Ankle-Brachial Index Predicts Vascular Calcification in SHPT

SAN DIEGO—Ankle-brachial index (ABI) may provide a simple and practice way to diagnose vascular calcification in patients on hemodialysis (HD) who have severe hyperparathyroidism (SHPT) and hyperphosphatemia, according to new study findings reported at the American Society of Nephrology’s Kidney Week 2018.

Maurilo Leite, MD, PhD, of Federal University of Rio de Janeiro in Brazil, and his colleagues assessed vascular calcification in 30 HD patients (mean age 44.8 years; 70% female; HD vintage 136.8 months) with mean intact parathyroid hormone levels (iPTH) of 2883.7 pg/mL and serum phosphorus of 6.1 mg/dL. Along with radiography, each patient had their ankle-brachial index (ABI) calculated.

Two-thirds (66%) of patients displayed calcification on radiographs of the hands and pelvis, with an Adragão Score greater than 3. Three quarters (76%) showed arteriovenous fistula (AVF) calcification and half (52%) lumbar aortic calcification.

Adragão score significantly correlated with calcification of the AVF and lumbar aorta, and an ABI of 1.79 significantly associated with Adragão score, AVF calcification, and phosphorus level.

According to Dr Leite’s team, these findings support a role for phosphorus in osteoblastic differentiation of vascular smooth muscle cells and calcification at the media of arterial walls. They added that ABI is a simple and practical clinical tool performed at bedside that can aid diagnosis in this population.

Reference

Leite M, Pichone A, Gomes Carlos. Ankle-brachial index predicts vascular calcification in hemodialysis patients with severe hyperparathyroidism. Presented at the American Society of Nephrology’s Kidney Week 2018 conference in San Diego, Oct. 23-28. Poster TH-PO224.