Commentary

Determining optimum medical management of patients who have had acute MI has been advancing through a series of randomised controlled trials. Such agents and interventions as aspirin, thrombolytics, β-blockers, ACE inhibitors, and percutaneous transluminal coronary angioplasty have been systematically studied in this setting. Although the current study by the CAPRICORN investigators shows that a clinical benefit existed in patients who were treated with carvedilol after acute MI with left ventricular dysfunction, some of the study's statistical aspects, such as changing the primary end point during the course of the trial, may affect its approval for this indication.¹ In fact, enrollment for this trial was impeded in several countries because of the considered-to-be established benefits of β-blocker treatment after acute MI, especially in high risk patients. For example, most of the mortality benefit of β-blockade in the β-Blocker Heart Attack Trial (BHAT)² was seen in the “high risk” groups, such as patients with heart failure. Similarly, the Survival and Ventricular Enlargement (SAVE) trial data³ showed that the benefits of β-blockade were seen in addition to ACE inhibitor treatment.

How should this trial alter current management? The intuitive answer is that it should not alter but should strengthen current treatment. A sound therapeutic approach would ensure that all patients with acute MI receive aspirin, some form of immediate revascularisation (pharmacological or non-pharmacological), and β-blockers. At the time of discharge, all eligible patients should receive ACE inhibitors and a statin in addition to aspirin and β-blockers.

This study highlights the fact that future trials of acute MI cannot ethically withhold β-blocker treatment. Furthermore, the beneficial effects may be a “class effect” and until such trials as the Carvedilol and Metoprolol European Trial⁴ are completed, insufficient data exist to choose a particular β-blocker in the clinical setting.