MORE than 30 years after the first clinical reports of thrombolytic therapy for the treatment of acute pulmonary embolism (PE)1,2its indications still remain uncertain. The most widely accepted indication for thrombolytic therapy for PE is in patients with hypotension secondary to massive PE.3However, the number of patients with PE who present with shock and who do not have 1 or more contraindications to thrombolytic treatment is very small. The first 2 thrombolytic agents that were approved by the Food and Drug Administration (FDA) for the treatment of acute PE were streptokinase (1977) and urokinase (1978). These 2 agents were compared with heparin in 2 randomized clinical trials.4,5 The successful results of recombinant tissue-type plasminogen activator (rt-PA) in the treatment of acute myocardial infarction led to its evaluation for the treatment of acute PE. The first report of rt-PA in the treatment of PE by Bounameaux
James E. Dalen (Mon,) studied this question.