Epidemiology and Prognosis of Heart Failure

Abstract

<span> In this article the state of the art of prevalence, incidence and prognosis of heart failure is discussed. Prevalence and incidence are two measures of disease occurrence. Briefly, prevalence is the proportion of the population affected by the disease at a certain point in time. Incidence indicates the number of new cases within a given time period in a population at risk for the disease (for example, elderly people). A related, prognostic measure is mortality, i.e. the incidence of death from the disease occurring in a period of time. In the case of chronic, steady- state disease such as heart failure, disease duration is directly affected by mortality, and prevalence may correspond to the incidence of disease multiplied by the average duration of disease . Prevalence rates of heart failure may, therefore, vary across studies depending on the variability in incidence as well as in survival between population samples. Also, given that heart failure is a complex syndrome with different phenotypes (see article 1), each with specific clinical characteristics and associated risk factors, prevalence and incidence rates may vary according to the definition of the heart failure subtype. Finally, rates may vary on the basis of the method of collecting data and the criterion for defining left ventricular systolic dysfunction that is applied in the study.</span>