Tolvaptan For Worsening Outpatient Heart Failure: Role of Copeptin In Identifying Responders

Inclusion Criteria: * ≥ 18 years of age * Presenting to clinic with worsening heart failure due congestion (fluid overload) Patient reported worsening fluid overload based on perception of edema and/or weight gain With at least one of the following symptoms * Worsening dyspnea on exertion or fatigue * Worsening orthopnea or paroxysmal nocturnal dyspnea (PND) * Perception of abdominal and/or lower extremity edema * Early satiety and/or decreased appetite And at least one of the following signs * Lower extremity edema * Ascites * Elevated jugular venous distension (JVD) * Pulmonary rales * Daily oral dose of loop diuretic * Prior history of heart failure with this diagnosis for at least 1 month with preserved or reduced left ventricular ejection fraction * Signed informed consent Exclusion Criteria: * Patients with symptomatic hyponatremia will be excluded from the study. * Patients with severe hyponatremia, defined as serum sodium \< 125 milliequivalents per Liter (mEq/L) at the time of screening, will be excluded regardless of whether they are symptomatic or not. * Patients with the following predisposing factors for osmotic demyelinating syndrome (ODS), assessed by the study investigator judgment, will be excluded: chronic alcoholism at the time of study, severe liver disease, marked malnutrition, and risk for chronic hypoxia. * Patients currently undergoing renal replacement therapy * Planned hospitalization for acute heart failure * History of primary significant liver disease or acute hepatic failure, as defined by the investigator * Hemodynamically significant arrhythmias * Acute coronary syndrome (ACS) or acute myocardial infarction within 4 weeks prior to study entry * Active myocarditis * Hypertrophic obstructive, restrictive, or constrictive cardiomyopathy * Severe stenotic valvular disease amendable to surgical treatment * Complex congenital heart disease * Constrictive pericarditis * Clinical evidence of digoxin toxicity * History of adverse reaction or clinical contraindication to tolvaptan * Concomitant use of strong cytochrome P450 3A4 (CYP3A4) inhibitors * Inability of patient to sense and/or respond to thirst * History of hypersensitivity to tolvaptan * Patient is anuric * Enrollment or planned enrollment in another randomized clinical trial during the study period * Pregnant or breast-feeding * Inability to comply with planned study procedures