Hemodynamic Effects of Ultrasound-Assisted, Catheter-Directed, Very Low-Dose, Short-Time Duration Thrombolysis in Acute Intermediate-High Risk Pulmonary Embolism (from the EKOS-PL Study).

Ultrasound-assisted, catheter-directed, low-dose thrombolysis (USAT) at an average alteplase dose of 20 mg infused over 12 to 24 hours reversed right ventricular disfunction and improved pulmonary hemodynamics in intermediate-high-risk pulmonary embolism patients. As bleeding risk increases with the thrombolytic dose, establishing a minimal effective USAT dosing regimen is of clinical importance. We aimed to investigate hemodynamic effects and safety of a very low-alteplase-dose USAT of 10 mg administered within 5 hours. We included 12 consecutive intermediate-high-risk pulmonary embolism patients with symptoms duration of <14 days and proximal thrombi location in pulmonary arteries. Pulmonary Embolism Response Team decision-based fixed, bilateral ultrasound-assisted alteplase infusions at the rate of 1mg/hour/catheter for 5 hours through EKOS system catheters were made. The primary efficacy measure was the change in invasive systolic and mean pulmonary arteries pressure, and in cardiac index from USAT start to termination. Safety measures were 180-day all-cause death or cardiopulmonary decompensation and bleeding complications. The systolic pulmonary arteries pressure and mean pulmonary arteries pressure decreased from 53 (45.5 to 59) to 37.5 (27.5 to 40.5) mm Hg (p = 0.02) and from 29.5 (27.5 to 32) to 21.5 (15.5 to 25) mm Hg (p = 0.02), respectively. The cardiac index increased from 1.6 (1.5 to 1.8) to 2.2 (1.9 to 2.4) l/min/m2, (p = 0.02). No deaths, decompensations, or need for therapy intensification occurred. There was 1 episode of access-site bleeding, which subsided after conservative management. No intracranial hemorrhages appeared. In conclusion, reduced dose and duration USAT improved pulmonary hemodynamics and cardiac function leading to cardiopulmonary stabilization in intermediate-high risk pulmonary embolism patients at a low periprocedural risk.