Angiotensin-converting enzyme inhibitors and aortic rupture: a population-based case-control study.
BACKGROUND
Angiotensin-converting enzyme (ACE) inhibitors prevent the expansion and rupture of aortic aneurysms in animals. We investigated the association between ACE inhibitors and rupture in patients with abdominal aortic aneurysms.


METHODS
We did a population-based case-control study of linked administrative databases in Ontario, Canada. The sample included consecutive patients older than 65 (n=15,326) admitted to hospital with a primary diagnosis of ruptured or intact abdominal aortic aneurysm between April 1, 1992, and April 1, 2002.


RESULTS
Patients who received ACE inhibitors before admission were significantly less likely to present with ruptured aneurysm (odds ratio [OR] 0.82, 95% CI 0.74-0.90) than those who did not receive ACE inhibitors. Adjustment for demographic characteristics, risk factors for rupture, comorbidities, contraindications to ACE inhibitors, measures of health-care use, and aneurysm screening yielded similar results (0.83, 0.73-0.95). Consistent findings were noted in subgroups at high risk of rupture, including patients older than 75 years and those with a history of hypertension. Conversely, such protective associations were not observed for beta blockers (1.02, 0.89-1.17), calcium channel blockers (1.01, 0.89-1.14), alpha blockers (1.15, 0.86-1.54), angiotensin receptor blockers (1.24, 0.71-2.18), or thiazide diuretics (0.91, 0.78-1.07).


CONCLUSIONS
ACE inhibitors are associated with a reduced risk of ruptured abdominal aortic aneurysm, unlike other antihypertensive agents. Randomised trials of ACE inhibitors for prevention of aortic rupture might be warranted.
Hackam
Daniel G
DG
Clinical Epidemiology and Health Care Research Program, Department of Health Policy, Management and Evaluation, University of Toronto, Toronto, Canada. daniel.hackam@ices.on.ca
Thiruchelvam
Deva
D
Redelmeier
Donald A
DA
D000368:Aged; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D017544:Aortic Aneurysm, Abdominal; D001019:Aortic Rupture / Q000401:mortality / Q000517:prevention & control*; D016022:Case-Control Studies; D015897:Comorbidity; D000075202:Contraindications; D016208:Databases, Factual; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009864:Ontario; D012189:Retrospective Studies
D000806:Angiotensin-Converting Enzyme Inhibitors