Angiotensin-Converting Enzyme Inhibitors versus AT1 Receptor Antagonist in Cardiovascular and Renal Protection

The development of pharmacologic agents that directly inhibit the angiotensin II receptor (angiotensin receptor blocker [ARB]) has provided clinicians with an alternative to the previously available angiotensin-converting enzyme inhibitors (ACEI) to downregulate the renin-angiotensin system. This review focuses on the available data that can guide the clinician to the use of these two classes of agents vis à vis their ability to provide cardiovascular (CV) and renal protection. Although the CV protective effect of ACEI in high-risk populations is widely appreciated, whether such an effect is entirely BP independent can be questioned. Most head-to-head comparisons between ACEI and ARB have yielded comparable CV protective effects, with ARB being associated with fewer adverse effects. Likewise, several-but not all-studies have demonstrated a CV protective effect of ACEI when compared with other active agents in patients with type 2 diabetes. One study demonstrated a similar protection with ARB when compared with a beta blocker. In terms of renal protection, there are ample data to support a role for both ACEI and ARB to prevent the progression from microalbuminuria to overt albuminuria in both type 1 and type 2 diabetes. However, when progression of renal disease is used as an end point, protection has been demonstrated with ACEI only for type 1 but not type 2 diabetes. In this latter group, only ARB have been shown to slow progression to ESRD.