ACEIs, but Not ARBs, Reduce Mortality in Patients with Diabetes

Two classes of renin-angiotensin system blockers have differing effects on mortality in diabetic patients, concludes a meta-analysis in JAMA Internal Medicine.

A systematic review identified 35 randomized trials evaluating the effects of renin-angiotensin system blockers on all-cause and cardiovascular mortality and major cardiovascular events in patients with diabetes. There were 23 trials comparing angiotensin-converting enzyme inhibitors (ACEIs) with placebo or active drugs, including 32,287 patients, and 13 trials comparing angiotensin II receptor blockers (ARBs) with no treatment, including 23,867 patients. The outcomes with ACEIs and ARBs were separately evaluated in random-effects meta-analyses.

With ACEIs, there were significant reductions in all-cause mortality, odds ratio (OR) 0.87; cardiovascular death, OR 0.83; and major cardiovascular events, OR 0.86. The reduction in cardiovascular events was significant for both myocardial infarction, relative risk (RR) 0.79; and heart failure, RR 0.81.

Neither mortality outcome was significantly reduced by treatment with ARBs. Overall cardiovascular events were unaffected as well, although there was a significant reduction in heart failure risk: RR 0.70. Neither class of drug reduced stroke risk. Metaregression analysis suggested that ACEIs reduced mortality independently of baseline blood pressure or proteinuria, patient age, type of ACEI, or presence of diabetes.

Treatment with ACEIs or ARBs is recommended for diabetic patients with high blood pressure. However, these two drug classes have differing mechanisms and may differ in their clinical effects.

The new meta-analysis found significant reductions in overall and cardiovascular mortality in diabetic patients receiving ACEIs but not ARBs. The ACEIs were also associated with a reduced risk of cardiovascular events, whereas ARBs reduced only heart failure risk. The results support ACEIs as “first-line therapy to limit the excess mortality and morbidity” in hypertensive patients with diabetes [Cheng J, et al. Effect 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 March 31, 2014. doi:10.1001/jamainternmed.2014.348].