Efficacy and safety of high dose versus low dose streptokinase for treatment of submassive pulmonary embolism

Abstract

Abstract Pulmonary embolism (PE) remains a major cause of morbidity and mortality in the general population, the established treatment for PE is anticoagulation. It has previously been demonstrated that thrombolytic therapy can be lifesaving in patients with massive PE (haemodynamic instability and right heart failure). However, the use of thrombolytic therapy in patients with submassive PE (haemodynamically stable) remains a controversial topic. Recent clinical studies, however, support evidence that thrombolysis may favorably affect the outcomes in a wider spectrum of high risk PE patients presenting with right ventricular dysfunction (RVD) as evidenced by decreased right ventricular end diastolic diameter (RVEDD), disappearance of paradoxical septal motion (PSM), and tricuspid regurge (TR) as well as decrease in the pulmonary artery pressure. The aim of this study was to evaluate the efficacy and safety of high dose streptokinase (SK) in 1 h versus low dose SK in 24 h in patients with submassive PE and RVD (high risk PE). The study included 60 patients (28 males and 32 females, mean age 45.5 ± 13.6 years) with submassive PE (positive spiral CT chest) and RVD (proved by echocardiography). Those without contraindications to SK were randomly assigned to receive either high dose (group I) or low dose (group II) of SK. Those with contraindication(s) to SK received anticoagulation (group III). Echocardiography was done before and 72 h after treatment. Right ventricular dysfunction (RVEDD, PSM, and TR) and mean pulmonary artery pressure (PAP) improved significantly 72 h after treatment in groups I and II, while a slight improvement in PAP was observed after treatment in group III. No significant difference was noticed between groups I and II regarding the effect of treatment on RVD or PAP. Statistically nonsignificant difference was found between groups I and II regarding the complications of SK, however a slightly higher risk of bleeding was observed in group I (high dose SK). No significant difference was found between the three groups regarding the mortality. These data suggest that SK can rapidly and safely reverse the pulmonary hypertension and RVD in contrast to anticoagulation. Both protocols of SK are equieffective in rapid reversal of RVD and pulmonary hypertension. Both protocols were safe as proved by absence of difference in mortality over anticoagulant group.