Ultrasound-Facilitated Catheter-Directed Therapy Improves Outcomes in Acute Pulmonary Embolism: Trial Suggests
USA: A multinational clinical trial published in the New England Journal of Medicine has reported that ultrasound-facilitated, catheter-directed fibrinolysis combined with anticoagulation may improve short-term outcomes in patients with acute intermediate-risk pulmonary embolism when compared with anticoagulation therapy alone.
The study, led by Kenneth Rosenfield and colleagues from Massachusetts General Hospital, evaluated whether a more aggressive catheter-based approach could reduce early clinical deterioration in patients at heightened risk of complications from pulmonary embolism.
Pulmonary embolism occurs when a blood clot blocks one or more arteries in the lungs. Although anticoagulation remains the standard treatment, uncertainty persists regarding whether it is sufficient for patients classified as having intermediate-risk disease, especially those showing signs of right heart strain and cardiorespiratory distress.
To investigate this question, researchers conducted a multinational adaptive-design trial with blinded outcome assessment. Eligible participants had intermediate-risk pulmonary embolism characterized by right ventricular enlargement and elevated troponin levels. In addition, patients were required to have at least two indicators of cardiorespiratory stress, including low systolic blood pressure, rapid heart rate, or elevated respiratory rate.
A total of 544 patients were included in the intention-to-treat analysis. Among them, 273 patients underwent ultrasound-facilitated, catheter-directed fibrinolysis with alteplase in addition to anticoagulation, while 271 patients received anticoagulation therapy alone according to standardized treatment protocols. The average patient age was 58.2 years, and women accounted for 42.6% of the study population.
The primary endpoint was a composite of pulmonary embolism-related death, cardiorespiratory decompensation or collapse, or symptomatic recurrence of pulmonary embolism within seven days of treatment initiation.
The study led to the following findings:
- Primary outcome events occurred in 4.0% of patients receiving ultrasound-facilitated, catheter-directed fibrinolysis plus anticoagulation compared with 10.3% of patients treated with anticoagulation alone.
- The intervention group demonstrated a 61% relative reduction in the risk of the composite primary outcome.
- The observed benefit was mainly driven by a lower incidence of cardiorespiratory decompensation or collapse among patients in the intervention group.
- Major bleeding within 7 days was reported in 4.1% of patients receiving catheter-directed therapy versus 2.2% in the anticoagulation-alone group.
- The difference in early major bleeding rates between the two groups was not statistically significant.
- At 30 days, major bleeding rates remained similar between the intervention and control groups.
- No cases of intracranial hemorrhage were observed during the study period.
The researchers also noted that no major differences were observed in the rates of other serious adverse events up to 30 days after randomization.
The findings suggest that ultrasound-facilitated, catheter-directed fibrinolysis combined with anticoagulation may offer an effective treatment strategy for selected patients with acute intermediate-risk pulmonary embolism by reducing early clinical deterioration without substantially increasing serious bleeding complications.
Reference:
DOI: 10.1056/NEJMoa2516567
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