Epidemiology and natural history of cardiac failure

Congestive heart failure is a major and growing public health problem. Its prevalence is 3-20 per 1,000, and increases steeply with age. Coronary heart disease is the underlying cause in 50% of the cases, idiopathic cardiomyopathy in 20%. Survival at 5 years after the onset of heart failure in the Framingham study was 25% in men and 38% in women; the mortality rate of heart failure patients was 6-7 times that of the general population. Three variables--functional class, natremia, left ventricular ejection fraction--are powerful prognostic factors. Quality of life of heart failure patients is severely impaired.