Diagnostic Utility of NT-proBNP in Tracking Cardiovascular Functional and Structural Changes in Advanced CKD and Post-Transplantation

Background: NT-proBNP is a critical biomarker in the management of heart failure. However, its role in tracking cardiovascular (CV) function and structure in patients with advanced chronic kidney disease (CKD) and after kidney transplantation remains unclear. Herein, we investigated the association between NT-proBNP with CV function and structure in advanced CKD and longitudinally post-kidney transplantation. Methods: We assessed 159 stage 5 CKD patients from the Cardiopulmonary Exercise Testing in Renal Failure and After Kidney Transplantation (CAPER) cohort, including kidney transplant recipients (KTR) and waitlisted controls (NTWC). All patients underwent cardiopulmonary exercise testing and echocardiography at baseline and one-year follow-up, and were stratified by baseline NT-proBNP quartiles (Q1-Q4). Results: Groups were balanced by sex and race (P > 0.05), however Q4 patients were older, had lower BMI, and were predominantly on hemodialysis (all P<0.03). Higher baseline NT-proBNP was associated with lower VO₂Max (gold-standard index of CV functional capacity), reduced peak HR, workload, endurance time and elevated LVMI (all P<0.007). Longitudinally, NTWCs demonstrated worsening VO₂Max, workload, peak HR, and endurance time, along with a mean 89% increase in NT-proBNP. In KTRs VO₂Max, workload, and endurance time improved in parallel with a mean 92% reduction in NT-proBNP after transplantation (all P≤0.02). Changes in logNT-proBNP before and after transplantation were associated with alterations in VO₂Max, peak HR, workload, and elevated LVMI (all P<0.02). Conclusion: Elevated NT-proBNP reflects impaired CV function and structure in advanced CKD and may serve as a prognostic biomarker for tracking improvements in cardiovascular health advanced CKD and undergoing kidney transplantation.