Patients presenting to the emergency department/hospital with symptoms of new or decompensated heart failure and who will be treated with at least one dose of diuretic.

Inclusion Criteria:

• Males and females 18 years of age or older;
• Patients presenting to the emergency department / hospital with symptoms of new or decompensated heart failure and who will be treated with at least one dose of IV diuretic;
• Ability to draw blood samples for baseline NGAL, BNP and creatinine levels either prior to the administration of the first dose of IV diuretic or within 1 hour after the first dose of an IV diuretic
• Ability to provide written informed consent from subject or their authorized representative.

Exclusion Criteria:

• Acute myocardial infarction or active ischemia;
• Patients who are intubated or otherwise not able to communicate or comply with study assessments;
• Cardiogenic shock or any other clinical condition that would contraindicate the administration of an IV agent with potent vasodilating properties;
• Known history of marked renal insufficiency (e.g., usual serum creatinine ≥ 3.0 mg/dL), on dialysis (either acute of chronic) or in imminent need of dialysis at enrollment;
• Prisoners or other institutionalized or vulnerable individuals;
• Participation in an interventional clinical study within the previous 30 days;
• Unlikely to be willing or able to comply with study procedures, including the follow-up at 30 and 90 days .