Clinical trial data on the cardioprotective effects of beta-blockade

Abstract

In most patients with heart failure the underlying cause is coronary artery disease (CAD). They have a poor prognosis and die slowly from deteriorating cardiac function or suddenly from ventricular fibrillation or atheromatous plaque rupture. Two key aims of treatment, therefore, are to slow the progression of underlying CAD and the resulting heart failure and to reduce the risk of sudden death.

The impact of drugs on CAD and sudden death can be assessed most effectively in patients who have recovered from a myocardial infarction (post-MI patients). Beta-blockers have been studied in at least 25 trials in post-MI patients and their capacity to reduce mortality and re-infarction has been well documented. About 50% of those who die in post-MI trials die suddenly and beta-blockers particularly propranolol, timolol and metoprolol have been shown to reduce the risk of sudden death significantly.

Further evidence that beta-blockers are cardioprotective in post-MI patients can be obtained from trials of other drugs by noting the mortality rates in those patients who were also on a beta-blocker. In three trials of antiarrhythmic drugs and two trials of ACE inhibitors, those on beta-blockers had a better prognosis. There is therefore good evidence that in a patient population known to have serious CAD, beta-blockers can effectively reduce the risk of major coronary events and are particularly effective in reducing the risk of sudden death.