Characterization of Risk Factors for Calciphylaxis in Hemodialysis Patients in the Fraser Health Renal Program - A Matched Case-Control Retrospective Review.

INTRODUCTION: Calciphylaxis is a lethal and rare disease characterized by ischemic and necrotic skin lesions caused by vascular calcification of adipose tissue. There have been many risk factors analyzed in the literature; however, the pathogenesis of calciphylaxis is still not well understood and treatment options are limited due to the lack of interventional studies. Our objectives were to describe risk factors, prevalence, incidence, and outcomes for calciphylaxis in hemodialysis patients within the Fraser Health Renal Program.

METHODS: This was a retrospective matched case-control study of hemodialysis patients within the Fraser Health Renal Program. Hemodialysis patients with calciphylaxis were matched to hemodialysis patients without calciphylaxis in a 1:2 ratio for age and sex from September 2, 2017 to July 3, 2020.

FINDINGS: There was a total of 40 calciphylaxis cases matched to 80 controls. In the univariate analysis, peritoneal dialysis, higher body mass index, lower serum iron, lower transferrin saturation, sevelamer, cinacalcet, warfarin, iron (PO), and insulin were associated with increased risk of calciphylaxis. In the multivariate analysis, only peritoneal dialysis, serum iron, sevelamer, and warfarin were identified as significant and strong risk factors associated with calciphylaxis. A low prevalence of 1.9% and high mortality rate of 57.5% at 12 months was found for calciphylaxis cases.

DISCUSSION: Significant risk factors associated with calciphylaxis were peritoneal dialysis, serum iron, sevelamer, and warfarin. Future studies should further investigate the impact of minimizing exposure to these risk factors to reduce calciphylaxis development.