Objectives: Venous limb gangrene has been reported to
occur after high warfarin doses in heparin-induced thrombocytopenia
(HIT), and this observation has been used to exclude warfarin
management in this condition. The outcome of patients receiving modest
doses of warfarin was studied.
study of 114 consecutive HIT patients who received diagnoses by
platelet aggregometry; 51 of the 114 patients received warfarin.
Setting: Tertiary-care medical center.
Results: Thirty-five patients received warfarin for non-HIT
indications, and 16 received warfarin for heparin-associated
thrombosis. Warfarin was given to 23 patients (47%) 2.4 ± 0.4 days
prior to the onset of HIT, in 19 while receiving IV heparin for an
overlap of 2.7 ± 0.4 days. Twenty-eight patients (53%) received
warfarin 2.8 ± 1.0 days after the diagnosis of HIT. Patients
received 11 ± 1 doses of warfarin over 16 ± 2 days, with a mean
daily dose of 3.5 ± 0.5 and a maximum dose of 9 ± 0.5 mg.
Prothrombin time at discharge was 17.3 ± 0.4 s with a maximum of
22.8 ± 0.8. The final international normalized ratio was
2.9 ± 0.3, and the maximum was 7.5 ± 1.4. The minimum therapeutic
range was reached in 59% of determinations. When compared to the 63
patients who did not receive warfarin, warfarin patients received more
IV heparin (86% vs 41%; p < 0.001), open heart surgery (78% vs
43%; p < 0.001), and had a lower mortality (8% vs 43%;
p < 0.001), but had no differences in
Conclusions: Modest doses of warfarin were
not associated with a worse outcome in patients with