April 16, 2026Open Access

Association Between the Early Postoperative Changes in Serum Brain Natriuretic Peptide and Allograft Survival After Kidney Transplantation: A Retrospective Cohort Study

Q: What is the clinical evidence from this study?

Study design: Cohort. Population: Kidney transplantation (n=179). Intervention: Early postoperative percentage increase in serum BNP (dBNP ratio). Primary outcome: Graft failure (HR 1.16, 95% CI 1.10-1.21, p=<0.001).

Q: What question did this study set out to answer?

To evaluate the association between early postoperative BNP changes and long-term kidney allograft survival.

Key Result

An increased early postoperative percentage change in serum BNP (dBNP ratio) was significantly associated with a higher risk of long-term kidney graft failure (HR 1.16; 95% CI 1.10-1.21; p<0.001).

Key Points

To evaluate the association between early postoperative BNP changes and long-term kidney allograft survival.
Retrospective cohort study of adult deceased-donor kidney transplant recipients from 2009 to 2018.
Categorized patients based on early graft function and measured serum BNP preoperatively and within 24 hours postoperatively.
Calculated percentage increase in BNP (dBNP ratio); performed Cox regression and ROC analyses.
Postoperative BNP levels and dBNP ratios varied significantly among graft function groups, with higher values in delayed graft function.
The dBNP ratio was significantly associated with graft failure (hazard ratio 1.16), indicating increased risk.
The dBNP ratio had better discriminatory performance for graft failure than postoperative BNP alone (0.815 vs. 0.596 area under the curve).
Recipients with dBNP ratio ≥ 18% showed poorer early graft function and reduced long-term survival.

Study Design

Type

Cohort (n=179)

Structured PICO

Is an early postoperative increase in serum BNP associated with long-term graft failure in adult recipients of deceased-donor kidney transplantation?

Population

179 adult recipients of deceased-donor kidney transplantation between 2009 and 2018.

Intervention

Early postoperative percentage increase in serum BNP (dBNP ratio) measured within 24 hours postoperatively.

Comparator

Lower dBNP ratio (<18%) or postoperative BNP alone.

Outcome

Long-term allograft survival / graft failure.hard clinical

An early postoperative increase in serum BNP (≥18%) is significantly associated with adverse long-term kidney allograft outcomes, suggesting its potential utility as a prognostic biomarker.

Main Result

Effect estimate: HR 1.16 (95% CI 1.10-1.21)

p-value: p=<0.001

Limitations

Potential for residual confounding

Abstract

Background: Kidney transplantation (KT) improves survival and quality of life in patients with end-stage kidney disease; however, long-term allograft survival remains a major challenge. Brain natriuretic peptide (BNP), a biomarker of cardiorenal stress and volume status, may be associated with early postoperative physiological changes after KT. This study evaluated the association between early postoperative BNP changes and long-term allograft survival, and explored the potential role of BNP-derived parameters in relation to graft outcomes. Methods: This retrospective cohort study included adult recipients of deceased-donor KT between 2009 and 2018. Patients were categorized according to early graft function. Serum BNP levels were measured preoperatively and within postoperative 24 h, and the percentage increase (dBNP ratio) was calculated. Cox regression and receiver operating characteristic analyses were used to identify risk factors for graft failure and evaluate the discriminatory performance of BNP-derived biomarkers, respectively. Results: Among the 179 recipients, postoperative BNP levels and dBNP ratios differed significantly across graft function groups, with higher values in delayed graft function. After multivariate adjustment, the dBNP ratio remained significantly associated with graft failure (hazard ratio, 1.16; 95% confidence interval, 1.10–1.21; p < 0.001). Additionally, the dBNP ratio demonstrated better discriminatory performance for graft failure compared with postoperative BNP alone (area under the curve, 0.815 vs. 0.596; p < 0.001), with an exploratory cutoff of approximately 18%. Recipients with a dBNP ratio ≥ 18% had poorer early graft function, lower longitudinal estimated glomerular filtration rates, and significantly reduced graft survival. Conclusions: An increased early postoperative dBNP ratio was significantly associated with adverse long-term kidney allograft outcomes. However, given the potential for residual confounding, these findings should be interpreted as associative and hypothesis-generating rather than predictive.