Doctors Are Underprescribing Key Blood Pressure Drug In Heart Attack Patients Most Likely To Benefit, Study Says

A national study led by a UC San Francisco researcher indicates that doctors are increasingly heeding the recommendation that they prescribe ACE inhibitors to patients who have had heart attacks, but they still are grossly under-prescribing the life-saving drug to the patients most in need.

In the study, published in the August issue of The Journal of the American College of Cardiology, the researchers evaluated data on 200,000 myocardial infarction patients seen between 1994 and 1996. The data, which included the patients' specific diagnoses and their prescriptions at discharge from the hospital, was drawn from the National Registry of Myocardial Infarction 2, which collects information on physician practices at more than 1,400 U.S. hospitals.

The study was led by Hal V. Barron, MD, FACC, an assistant professor of medicine and cardiology at UCSF and associate director of research at Genentech, Inc. In their findings, the researchers report that prescription of ACE inhibitor therapy, used to reduce blood pressure, increased to 38.7 percent in 1996, compared to 25 percent in 1994, at hospital discharge, and that prescriptions most often were given to patients with the greatest expected benefit, including those with congestive heart failure.

However, the researchers also report that less than half of the patients most in need of the drug received it. "If the American College of Cardiology/American Heart Association guidelines had been followed in the treatment of the 75,173 patients in the study with congestive heart failure or left ventricular ejection fraction, 1,800 lives could have been saved in the first year alone," said Andrew D. Michaels, MD, a clinical cardiology fellow at UCSF and an author of the study.

"The encouraging news is that doctors are listening to the results of the numerous large scale clinical trials that have indicated the importance of using ACE inhibitors, and they're prescribing them in the patients most likely to benefit from this therapy," he said. "But we need to do more." The researchers detected mild regional variations in physician practices regarding ACE inhibitors but they said the distinctions were too small to be clinically significant.

ACE (angiotensin converting enzyme) inhibitors may reduce the risk of first-time heart attack and stroke. But they dramatically reduce the risk of heart attack and congestive heart failure in patients who have already had a heart attack, and reduce the risk of dying in patients with congestive heart failure.

Clinical trials have shown that prescribing ACE inhibitor therapy soon after a heart attack typically saves five lives per 1,000 patients treated in the first month. Other trials have shown that starting long-term ACE inhibitor therapy in the weeks after a heart attack in these patients saves about 24 lives per year.

Current American College of Cardiology and American Heart Association recommendations suggest that ACE inhibitor therapy begin within 24 hours of suspected acute myocardial infarction and be continued for four to six weeks in those patients without contraindications.

The research study, as well as the National Registry of Myocardial Infarction 2, an observational study, were supported by Genentech, Inc. Researchers from University of Washington also participated in the study.