Figure 20. In the EVOLVE trial, parathyroidectomy was performed in 140 (7%) cinacalcet-treated and 278 (14%) placebo-treated patients. Key independent predictors of parathyroidectomy included younger age, female sex, geographic region and absence of history of peripheral vascular disease. One hundred and forty-three (7%) cinacalcet-treated and 304 (16%) placebo-treated patients met the biochemical definition of severe, unremitting (« tertiary ») hyperparathyroidism. Considering the pre-specified biochemical composite or surgical parathyroidectomy as an endpoint, 240 (12%) cinacalcet-treated and 470 (24%) placebo-treated patients developed severe, unremitting hyperparathyroidism (254).