The rationale for choosing telmisartan and ramipril in the ONTARGET programme

The renin–angiotensin system (RAS) has been a drug target of particular interest because of its involvement in the cardiovascular and renal disease progression. The angiotensin-converting enzyme (ACE) inhibitors and the selective angiotensin II receptor blockers (ARBs) inhibit the RAS by different mechanisms of action that may have therapeutic implications. The ACE inhibitors have been proven effective for reducing cardiovascular events and mortality in patients with cardiovascular disease. Evidence from clinical trials has shown that ARBs and ACE inhibitors can reduce the risk of cardiovascular and renal events in specific patient populations. Ramipril is an ACE inhibitor proven, in the HOPE trial, to reduce cardiovascular risk. Telmisartan is an ARB with a high degree of lipophilicity, tissue penetration, and high affinity for the angiotensin II type 1 receptor. The ONTARGET study demonstrated that telmisartan provided equivalent efficacy to ramipril in preventing morbidity and mortality from cardiovascular causes in a broad cross section of high-risk patients, but with better tolerability and fewer discontinuations. The combination of telmisartan and ramipril was no more effective but was associated with worse tolerability.