Reduction in Infarct Size, Arrhythmias and Chest Pain by Early Intravenous Beta Blockade in Suspected Acute Myocardial Infarction

YUSUF, SALIM M.R.C.P., D.PHIL.
SLEIGHT, PETER M.D., D.M., F.R.C.P.
ROSSI, PAULO M.D.
RAMSDALE, DAVID M.D., M.R.C.P.
PETO, RICHARD M.A., M.Sc.
FURZE, LYNETTE S.R.N.
STERRY, HEATHER B.Sc.
PEARSON, MARIAN PH.D.
MOTWANI, RAMESH M.SC.
PARISH, SARAH D.PHIL.
GRAY, RICHARD M.A., M.Sc.
BENNETT, DAVID M.D., M.R.C.P.
BRAY, COLIN F.R.C.P.

From the Department of Cardiovascular Medicine, John Radcliffe Hospital, Oxford; Regional Cardiac Centre, Wythenshawe Hospital, Manchester; ICRF Cancer Studies Unit, Nuffield Department of Clinical Medicine, Radcliffe Infirmary, Oxford; and Clin Path Laboratories, Harley Street, London, England.

Address for correspondence: S. Yusuf, Cardiac Department, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom.

Supported by the British Heart Foundation and I.C.I. Pharmaceuticals.

Circulation 67(6):p I32-I41, June 1983.

SUMMARY

Four hundred seventy-seven patients suspected of having had acute myocardial infarction within less than 12 hours were randomized to receive i.v. atenolol followed by oral treatment for 10 days or to a control group. In patients with ECG changes indicative of infarction at entry, i.v. atenolol significantly reduced enzyme release by one-third and enhanced R-wave preservation. In patients without such ECG changes, treatment significantly prevented the development of infarction in a proportion of patients. There was also a significant reduction in R-on-Tectopics, repetitive ventricular arrhythmias and supraventricular arrhythmias. Treated patients had significantly greater pain relief and required fewer opiate analgesics. Significantly fewer atenolol-treated patients died by 10 days (the treatment period), had nonfatal cardiac arrests, developed heart failure, or suffered reinfarction.