A meta-analysis of outcomes of catheter-directed thrombolysis for high- and intermediate-risk pulmonary embolism

Objective: During the past few years, there has been a surge in the use of catheter-directed thrombolysis (CDT) for acute pulmonary embolism (PE), in the form of either standard CDT or ultrasound-assisted CDT (usCDT). This is a systematic review and meta-analysis of all published series on contemporary CDT for acute PE seeking to determine their clinical efficacy, stratifying by PE severity and CDT modality. Methods: A comprehensive MEDLINE and Embase search was performed to identify studies that reported outcomes of CDT for acute PE published from 2009 to July 2017. Outcomes included clinical success (in-hospital survival with stabilization of hemodynamics, without decompensation or any major complication), in-hospital mortality, major bleeding, right ventricular/left ventricular ratio, and Miller score changes after CDT. Meta-analyses assumed random effects. Results: Twenty studies with 1168 patients were included in the meta-analysis. Available for subgroup analysis were 210 patients with high-risk PE and 945 patients with intermediate-risk PE; 181 patients received CDT using a standard multiside hole catheter, and 850 received usCDT. The pooled average right ventricular/left ventricular improvement and Miller score drop after CDT were 0.30 (95% confidence interval [CI], 0.22-0.39) and 8.8 (95% CI, 7.1-10.5). For high-risk PE, the pooled estimate for clinical success was 81.3% (95% CI, 72.5%-89.1%), the 30-day mortality estimate was 8.0% (95% CI, 3.2%-14.0%), and major bleeding was 6.7% (95% CI, 1.0%-15.3%). For intermediate-risk PE, the pooled estimate for clinical success was 97.5% (95% CI, 95.3%-99.1%), the 30-day mortality was 0% (95% CI, 0%-0.5%), and major bleeding was 1.4% (95% CI, 0.3%-2.8%). In high-risk PE, clinical success for CDT and usCDT was 70.8% (95% CI, 53.4%-85.8%) and 83.1% (95% CI, 68.5%-94.5%), respectively. In intermediate-risk PE, clinical success for CDT and usCDT was 95.0% (95% CI, 88.5%-99.2%) and 97.5% (95% CI, 95.0%-99.4%), respectively. Conclusions: Catheter thrombolysis has high clinical success rates in both high- and intermediate-risk PE, but higher mortality and bleeding rates should be anticipated in high-risk PE. Ultrasound-assisted thrombolysis may be more effective than standard CDT in the higher risk population.