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

Abstract

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.