Importance: Thrombolytic therapy may be beneficial in the treatment of some patients with pulmonary embolism. To date, no analysis has had adequate statistical power to determine whether thrombolytic therapy is associated with improved survival, compared with conventional anticoagulation.
Objective: To determine mortality benefits and bleeding risks associated with thrombolytic therapy compared with anticoagulation in acute pulmonary embolism, including the subset of hemodynamically stable patients with right ventricular dysfunction (intermediate-risk pulmonary embolism).
Data sources: PubMed, the Cochrane Library, EMBASE, EBSCO, Web of Science, and CINAHL databases from inception through April 10, 2014.
Study selection: Eligible studies were randomized clinical trials comparing thrombolytic therapy vs anticoagulant therapy in pulmonary embolism patients. Sixteen trials comprising 2115 individuals were identified. Eight trials comprising 1775 patients specified inclusion of patients with intermediate-risk pulmonary embolism.
Data extraction and synthesis: Two reviewers independently extracted trial-level data including number of patients, patient characteristics, duration of follow-up, and outcomes.
Main outcomes and measures: The primary outcomes were all-cause mortality and major bleeding. Secondary outcomes were risk of recurrent embolism and intracranial hemorrhage (ICH). Peto odds ratio (OR) estimates and associated 95% CIs were calculated using a fixed-effects model.
Results: Use of thrombolytics was associated with lower all-cause mortality (OR, 0.53; 95% CI, 0.32-0.88; 2.17% [23/1061] vs 3.89% [41/1054] with anticoagulants; number needed to treat [NNT] = 59) and greater risks of major bleeding (OR, 2.73; 95% CI, 1.91-3.91; 9.24% [98/1061] vs 3.42% [36/1054]; number needed to harm [NNH] = 18) and ICH (OR, 4.63; 95% CI, 1.78-12.04; 1.46% [15/1024] vs 0.19% [2/1019]; NNH = 78). Major bleeding was not significantly increased in patients 65 years and younger (OR, 1.25; 95% CI, 0.50-3.14). Thrombolysis was associated with a lower risk of recurrent pulmonary embolism (OR, 0.40; 95% CI, 0.22-0.74; 1.17% [12/1024] vs 3.04% [31/1019]; NNT = 54). In intermediate-risk pulmonary embolism trials, thrombolysis was associated with lower mortality (OR, 0.48; 95% CI, 0.25-0.92) and more major bleeding events (OR, 3.19; 95% CI, 2.07-4.92).
Conclusions and relevance: Among patients with pulmonary embolism, including those who were hemodynamically stable with right ventricular dysfunction, thrombolytic therapy was associated with lower rates of all-cause mortality and increased risks of major bleeding and ICH. However, findings may not apply to patients with pulmonary embolism who are hemodynamically stable without right ventricular dysfunction.