The Role of Double Renin-Angiotensin System Blockade

Blockade of the renin-angiotensin system (RAS) is now recognized as an effective means of lowering blood pressure and protecting hypertensive patients from end-organ damage.  There are three pharmacologic approaches to blockade of the RAS, with angiotensin-converting enzyme (ACE) inhibitors, with angiotensin II receptor blockers (ARBs), and with direct renin inhibitors. Clinical studies with the first two classes have shown that neither one achieves complete blockade of the RAS. However, an almost complete blockade of the RAS can be achieved by combination of an ACE inhibitor plus an ARB, albeit not with consistent benefits. A complete blockade of the RAS can also be obtained by combination of an ARB with a renin inhibitor. Further outcome trials are needed to show which combination offers long-term advantages in terms of end-organ protection