Aug 3 2004
Almost a third of heart failure patients face an increased risk of death because they do not receive an angiotensin-converting enzyme (ACE) inhibitor, according to a report in today’s rapid access issue of Circulation: Journal of the American Heart Association.
Overwhelming evidence accumulated during almost 20 years of clinical experience has established the benefits of this drug, which blocks the harmful effects of angiotensin, a substance that causes blood vessels to narrow, said the study authors.
A review of data from the Centers from Medicare and Medicaid Services’ National Heart Care Project showed that 32 percent of elderly heart failure patients were discharged from hospitals without prescriptions for ACE inhibitors. Patients discharged without anti-angiotensin therapy had a 14 percent greater risk of dying within a year compared to patients treated with ACE inhibitors. The use of angiotensin receptor blockers (ARBs), an alternative to ACE-inhibitors in some patients with heart failure, did not explain the low rates of appropriate therapy.
“The under-use of life-saving medications in patients with systolic heart failure is a pervasive problem throughout the health care community,” said Frederick Masoudi, M.D., M.S.P.H., lead author of the study and assistant professor of medicine at Denver Health Center and the University of Colorado Health Sciences Center in Denver. “Our study provides good evidence… to validate current guideline recommendations that all patients with systolic dysfunction should be getting ACE inhibitors, unless they have a contraindication to the use of these drugs.”
The study adds to previous evidence that ACE inhibitors are widely underused in patients who are eligible to receive the drugs. In particular, prescription rates for ACE inhibitors have not increased for hospitalized Medicare patients who should be receiving the drugs to treat heart failure, Masoudi and co-authors report.
Multiple factors probably contribute to the under-use of ACE inhibitors in heart failure patients, they said. To gain more insight into the problem, investigators reviewed records on 17,456 Medicare patients who had heart failure and left ventricular systolic dysfunction. The review covered two time periods: April 1998 to March 1999 and July 2000 to June 2001. All the patients were at least 65 years old (average age of 78), and none had contraindications to treatment with an ACE inhibitor.
Overall, 68 percent of the patients had prescriptions for ACE inhibitors upon hospital discharge. The proportion of patients treated with ACE inhibitors was 69 percent during 1998–1999 and 67 percent between 2000 and 2001. When ACE inhibitors and ARBs were considered together, 78 percent of patients had prescriptions at hospital discharge.
Treatment with an ACE inhibitor was associated with a lower risk of death during the first year after hospital discharge. Patients receiving an ACE inhibitor at hospital discharge had a one-year mortality of 33 percent, compared to 42 percent for patients who did not have one. After adjusting for differences in patient and provider characteristics, the prescription of an ACE-inhibitor was associated with a 14 percent lower risk of death at one year.
The study shows the benefits of ACE inhibitors in patients underrepresented in clinical studies, or for whom the benefits of ACE-inhibitors have been controversial, Masoudi said. Those patients have included the very old, women, African-Americans, and patients with kidney disease and other high-risk conditions.
An analysis of factors related to ACE inhibitor therapy showed that patients who had more severe kidney disease (as defined by higher levels of the protein creatinine) were significantly less likely to receive ACE inhibitors. Other patient factors, physician characteristics and hospital characteristics were only weakly related to a patient’s likelihood of receiving an ACE inhibitor prescription.
Researchers said physicians might be reluctant to prescribe ACE inhibitors in certain high-risk patients, such as those with kidney disease. Some health care delivery systems might lack the necessary structure, controls or resources to ensure that heart failure patients receive the best care possible. Or, some physicians possibly lack awareness about the potential benefits of treatment with ACE inhibitors.
The answer is better approaches to providing care for heart failure patients, Masoudi said.
“These findings reflect the failure of current quality control systems in clinical practice. The key to optimizing the quality of care is re-engineering systems to ensure that clinicians provide the best possible care at all times,” he said.
Stanford University health services researcher Mark Hlatky, M.D., agreed with Masoudi’s assertion. In an editorial accompanying the article, Hlatky noted that using ACE inhibitors to treat heart failure has reached a plateau in recent years, leaving a substantial gap between current medical practices and optimal care.
“If we’re going to get to the next stage [in ACE inhibitor use], we have to do more than tell people ‘just do this’,” said Hlatky, professor of medicine and of health research and policy.
Masoudi’s co-authors are Saif S. Rathore, M.P.H.; Yongfei Wang, M.S.; Edward P. Havranek, M.D.; Jeptha P. Curtis, M.D.; JoAnne Micale Foody, M.D.; and Harlan M. Krumholz, M.D.