-added instruction about stopping study drug if infusion is discontinued multiple times within a 24 hour period -removed instruction to discontinue study drug after 48 hours -removed exclusion criteria of pulmonary hypotension -added exclusion criteria for significant pulmonary disease

-revised randomization scheme following interim analysis from 1:1:1:1 to 2:1:1:1 (placebo:TRV027 1.0 mg/hr:TRV027 5.0 mg/hr:TRV027 25 mg/hr) -included additional secondary efficacy measure: average Z comprising the components of the primary endpoint and incorporating changes in troponin-T and cystanin-C baseline to 48 hours -amended enrollment to be approx. 620 patients -revised inclusion criteria so that the definition of ADHF must include radiographic evidence of chest congestion -revised safety systolic blood pressure measurement between 105 mmHg and 160 mmHg, inclusive -refined inclusion criteria that pre-existing HF diagnosis may be reported but must include treatment for at least the last 30 days with daily oral loop diuretics plus an ACE inhibitor and/or beta-adrenergic blocker for all patients for whom ACE inhibitors and beta blockers are not documented as contraindicated -clarified that current suspicion of ACS, coronary revascularization within the 3 months prior to screening are exclusions -added exclusion criteria that clinical presentation may not include a serum sodium >145 mEq/L (145 mmol/L) -clarified that current or planned thoracentesis is an exclusion criteria -clarified exclusion criteria for history of current use of left ventricular assist devices or use within the last year prior to screening of intra-aortic balloon pumps