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. CHADS2 and CHA2DS2VASc 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 CHADS2 and CHA2DS2VASc 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 CHADS2 (0.639; 95% CI: 0.552–0.726) and CHA2DS2VASc (0.633; 95% CI: 0.546–0.720) scores (P < 0.05 for all). The addition of NT-proBNP levels to CHADS2 (0.783; 95% CI: 0.713–0.854) and CHA2DS2VASc (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 CHADS2 and CHA2DS2VASc 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 CHADS2 and CHA2DS2VASc 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 CHADS2 and CHA2DS2VASc scores.