45852 patients admitted to 1250 hospitals within 24 hours of the onset of suspected acute MI were randomly allocated to receive metoprolol (up to 15 mg intravenous followed by 200 mg oral daily) or matching placebo. 93% had ST-segment elevation or bundle branch block, and 7% had ST-segment depression. Treatment was to continue until discharge or up to a maximum of 4 weeks in hospital (mean 15 days in survivors), and 89% completed it. The two pre-specified co-primary outcomes were: (i) the composite of death, reinfarction or cardiac arrest; and (ii) death from any cause during the scheduled treatment period. Comparisons were between all metoprolol-allocated and all placebo-allocated patients (ie, “intention-to-treat”), and used the log-rank method.