Prospective analysis of coronary calcium in patients on dialysis undergoing a near-total parathyroidectomy

Abstract

Background: Patients with secondary hyperparathyroidism and on dialysis are more likely to die of cardiovascular disease than the general population; and we have reported that near-total parathyroidectomy (NTPTX) reduces that mortality rate. Patients on dialysis experience an average of a 15% increase in coronary calcification yearly, contributing to cardiovascular death. Cardiac computed tomography (CT) enables objective measuring of coronary calcium. The purpose of our study was to determine the impact of NTPTX on coronary artery calcium score (CACS).

Methods: CACS measurement was performed in patients with stage 5 chronic kidney disease before and after NTPTX from 2001 to 2008. Demographics, morbidities, CACS, outcomes, intact parathyroid hormone (PTH) measurements in follow-up (mean, 5.1 years) were maintained in an institutional review board-approved prospective database. Of 31 patients, 19 (61%) returned for a follow-up coronary CT.

Results: Preoperative mean PTH level and CACS were 1,794 ± 943 pg/mL and 979 ± 079, respectively; postoperatively, PTH and CACS were 321 ± 244 pg/mL (P < .001) and 1,285 ± 1,577 (P = .044), respectively. CACS was stable or reduced (<10% per year) in 6 of 19 patients (32%), and 42% of patients (n = 8) had nearly undetectable (<1% per year) change in CACS after NTPTX. In patients with stable CACS, mean postoperative PTH was 251 versus 516 pg/mL in patients with increasing CACS (P = .02). In patients with recurrent hyperparathyroidism (PTH > 400) compared with patients with stable postoperative PTH, CACS increased by 804 ± 1082 versus 16 ± 84 (P = .02).

Conclusion: Successful NTPTX with stable postoperative PTH levels is associated with stabilization of CACS in patients with severe secondary hyperparathyroidism undergoing hemodialysis, which could contribute to the improved survival seen after NTPTX.