title: The impact of confounders on the test performance of natriuretic peptides for cardiac dysfunction in subjects aged 80 and older.
abstract: The hypothesis that natriuretic peptides could be used to identify 'pancardiac' damage has been proposed. However, multiple factors are known to influence circulating levels of natriuretic peptides, especially in the very old. Therefore, the impact of confounders on the association between natriuretic peptide levels and cardiac dysfunction was further explored in subjects aged 80 and older. A diagnostic cross-sectional study embedded within the BELFRAIL study (n=567) was performed. Baseline BNP and NT-proBNP levels were measured and echocardiograms were performed at the subject's home. Cardiac dysfunction was defined as systolic dysfunction, valvular heart disease or isolated severe diastolic dysfunction. Several functional and structural echocardiographic parameters were independently related to circulating levels of natriuretic peptides. Cystatin C, BMI, β blockers, diabetes, heart frequency, usCRP, age and sex were identified as confounders. The prevalence of cardiac dysfunction was 17.1% in the subjects without and 30.8% in the subjects with chronic atrial fibrillation (CAF) or pacemaker (PM). Only in subjects with CAF or PM the C statistic for cardiac dysfunction improved after correcting for confounders. The post-test probability for a negative test (PTP-) ranged from 3.7% to 12.2% and the PTP+ ranged from 21.9% to 62.2% in different strata of confounders. According to these data adjusting for identified confounders does not improve the diagnostic accuracy of the natriuretic peptides for cardiac dysfunction, except in subjects with CAF or PM. Stratifying for individual confounders showed that different cut-off values could be used to optimize the diagnostic characteristics of natriuretic peptides.
authors.affiliation: Institut de Recherche Santé et Societé, Université Catholique de Louvain (UCL), Brussels, Belgium. Bert.Vaes@uclouvain.be
authors.forename: Bert
authors.initials: B
authors.lastname: Vaes
authors.forename: Damien
authors.initials: D
authors.lastname: Gruson
authors.forename: Gijs
authors.initials: G
authors.lastname: Van Pottelbergh
authors.forename: Agnes
authors.initials: A
authors.lastname: Pasquet
authors.forename: Catharina
authors.initials: C
authors.lastname: Matheï
authors.forename: Wim
authors.initials: W
authors.lastname: Adriaensen
authors.forename: Nawel
authors.initials: N
authors.lastname: Rezzoug
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Vanoverschelde
authors.forename: Jan
authors.initials: J
authors.lastname: Degryse
mesh_terms: D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000097:blood; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D004452:Echocardiography; D005260:Female; D006331:Heart Diseases / Q000097:blood* / Q000503:physiopathology; D006801:Humans; D008297:Male; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010138:Pacemaker, Artificial; D010446:Peptide Fragments / Q000097:blood*; D011237:Predictive Value of Tests; D011446:Prospective Studies
chemical_list: D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain