Ultrasound‑Aided Catheter Treatment Cuts Early Collapse in Pulmonary Embolism

Systemic thrombolysis can dissolve clots but is limited by a high risk of major bleeding, particularly intracranial events. To help address this challenge, investigators evaluated an ultrasound‑facilitated, catheter‑directed fibrinolysis technique that targets drug delivery to the obstructing thrombus. A new study reports reduced early clinical collapse with this approach compared with anticoagulation alone.

The intervention, ultrasound‑facilitated, catheter‑directed fibrinolysis, uses a thin intravascular catheter advanced from a femoral vein to the pulmonary arteries. Thrombolytic medication is infused directly into the clot to localize therapy. Concurrent application of ultrasound energy accelerates fibrinolysis, which shortens treatment time and allows a lower thrombolytic dose.

Investigators tested the method in the Higher‑Risk Pulmonary Embolism Thrombolysis (HI‑PEITHO) trial, a multicenter study of 544 adults with acute pulmonary embolism at moderate to high risk of complications. Participants were enrolled in Germany, seven other European countries, and the United States. One group received catheter‑directed fibrinolysis plus standard anticoagulation, and the control group received anticoagulation alone. The primary endpoint was a composite of mortality or life‑threatening cardiovascular collapse within seven days.

Event rates favored the catheter‑based strategy. Mortality or life‑threatening cardiovascular collapse occurred in 4% of patients treated with ultrasound‑facilitated, catheter‑directed fibrinolysis and in 10.3% of patients treated with anticoagulation alone, corresponding to a 61% reduction in the primary endpoint. Serious complications were infrequent across study arms, and no cerebral hemorrhages were observed in either group.

The study was initiated and co‑led by University Medical Center Mainz in partnership with the Pulmonary Embolism Response Team (PERT) Consortium in the United States, with Boston Scientific as the study sponsor. The results were published on March,28, 2026 in the New England Journal of Medicine. The findings outline a targeted reperfusion option that was associated with early clinical benefit while maintaining a low observed rate of major bleeding complications.

“The HI‑PEITHO study is the largest to date and the first of its kind in the field of pulmonary embolism. It shows that a catheter-based procedure can be effective and can improve the prognosis for certain patients with severe pulmonary embolism while carrying a low risk of bleeding complications,” said Professor Stavros Konstantinides, MD, FESC, Medical Director of the Center for Thrombosis and Hemostasis (CTH) at University Medical Center Mainz

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