Benefits of ARBs Not the Same as ACE Inhibitors

The effects of ACEIs and ARBs on multiple outcomes in type 2 diabetes patients…. 

Angiotensin-converting enzyme inhibitors (ACEIs) are a mainstay class of antihypertensive medications with proven benefits in not only hypertensive patients but also in conditions such as diabetes. Some patients taking ACEIs may experience a chronic, dry, nonproductive cough, prompting the switch to a similar class of medications which don’t cause this side effect; Angiotension II receptor blockers (ARBs). While both of these drug classes are closely related, their effects on preventing secondary complications in patients with diabetes may be much different.

In a recent meta-analysis, researchers evaluated the effects of ACEIs and ARBs on multiple outcomes, in type 2 diabetes patients, including; all-cause mortality, cardiovascular deaths and major cardiovascular events. Data sources for this study included; EMBASE (1988 to 2012), MEDLINE (1966 to 2012) and Cochrane Controlled trial register. Of the trials evaluated, 23 evaluated ACE inhibitors against placebo or active drugs (32,827 patients) and 13 trials compared Angiotensin II receptor blockers against controls (23,867 patients).

Using risk ratios with 95% confidence intervals, random-effects models were analyzed. Further, meta-regression analysis was performed to identify sources of heterogeneity. Researchers found that ACEIs displayed a 13% reduced risk of all-cause mortality (RR= 0.87, CI 95%, 0.78 to 0.98). ACEIs also reduced cardiovascular death rate by 17% (RR=0.83, CI 95%, 0.70-0.99), and major CV events by 14% (RR=0.86, CI 95%, 0.77 to 0.95). Further, ACEIs lowered myocardial infarction by 21% (RR=0.79, CI 95%, 0.65 to 0.95) and heart failure by 19% (RR=0.81, CI 95%, 0.71 to 0.93).

Similar findings were not seen with ARBs. The effect of ARBs on all-cause mortality was not considered significant (RR=0.94, 95% CI, 0.82 to 1.08). Treatment with ARBs did not have a significant effect on neither all-cause mortality (RR=0.94, CI 95%, 0.82 to 1.08), cardiovascular death rate (RR=1.21, CI 95%, 0.81 to 1.80), and major cardiovascular events (RR=0.94, CI 95%, 0.85 to 1.01). ARBs, however, did show a significant reduction in heart failure (RR=0.70, CI 95%, 0.59 to 0.82).

In patients with diabetes, no association of decrease stroke risk was seen for both ACEIs and ARBs. Further, meta-regression analysis showed no significant differences in outcome between baseline proteinuria and blood pressure, type of diabetes and particular ACE inhibitor medication being used.

Practice Pearls:

• ACEIs may significantly reduce all-cause mortality, cardiovascular mortality, and major cardiovascular events in patients with diabetes
• ARBs may not have the same benefits as ACEIs for reducing secondary complications of diabetes
• ACEIs should be considered the first line therapy for reducing morbidity and mortality from diabetes-related secondary complications

Cheng J, Zhang W, Zhang X, 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. 2014;