Evidence-based Medicine

Beta blockers may be the most effective first-line treatment for stable angina

Stable angina (suffocating chest pain) affects more than 7 million people in the United States. Long-term drug therapy to prevent anginal symptoms has consisted of beta blockers, calcium antagonists (also called calcium channel blockers), long-acting nitrates, or their combinations. Current treatment of stable angina in the United States frequently does not include beta blockers, even though several treatment guidelines recommend beta blockers as the first-line agent for these patients. A recent study supported by the Agency for Health Care Policy and Research (Contract No. 290-97-0013) supports these recommendations and adds evidence that beta blockers are tolerated as well as or better than calcium antagonists and provide equivalent relief.

A team of researchers from the University of California, San Francisco-Stanford Evidence-based Practice Center performed a meta-analysis of 90 studies conducted between 1966 and 1997 that directly compared beta blockers, calcium antagonists, and long-acting nitrates in patients who had stable angina. The analysis revealed that beta blockers were as well tolerated as calcium antagonists. The calcium antagonists were associated with a greater number of adverse events, but they did not provide greater angina relief (measured by number of angina episodes, nitroglycerine use, and exercise time) than beta blockers. For example, there were 0.31 fewer episodes of angina per week with beta blockers, and they were discontinued 28 percent less often because of adverse events than calcium antagonists (odds ratio, OR 0.72). There was no significant difference in rates of cardiac death and heart attack for both treatments, but more long-term comparative trials are required to determine whether the different therapies are responsible for a significant mortality difference in these patients. Too few studies compared long-acting nitrates with calcium antagonists or beta blockers to determine differences in survival, symptoms, or adverse events.

See "Meta-analysis of trials comparing beta-blockers, calcium antagonists, and nitrates for stable angina," by Paul A. Heidenreich, M.D., M.S., Kathryn M. McDonald, M.M., Trevor Hastie, Ph.D., and others, in the May 26, 1999, Journal of the American Medical Association 281(20), pp. 1927-1936.

Editor's note: This paper is based on an evidence report prepared for AHCPR by the UCSF-Stanford Evidence-based Practice Center. A summary (AHCPR Publication No. 99-E021) is available from the AHCPR Clearinghouse. Copies of the full report, An Evaluation of Beta-Blockers, Calcium Antagonists, Nitrates, and Alternative Therapies for Stable Angina (AHCPR Publication No. 99-E022), will be available from AHCPR in late 1999.

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