11
The authors concluded that preliminary data suggest LAAC with WATCHMAN to be safe and feasible.
Understand which patients may be candidates for a WATCHMAN LAAC Implant
*WATCHMAN FLX is an FDA approved device being studied for an expanded indication as a first line therapy vs NOAC for AFib patients. The use of WATCHMAN as a first-line therapy for stroke risk reduction in AFib patients is considered investigational.
†WATCHMAN FLX is an FDA approved device being studied for an expanded indication as a first line therapy vs NOAC for AFib patients post-ablation. The use of WATCHMAN as a first-line therapy for stroke risk reduction in AFib patients post-ablation is considered investigational.
References
1. Wazni O, et al. Randomized Comparison of Left Atrial Appendage Closure with Oral Anticoagulation After Catheter Ablation for Atrial Fibrillation. Late Breaking Clinical Trial, American Heart Association 2024.
2. Kar, S., et al, Primary Outcome Evaluation of the Next Generation LAAC Device: Results from the PINNACLE FLX Trial, Circulation, 2021.
3. Piccini J et al. Outcomes with WATCHMAN FLX Pro in Everyday Clinical Practice: Early Results from SURPASS Pro, HRS 2025.
4. Kapadia SR et al. Outcomes With the WATCHMAN FLX in Everyday Clinical Practice From the NCDR Left Atrial Appendage Occlusion Registry, Circulation: Cardiovascular Interventions, 2024.
5. Freeman et al, The NCDR Left Atrial Appendage Occlusion (LAAO) Registry™: Review of the First 3 Years, JACC, March 2020
6. Reddy VY, et al. JACC 2017; 70(24): 2964-2975.
7. Journal of the American College of Cardiology, 2019. David R. Holmes, JR, MD, Vivek Y. Reddy, MD, Nicole T. Gordon, BSEE, David Delurgio, MD, Shephal K. Doshi, MD, Amish J. Desai, MD, James E. Stone, JR, MD, Saibal Kar, MDh
8. Reddy VY, et al. JACC 2017; 69(3): 253-261.
9. Holmes DR Jr, Kar S, Price MJ, et al. Prospective randomized evaluation of the WATCHMAN Left Atrial Appendage Closure device in patients with atrial fibrillation versus long-term warfarin therapy: the PREVAIL Trial. J Am Coll Cardiol. 2014;64(1):1-12.
10. Reddy VY, Sievert H, Halperin J, et al; for the PROTECT AF Steering Committee and Investigators. Percutaneous left atrial appendage closure vs warfarin for atrial fibrillation: a randomized clinical trial. JAMA. 2014;312(19):1988-1998.
11. Sick PB, Schuler G, Hauptmann KE, et al. Initial worldwide experience with the WATCHMAN Left Atrial Appendage System for stroke prevention in atrial fibrillation. J Am Col Cardiol. 2007;49(13):1490-1495.