Boston Scientific has reported positive data from the PINNACLE FLX clinical trial of its WATCHMAN FLX Left Atrial Appendage Closure (LAAC) device in non-valvular atrial fibrillation (NVAF) patients.

The prospective, non-randomised trial assessed the safety and efficacy of the device as a substitute to long-term oral anticoagulation treatment for lowering stroke risk in this patient population.

Non-vitamin K antagonist oral anticoagulants (NOACs) were included in the study as anticoagulation therapy.

The trial enrolled a total of 400 anticoagulant-eligible subjects in the US who sought a non-pharmaceutical alternative.

Data showed that the trial met the secondary efficacy goal with a 3.4% rate of systemic embolism or ischemic stroke incidence at 24 months versus the 8.7% performance goal.

As per the previously reported 12-month data, the trial met its primary safety and efficacy goals.

Furthermore, the latest results found that no trial subject reported device embolisation or pericardial effusion needing cardiac surgery, which is favourable with respect to earlier clinical trials.

Boston Scientific global chief medical officer Dr Ian Meredith said: “The final results of this pivotal study underscore how to 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.”

In March 2019, the WATCHMAN FLX device received CE mark, and it was approved by the US Food and Drug Administration in July last year.

Currently, two prospective, randomised controlled trials, OPTION and CHAMPION-AF, are evaluating the WATCHMAN FLX device in NVAF patients.

The OPTION trial is comparing the device to oral anticoagulants in patients undergoing a cardiac ablation procedure while CHAMPION-AF is assessing the device versus NOACs to prevent embolic stroke in wider anticoagulant-eligible patients.

Last month, Boston Scientific exercised its right to acquire the remaining 73% shares in medical device company Farapulse for an upfront payment of nearly $295m.