#5922 CINACALCET IMPACT ON ESTIMATED GLOMERULAR FILTRATION RATE AMONG KIDNEY TRANSPLANT RECIPIENTS WITH SECONDARY HYPERPARATHYROIDISM: A CASE-CONTROL STUDY

Abstract

Abstract Background and Aims Secondary hyperparathyroidism (sHPT) is common in kidney transplant recipients. It remains unknown if Calcimimetic agents (as cinacalcet), oftenly used in this context, have an impact on mortality or morbidity. The objective of this work was to compare the renal and cardiovascular outcome of kidney transplanted patients with sHPT. Method Data from January 2008 to December 2019 were retrospectively extracted from the DIVAT database. 575 kidney transplant recipients with sHPT (PTH > 100 pg/ml) followed in Nantes University Hospital, were separated into two groups: Treated (cinacalcet) and sHPT Controls (no cinacalcet). A propensity score was used to match the patients (age, sex, first transplant, transplantation before/after 2015, time on dialysis, history of cardiovascular disease, initial condition, anti-HLA class I and II immunization, corticosteroids, serum parathormone level). Biological data (including estimated glomerular filtration rate by CKD-Epi formula), cardiovascular events (coronaropathy, obliterating arteriopathy of the lower limbs, stroke), return in dialysis or related death were extracted from one year of transplantation to the last follow-up. Time-varying exposure Cox PH model was used. Results 292 patients were included after matching (146 Treated, 146 sHPT Controls). After one year of transplantation, serum parathormone was significantly higher in Treated patients compared to sHPT Controls (152 pg/mL vs 111 pg/mL respectively, p < 0.001), suggesting a more severe sHPT in Treated patients. 7% of Treated and 10% of sHPT Controls suffered from a cardiovascular event or related death during the follow up (HR = 1.28 [0.52; 3.14], p = 0.6). Return to dialysis or related death were more frequent in the Treated patients (HR: 1.90 [0.97 - 3.75, p = 0.06]. At 48 months post-transplantation, estimated glomerular filtration rate was significantly decreased in Treated patients compared to sHPT controls (52.3 mL/min/1.73 m2 vs 44.1, p = 0.006). Conclusion Our study highlights that kidney transplant recipients with sHPT treated with cinacalcet have a worse kidney graft outcome than non-treated sHPT patients. It remains to be assessed if this reflects an underlying more severe sHPT condition or a direct effect of cinacalcet on the graft function. This study needs to be completed by the assessment of bone mineralization. Parathyroidectomy for sHPT should be discussed in kidney transplant recipients with impaired glomerular filtration rate and/or cardiovascular events.