Intracranial hemorrhage rates and effect of immediate beta-blocker use in patients with acute myocardial infarction treated with tissue plasminogen activator

In acute myocardial infarction (AMI), immediate β-blocker therapy reduces the incidence of reinfarction and recurrent chest pain in patients receiving tissue plasminogen activator (t-PA). Data from the Thrombolysis in Myocardial Infarction (TIMI)-2 trial also raises the possibility that such therapy may reduce the rate of intracranial hemorrhage (ICH). We reviewed data obtained from 60,329 patients treated with t-PA who were enrolled in the National Registry of Myocardial Infarction 2. Of the 60,329 in the study cohort, 23,749 patients (39.4%) were treated with immediate β-blocker therapy and 542 patients (0.9%) developed an ICH. In a multivariate model that included all covariates known to be associated with the development of ICH, immediate β-blocker therapy was associated with a 31% reduction in the ICH rate (odds ratio 0.69, 95% confidence intervals 0.57 to 0.84). Thus, in the present study, the use of immediate β-blocker therapy in patients with AMI treated with t-PA was associated with a significant reduction in ICH. This finding supports the observations made in the TIMI 2 trial and serves to reinforce the recommendations made by the American College of Cardiology/American Heart Association task force that immediate β-blocker therapy should be administered to all patients with AMI who do not have contraindications to this therapy.