Review: Prospects for ARB in the next five years

JRAAS 2001;2:215-18 Based on multiple, well-conducted, randomised clinical outcome trials (RCT), inhibition of the renin-angiotensin system (RAS) with an angiotensin-converting enzyme inhibitor (ACE-I) has become a firmly established therapeutic approach for reducing morbidity and the risk of death across a broad spectrum of cardiovascular diseases (Figure 1). More recently, another pharmacologic class of agents that inhibits the RAS has become clinically available.Angiotensin II (Ang II) type 1 (AT1)-receptor blockers (ARBs) offer a more complete and specific way of inhibiting the actions of Ang II at the AT1-receptor. Unlike ACEI, ARBs do not directly interfere with the breakdown of bradykinin. When introduced, ARBs promised more complete inhibition of the RAS with greater efficacy and better tolerance than ACE-I. Although the better tolerance comparison appears to have been substantiated, the more important issue of clinical effectiveness of ARBs remains unsettled. We are fortunately in the midst of an impressive series of RCTs, which collectively will evaluate and quantitate the role of ARBs in clinical practice. Based on the ACE-I experience,we provide a framework to consider the completed and ongoing clinical outcomes RCTs with ARBs (Figure 2).