Evaluating the validity of subclassifying warfarin-associated nonuremic calciphylaxis: a retrospective cohort study

Background: Calciphylaxis is a devastating multifactorial disorder of the subcutaneous fat that is known to be associated with hypercoagulability. Recent literature has proposed subclassifying patients with calciphylaxis as having warfarin-associated or warfarin-unassociated disease. Aim: We aimed to determine whether patients with warfarin-associated calciphylaxis differ clinically from patients with warfarin-unassociated calciphylaxis. Materials and methods: We performed a subgroup analysis of patients with nonuremic calciphylaxis from a previously studied cohort and compared clinical and outcomes features of patients who were taking warfarin at the time of disease onset to those of patients who were not. Results: Nineteen patients with nonuremic calciphylaxis were identified, including 10 (53%) who had been on warfarin at the time of disease onset and 9 (47%) who had not. Of all clinical and outcomes parameters tested, no significant differences were detected between the two groups. Discussion and Conclusions: Though this study is limited by its retrospective nature and the relatively small number of patients studied, available data do not support subclassifying patients with nonuremic calciphylaxis as having warfarin-associated or warfarin-unassociated disease. Rather, the body of literature would suggest that identification and correction of underlying disorders of hypercoagulability should be prioritized.