Boston Scientific’s Watchman FLX Device for LAAC Evaluated at 1 Year in SURPASS Analysis

February 27, 2023—Boston Scientific announced the presentation of 1-year real-world outcomes with the company’s Watchman FLX left atrial appendage closure device in the SURPASS study of 66,894 patients with nonvalvular atrial fibrillation within the National Cardiovascular Data Registry Left Atrial Appendage Occlusion registry. The analysis represents the largest commercial Watchman FLX patient population studied to date, noted the company.

The SURPASS data were presented by Samir Kapadia, MD, during a late-breaking trial session at CRT 2023, the Cardiovascular Research Technologies conference held February 25-28 in Washington, DC.

The company noted that the findings build on the positive 45-day outcomes presented at CRT 2022 conference held last February 26 to March 1 in Washington, DC.

According to the company, the findings presented by Dr. Kapadia at CRT 2023 reinforced the safety and long-term efficacy of the Watchman FLX device in a routine, real-world clinical practice.

Boston Scientific highlighted the following key data:

• There was a 0.49% procedural adverse event rate within 7 days or hospital discharge, further supporting the safety profile observed in separate controlled and real-world analyses. By comparison, there was a 0.5% adverse event rate in the pivotal PINNACLE FLX trial, presented in 2020.
• There was a 1.6% all-stroke rate, including 1.2% ischemic stroke rate at 1 year. By comparison, there was 2.6% all-stroke/ischemic stroke rate in the PINNACLE FLX trial.
• There was a 98% procedural success rate.

Adverse events were defined as the occurrence of all-cause death, ischemic stroke, systemic embolism, or device- or procedure-related events requiring open cardiac surgery or major endovascular intervention between device implantation and 7 days or hospital discharge (whichever is later).

In his presentation, Dr. Kapadia summarized the SURPASS analysis findings as follows:

• Watchman FLX implantation can be accomplished safely with clinical outcomes similar to pivotal trials (at 30 days and 1 year) in a large number of patients (> 60,000) at a large number of sites (743) by a large number of operators (2,384).
• These data provide benchmarks for success and complications with in-hospital and 1-year outcomes. In-hospital outcomes included death, 0.10%; stroke, 0.09%; pericardial effusion requiring intervention, 0.38%; and high rates of complete seal, 96% with leak < 3 mm and 84% with no leak. The 1-year outcomes included stroke, 1.6%; ischemic stroke, 1.2%; mortality, 8.3%; and major bleeding, 6.7%.

The investigators also found that overall outcomes were similar in women and men. Mortality was higher in men than women, whereas women experienced more major bleeding and pericardial effusion requiring intervention within 1 year.