Stage A: Patients without structural changes, but with a high risk for developing congestive heart failure, are subsumed to stage A.
Factors: Risk to develop congestive heart failure. Myocardium, valves and pericardium structurally and functionally uneventful.
Possible characteristics: Hypertension, diabetes mellitus, rheumatic fever or cardiotoxic substances in the history, genetic evidence of cardiomyopathies.

Stage B-diagnosis, which includes asymptomatic patients and patients with first structural changes, is equivalent to classification of NYHA-I.
Factors: Structural heart disease or reduced ventricular function, no symptoms or signs of congestive heart failure.
Possible characteristics: Hypertrophy, dilatation or reduced contractility of the left ventricle, valvular diseases, Infarction-scar.

Stage C defines patients with structural changes and symptoms of congestive heart failure. Also in this stage patients can be judged according to the classes II to IV.
Factors: Proof of ventricular dysfunction, actual or history of congestive heart failure.
Possible characteristics: Shortening of breath/dyspnea with left-ventricular dysfunction, asymptomatic patient with sufficient treatment of congestive heart failure.

Stage D defines patients with therapy-refractory congestive heart failure.
Factors: Terminal end-stage congestive heart failure.
Possible characteristics: Hospitalized congestive heart failure-patients, out-patients with mechanical assist devices, palliatively treated end-stag disease patients.