REN and Hypertension resistant to conventional therapy: Consistent with our hypothesis that resistant hypertension is predominantly a sodium-retaining state, we expected plasma renin to be relatively suppressed despite background treatment with an ACE inhibitor or an ARB, a CCB, and a diuretic—ie, the so-called A+C+D treatment strategy.3, 4 A finding of a suppressed renin concentration, despite treatments that usually increase plasma renin, would be consistent with resistant hypertension being a sodium-retaining state.