Amino Terminal pro-Brain Natriuretic Peptide (NTproBNP) is secreted in conditions of cardiac wall stress. NTproBNP levels are used in addition to clinical assessment to diagnose heart failure (HF). The purpose of this clinical study is to collect data to substantiate the use of the VITROS NT-proBNP II assay.

A prospective clinical sample collection and NT-proBNP testing will be conducted in two populations. Patients presenting to the Emergency Department (ED) and patients presenting to outpatient centers will be approached for enrollment.

Clinical and laboratory data will be collected to demonstrate product performance compared to adjudicated clinical diagnosis. Approximately 4300 evaluable subjects at geographically dispersed sites in the US will be enrolled in the study.

Sample collection and testing of clinical samples with the VITROS NT-proBNP II assay will be performed under two separate protocols.

Acute HF Population (ED setting):

Inclusion Criteria:

• Subjects must have suspicion of HF and acute symptoms at presentation.
• Subjects must be at least 22 years of age.
• Subjects must be willing and able to provide informed consent.

Exclusion Criteria:

• Acute symptoms clearly not secondary to HF.
• Subjects with renal disease on dialysis.
• Subjects unable to comply with the study requirements.

Population with suspicion of HF (Outpatient Setting):

Inclusion Criteria:

• Subjects must be at least 22 years of age.
• Subjects must be willing and able to provide informed consent.
• Subjects who present to outpatient centers with suspicion HF.

Exclusion Criteria:

• Symptoms clearly not secondary to HF.
• Subjects with renal disease on dialysis.
• Subjects unable to comply with the study requirements.
• Subjects previously diagnosed with heart failure.

The ED population represents an acute HF population enrolled at Emergency Departments. Patients presenting with a suspicion of HF and acute symptoms will be approached for enrollment.

The outpatient population represents a population with suspicion of HF presenting to outpatient centers. Patients presenting with a suspicion of HF will be approached for enrollment.