implanter wearing mask in hospital

Clinical Evidence





Recent Studies


The SURPASS analysis of the NCDR-LAAO Registry™ includes the largest number of commercial WATCHMAN FLX patients to date. This data reinforces the outstanding safety of WATCHMAN FLX with a 0.37% major procedural adverse event rate within 7 days or hospital discharge and 98% procedural success in >16,000 real-world NVAF patients.1 

Heart Rhythm Meta-Analysis

The Meta-Analysis is the largest comparison of peri-procedural success and short-term outcomes of WATCHMAN FLX vs Amplatzer Amulet reveals superior procedural safetyhigher procedural success, and better LAA closure with WATCHMAN FLX.2


SEAL FLX is the first study to compare Amulet exclusively to WATCHMAN FLX and the results demonstrated that statistically superior complete occlusion* was achieved when using WATCHMAN FLX.3


The U.S. IDE Trial was designed to establish the procedural safety and left atrial appendage closure efficacy of WATCHMAN FLX™ LAAC device. 

Clinical Trials

Trials Currently Enrolling


With over 150,000 patients implanted with the WATCHMAN platform, CHAMPION-AF extends Boston Scientific’s LAAC leadership by evaluating WATCHMAN FLX™ as a safe and effective first-line option versus NOAC to reduce stroke risk.

Clinical Trial Results

OPTION Clinical Trial

This trial is active and has reached full enrollment.

PINNACLE FLX Clinical Study

The PINNACLE FLX US IDE Trial was designed to establish the Procedural Safety and LAA Closure Efficacy with the WATCHMAN FLX LAAC Device.

* Complete LAA occlusion defined as no visible peri-device leak (PDL) and absence of contrast patency in the distal LAA (LAA/left atrium Hounsfield ratio <0.25)
1. Late Breaking Clinical Trial at CRT 2022, Presented by Dr. Samir Kapadia 

2. Della Rocca, D., Magnocavallo, M., Gianni, C., Horton, R., Biase, L., Natale, A., Procedural and short-term follow-up outcomes of Amplatzer Amulet Occluder versus Watchman FLX Device: A Meta-Analysis, Heart Rhythm, February 2022,
3. Korsholm-K et al.; TCT 2021