Etelcalcetide use During Maintenance Hemodialysis and Incidence of Parathyroidectomy After Kidney Transplantation

Introduction: Etelcalcetide is an i.v. calcimimetic agent, effectively reducing parathyroid hormone levels in patients on maintenance hemodialysis (HD). The clinical impact of discontinuing etelcalcetide at the time of kidney transplantation is unknown. Methods: We retrospectively reviewed all patients on HD meeting prede fi ned criteria who received a kidney transplant at our institution between January 1, 2015, and December 12, 2022. The incidence of parathyroidectomy and the evolution of calcium, phosphate, and intact parathyroid hormone (iPTH) levels after transplantation was analyzed according to the type of calcimimetic treatment before transplantation (cinacalcet vs. etelcalcetide vs. none). Results: Overall, 372 patients (aged 53 years; interquartile range [IQR]: 42 - 62 years) were included. At the time of transplantation, 35, 75, and 262 patients were under etelcalcetide, cinacalcet, or no calcimimetic, respectively. After 1064 (IQR: 367 - 1658) days, the incidences of parathyroidectomy in the etelcalcetide, cinacalcet, no calcimimetic groups were 29%, 12%, and 1%, respectively ( P < 0.001). Etelcalcetide was associated with an increased incidence of parathyroidectomy after adjustment for age, sex, and HD vintage (hazard ratio [HR]: 97.0, 95% con fi dence interval [CI]: 19.1 - 493.9, P < 0.001). The incidence of parathyroidectomy was related to etelcalcetide dosage (6/11 [54.6%] in patients with >= 10 mg vs. 4/24 [16.7%] in patients with < 10 mg, P 1 / 4 0.02). Moreover, peak calcium levels were higher ( P < 0.001) and parathyroidectomy was performed earlier (median 80 vs. 480 days, P < 0.001) in the etelcalcetide compared with the cinacalcet group. Long-term graft function, graft loss, and mortality were similar. Conclusion: Etelcalcetide use during maintenance HD is associated with an increased incidence of early parathyroidectomy after transplantation compared to cinacalcet or no calcimimetic.