OP.2B.06] RENAL RESISTIVE INDEX AND PULSE PRESSURE AT 3 MONTHS HAVE A DIFFERENT IMPACT ON LONG-TERM RISK OF DEATH AND GRAFT LOSS IN RENAL TRANSPLANTATION

Abstract

Objective: Some studies suggest that pulse pressure (PP) and renal resistive index (RI) could be predictive of the risk of death; however, whether they also predict graft loss is debated. It was recently demonstrated that RI reflects large artery arterial stiffness as PP does but RI is also affected by alteration in renal microcirculation alteration. Finally, the respective predictive value of these 2 parameters considered together on graft loss and death is unknown. Design and method: Cohort study of consecutive patients who received a renal graft in Tours from 1985 to 2014 in whom PP and RI were measured at 3 months. The long-term risk of death and graft loss was assessed. Results: 1237 renal transplant recipients were included (age: 49.3 ± 14.5; 61.8% men). At 3 months, RI was 0.68 ± 0.08 (RI > 0.75: 17.2%; RI > 0.80: 5.8%). Arterial pressure was 138 ± 16/79 ± 11 (PP: 59.6 ± 14.5 mmHg; médiane: 60 mmHg); 55.4% were uncontrolled (i.e. PA> = 140/90 mmHg). During follow-up (meidan: 5.9 years; range: 0.4–27.5; 9772 patients-years), 130 patients died and 216 lost their graft. In univariate analysis, RI (as well as PP) was associated with the risk of death (RI > 0.80: HR = 2.50 [1.63–3.83]; RI > 75: HR = 3.19 [2.32–4.39], both: P < 0.0001) and graft loss (RI > 0.80: HR = 1.71 [1.16–2.52], P = 0.0068; RI > 75: HR = 1.53 [1.15–2.03], P = 0.0035). RI significantly predicted death (RI > 0.80: HR = 2.98 [2.10–4.23]; RI > 75: HR = 3.63 [2.32–5.69], both: P < 0.0001) but not PP > 60 mmHg after adjustment on RI > 0.80 (HR = 1.07 [0.75–1.52], P = 0.7088) or RI > 0.75 (HR = 1.04 [0.74–1.48], P = 0.8109) when RI and PP were simultaneously considered in multivariate analyses. Similar results were observed when RI and PP were expressed as continuous parameters, and after adjustment on recipient age. In contrast, only PP > 60 mmHg was associated with the risk of graft loss after adjustment on RI (HR for adj. on RI > 0.80: HR = 1.31 [1.01–1.71], P = 0.0457; HR for adj. on RI > 0.75: HR = 1.30 [1.00–1.70], P = 0.0516), and adjustment on RI and age (HR = 1.32 [1.01–1.73], P = 0.0406; HR = 1.32 [1.01–1.72], P = 0.0441 respectively); RI was not (RI > 80: HR = 1.17 [0.68–2.01], P = 0.5765; RI > 75: HR = 1.20 [0.85–1.69], P = 0.2933). Conclusions: Pulse pressure and renal resistive index at 3 months differently impact the long-term risk of death and graft loss.