Effect ofveryearly intervention withmetoprolol on myocardial infarct size

SUMMARY Allpatients with apresumptive diagnosis ofmyocardial infarction, whowere seen widtin six hours ofthe onsetofsymptomsandhadno reasonforexclusion, were considered for entryinto a trial tocomparetheeffects ofmetoprolol andplacebo on creatine kinase MB isoenzyme release. The trial wasrandomised anddouble blind. Themedian timefromonsetofsymptoms toreceiving trial drug was just under twohours. Twohundred andfourpatients (ofwhom120hadmyocardial infarction) received metoprolol and187(ofwhom105hadmyocardial infarction) received placebo. Infarct size wasestimated semiquantitatively