The role of thrombolytic therapy in pulmonary embolism

Pulmonary embolism (PE) has an incidence rate of 60 to100 cases per 100 000 patients per year, with a 30-day case fatality rate of 10% to 30%.1-3 It accounts for at least 200 000 hospital discharges and 30 000 deaths each year.4 The standard of care for PE has been anticoagulation; the addition of thrombolysis may be beneficial but its effects remain controversial. In earlier studies, thrombolytic treatment demonstrated superior efficacy in clot resolution and improvement in hemodynamics compared with anticoagulation alone, leading to the approval of streptokinase, urokinase, and alteplase by the US Food and Drug Administration in the treatment of PE with hemodynamic instability (massive/unstable PE). However, the impact of thrombolysis on mortality has not been demonstrated definitively, given the relatively small number of patients enrolled in each randomized controlled trial (RCT). The increased risk of bleeding, on the other hand, has been shown repeatedly, so the net clinical benefit of thrombolysis in PE is debatable, particularly in patients who are hemodynamically stable (stable PE). A number of meta-analyses were recently published but reached different conclusions.5-8 The aim of this review is to provide evidence-based practice recommendations for the use of thrombolytic therapies in the treatment of PE with and without hemodynamic instability. In addition, we intend to determine the optimal regimen of thrombolytic therapy based on available data. We made our recommendations using the guidelines suggested by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) working group (http://www.gradeworkinggroup.org) (see supplemental Appendix 1 on the Blood Web site).