ACE inhibitors and aortic rupture.

摘要

Daniel Hackam and colleagues (Aug 19, p 659) found that use of an angiotensin-converting-enzyme (ACE) inhibitor in the past year, including the past 3 months, was negatively associated with admission for ruptured abdominal aortic aneurysm (odds ratio 0-82, 95% CI 074-0-90). They also found that when the ACE inhibitor was discontinued (used in the past year but not in the past 3 months), patients were not protected from rupture. Hackam and colleagues regard this second finding as supporting their conclusion that ACE inhibitors are protective against rupture, an effect they attribute to inhibition of disease progression. What they do not emphasise in the paper is that, in the discontinued situation, the association was significant in the direction of ACE inhibitors being harmful (1-39, 1-09-1-77), and that the effect size was largerthanthe beneficial effect reported for current use.Hackam and colleagues need to explain how a drug could reduce disease progression if used in the past year, including the past 3 months, but worsen disease progression if used in the past year but not the past 3 months. Of note, their earlier paper,2 cited as the precedent for their definition of drug use, did not include the "3 months immediately before" proviso. It seems more appropriate to combine these two groups into "all patients who used ACE inhibitors in the past year", whereupon the opposite effects presumably cancel and the conclusion is no drug effect.We declare that we have no conflict of interest.