An ARB was as efficacious as an ACE inhibitor, but combination therapy failed to show any advantages.
Angiotensin-converting–enzyme inhibitors lower the incidence of adverse cardiovascular events among people with heart failure, vascular disease, or high-risk diabetes. However, ACE inhibitors do not fully block production of all angiotensin II. In a multinational study, researchers assessed whether an angiotensin-receptor blocker (ARB; telmisartan), alone or in combination with an ACE inhibitor (ramipril), was equivalent or superior to ACE inhibition alone. More than 25,000 patients with vascular disease or high-risk diabetes were randomized to ramipril alone, telmisartan alone, or the combination. The trial was supported by the maker of telmisartan.
After a median follow-up of 56 months, the rate of the primary composite outcome (death from cardiovascular causes, myocardial infarction, or stroke; or hospitalization for heart failure) was similar across all arms (ramipril, 16.5%; telmisartan, 16.7%; and combination treatment, 16.3%). Mean blood pressure reduction was greater in the combination (2.4/1.4 mm Hg) and telmisartan (0.9/0.6 mm Hg) groups than in the ramipril group. Compared with ramipril patients, telmisartan patients had lower rates of cough (1.1% vs. 4.2%) and angioedema (0.1% vs. 0.3%). Rates of renal impairment were higher in the combination group (13.5%) than in the ramipril or telmisartan group (10.2% and 10.6%, respectively). Hypotensive symptoms were also more common with combination therapy.
Comment: In this large trial, an ARB alone was as efficacious as an ACE inhibitor among individuals at high risk for adverse cardiovascular events. Combining an ARB and an ACE inhibitor failed to improve outcomes further and was associated with more adverse side effects. Because many ACE inhibitors are available as generics in the U.S., they are generally much less expensive than ARBs.
— Jamaluddin Moloo, MD, MPH
Dr. Moloo served as a site investigator for ONTARGET.
Published in Journal Watch General Medicine April 17, 2008
Yusuf S et al. for the ONTARGET Investigators. Telmisartan, ramipril, or both in patients at high risk for vascular events. N Engl J Med 2008 Apr 10; 358:1547.