In patients with diabetes mellitus, are angiotensin II receptor blockers (ARBs) and angiotensin-converting enzyme (ACE) inhibitors similarly effective in preventing cardiovascular events?
In patients with diabetes, ACE inhibitors decrease cardiovascular events and all-cause mortality. ARBs do not. Both drug classes decrease heart failure incidence. Although both drug classes have been available for almost 15 years, there is only one study of 250 patients that directly compared their effectiveness in patients with diabetes. So, we have to rely on this network analysis of studies that compared each drug class with other treatments. (Level of Evidence = 1a)
These researchers in China started their analysis by searching three databases, including the Cochrane Central Register of Controlled Trials, to identify randomized controlled studies comparing ACE inhibitors and ARBs with no treatment, placebo, or active control treatment in patients with diabetes. They also searched a trial registry and meeting abstracts to find unpublished data. They identified 23 studies that evaluated ACE inhibitors and 13 that tested ARBs. Only one study (enrolling just 250 patients) compared an ARB with an ACE inhibitor in this patient population. The quality of these studies is not great, so we have to be concerned about the validity of the data. ACE inhibitors decreased all-cause mortality by 13% (95% confidence interval [CI], 2% to 22%), major cardiovascular events by 14% (95% CI, 5% to 33%), and heart failure by 19% (95% CI, 7% to 29%), and did not decrease stroke risk compared with placebo or other treatments. ARBs did not affect any of these outcomes other than heart failure (30% decrease; 95% CI, 18% to 41%). Ten of the 13 studies of ARBs used a placebo comparison group, which should have inflated their relative benefit.
Study design: Meta-analysis (randomized controlled trials)
Funding source: Government
Setting: Various (meta-analysis)
Reference: ChengJZhangWZhangXet alEffect of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers on all-cause mortality, cardiovascular deaths, and cardiovascular events in patients with diabetes mellitus: a meta-analysis. JAMA Intern Med.2014; 174( 5): 773– 785.