Blockade of renin-angiotensin-aldosterone system in kidney and heart disease: how much do we need?

The renin-angiotensin-aldosterone system (RAAS) plays a pivotal role in both cardiac and renal injury. Inhibition of RAAS with either an angiotensin converting enzyme inhibitor (ACE-I) or an angiotensin receptor blocker (ARB) provides both cardiac and renal protection, which is independent and additive to the benefit obtained from lowering blood pressure (BP). The combination of an ACE-I and an ARB should be used only for proteinuric renal disease and not for BP reduction. Patients with proteinuria >1 g/day despite optimal BP control with maximal dose of ACE-I or ARB monotherapy may benefit from a combination therapy. Inhibition of aldosterone with spironolactone or eplerenone provides survival advantage in patients with low LV ejection fraction and may also have antiproteinuric effects. Until further information is available, the routine combined use of all three inhibitors of the RAAS cannot be recommended.