Parathyroidectomy in the calcimimetic era

With the introduction of the calcimimetic cinacalcet HCl, some patients who would previously have undergone parathyroidectomy are likely to remain on medical therapy. Data is available on complication rates and some important outcome measures of parathyroidectomy, but the efficacy of calcimimetics to influence patient-based endpoints such as cardiovascular mortality and renal osteodystrophy has not been established. Nevertheless, cinacalcet HCl has been demonstrated to improve levels of calcium, phosphate, the calcium phosphate product and parathyroid hormone (PTH). Based on available data, parathyroidectomy is proposed as the preferred treatment option when averaged levels of intact PTH (iPTH) exceed 85-95 pmol/L despite optimal therapy. When iPTH levels exceed 50 pmol/L, parathyroidectomy should be considered if levels of serum calcium, phosphate or the calcium phosphate product are above established target ranges or when patients with established osteoporosis have progressive loss of bone mineral density. Because the currently-recommended biochemical targets are difficult to achieve and maintain for many patients on dialysis, parathyroidectomy rates are likely to increase if these management proposals are followed. This highlights the need for prospective studies with 'hard' endpoints, to establish evidence-based roles for parathyroidectomy and calcimimetic therapy.