COMPARATIVE EFFICACY OF A 2-HOUR REGIMEN OF STREPTOKINASE VERSUS ALTEPLASE IN ACUTE MASSIVE PULMONARY-EMBOLISM - IMMEDIATE CLINICAL AND HEMODYNAMIC OUTCOME AND ONE-YEAR FOLLOW-UP

Objectives. This study sought to compare the efficacy of 2-h regimens of alteplase and streptokinase in acute massive pulmonary embolism. Th e primary end point was immediate hemodynamic improvement, and seconda ry end points included early clinical efficacy and safety, as well as 1-year clinical outcome. Background. Several thrombolytic regimens hav e been compared for the past 10 years in randomized studies, shelving that 2-h infusion regimens of alteplase or urokinase lead to faster he modynamic improvement than former 12- to 24-h administration protocols in acute massive pulmonary embolism. Many trials have focused on imme diate hemodynamic and angiographic outcomes, but none has addressed lo ng-term follow-up after thrombolysis. Methods. Sixty-six patients with acute massive pulmonary embolism (Miller score >17 and mean pulmonary artery pressure >20 mm Hg) were randomly assigned to receive either a 100-mg 2-h infusion of alteplase (n = 23) or 1.5 million IU of strept okinase over 2 h (n = 43). In both groups, heparin infusion was starte d at the end of thrombolytic infusion and adapted thereafter. Total pu lmonary resistance was monitored over a 12-h period. Pulmonary vascula r obstruction was assessed 36 to 48 h after thrombolytic therapy. One- year follow-up information included death, cause of death, recurrent p ulmonary embolism, chronic thromboembolic pulmonary hypertension, stro ke and bleeding. Results. Both groups had similar baseline angiographi c and hemodynamic characteristics of severity, with maintained cardiac output in 64 (97%) of 66 patients. The results (mean +/- SD) demonstr ated that despite a faster total pulmonary resistance improvement obse rved at 1 h in the alteplase group compared with the streptokinase gro up (33 +/- 16% vs. 19 +/- 16%, p = 0.006), a similar hemodynamic effic acy was obtained at 2 h when both thrombolytic regimens were completed (38 +/- 18% vs. 31 +/- 19%). There was no significant difference in e ither pulmonary vascular obstruction at 36 to 38 h or bleeding complic ation rates. One-year event-free survival was similar in both groups, as most events were related to concomitant diseases. Conclusions. Thes e results suggest that a 2-h regimen of streptokinase can be routinely used in patients with massive pulmonary embolism and maintained cardi ac output without obviously compromising efficacy or safety. (C)1998 b y the American College of Cardiology.