Boston Scientific's EKOS System Outperforms Standard of Care for Acute Pulmonary Embolism

Landmark HI-PEITHO trial demonstrates significant reduction in clinical event rates with EKOS plus anticoagulation versus anticoagulation alone.

Mar. 28, 2026 at 3:00pm

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Boston Scientific announced positive results from the global HI-PEITHO randomized clinical trial, which found that the EKOS Endovascular System plus anticoagulation was superior to the current standard of care - anticoagulation alone - for the treatment of acute pulmonary embolism (PE). The trial met its composite primary endpoint, showing a 61% reduction in PE-related mortality, non-fatal hemodynamic cardiorespiratory decompensation or collapse, and non-fatal symptomatic recurrence of PE within seven days.

Why it matters

Pulmonary embolism is a serious and potentially life-threatening condition, and the third leading cause of cardiovascular mortality. The HI-PEITHO trial provides robust clinical evidence to support the use of the EKOS system as a first-line therapy, offering clinicians a new minimally invasive treatment option that can significantly improve outcomes for patients with intermediate-risk PE.

The details

The randomized, controlled HI-PEITHO trial enrolled 544 patients with intermediate-risk PE across 59 sites in the U.S. and Europe. The EKOS system, which delivers a low dose of clot-dissolving medication directly to the blood clot and uses ultrasound energy to facilitate medication dispersion, demonstrated superiority to anticoagulation alone. Patients treated with EKOS plus anticoagulation had a lower rate of cardiorespiratory decompensation or collapse, a serious complication that can require emergency intervention.

  • The HI-PEITHO trial findings were presented at the American College of Cardiology's Annual Scientific Session & Expo on March 28, 2026.
  • The results were simultaneously published in The New England Journal of Medicine on March 28, 2026.

The players

Boston Scientific Corporation

A global medical technology leader that develops innovative devices and therapies to improve patient health.

Dr. Stavros Konstantinides

The principal investigator of the HI-PEITHO trial and medical director of the Center for Thrombosis and Hemostasis at the University Medical Center Mainz in Germany.

The PERT Consortium

A collaborative research partnership that co-led the HI-PEITHO trial with Boston Scientific.

University Medical Center of Mainz

A German academic medical center that co-led the HI-PEITHO trial with Boston Scientific.

PEITHO International Study Network

A global network of researchers that collaborated on the HI-PEITHO trial.

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What they’re saying

“The data presented today offer clinicians a greater understanding of the impact of intervention via ultrasound-facilitated catheter-directed thrombolysis with the EKOS system. These highly anticipated findings underscore the clinical efficacy for patients treated with this therapy, while also demonstrating that treatment was not accompanied by an increased risk of major bleeding and offered the added benefit of a shorter hospital stay compared to patients treated with anticoagulation alone.”

— Dr. Stavros Konstantinides, Principal Investigator, HI-PEITHO Trial

“The HI-PEITHO trial evaluated clear, clinically meaningful endpoints using rigorous patient enrollment criteria and demonstrated a definitive impact with the EKOS system over the standard of care for treating acute PE. For the first time, we have robust randomized clinical trial data available to inform treatment decisions by interventionalists and referring physicians and support consideration of EKOS plus anticoagulation as a first-line therapy.”

— Dr. Michael R. Jaff, Vice President and Chief Medical Officer, Vascular Therapies, Boston Scientific

What’s next

Patients enrolled in the HI-PEITHO trial will be followed for one year post-procedure to gather additional long-term data on the EKOS system's performance.

The takeaway

The HI-PEITHO trial results represent a significant advancement in the treatment of acute pulmonary embolism, providing clinicians with a new minimally invasive option that can substantially improve outcomes for high-risk patients compared to the current standard of care. This landmark study underscores Boston Scientific's commitment to developing innovative therapies that address unmet medical needs and transform patient lives.