Paradoxical venous limb gangrene complicating oral anticoagulation in a patient with cancer-associated deep venous thrombosis

Ovarian malignancy unmasked by venous gangrene in a patient on warfarin therapy: a case report

Background

Venous gangrene complicating deep vein thrombosis in the context of anticoagulation use in patients with gynecologic malignancy is rarely reported. We report an unusual presentation of venous gangrene of the lower limbs associated with warfarin therapy in a 53-year-old woman from the Cook Islands with an occult ovarian cancer.

Case presentation

A 53-year-old woman of Cook Islands origin presented with exertional dyspnea, rapid atrial fibrillation, bilateral lower limb edema, and painful digital ischemia of her hallux. She was on warfarin therapy for atrial fibrillation and had a stable therapeutic international normalized ratio. Bilateral proximal lower limb deep vein thrombosis and digital gangrene subsequently developed in the setting of a supratherapeutic international normalized ratio and platelet count depletion. Her warfarin was reversed and heparin therapy was commenced with resulting correction of her thrombocytopenia.

Conclusions

We would like to attract the attention of the reader to the potential hazard of the use of warfarin in patients with malignancy. In our case, we also demonstrated a predictive value of supratherapeutic international normalized ratio and platelet count depletion that could herald massive thrombosis and gangrene in a patient who was previously stable on warfarin therapy. Early recognition and prompt reversal of warfarin in these circumstances is essential to correct the unbalanced prothrombotic process that leads to extensive thrombosis and gangrene. The outlook of such cases remains dismal and results in extensive morbidity and mortality.

Review: Recent Advances in Argatroban-Warfarin Transition in Patients With Heparin-induced Thrombocytopenia

Heparin-induced thrombocytopenia is a devastating, life-threatening, immune-mediated complication of therapy with unfractionated heparin, and less frequently, with low molecular weight heparin. Direct thrombin inhibitors are now standard therapy for the prevention of thrombosis in heparin-induced thrombocytopenia. Argatroban, a small synthetic molecule that inhibits thrombin at its active site, is increasingly used as the direct thrombin inhibitors of choice. Transition to longer term oral anticoagulation needs to be instituted after the platelet count has risen, because of the persistent risk of thrombosis. Although guidelines available in the literature outline the management of heparin-induced thrombocytopenia, they are not presented in a concise and comprehensive manner easily followed by physicians. This article reviews current recommendations, relevant studies, and clinical management trials carried out on patients with heparin-induced thrombocytopenia and provides updated, detailed guidelines for treatment of heparin-induced thrombocytopenia with emphasis on a key part of the management, the argatroban—warfarin transition.

Transition to an oral anticoagulant in patients with heparin-induced thrombocytopenia

Recommendations for transitioning from therapy with heparin or a low-molecular-weight heparin preparation to therapy with an oral anticoagulant in patients with acute venous or arterial thromboembolism have undergone several changes during the last two decades. Physicians are now comfortable with beginning treatment with an oral anticoagulant once the diagnosis is confirmed, and loading doses are no longer considered to be necessary. Exceptions to early transition may be necessary in patients with an extensive iliofemoral or axillary-subclavian vein thrombosis or pulmonary embolism where thrombolytic agents may be indicated, or in individuals who require surgery or other invasive procedures, or if there are concerns about bleeding. The avoidance of early transition to oral anticoagulants in patients with acute heparin-induced thrombocytopenia also has been advised because of the potential for further thrombotic complications, including venous limb gangrene and warfarin-induced skin necrosis.