Early Use of β -Adrenergic-Blocking Agents in Acute Myocardial Infarction

Abstract

Of recent interest is the acute use of β-adrenergic-blocking agents in patients who have suffered an acute myocardial infarction (AMI). Acute use of β-blockers refers to initiation of therapy within hours following the onset of symptoms suggestive of AMI. The proposed goal of therapy is to alter the infarction process to improve mortality. Because of the hyperadrenergic activity present in patients during an infarction, β-blockers are theoretically an attractive therapeutic intervention because of their sympatholytic properties. Acute use of β-blockers has been shown to limit infarct size, as determined by cardiac enzyme activity, and reduce the incidence of major ventricular arrhythmias. β-blockers may also prevent infarction in patients with symptoms suggestive of infarction. However, the acute use of β-adrenergic-blocking agents has not been shown to reduce short-term (≤30 d) mortality. In view of this fact, the acute use of β-adrenergic-blocking agents cannot be recommended.