The patient's serum Ca level was 9.8 mg/dL, phosphorus 4.5 mg/dL, albumin 3.8 g/dL, and intact parathyroid hormone (iPTH) 652 pg/mL.
A 55-year-old African-American man with a history of hypertensive nephrosclerosis who has been on hemodialysis (HD) for the past 7 years was doing dialysis rounds. On physical exam he was well appearing, BP was 138/90 mm Hg, and his pulse was 84 bpm. He had no lower extremity edema and no rashes or skin lesions. A chest radiograph obtained the previous month was notable for calcifications in the right brachial artery. His only medications were metoprolol 25 mg twice daily and sevelamer 1600 mg 3 times a day with meals. His serum Ca level was 9.8 mg/dL, phosphorus level was 4.5 mg/dL, albumin level was 3.8 g/dL, and intact parathyroid hormone (iPTH) level was 652 pg/mL.
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This case was provided by Kevin Harley, MD, Assistant Clinical Professor of Medicine at the University of California in Irvine, and Antoney Ferrey, MD, Nephrology Fellow.
Chertow GM, Block GA, Correa-Rotter R, et al. Effect of cinacalcet on cardiovascular disease in patients undergoing dialysis. N Engl J Med 2012;27;367:2482-2494.
Kakuta T, Tanaka R, Hyodo T, et al. Effect of sevelamer and calcium-based phosphate binders on coronary artery calcification and accumulation of circulating advanced glycation end products in hemodialysis patients. Am J Kidney Dis 2011;57:422-431.
The patient’s elevated iPTH is above recommended goals for the management of secondary hyperparathyroidism attributed to renal disease. The addition of calcitriol and paracalcitol might decrease iPTH to goal, but could lead to hypercalcemia or worsened hyperphosphatemia. Active vitamin D is contraindicated in patients whose serum calcium is above 9.5 mg/dL. Dietary phosphorus reduction is advisable but with careful attention not to worsen overall nutrition and surrogate markers.
A number of studies have suggested that non-calcium-based binders are associated with less vascular calcifications than use of calcium-based binders in some patients. The EVOLVE trial was a randomized clinical trial that compared cinacalcet to placebo in patients who could receive conventional therapy including vitamin D and phosphate binders as indicated. In this study, the use of cinacalcet did not significantly reduce the risk of death or major cardiovascular events. However, such agents did lower iPTH and decreased the need for parathyroidectomy among HD patients. In this case, the use of a calcimemtic would improve PTH and not result in hypercalcemia making it the best answer.