Fibrinolytic and Anticoagulation Therapy in Patients Undergoing Ultrasound-Assisted Catheter-Directed Thrombolysis for Pulmonary Embolism

Background: Ultrasound-assisted, catheter-directed thrombolysis (UA-CDT) relieves right ventricular stress without a significant increase in the risk of bleeding compared to systemic thrombolysis. Although concomitant anticoagulation is provided to prevent thrombus expansion, the optimal anticoagulation regimen in patients receiving UA-CDT remains unknown. Objective: We sought to describe anticoagulation practices for patients receiving UA-CDT. Methods: Patients receiving UA-CDT for acute pulmonary embolism (PE) between Jan 1, 2013 to Sept 30, 2014 at a single center were analyzed. We collected patient characteristics, fibrinolytic and anticoagulant usage as well as clinical outcomes. Results: Fourteen patients were included in the final analysis. The mean alteplase dose was 16.8 ± 5.6 mg and 24.3 ± 3.4 mg in unilateral and bilateral PE, respectively. Mean unfractionated heparin (UFH) rates were 7.4 (±2.17) IU/kg/hr and 12.4 (±3.1) IU/kg/hr during and after fibrinolytic therapy, respectively. The median aPTT was 42.4 sec [IQR 34.5-51.8] and 77.9 sec [IQR 66.5-96.8] during and after fibrinolytic therapy, respectively. There were no recurrent VTE within 30 days of hospital discharge. One patient had a major bleeding event (intracranial hemorrhage). Conclusion: In patients with acute PE, our institution utilized low levels of anticoagulation during fibrinolytic administration and therapeutic doses after completion of fibrinolytic infusion. Standardized protocols for anticoagulation during UA-CDT are warranted.