In-patient treatment for acutely decompensated CHF with intravenous vasodilator therapy (such as nitroglycerin or nitroprusside) is useful for a number of reasons. Vasodilators reduce ventricular filling pressure and volume, decreasing pulmonary congestion and the resulting symptoms of breathlessness. Intravenous vasodilators may also achieve afterload reduction leading to decreased mitral regurgitation and increased forward stroke volume. IV administration of externally produced hBNP leads to vasodilation, antagonism of the renin-aldosterone system and an increase in diuresis. hBNP may be a potent agent for the treatment of CHF, with a unique combination of desirable blood flow throughout the body, hormones secreted by the sympathetic nervous system, and renal effects not possessed by currently available therapies. In a 6-hour placebo-controlled comparison in patients with acutely decompensated CHF, Natrecor® was associated with significant improvements in the symptoms of CHF (including dyspnea and fatigue), a decrease in aldosterone, and an increase in urine output. (According to LeJemtel et al 1998) The VMAC trial (Vasodilation in the Management of Acute CHF) is a double-blinded, randomized, active-controlled and placebo-controlled study in which the study drug would be added to standard care therapies such as diuretics, dobutamine, or dopamine. This study compares the effects of the addition of Natrecor®, nitroglycerin, or placebo to standard care (diuretics, dobutamine, dopamine, or other long-term cardiac therapies) in patients requiring hospitalization for the treatment of dyspnea at rest due to acutely decompensated CHF. Based on the cumulative experience with Natrecor, the dose of Natrecor was modified for the VMAC trial to a 2-µg/kg bolus followed by a 0.01-µg/kg/min infusion.