Prevention of sudden cardiac death with beta blockers.

Beta blockers have been shown to reduce the risk of sudden cardiac death in more than 50 randomized trials involving more than 55,000 patients. Relative reductions (vs. placebo) in cardiac death in some of these trials ranged from 30 to 50%. These reductions are substantially greater than trials of other drug classes including angiotensin-converting enzyme inhibitors. However, not all beta blockers confer equal benefit to patients at risk of sudden cardiac death. Results from various trials suggest that lipophilic beta blockers--such as timolol, metoprolol, propranolol, bisoprolol, and carvedilol--may be more beneficial than hydrophilic beta blockers. Results of animal studies have indicated that sudden cardiac death is mediated, at least in part, by the central nervous system, which may account for why lipophilic agents have more pronounced clinical effects. Based on the results of numerous clinical and mechanistic studies, it is suggested that beta blockers should be given to all patients at risk for sudden cardiac death, including those patients with previous myocardial infarction, hypertension, or congestive heart failure.