In the largest comparison of angiotensin receptor blockers (ARBs) and ACE inhibitors to date, a study of nearly 2.3 million patients starting the drugs as monotherapy shows no significant differences between the two in the long-term prevention of hypertension-related cardiovascular events.
Dr. George Hripcsak
However, side effects were notably lower with ARBs.
“This is a very large, well-executed observational study that confirms that ARBs appear to have fewer side effects than ACE inhibitors, and no unexpected ARB side effects were detected,” senior author George Hripcsak, MD, professor and chair of biomedical informatics at Columbia University, New York, told this news organization.
“Despite being equally guideline-recommended first-line therapies for hypertension, these results support preferentially starting ARBs rather than ACE inhibitors when initiating treatment for hypertension for physicians and patients considering renin-angiotensin system (RAS) inhibition,” the authors added in the study, published online July 26, 2021, in the journal Hypertension.
They noted that both drug classes have been on the market a long time, with proven efficacy in hypertension and “a wide availability of inexpensive generic forms.”
They also stressed that their findings only apply to patients with hypertension for whom a RAS inhibitor would be the best choice of therapy.
Dr. George Bakris
Commenting on the research, George Bakris, MD, of the American Heart Association’s Comprehensive Hypertension Center at the University of Chicago, said the findings were consistent with his experience in prescribing as well as researching the two drug classes.
“I have been in practice for over 30 years and studied both classes, including head-to-head prospective trials to assess blood pressure, and found in many cases better blood pressure lowering by some ARBs and always better tolerability,” he told this news organization. “I think this study confirms and extends my thoughts between the two classes of blood pressure–lowering agents.”
Head-to-head comparisons of ACE inhibitors and ARBs limited to date
ACE inhibitors and ARBs each have extensive evidence supporting their roles as first-line medications in the treatment of hypertension, and each have the strongest recommendations in international guidelines.
However, ACE inhibitors are prescribed more commonly than ARBs as the first-line drug for lowering blood pressure, and head-to-head comparisons of the two are limited, with conflicting results.
For the study, Dr. Hripcsak and colleagues evaluated data on almost 3 million patients starting monotherapy with an ACE inhibitor or ARB for the first time between 1996 and 2018 in the United States, Germany, and South Korea, who had no history of heart disease or stroke.
They identified a total of 2,297,881 patients initiating ACE inhibitors and 673,938 starting ARBs. Among new users of ACE inhibitors, most received lisinopril (80%), followed by ramipril and enalapril, while most patients prescribed ARBs received losartan (45%), followed by valsartan and olmesartan.
With follow-up times ranging from about 4 months to more than 18 months, the data show no statistically significant differences between ACE inhibitors versus ARBs in the primary outcomes of acute myocardial infarction (hazard ratio, 1.11), heart failure (HR, 1.03), stroke (HR, 1.07), or composite cardiovascular events (HR, 1.06).
For secondary and safety outcomes, including an analysis of 51 possible side effects, ACE inhibitors, compared with ARBs, were associated with a significantly higher risk of angioedema (HR, 3.31; P < .01), cough (HR, 1.32; P < .01), acute pancreatitis (HR, 1.32; P = .02), gastrointestinal bleeding (HR, 1.18; P = .04), and abnormal weight loss (HR, 1.18; P = .04).
While the link between ACE inhibitors and pancreatitis has been previously reported, the association with GI bleeding may be a novel finding, with no prior studies comparing those effects in the two drug classes, the authors noted.
Despite most patients taking just a couple of drugs in either class, Dr. Hripcsak said, “we don’t expect that other drugs from those classes will have fewer differences. It is possible, of course, but that is not our expectation.”