B-type natriuretic peptide levels and cardiovascular risk in patients with diastolic dysfunction on chronic haemodialysis: cross-sectional and observational studies.

BACKGROUND Elevated B-type natriuretic peptide (BNP) levels are predictive of cardiovascular events in patients on chronic maintenance haemodialysis, even in those without apparent cardiovascular disorders when they start dialysis. In the present study, we tested the hypothesis that left ventricular diastolic dysfunction increases BNP levels and can predict cardiovascular events in patients on chronic haemodialysis without apparent cardiac disease. METHODS Patients on chronic maintenance haemodialysis in a stable condition and with normal systolic function were enrolled (n=98). BNP concentrations were measured, and left ventricular diastolic function was assessed using echocardiography after the first dialysis session of the week. Then, they were followed up for 2 years with the end point being the incidence of cardiovascular events. RESULTS At baseline, left ventricular diastolic dysfunction was detected in 39 of 98 patients. After adjustment for known risk factors, multivariable regression analysis demonstrated that diastolic dysfunction was a significant predictor of increased BNP levels (P<0.05). During the follow-up period, 17 patients experienced cardiovascular events. Kaplan-Meier analysis demonstrated that the incidence of cardiovascular events was higher in patients with (28.2%) than without (10.2%) left ventricular diastolic dysfunction (log-rank, P<0.01). Univariate Cox proportional hazards regression analysis indicated that diastolic dysfunction and BNP were significant predictors of cardiovascular events (hazard ratio 3.63 and 4.87, respectively; P<0.05). CONCLUSIONS Left ventricular diastolic dysfunction is associated with increased BNP levels and an increased risk of cardiovascular events in patients on haemodialysis.