Cardiac Function and Heart Failure

Abstract

Background: There is scant data regarding methods to identify subjects in the community with preclinical left ventricular (LV) systolic and diastolic dysfunction. Methods: A population-based sample of 1229 older adults underwent examination with transthoracic echocardiography and measurement of circulating aminoterminal pro-Btype natriuretic peptide (N-BNP) levels. Heart failure status was ascertained according to past history and clinical examination. The ability of N-BNP to detect preclinical LV ejection fraction (EF) <=40% and/or moderate-severe LVDD in the entire cohort and a high-risk subset (hypertension, diabetes and/or coronary disease) was assessed using age/gender-specific optimal discriminatory levels. Results: Of the 1150 subjects (48.9% men; mean age 69.2 years) without prior history or current clinical evidence of congestive heart failure, 71 subjects (6.2%; 95%CI 4.9- 7.7%) had evidence of preclinical advanced LV dysfunction, of which 6 (0.5%; 95%CI 0.2-1.1%) had an EF<=40%.The overall N-BNP performance to identify subjects with preclinical EF<=40% and/or moderate-severe DD was good (AUC 0.83-0.91). However, given the relatively low prevalence of preclinical disease and characteristics of the test, 41-74% of subjects identified with N-BNP screening would have “negative” confirmatory echocardiograms at the expense of missing 9-22% of cases (Table). Conclusions: N-BNP performs well as a marker of LV dysfunction, but its screening utility is limited in the community.