Patients who underwent ultrasound-facilitated, catheter-directed fibrinolysis for acute pulmonary embolism (PE) had significantly better outcomes than those who received standard systemic anticoagulants, according to a study presented today at the American College of Cardiology’s Annual Scientific Session (ACC.26; 28–30 March, New Orleans, USA). The targeted catheter-based approach reduced early PE-related death, circulatory collapse or PE recurrence by more than 60%.
HI-PEITHO is the first trial to directly compare clinical outcomes from a catheter-based strategy versus systemic anticoagulation alone in patients with elevated-risk forms of PE. The study was published online in the New England Journal of Medicine at the time of presentation at ACC.26.
“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 (University Medical Center of the Johannes Gutenberg University, Mainz, Germany), 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.”
The trial enrolled 544 patients at 59 sites in the USA 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, 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.
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 randomisation. 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. 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.
Researchers said that the ultrasound-facilitated catheter-directed thrombolysis approach used in the study is feasible to perform for physicians experienced in cardiovascular interventions and in hospitals that are equipped with a catheterisation lab and a team qualified to support the procedure around the clock.
“The results regarding effectiveness are very convincing,” Konstantinides said. “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.”
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 healthcare utilisation. They said the results might differ in ethnologically more diverse populations, and that the study was not powered to exclude potential differences in bleeding risk between groups. They also said 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 recently published American Cardiology (ACC)/American Heart Association (AHA) guideline for the evaluation and management of acute PE in adults establishes a new clinical classification system to assess PE severity and guide treatment strategies.
The HI-PEITHO trial was an investigator-initiated study funded by Boston Scientific and conducted in partnership with the University Medical Center Mainz in Germany and the PERT Consortium in the USA.
