In patients with acute, intermediate-risk pulmonary embolism (PE), ultrasound-facilitated, catheter-directed fibrinolysis plus anticoagulation led to a lower risk of PE-related death, cardiopulmonary decompensation or collapse, or recurrence of PE compared with anticoagulation alone. These findings from the HI-PEITHO trial were presented at ACC.26 in New Orleans and simultaneously published in NEJM.

The trial enrolled 544 patients at 59 sites in the U.S. and eight European countries (Austria, France, Germany, Ireland, Poland, Switzerland, The Netherlands and the UK). Participants had intermediate-risk PE with two additional indicators of clinical severity. Half of the patients were randomly assigned to ultrasound-facilitated catheter-directed thrombolysis, and the other half received standard systemic anticoagulation (control group).

At 30 days, 4% of those in the catheter-based treatment group and 10.3% of those in the control group experienced the trial’s primary composite endpoint of PE-related death, cardiorespiratory decompensation or collapse, or symptomatic PE recurrence within seven days of randomization. The 61% between-group difference was significant in favor of the catheter-based treatment arm and was driven by a reduction in the rate of cardiorespiratory decompensation or collapse in this group, said researchers.

In other findings, no brain bleeds occurred, and there were few deaths in either study arm. In addition, the results showed no significant difference in deaths of any cause or in major bleeding complications between groups.

The trial is the first to directly compare clinical outcomes from a catheter-based strategy vs. systemic anticoagulation alone in patients with elevated-risk forms of PE. “This trial shows that a catheter intervention can indeed be effective and improve the prognosis for patients with severe PE and elevated risk of early death or life-threatening complications,” said Stavros V. Konstantinides, MD, PhD, the study’s lead author. “If the right patients are selected for this procedure, it can prevent patients from deteriorating and it can do so at an acceptably low risk of bleeding complications.”

Researchers are currently tracking patient outcomes up to 12 months to assess potential differences in long-term survival, late complications, functional outcomes, quality of life and health care utilization.

In a related editorial comment, Alex C. Spyropoulos, MD, and Suresh Vedantham, MD, say the findings “support a lower threshold for the use of ultrasound-facilitated, catheter-directed thrombolysis in patients with PE who would have been categorized as having intermediate-high risk or the equivalent according to recent guidelines.” However, they caution that the “wisdom of applying this approach to patients with less severe intermediate-risk PE remains unclear and will benefit from additional studies.”

Clinical Topics: Anticoagulation Management, Vascular Medicine

Keywords: ACC Annual Scientific Session, ACC26, Quality of Life, Pulmonary Embolism, Anticoagulants, Hemorrhage, Thrombolytic Therapy, Catheters, New Orleans