Randomized Controlled Trial of Ultrasound-Assisted Catheter-Directed Thrombolysis for Acute Intermediate-Risk Pulmonary Embolism
Background—In patients with acute pulmonary embolism (PE), systemic thrombolysis improves right ventricular (RV) dilatation, is associated with major bleeding, and is withheld in many patients at risk. This multicenter randomized controlled trial investigated whether ultrasound-assisted catheter-directed thrombolysis (USAT) is superior to anticoagulation alone in the reversal of RV dilatation in intermediate-risk patients.
Methods and Results—Fifty-nine patients (63±14 years) with acute main or lower lobe PE and echocardiographic right-to-left ventricular dimension (RV/LV) ratio ≥1.0 were randomized to receive unfractionated heparin (UFH) and an USAT regimen of 10-20 mg rt-PA over 15 hours (N = 30, USAT group), or UFH alone (N = 29, heparin group). Primary outcome was the difference in the RV/LV ratio from baseline to 24 hours. Safety outcomes included death, major and minor bleeding, and recurrent venous thromboembolism (VTE) at 90 days. In the USAT group, the mean RV/LV ratio was reduced from 1.28±0.19 at baseline to 0.99±0.17 at 24 hours (p<0.001); in the heparin group, mean RV/LV ratio was 1.20±0.14 and 1.17±0.20, respectively (p=0.31). The mean decrease in RV/LV ratio from baseline to 24 hours was 0.30±0.20 versus 0.03±0.16 (p<0.001), respectively. At 90 days, there was one death (in the heparin group), no major bleeding, 4 minor bleedings (3 in the USAT group and 1 in the heparin group; p=0.61), and no recurrent VTE.
Conclusions—In PE patients at intermediate risk, a standardized USAT regimen was superior to anticoagulation with heparin alone in reversing RV dilatation at 24 hours, without an increase in bleeding complications.
Clinical Trial Registration Information—http://clinicaltrials.gov. Identifier: NCT01166997.
- Received August 9, 2013.
- Revision received October 20, 2013.
- Accepted October 22, 2013.