Age affects the diagnostic accuracy of serum N-terminal pro-B-type natriuretic peptide for heart failure in patients with pleural effusion

Background: Serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a well-recognized diagnostic marker for heart failure (HF) in patients with dyspnea or pleural effusion (PE). The effects of age on the diag-nostic accuracy of NT-proBNP in dyspneic patients are widely known; however, whether its diagnostic accuracy is affected by age in patients with PE remains unknown. This study aimed to investigate the influence of age on the diagnostic accuracy of serum NT-proBNP for HF in patients with PE. Methods: Patients with PE were recruited from the BUFF (Biomarkers for patients with Undiagnosed pleural eFFusion) cohort and the SIMPLE (a Study Investigating Markers in PLeural Effusion) cohort. Serum NT-proBNP on admission and final diagnosis were extracted from the participant's medical records. The diagnostic accuracy of serum NT-proBNP was evaluated by a operating characteristic (ROC) curve analysis. The influence of age on the diagnostic accuracy of NT-proBNP was investigated through subgroup analyses. Results: One hundred and four participants were enrolled from the BUFF cohorts (HF, 32; non-HF, 72). One hundred and sixteen participants were enrolled from the SIMPLE cohort (HF, 21; non-HF, 95). The area under the ROC curve (AUCs) of NT-proBNP in the pooled cohort was 0.78 (95 %CI: 0.71 - 0.85). The AUC of NT-proBNP decreased in older patients. Conclusion: Serum NT-proBNP has moderate diagnostic accuracy for HF in old patients with PE. The diagnostic accuracy of serum NT-proBNP in these patients decreases with the advancement of age.