Heart failure (HF) is a major public health problem. The New York Heart Association (NYHA) Functional Classification by a HF provider helps to guide their decisions in patient treatment. The purpose of this study is to further examine the NYHA Classification Guide that is designed to assist healthcare providers. The investigators will conduct the study in the outpatient clinic setting where adult patients with chronic heart failure are treated. HF providers will be asked to complete the NYHA classification Guide and then participants will complete a standardized 6-minute walk test which is considered as the gold standard. Participant results will be compared between providers' assigned class and the results from the 6-minute walk test. The subsequent phase of the study will be incorporation of the NYHA Classification Guide into clinical practice. HF providers will use the NYHA Classification Guide for 30 days in the clinic setting and will report their perceptions.

As a continuation of prior work, the purpose of this study is to further examine the reliability and validity of the New York Heart Association (NYHA) Classification Guide and application into practice. The investigators will conduct a prospective cross-sectional study in the ambulatory care settings that manages adult patients with chronic heart failure (both heart failure with reduced ejection fraction [HFrEF] and heart failure with preserved ejection fraction [HFpEF]). HF providers will be asked to complete the NYHA classification Guide and assign one of 4 functional classes: Class I, Class II, Class III, or Class IV. Participants will then complete a standardized 6-minute walk test (6MWT), considered as the gold standard. Participant results will be compared between providers' assigned class and the results from the 6-minute walk test. The subsequent phase of the study will be incorporation of the NYHA Classification Guide into clinical practice. Clinicians will utilize the NYHA Classification Guide for 30 days and will report perceived barriers and facilitators. Data reporting NYHA Class and HF Stage will be obtained from 30 days prior implementation and compared to during implementation.

Participant Inclusion Criteria:

• A documented confirmed diagnosis of Heart Failure (HF)
• Under the care of a Cardiologist and/or Advanced Practice Provider working in Cardiology
• 18 years of age or older and less than 90 years of age
• Alert and oriented to person, place, and time
• Ability to walk without assistance
• Able to read and speak English

Participant Exclusion Criteria:

• Diagnosed with myocardial infarction, coronary artery bypass graft (CABG), angioplasty or stent in the previous 30-days
• Unstable angina in the previous 30 days
• Active endocarditis
• Acute myocarditis or pericarditis
• Symptomatic severe aortic stenosis
• Uncontrolled hypertension with systolic blood pressure readings > 180 mmHg or diastolic pressure readings > 100 mmHg
• Uncontrolled atrial dysrhythmia or 3rd degree heart block
• Active ventricular arrhythmias resulting in 1 or more shocks in the past month
• Acute pulmonary embolus or pulmonary infection
• Thrombosis of the lower extremities
• Suspected dissecting aneurysm
• Uncontrolled asthma
• Pulmonary edema
• Room air oxygen saturation (SPO2) at rest less than 90%
• Acute respiratory failure
• Acute noncardiopulmonary disorder that may affect exercise performance or be aggravated by exercise such as, infection, thyrotoxicosis
• Left ventricular assist device
• Mental impairment leading to inability to cooperate

Provider Inclusion Criteria:

• Licensed healthcare providers (Physicians and Advance Practice Providers) in HF ambulatory clinical sites who care for adult patients with HF.

Providers Exclusion Criteria:

• Providers who do not actively manage adult patients with HF.

Aggregate data will be published.

For the 6-minute walk test the technician performing the test is masked. The remainder of the data is not masked.