ACE Inhibitors after Heart Attacks: Varying Effects?

Summaries for Patients are a service provided by Annals to help patients better understand the complicated and often mystifying language of modern medicine.

Summaries for Patients are presented for informational purposes only. These summaries are not a substitute for advice from your own medical provider. If you have questions about this material, or need medical advice about your own health or situation, please contact your physician. The summaries may be reproduced for not-for-profit educational purposes only. Any other uses must be approved by the American College of Physicians.

The summary below is from the full report titled "Mortality Rates in Elderly Patients Who Take Different Angiotensin-Converting Enzyme Inhibitors after Acute Myocardial Infarction: A Class Effect?" It is in the 20 July 2004 issue of Annals of Internal Medicine (volume 141, pages 102-112). The authors are L. Pilote, M. Abrahamowicz, E. Rodrigues, M.J. Eisenberg, and E. Rahme.

What is the problem and what is known about it so far?

Heart attacks occur when blood flow through the arteries to the heart is blocked for a long enough time to damage or kill a portion of heart muscle. Although some people with heart attacks die immediately, most survive. Doctors usually recommend that these survivors take several drugs. They often prescribe drugs called angiotensin-converting enzyme (ACE) inhibitors because several studies showed that these drugs helped prevent future heart attacks and death. However, there are many different ACE inhibitors, and some were not tested in the trials. Most doctors think that all ACE inhibitors have similar effects; however, some of these drugs might prevent future heart problems and death better than others.

Why did the researchers do this particular study?

To determine whether the risk of dying in the first year after a heart attack is similar among people taking different ACE inhibitors.

Who was studied?

7512 patients older than 65 years of age who received prescriptions for ACE inhibitors after a heart attack.

How was the study done?

The researchers used a database of discharge summaries from 109 hospitals in Quebec, Canada, to identify older patients who survived heart attacks between 1996 and 2000. They then used a claims database to identify the patients who filled prescriptions for an ACE inhibitor after leaving the hospital. They selected patients who refilled prescriptions for the same ACE inhibitor several times rather than patients who switched drugs. The researchers then compared death rates 1 year after the heart attack among patients taking different ACE inhibitors.

What did the researchers find?

Patients who filled prescriptions for ramipril had lower death rates within the first year of hospital discharge than did those who filled prescriptions for several other ACE inhibitors, including captopril, enalapril, fosinopril, and quinapril.

What were the limitations of the study?

The databases used by the researchers lacked detailed clinical information. Some doctors may have given sicker patients certain ACE inhibitors more frequently. The researchers addressed this possibility in their analyses, but they may not have accounted for all situations that could make the risk of death seem to be related to a particular ACE inhibitor.

What are the implications of the study?

Doctors and patients should not assume that all ACE inhibitors have similar effects on death rates after heart attacks.