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

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.

We aimed to determine whether patients with warfarin-associated calciphylaxis differ clinically from patients with warfarin-unassociated calciphylaxis.

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.

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.

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.