Thrombolytic therapy for the treatment of acute pulmonary embolism

To determine whether thrombolytic therapy reduces the rate of death or complications in patients with acute pulmonary embolism and whether a particular thrombolytic regimen is more effective than others.

The key words "fibrinolytic agents," "plasminogen activators," "streptokinase," "urokinase" and "pulmonary embolism" were used to search MEDLINE for relevant articles in English; the bibliographies of these articles were reviewed for additional publications.

Articles were included if they were of a randomized controlled design; 10 such articles were found.

Ten trials were appraised with the use of the following methodologic criteria: a clear description of the study population; use of objective criteria to diagnose pulmonary embolism and to assess outcomes; use of clinically relevant outcomes; and blinded outcome assessments.

In the nine trials that met the methodologic criteria thrombolytic therapy led to a more rapid resolution of the radiographic and hemodynamic abnormalities associated with acute pulmonary embolism than did anticoagulant therapy alone, although these benefits were short-lived. No difference was detected in the death rate or the resolution of symptoms between patients receiving thrombolytic therapy and those receiving anticoagulant therapy alone. In addition, bleeding complications were more frequent and serious in patients who received lytic therapy, although these events were related to the use of invasive procedures.

There is a lack of evidence that thrombolytic therapy improves clinically relevant outcomes of patients with acute pulmonary embolism. This may be a reflection of the small sample size of the clinical trials. Further research is required to define the role of thrombolytic therapy in the management of patients with acute pulmonary embolism.