Evaluation of the older cadaveric kidney donor: The impact of donor hypertension and creatinine clearance on graft performance and survival

Background. The use of older donors for cadaveric renal transplantation (CRT) remains controversial because older donors are associated with decreased graft survival, yet offer the opportunity for donor pool expansion. We investigated the impact of two age-related donor factors, hypertension and calculated creatinine clearance (C-Cr), as predictors of graft outcome in recipients of CRTs from donors greater than or equal to 55 years of age. Methods. We reviewed 33,595 recipients of CRTs reported to UNOS since 4/1/94, of which 4,732 were from donors aged greater than or equal to 55 years. Outcome measures were graft survival, serum creatinine, and incidence of delayed graft function with 3 years of follow-up. We first analyzed the effect of hypertension on outcome from donors greater than or equal to 55 years: 2679 donors had no hypertension, 1058 had hypertension less than or equal to 10 years, and 557 had hypertension >10 years. Next, the effect of donor C-Cr as a risk predictor was investigated. Based on this analysis, recipients of older donors were grouped into two cohorts for comparison: 2570 donors with C-Cr <80 ml/min and 2162 donors with C-Cr greater than or equal to 80 ml/min. Results. Actuarial graft survival from donors aged <55 years was 88.0, 83.4, and 78.5% at 1, 2, and 3 years, vs. 80.6, 73.5, and 65.3% from donors greater than or equal to 55 years (P<0.0001). When stratified by hypertension, older donors hypertensive >10 years had survivals of 77, 66, and 57% vs. 81, 73, and 65% from donors without hypertension (P<0.017) and 80, 74, and 66% from donors hypertensive <10 years (P<0.017). When stratified by C-Cr, older donors with C-Cr <80 ml/min had survivals of 77, 69, and 62% vs. 83, 76, and 66% from donors with C-Cr greater than or equal to 80 (P<0.0001). Finally, older donors with both hypertension less than or equal to 10 years and C-Cr <80 ml/min had survivals of 77, 61, and 53%. Conclusions. Long-standing hypertension and low calculated creatinine clearance are risk factors for decreased graft survival of CRTs from older donors. When both factors are present, graft survival is significantly decreased.