Protocol adherence and the progression of cardiovascular calcification in the ADVANCE study.

Background: The ADVANCE study assessed the progression of vascular and cardiac valve calcification in 360 hemodialysis patients with secondary hyperparathyroidism (sHPT) assigned randomly to treatment either with cinacalcet plus low-dose vitamin D (≤ 6 µg/week of intravenous paricalcitol equivalent) or with varying doses of vitamin D alone for 52 weeks. The primary efficacy endpoint was progression of coronary artery calcification (CAC).

Methods: In this post-hoc analysis, we compared CAC progression among 70 protocol-adherent subjects given cinacalcet and low doses of vitamin D (CPA) as specified in the study protocol and 120 control subjects given vitamin D sterols.

Results: Baseline patient characteristics did not differ between CPA and control subjects. The mean (standard error of the mean, SEM) doses of vitamin D at week 2 were 4.7 (0.3) and 12.8 (1.0) µg/week in CPA and control subjects, respectively, and the corresponding mean cumulative doses of vitamin D over 52 weeks in each group were 225 (22) and 671 (47) µg. The median change in Agatston CAC score after 52 weeks was less in CPA subjects than in controls (17.8% versus 31.3%, P = 0.02). The median increase in calcification scores in the aortic valve also was less in CPA subjects than in controls (6.0% versus 51.5% P = 0.02). Reductions in serum parathyroid hormone, calcium and phosphorus levels were significantly greater in CPA subjects than in controls (P < 0.05).

Conclusions: The progression of cardiovascular calcification was attenuated among cinacalcet-treated subjects with sHPT given low doses of vitamin D per protocol compared with control subjects in whom sHPT was treated with higher doses of vitamin D sterols alone.