Two-year results from the PINNACLE FLX clinical trial assessing the safety and efficacy of the next-generation Watchman FLX (Boston Scientific) left atrial appendage closure (LAAC) device for patients with non-valvular atrial fibrillation (NVAF) have shown that patients implanted with the device recorded a low rate of ischaemic stroke out to 24 months.
Presented as late-breaking clinical science at TVT 2021 (The Structural Heart Summit, 20–22 July, Miami Beach, USA and virtual) the study evaluated the Watchman FLX device as an alternative to long-term oral anticoagulation therapy, including non-vitamin K antagonist oral anticoagulants (NOACs), for stroke risk reduction in patients with NVAF.
The prospective, non-randomised PINNACLE FLX trial included 400 patients in the USA with NVAF who were eligible for anticoagulation therapy to reduce the risk of stroke but had appropriate rationale to seek a non-pharmaceutical alternative.
Following the positive 12-month results in which the trial met its primary safety and efficacy endpoints, the trial met its secondary effectiveness endpoint—defined as the occurrence of ischaemic stroke or systemic embolism over 24 months—with a rate of 3.4% compared to the performance goal of 8.7%.
“These findings demonstrate sustained device performance over two years and reinforce the excellent safety and efficacy profile of the Watchman FLX technology,” said Saibal Kar, study co-principal investigator and interventional cardiologist at Los Robles Regional Medical Center and Bakersfield Heart Hospital, Oakland, USA. “Building upon the low complication rates and 100% rate of effective LAA closure seen at 12 months, the 3.4% rate of ischaemic stroke and systemic embolism at 24 months is very encouraging in this complex, elderly patient population.”
In addition to the low rate of ischaemic stroke, the data through to 24 months also demonstrated that no patients experienced a device embolisation or pericardial effusion requiring cardiac surgery, all of which is favourable in the context of previous clinical studies.
“The final results of this pivotal study underscore how design advancements of the Watchman FLX device—which allow for improved anchoring, a faster, more effective LAA closure and compatibility with more complex anatomies—have translated into a safe, effective and durable option for patients with NVAF at increased risk for stroke and systemic embolism and an appropriate rationale to seek a non-pharmaceutical alternative,” said Ian Meredith, global chief medical officer, Boston Scientific.
The Watchman FLX device received US Food and Drug Administration (FDA) approval in July 2020 and CE mark in March 2019.