Calcific Uremic Arteriolopathy: Mortality Outcomes with and without Sodium Thiosulfate Therapy

Calcific uremic arteriolopathy (CUA) is commonly seen in patients with end stage kidney disease (ESKD) and carries a high mortality risk. Treatment with intravenous sodium thiosulfate (STS) is beneficial but its mortality advantage over therapy without STS is unknown.

We retrospectively reviewed our ESKD patient's records over a 10-year period and identified 45 biopsy confirmed cases of CUA. Associations between patients who received STS therapy and those who did not and various categorical end points were assessed using the chi-squared tests while differences in continuous end points were examined using Mann-Whitney- U tests. Multivariate logistic regression (MLR) models were used to evaluate associations between mortality and several clinical variables. Survival analysis utilized Kaplan-Meier plots.

The mean age of the 45 cases was 63, 60% female, mean body mass index was 34 and mean dialysis vintage was 4yrs. Of the 45 cases, 23 (51%) received STS while 22 (49%) did not. The mean level of serum albumin, phosphorus and parathyroid hormone was 2.8 g/dl, 6.7 mg/dl and 989 pg/dl respectively. One –year mortality was higher in patients with proximal than those with distal lesions (48% vs. 20%, p = 0.05). Overall mortality was 26% in patients who received STS vs. 59% in those who could not receive STS (p = 0.03). Patients who did not receive STS were also more likely to have major surgeries than those who did, 86% vs. 52%, p = 0.01. Adjusted MLR analysis showed a significant association between mortality and: serum phosphorus, Odds Ratio (OR) 3.4, p = 0.03; proximal skin lesions, OR 8.4, p = 0.05; and severe lesions, OR 17.0, p =0.03.

Sodium thiosulfate therapy may confer a survival advantage over no STS. We encourage hospitals and dialysis companies to procure and make this agent more available to physicians.