Prevalence of heart failure and systolic ventricular dysfunction in older Australians: the Canberra Heart Study.
OBJECTIVE
To estimate the prevalence of heart failure (HF) and left ventricular (LV) systolic dysfunction in a population-based sample of older Australians.


METHODS
A cross-sectional survey of 2000 randomly selected residents of Canberra, aged 60-86 years, conducted between February 2002 and June 2003. Participants were assessed by history, physical examination by a cardiologist, and echocardiography.


METHODS
Age- and sex-specific prevalence rates of clinical HF and LV systolic dysfunction (defined as LV ejection fraction < or = 50%).


RESULTS
Of 1846 people eligible for our study, 1388 (75%) agreed to participate and 1275 completed all investigations (mean age, 69.4 years; 50% men). In the study sample, 72 subjects (5.6%; 95% CI, 4.4%-7.1%) had clinical HF that had been previously diagnosed and was confirmed by our assessment. A further 0.6% (95% CI, 0.3%-1.2%) had undiagnosed clinical HF (ie, evidence of structural heart disease and symptoms/signs of cardiac insufficiency without a previous diagnosis of clinical HF). Thus, the overall prevalence of clinical HF in the sample was 6.3% (95% CI, 5.0%-7.7%). Clinical HF increased in prevalence with advancing age (a 4.4-fold increase from the 60-64-years age group to the 80-86-years age group; P < 0.0001). Of the 75 subjects (5.9%; 95% CI, 4.7%-7.3%) with LV systolic dysfunction, 44 (59%) were in the preclinical stage of disease.


CONCLUSIONS
Diagnosed HF cases represent the "tip of the iceberg" for the national burden of HF and LV systolic dysfunction. Clinically identifiable HF cases can remain undiagnosed, and the majority of people with LV systolic dysfunction are in a preclinical stage of the disease.
Division of Cardiovascular Diseases, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA. abhayaratna.walter@mayo.edu
Walter P
WP
Abhayaratna
Wayne T
WT
Smith
Niels G
NG
Becker
Thomas H
TH
Marwick
Ian M
IM
Jeffery
Darryl A
DA
McGill
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D020958:Australian Capital Territory / Q000453:epidemiology; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D003627:Data Interpretation, Statistical; D004452:Echocardiography; D005260:Female; D006333:Heart Failure / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011897:Random Allocation; D012737:Sex Factors; D011795:Surveys and Questionnaires; D013599:Systole; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000453:epidemiology*