Go to content

ACE inhibitors significantly reduce risk of ruptured abdominal aneurysms


A new study from the Institute for Clinical Evaluative Sciences (ICES) shows that the antihypertensive medications angiotensin-converting enzyme (ACE) inhibitors significantly reduce the risk of someone experiencing a potentially fatal ruptured abdominal aortic aneurysm (AAA).

“Previous clinical trials have shown that ACE inhibitors prevent the expansion and rupture of aortic aneurysms in animals. However, this study is the first to demonstrate that this effect may also extend to humans,” said study lead author and ICES research fellow Dr. Daniel Hackam. “This is particularly significant because the mortality rate following rupture of an AAA is between 80-90%.”

The study tracked over 15,000 elderly Ontario patients 66 years and older hospitalized with either a ruptured (22%) or intact (78%) AAA between 1992 and 2002, and examined whether they were taking ACE inhibitors prior to hospitalization. The authors also analyzed other antihypertensive and non-antihypertensive medications to determine whether the findings with ACE inhibitors were unique or shared with other medications.

Overall, 3,426 patients (22%) received ACE inhibitor therapy prior to hospitalization, including 665 (20%) patients with ruptured AAAs and 2,761 (23%) patients with intact AAAs. Patients who received ACE inhibitors had an 18% lower risk of aortic rupture than patients who did not receive ACE inhibitors. In contrast to ACE inhibitors, this association was not observed for other antihypertensive therapies such as beta blockers, calcium channel blockers, thiazide diuretics, alpha blockers, and angiotensin receptor blockers.

In addition, although a number of patients were taking antidepressants, gastric acid suppressants, thyroid hormone replacement, sedatives, cholesterol-lowering agents, and anti-osteoporosis medications, there was no association between these medications and a reduced risk of aortic rupture.

“These findings have important implications for patient care and research,” said Dr. Hackam. “First, patients with established AAAs who are not candidates for repair might benefit from ACE inhibitor therapy. Second, our results emphasize the high incidence of unrelated diseases (such as infections and trauma) in patients with aortic aneurysms, which may have consequences for health promotion and prevention in this population. And third, given the current lack of proven medical therapies for this disease, our results provide substantial motivation for additional clinical trials on this phenomenon.”

The study, “Angiotensin-converting enzyme inhibitors and aortic rupture: a population-based case-control study”, is in the August 19, 2006 issue of The Lancet.

Author affiliations: ICES (All authors); Clinical Epidemiology and Healthcare Research Program, Department of Health Policy, Management and Evaluation, University of Toronto (Drs. Hackam and Redelmeier); Secondary Prevention and Cardiac Rehabilitation Program, Toronto Rehabilitation Institute (Dr. Hackam); Patient Safety Service, Sunnybrook Health Sciences Centre (Dr. Redelmeier); Division of General Internal Medicine, Department of Medicine, University of Toronto (Dr. Redelmeier).

ICES is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy.


Read the Journal Article