Ultrasound assisted thrombolysis in intermediate-risk patients with pulmonary thromboembolism

Background: Systemic thrombolytic therapy is not recommended for patients with intermediate-risk pulmonary embolism (PE) because of major bleeding and intracranial bleeding overcomes the benefit of reperfusion. Patients and methods: A total of 342 PE patients with intermediate-risk PE from the multicenter Serbian PE registry were involved in the study. Of this group, 227 were not treated with reperfusion therapy (anticoagulation only), 91 were treated with conventional thrombolysis protocols at the discretion of their physicians and 24 patients were treated with ultrasound assisted catheter thrombolysis (USACT) with the EKOS (R) system. All patients treated with USACT had at least one factor which is associated with an increased risk of bleeding. Other patient characteristics were similar across the treatment groups. All-cause and PE-related mortality at 30 days and rate of major bleeding at 7 days were the main efficacy and safety outcomes of the study. Results: The 30-day all-cause mortality were 11.5% versus 17.6% versus 0.0% for no reperfusion, conventional thrombolysis protocols and USACT groups (p = 0.056), respectively. The difference between the rate of 30-day PE-related mortality was in a favour of EKOS and no reperfusion compare to conventional protocols (0.0% vs. 3.5% vs. 11.0%, p = 0.013, respectively). Major bleeding at 7 days, was presented in 1.8% versus 7.7% versus 8.0% (p = 0.021) in no reperfusion, conventional thrombolysis and USACT groups with no intracranial bleeding. Conclusion: In the patients with intermediate-risk PE and at least one bleeding factor, USACT could be an alternative treatment to anticoagulant therapy only and conventional thrombolytic protocols.