Pre-Transplant Duration of Dialysis, N-terminal Pro-Brain Natriuretic Peptide and Post-Transplant Mortality in Renal Transplant Recipients

M.H. Yeung, M. van Londen, U. Nakshbandi, Y.M. Said, M.F. Eisenga, B. Hepkema, I.M. Nolte, S.P. Berger, M.H. de Borst, S.J.L. Bakker

Friday 16 march 2018

10:20 - 10:25h at Willem Burger Foyer

Categories: Clinical, Session (poster)

Parallel session: Poster session 6: Clinical

Background and objective

Pre-transplant dialysis duration is associated with increased mortality in renal transplant recipients (RTRs) due to accelerated atherosclerosis, intradialytic volume overload and subsequent progression of left ventricular hypertrophy. As a result, the cardiovascular system could deteriorate into a worse state in potential renal recipients. N-terminal pro brain natriuretic peptide (NT-proBNP), a protein released by ventricular cells in response of ventricular wall stress caused by volume overload, is a prognostic predictor of mortality in end-stage renal disease patients. The aim is to assess whether dialysis duration is independently associated with mortality in RTRs and if NT-proBNP explains the association between dialysis duration with mortality in RTRs.

Material and methods

648 patients, transplanted between January 1995 and December 2005 in the University Medical Center Groningen, were prospectively analysed after exclusion of 225 patients without sera NT-proBNP and 39 patients with graft failure within 1 year after transplantation. Multivariable Cox regression models were used to study the associations of dialysis duration and NT-proBNP with all-cause mortality. Mediation analysis was performed to evaluate whether the associations between dialysis duration and mortality were mediated by NT-proBNP.

Results

In multivariable Cox regression dialysis duration was associated with increased risk for post-transplant mortality, independent of potential confounders including age, gender, creatinine, diastolic blood pressure, diabetic nephropathy, donor type, delayed graft function, pre-emptive transplantation and CMV seropositivity (Hazard ratio [HR]: 1.39; 95% confidence interval [CI]: 1.11-1.75; P=0.004). This association weakened after adjustment for NT-proBNP (Hazard ratio [HR]: 1.25; 95% CI: 0.99-1.58; P=0.06). In this model NT-proBNP was independently associated with all-cause mortality in RTRs (HR: 1.46; 95% CI: 1.23-1.74; P=<0.001). In mediation analyses NT-proBNP was found to explain 47.3% of the effect of dialysis duration on all-cause mortality in RTRs.

Conclusion

Dialysis duration is a predictor of mortality in RTRs and variation in NT-proBNP at the time of transplantation to a large extent captures and mediates the effect of dialysis duration on mortality risk in RTRs. Future studies are needed to evaluate the potential value of NT-proBNP as check of cardiac patency of patients on the transplantation waiting list.