Assessment of Anticoagulation in Patients Receiving Ultrasound-Assisted Catheter-Directed Thrombolysis for Treatment of Pulmonary Embolism

Background: Ultrasound-assisted, catheter-directed thrombolysis (USAT) has emerged as a popular treatment option for submassive pulmonary embolism (PE). The optimal strategy for transitioning patients from full-intensity to reduced-intensity heparin during the procedure has yet to be established. Objective: The goal of this study was to evaluate the anticoagulation management in patients receiving catheter-directed thrombolysis with USAT. Methods: A retrospective chart review was conducted of patients who received USAT for the treatment of PE. Institutional review board approval was obtained. The primary objective was to determine the proportion of patients with a therapeutic activated partial thromboplastin time (aPTT) prior to and during tissue-plasminogen activator (tPA) infusion. Secondary outcomes included heparin requirements, the rate of bleeding complications, and the appropriateness of long-term venous thromboembolism management. Results: A therapeutic aPTT value was achieved in 32 patients (54.2%) prior to USAT and 35 patients (59.3%) during tPA infusion. Heparin requirements were reduced from 15.1 ± 4.1 to 12.8 ± 4.2 U/kg/h for patients who achieved a therapeutic aPTT both prior to and during tPA infusion. Bleeding occurred in 34.4% of patients and tended to be minimal (20.3%) or minor (10.9%). The majority of patients were discharged on a direct oral anticoagulant (63%), followed by warfarin (32%) and enoxaparin (5%). Conclusion and Relevance: To our knowledge, this is the first study that has assessed heparin management in the setting of USAT. The results of these data may aid in empirically dose adjusting unfractionated heparin to ensure safe and effective anticoagulation for patients receiving USAT.