Estimated Glomerular Filtration Rate at Re-Initiation of Dialysis and Mortality in Failed Kidney Transplant Recipients

Abstract

Background. Recent observational studies and a controlled trial suggest more favorable outcomes upon later dialysis initiation in chronic kidney disease. The role of estimated glomerular filtration rate (eGFR) in predicting outcome at reinitiation of dialysis in failed kidney transplant recipients is unclear. Methods. Five-year data in a large dialysis organization was linked to the 'Scientific Registry of Transplant Recipients' to identify 747 failed kidney transplant patients with CKD Stage 5, who had restarted dialysis therapy. A propensity score for early (eGFR >10.5 mL/min/1.73m 2 ) versus late reinitiation of dialysis was fit by logistic regression. The mortality hazard ratio (HR) was estimated across tertiles of the fitted score. Results. Patients were 44 ± 14 years old and included 42% women. Male gender {odds ratio (OR), [95% confidence interval (CI)]: 1.82 (1.22-2.73)}, diabetes mellitus [OR: 1.75 (1.14-2.68)] and peripheral vascular disease [OR: 3.55 (1.17-10.77)] were associated with higher odds of early dialysis reinitiation. Each mL/min/1.73m 2 higher eGFR was associated with 6% higher death risk in unadjusted model [HR: 1.06 (1.01-1.11)], and although not significant in fully adjusted models [HR: 1.02 (0.96-1.07)], it was significant in some subgroups including women and younger patients. The death HR of higher eGFR across lowest to highest tertiles of propensity score of early dialysis initiation (corresponding healthiest to sickest patients) were 1.10 (0.98-1.24), 1.00 (0.91-1.10) and 0.99 (0.92-1.07), respectively (P for trend <0.05), indicating a trend toward higher mortality risk with earlier dialysis initiation in the healthiest patients. Conclusions. Earlier return to dialysis therapy in failed kidney transplant patients tends to correlate with worse dialysis survival especially among healthiest and younger patients and women. Additional studies need to verify these findings.