|A||Patients at high risk for HF but without structural heart disease or symptoms of HF (e.g., patients with hypertension, atherosclerotic disease, diabetes, obesity, and metabolic syndrome or patients using cardiotoxins or with a family history of cardiomyopathy). Such patients have no identified structural or functional abnormalities of the pericardium, myocardium, or cardiac valves and have never shown signs or symptoms of HF|
|B||Patients who have developed structural heart disease that is strongly associated with the development of HF (e.g., previous myocardial infarction; LV remodeling, including LVH and low EF; or asymptomatic valvular disease) but without signs or symptoms of HF|
|C||Patients with structural disease who have current or prior symptoms of HF (e.g., known structural heart disease and shortness of breath and fatigue, reduced exercise tolerance)|
|D||Patients with refractory HF requiring specialized interventions (e.g., marked symptoms of HF at rest despite maximal medical therapy—those who are recurrently hospitalized or cannot be safely discharged from the hospital without specialized interventions)|
Adapted from Hunt et al (18,19).
EF indicates ejection fraction; HF, heart failure; LV, left ventricular; and LVH, left ventricular hypertrophy.