HI-PEITHO: Boston Scientific’s Ekos System Superior to Anticoagulation Alone in Acute Intermediate-Risk PE

March 28, 2026—Boston Scientific Corporation announced that the HI-PEITHO global randomized clinical trial evaluating the use of the Ekos endovascular system in patients with intermediate-risk pulmonary embolism (PE) met the composite primary endpoint.

According to Boston Scientific, the data demonstrated that the Ekos system plus anticoagulation was superior to the current standard of care—anticoagulation alone—for the treatment of acute PE.

The randomized, controlled HI-PEITHO trial enrolled 544 patients with intermediate-risk PE across 59 sites in the United States and Europe. Patients will be followed to 1 year post procedure, noted the company.

As summarized in the company’s press release, the trial met the combined primary endpoint of PE-related mortality, nonfatal hemodynamic cardiorespiratory decompensation or collapse, and nonfatal symptomatic recurrence of PE within 7 days.

Specifically, the Ekos system plus anticoagulation demonstrated superiority to anticoagulation alone (4.0% vs 10.3%; P = .005), representing a 61% reduction in primary endpoint events. Additionally, patients treated with the Ekos system demonstrated a lower rate of cardiorespiratory decompensation or collapse (3.7% vs 10.3%). These results were achieved with no episodes of bleeding within the brain through 30 days, stated the press release.

The HI-PEITHO data were presented in a late-breaking science session at ACC.26, the American College of Cardiology’s annual scientific session. The study findings were simultaneously published by Kenneth Rosenfield, MD, et al in The New England Journal of Medicine.

Stavros Konstantinides, MD, and Dr. Rosenfield are Principal Investigators of the HI-PEITHO trial.

“The data presented today offer clinicians a greater understanding of the impact of intervention via ultrasound-facilitated catheter-directed thrombolysis with the Ekos system,” commented Dr. Konstantinides in Boston Scientific’s press release. “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.”

The HI-PEITHO trial is a joint research study led by Boston Scientific in partnership with The PERT Consortium and the University Medical Center of Mainz, Germany, and in collaboration with the PEITHO International Study Network, noted the company.