Vasopressin receptor antagonists: from pivotal trials to current practice

Heart failure is a growing health and economic problem in America, and outcomes continue to remain dismal, particularly for those presenting with acute heart failure syndrome (AHFS). In theory, arginine vasopressin antagonists (VRAs) could be useful in both acute and chronic heart failure, depending on which vasopressin receptor is targeted. Most studies of VRAs in heart failure have focused on V2 receptor antagonism, and to a lesser extent on combined V1a/V2 antagonism, due to the availability of appropriate agents and the unmet need of improving outcomes in AHFS. These agents are particularly attractive as adjunctive or alterative agents in AHFS because of their ability to produce a substantial diuresis without some of the drawbacks intrinsic to loop diuretics. While VRAs have been shown to ameliorate signs and symptoms of congestion when added to standard care, the largest trial of these agents showed no improvement in long-term morbidity, mortality, or hospitalization rates when added to standard care. This article reviews the mechanism of action of VRAs, the relevant clinical trials data, and current recommendations for clinical use, and suggests future directions for study of these agents in patients with heart failure.