CURRENT OPINION Of fads, fashion, surrogate endpoints and dual RAS blockade

Background Dual renin–angiotensin system (RAS) blockade, mostly by combining an angiotensin converting enzyme (ACE) inhibi-tor with an angiotensin receptor blocker (ARB), is increasingly used in patients with hypertension and diabetes and/or proteinuria and in those with resistant heart failure. However, in the zest of achieving greater nephroprotection and cardioprotection, even patients with uncomplicated essential hypertension are not uncommonly treated with dual RAS blockade. Evidence In 2003 the COOPERATE trial, seemed to confirm that dual RAS blockade was beneficial and that proteinuria reduction was synonymous with nephroprotection. This study had to be withdrawn recently attesting to the suspi-cion that the data looked to good to be true. Moreover, the large prospective ONTARGET data argue against a nephroprotective effect of dual RAS blockade and together with renal findings from ACCOMPLISH, cast doubt on albuminuria/proteinuria being a reliable surrogate endpoint for renal outcome. Although in heart failure, dua