N-terminal pro-brain natriuretic peptide levels had an independent and added ability in the evaluation of all-cause mortality in older Chinese patients with atrial fibrillation

BACKGROUND: Atrial fibrillation (AF) is the most common arrhythmia and has increased prevalence in older patients, leading to poor prognosis for these patients. There is a need for a biomarker or a model of prognostic evaluation in older patients with AF, especially in China. CHADS(2) and CHA(2)DS(2)VASc scores have been applied to evaluate their prognosis in patients with AF. This analysis was designed to examine whether N-terminal pro-brain natriuretic peptide (NT-proBNP) levels significantly improved the evaluation of all-cause mortality in older Chinese patients with AF when added to CHADS(2) and CHA(2)DS(2)VASc scores. METHODS: There were 219 older patients with AF, and follow-up was 100% complete over an average of 1.11 years. Cox regression analysis was applied to determine the variables independently associated with all-cause mortality. RESULTS: Median age was 85 years, and all-cause mortality was 24.2% (53 patients). Plasma NT-proBNP levels were significantly associated with all-cause mortality in univariate [hazard ratio (HR): 1.842; 95% confidence interval (CI): 1.530–2.218] and multivariate (HR: 1.377; 95% CI: 1.063–1.785) Cox regression analyses and had significantly higher c-statistic (0.771; 95% CI: 0.698–0.845) than CHADS(2) (0.639; 95% CI: 0.552–0.726) and CHA(2)DS(2)VASc (0.633; 95% CI: 0.546–0.720) scores (P < 0.05 for all). The addition of NT-proBNP levels to CHADS(2) (0.783; 95% CI: 0.713–0.854) and CHA(2)DS(2)VASc (0.775; 95% CI: 0.704–0.846) scores significantly increased their c-statistics (P < 0.001 for all). Model based on NT-proBNP levels including age, hemoglobin, fasting blood glucose, glomerular filtration rate and NT-proBNP levels had a significantly higher c-statistic (0.890; 95% CI: 0.841–0.938) than CHADS(2) and CHA(2)DS(2)VASc scores (P < 0.001 for all). Model based on NT-proBNP levels had significantly higher c-statistic than the addition of NT-proBNP levels to CHADS(2) and CHA(2)DS(2)VASc scores (P < 0.05). CONCLUSION: NT-proBNP levels were an independent biomarker associated with an increased all-cause mortality in older Chinese patients with AF, and had an independent and added ability to evaluate their all-cause mortality compared with CHADS(2) and CHA(2)DS(2)VASc scores.