Intravenous and intrapulmonary recombinant tissue-type plasminogen activator in the treatment of acute massive pulmonary embolism.

Eight centers participated in a study in which intrapulmonary and intravenous administration of recombinant tissue-type plasminogen activator (rt-PA) were compared in 34 patients with acute massive pulmonary embolism. All patients received intravenous heparin in a bolus of 5,000 IU followed by 1,000 IU/hr. After 50 mg rt-PA given over 2 hr the severity of embolism, determined from pulmonary angiograms, declined by 12% in the intrapulmonary drug group (p less than .005) and 15% in the intravenous drug group (p less than .005); mean pulmonary arterial pressure fell from 31 +/- 7 to 22 +/- 6 mm Hg (p less than .005) and from 31 +/- 12 to 21 +/- 9 mm Hg (p less than .005) in the respective groups. After a further 50 mg given over 5 hr (22 patients), the angiographically determined severity of embolism had decreased by 38% from baseline in the intrapulmonary drug group and by 38% in the intravenous drug group. The mean pulmonary arterial pressure further declined to 18 +/- 7 and 12 +/- 5 mm Hg in the respective groups. Fibrinogen levels dropped to 48% of baseline after 50 mg and to 36% of baseline after 100 mg rt-PA. Some degree of bleeding at puncture and/or operation sites was noted in 16 patients, including four who required a transfusion of two or more units of blood and had been operated on an average of 7.5 days (range 2 to 13) before thrombolytic treatment was started.(ABSTRACT TRUNCATED AT 250 WORDS)