[Renin-angiotensin-aldosterone system inhibition and cardiovascular protection]

The primary aim of the treatment in hypertension is to prevent cardiovascular complications. All hypertensives reduce the risk for cardiovascular events by providing effective blood pressure control. Besides blood pressure-lowering effect, the contribution of an antihypertensive agent to reduce the risk for cardiovascular events at high-risk patients was first demonstrated in 2000 in the HOPE study (Heart Outcomes Prevention Evaluation), which used an angiotensin-converting enzyme (ACE) inhibitor, ramipril 10 mg (N Engl J Med 2000;342:145-53). However, at the time the results of this study appeared, the use of angiotensin-receptor blockers (ARB) was gaining popularity in the treatment of hypertension as an alternative to ACE inhibitors. This raised the question as to whether an ARB would also offer benefit comparable to that derived from ramipril. A non-inferiority trial was planned by the same research group to test whether telmisartan 80 mg was as effective as ramipril 10 mg in a similar patient population. In order to obtain reliable results, 25,000 patients from all over the world had to be followed-up for five years (Am Heart J 2004;148:52-61). The results of the ONTARGET study (The Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial) which were presented at the annual meeting of the American College of Cardiology in March 2008 were suggestive of a new indication for telmisartan. In August, 2009, the U.S. Food and Drug Administration reported that a new indication might be justified for the use of telmisartan, an angiotensin-receptor blocker: In order to reduce the risk for cardiovascular diseases and if an ACE inhibitor (ramipril 10 mg) cannot be used, telmisartan 80 mg can be used in patients with a high cardiovascular risk profile (Press announcements, FDA). The aim of this review is to provide a comprehensive analysis of the course of this recent development in cardiovascular protection.