A landmark trial called HI-PEITHO found that catheter-based therapy significantly improved outcomes for patients with intermediate-risk pulmonary embolism, reducing early mortality and complications by over 60% compared to standard anticoagulation, according to findings presented at ACC.26 and published in the New England Journal of Medicine.
The HI-PEITHO study, led by Stavros V Konstantinides, compared ultrasound-facilitated catheter-directed thrombolysis with traditional systemic anticoagulation for 544 patients with intermediate-risk pulmonary embolism. The results, published online in the New England Journal of Medicine at the time of the ACC.26 conference, showed a 61% reduction in the primary composite endpoint of PE-related death, circulatory collapse, or recurrence within 30 days for those receiving the catheter-based approach.
HI-PEITHO finds catheter-based procedure improves pulmonary embolism outcomes
The trial, presented at the American College of Cardiology’s Annual Scientific Session (ACC.26) in New Orleans, enrolled patients with intermediate-risk PE who had additional indicators of clinical severity, such as tachycardia, low blood pressure (although not at a level indicating shock), or low oxygen saturation. Half of the participants received ultrasound-facilitated catheter-directed thrombolysis, while the other half received standard systemic anticoagulation. At 30 days, 4% of the catheter-based group and 10.3% of the control group experienced the primary composite endpoint, a statistically significant difference.
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. 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.
The study noted that no brain bleeds occurred, and there were few deaths in either study arm; the results showed no significant difference in deaths of any cause or in major bleeding complications between groups.
The trial, conducted across 59 sites in the USA and eight European countries (Austria, France, Germany, Ireland, Poland, Switzerland, the Netherlands and the UK), included patients with intermediate-risk PE who had two additional clinical severity indicators. The catheter-based treatment involved delivering low-dose clot-busting drugs directly to the site of a pulmonary embolism via a catheter using ultrasound to enhance their effect.
Catheter-based approach improves prognosis in pulmonary embolism patients
According to the study, a substantial proportion (at least 20%-25%) of PE cases fall into a category of elevated clinical severity and threatening or beginning cardiopulmonary failure, a condition that may lead to death rates as high as 15% in the real world. Although clot-buster medications given through the vein can effectively dissolve the clots that cause PE, they can also cause dangerous bleeding in the brain and are typically used only in the most severe cases—when a patient is already in shock and at risk of imminent death.
The HI-PEITHO trial is the first to directly compare clinical outcomes from a catheter-based strategy versus systemic anticoagulation alone in patients with elevated-risk forms of PE. The trial enrolled 544 patients at 59 sites in the USA and eight European countries. Participants had intermediate-risk PE with two additional indicators of clinical severity, including: tachycardia, low blood pressure (although not at a level indicating shock) and/or low oxygen saturation. Half of the patients were randomly assigned to ultrasound-facilitated catheter-directed thrombolysis, and the other half received standard systemic anticoagulation.
Physicians used standardised protocols for administering the study medications in both treatment arms, and they also followed standard protocols for initiating rescue treatment if patients suffered cardiorespiratory decompensation or a repeat PE. The 61% between-group difference was significant in favour of the catheter-based treatment arm and was driven by a reduction in the rate of cardiorespiratory decompensation or collapse in this group.
Current status of ECMO for massive pulmonary embolism
The study’s lead author emphasized that the results should not be extrapolated to apply to all catheter-based PE treatment approaches, which include a wide range of devices and methods. 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,
Konstantinides stated. In addition, the study offers a precedent for how to evaluate the effects of catheter treatments for PE. There are many types of catheter treatment, and as more trials are conducted, we hope that we will have increasingly strong evidence to inform guidelines on what strategies to recommend.
Readers should note that the study results should not be extrapolated to apply to all catheter-based PE treatment approaches, which include a wide range of devices and methods. The trial’s lead author, Stavros V Konstantinides, highlighted the importance of selecting appropriate patients for the procedure. 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,
he said.
Practical next steps for patients and healthcare providers include consulting qualified professionals to determine the best course of treatment based on individual risk factors and clinical guidelines. The study’s findings underscore the potential of targeted catheter-based therapies but emphasize the need for further research to validate these results across broader populations. As more trials are conducted, the evidence may inform future guidelines on optimal strategies for managing intermediate-risk pulmonary embolism.
