"We found that even elderly patients or those with low blood pressure or kidney damage did better with ACE inhibitors, as long as they also had impaired heart function following a heart attack," says Stephen Gottlieb, M.D., a cardiologist who heads the Heart Failure Service at the University of Maryland Medical Center.
For the study, researchers analyzed data from the Health Care Financing Administration's Quality Improvement Project for Medicare beneficiaries, which included more than 200,000 heart attack patients. The study then focused on 127,000 patients for whom complete information was available.
The mean age of the patients was 74 years, and 54 percent were men. The researchers took into account 21 clinical and demographic factors that probably affected survival in this group of patients.
Dr. Gottlieb says ACE inhibitors increased patient survival by about 30 percent overall, but the impact of the drugs varied according to how well patients' hearts were able to pump blood, which doctors measure by the ejection fraction. The higher the ejection fraction, the better the heart's pumping ability. In this study, an ejection fraction of less than 45 percent marked the dividing line between patients who did better with ACE inhibitors and those who did worse.
ACE inhibitors open blood vessels, help heart muscle to pump more effectively, and prevent further deterioration. Of the 127,000 patients analyzed, two-thirds of those who should have been given ACE inhibitors did not receive the drugs. The analysis supports the use of ACE inhibitors in almost all patients with impaired heart function when they are discharged from the hospital following a heart attack.
"Doctors are often reluctant to prescribe these drugs in patients with certain conditions," says Dr. Gottlieb. "But, we found that older age, evidence of kidney disease and low blood pressure do not diminish the beneficial effect of the drugs in these patients, as long as they have impaired heart function."
Gottlieb adds a word of caution, "These data do suggest, though, that patients with good heart function may be harmed by ACE inhibitors, and they should not be routinely used in this group unless there are other indications."
Dr. Gottlieb's co-authors in the study were Robert J. McCarter, Jr. ScD and Robert A. Vogel, M.D.