Thrombolysis for acute intermediate-risk pulmonary embolism: A meta-analysis

Background: The use of thrombolytic therapy in patients with intermediate-risk pulmonary embolism is controversial. To compare with anticoagulation alone, no analysis before has determined whether thrombolytic therapy is associated with improved survival or lower incidence of adverse clinical outcomes for intermediate-risk pulmonary embolism.

Objective: This meta-analysis was performed to assess mortality benefits, bleeding and recurrent pulmonary embolism risks associated with thrombolytic therapy compared with anticoagulation in patients with intermediate-risk pulmonary embolism.

Methods: The Web of Science, PubMed, Embase, EBSCO, and the Cochrane Library databases were searched for randomized clinical trials comparing thrombolytic therapy with anticoagulation in intermediate-risk pulmonary embolism patients (in which the mortality data were reported) from inception to August 5, 2014. Primary outcomes were all-cause mortality and major bleeding. Secondary outcomes were recurrent pulmonary embolism and minor bleeding. The pooled relative risk (RR), Mantel-Haenszel corresponding method and fixed-effect model were used to estimate the efficacy and safety of thrombolytic therapy with 95% confidence intervals.

Results: Eight clinical randomized controlled trials involving 1755 patients with intermediate-risk pulmonary embolism were included. Patients treated with thrombolytics presented lower mortality than patients in the anticoagulation cohort (RR, 0.52; 95% CI, 0.28-0.97; 1.39% [12/866] vs. 2.92% [26/889]). Compared with anticoagulation, thrombolytic therapy was associated with a higher risk of major (RR, 3.35; 95% CI, 2.03-5.54; 7.80% [64/820] vs. 2.28% [19/834]) and minor (RR, 3.66; 95% CI, 2.77-4.84; 32.78% [197/601] vs. 8.94% [53/593]) bleeding. Furthermore, thrombolytic therapy was associated with a lower incidence of recurrent pulmonary embolism (RR, 0.33; 95% CI, 0.15-0.73; 0.73% [6/826] vs. 2.72% [23/846]).

Conclusion: Compared with anticoagulation, thrombolytic therapy in patients with intermediate-risk pulmonary embolism is associated with lower all-cause mortality and recurrent pulmonary embolism risk despite increased major and minor bleeding risks.