Catheter-directed ultrasound-accelerated thrombolysis for the treatment of acute pulmonary embolism

Background: Systemic thrombolysis rapidly improves right ventricular (RV) dysfunction in patients with acute pulmonary embolism (PE) but is associated with major bleeding complications in up to 20%. The efficacy of low-dose, catheter-directed ultrasound-accelerated thrombolysis (USAT) on the reversal of RV dysfunction is unknown. Materials and methods: We performed a retrospective analysis of 24 PE patients (60 +/- 16 years) at intermediate (n=19) or high risk (n=5) from the East Jefferson General Hospital who were treated with USAT (mean rt-PA dose 33.5 +/- 15.5 mg over 19.7 hours) and received multiplanar contrast-enhanced chest computed tomography (CT) scans at baseline and after USAT at 38 +/- 14 hours. All CT measurements were performed by an independent core laboratory. Results: The right-to-left ventricular dimension ratio (RV/LV ratio) from reconstructed CT four-chamber views at baseline of 1.33 +/- 0.24 was significantly reduced to 1.00 +/- 0.13 at follow-up by repeated-measures analysis of variance (p<0.001). The CT-angiographic pulmonary clot burden as assessed by the modified Miller score was significantly reduced from 17.8 +/- 5.3 to 8.7 +/- 5.1 (p<0.001). All patients were discharged alive, and there were no systemic bleeding complications but four major access site bleeding complications requiring transfusion and one suspected recurrent massive PE event. Conclusions: In patients with intermediate and high risk PE, low-dose USAT rapidly reverses right ventricular dilatation and pulmonary clot burden. (C) 2011 Elsevier Ltd. All rights reserved.