The epidemiology of "asymptomatic" left ventricular systolic dysfunction: implications for screening.

Congestive heart failure is a progressive disorder that is frequently preceded by asymptomatic left ventricular systolic dysfunction. We reviewed the epidemiology, diagnosis, and natural history of asymptomatic left ventricular systolic dysfunction and evaluated community-wide screening for this condition as a potential strategy to reduce the incidence of heart failure. Asymptomatic left ventricular systolic dysfunction has an estimated prevalence of 3% to 6%, and is at least as common in the community as systolic heart failure. Because it often occurs in the absence of known cardiovascular disease, this condition may go unrecognized and undertreated. In randomized trials, individuals with asymptomatic left ventricular systolic dysfunction have high rates of incident heart failure and death. However, little is known about the prognosis of individuals with this condition in the community, who have a substantially lower prevalence of myocardial infarction, have milder degrees of systolic dysfunction, and are older than patients enrolled in clinical trials. Current evidence is inadequate to support community-wide screening for asymptomatic left ventricular systolic dysfunction, either with echocardiography or with assays for natriuretic peptides. Given the increasing prevalence of heart failure, additional studies are needed to develop effective strategies to detect and optimally manage individuals with asymptomatic left ventricular dysfunction in the community.