Diagnostic value of B-type natriuretic peptide for estimating left atrial size and its usefulness for predicting all-cause mortality and cardiovascular events among chronic haemodialysis patients

Aim: Estimating fluid balance in haemodialysis patients is essential when determining dry weight, but limited methods are currently available. B-type natriuretic peptide (BNP) is a useful surrogate marker in patients with congestive heart failure (CHF), but whether its validity could be generalized to haemodialysis patients has not been studied well. Methods: A total of 457 haemodialysis patients at a dialysis centre were analyzed. Determinants of BNP were assessed in connection with ultrasound cardiography (UCG) records, Kt/V, ultrafiltration rate (UFR), and demographic factors. All-cause death and cardiovascular (CV) events were recorded as the main outcome. Results: Among the UCG records, left atrial diameter (LAD), left ventricular ejection fraction (LVEF), were determinants of log-transformed (ln) BNP; UFR, age and sex were also significant. There was a positive correlation between BNP and LAD (r = 0.285, P < 0.001). Receiver operating characteristic (ROC) analysis revealed that BNP had 90% and 80% sensitivity to predict the presence of LA enlargement of 77.9 pg/mL and 133.2 pg/mL, respectively. Higher BNP and lower LVEF were associated with higher risk for developing all-cause death and CVD. In the adjusted model, patients with BNP higher than 471 pg/mL had hazard ratio of 2.18 (95% confidence interval (CI) 1.20-3.96, P = 0.01), compared to those with BNP <109 pg/mL. Conclusion: B-type natriuretic peptide was determined by LAD, LVEF, UFR, age and sex. BNP and LAD had positive correlation and BNP could become a useful tool for estimating the presence of LA enlargement. BNP and LVEF was a strong risk factor for predicting all-cause death and CV events among patients undergoing haemodialysis.