On March 28, 2026, Boston Scientific Corporation (NYSE: BSX) announced significant findings from two pivotal clinical trials: the HI-PEITHO trial and the CHAMPION-AF trial. The HI-PEITHO trial demonstrated that the EKOS™ Endovascular System is superior to standard anticoagulation therapy for treating acute pulmonary embolism (PE) in patients at intermediate risk. The trial met its primary endpoint, showing a statistically significant reduction in clinical event rates when patients were treated with the EKOS device combined with anticoagulation compared to anticoagulation alone. Specifically, the results indicated a 61% reduction in primary endpoint events, with rates of 4.0% in the EKOS group versus 10.3% in the anticoagulation-only group (P=0.005). These findings were presented at the American College of Cardiology's Annual Scientific Session and published in The New England Journal of Medicine.

In addition, the CHAMPION-AF trial evaluated the WATCHMAN FLX™ Left Atrial Appendage Closure Device as a first-line therapy for stroke risk reduction in patients with non-valvular atrial fibrillation (NVAF). The trial met all primary and secondary safety and efficacy endpoints, showing that the WATCHMAN FLX device provided statistically superior protection from bleeding compared to non-vitamin K antagonist oral anticoagulants (NOACs). The primary safety endpoint was achieved with a significant reduction in non-procedural major and clinically relevant non-major bleeding (10.9% vs. 19.0%, P<0.001). Furthermore, the WATCHMAN FLX device demonstrated statistical non-inferiority in terms of efficacy compared to NOACs, with a primary efficacy endpoint of 5.7% versus 4.8% (P<0.001). These results position the WATCHMAN FLX device as a viable alternative for patients who struggle with adherence to anticoagulant therapy.

Both trials underscore Boston Scientific's commitment to advancing innovative medical technologies that improve patient outcomes. The positive results from these studies are expected to influence clinical practice and may lead to updated treatment guidelines for managing PE and stroke risk in patients with atrial fibrillation.

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