Streptokinase vs alteplase in massive pulmonary embolism: A randomized trial assessing right heart haemodynamics and pulmonary vascular obstruction

The aim of the study was to test the efficacy of recombinant tissue plasminogen activator and streptokinase in massive pulmonary embolism, the primary endpoints being haemodynamic improvement and thrombus lysis, and the secondary endpoints efficacy and safety.

Fifty patients with massive pulmonary embolism were randomly allocated either to a 100 mg 2 h infusion of recombinant tissue plasminogen activator followed by a 20 IU.kg⁻¹.h⁻¹ infusion of heparin, or to a 100 000 IU.h⁻¹ 12 h infusion of streptokinase after a initial bolus of 250 000 IU over 15 min, followed by heparin infusion of 10 IU.kg⁻¹.h⁻¹. Total pulmonary resistance and right ventricular ejection fraction were monitored over a 12 h period. Pulmonary vascular obstruction was assessed at 24 to 48 h and 10 days after thrombolytic therapy.

Thrombolysis occurred more rapidly with recombinant tissue plasminogen activator than with streptokinase, but without any significant difference in terms of right heart haemodynamics at 12 h or in improvement of pulmonary vascular obstruction at 24–48 h or at 10 days. There was no significant difference in bleeding complication rates and no patients suffered intracranial haemorrhage.

These results proved that, when the full dose of streptokinase has been given over 12 h, its efficacy is as good as that of 2 h of recombinant tissue plasminogen. A further trial aimed at comparing recombinant tissue plasminogen activator and streptokinase infused over a 2 h period is needed to determine whether a similar efficacy can be obtained.