Impact of chronic kidney disease on the risk of clinical outcomes in patients with cancer-associated venous thromboembolism during anticoagulant treatment.

Background: Information on recurrent venous thromboembolic events (VTEs) and major bleeding risks during anticoagulant treatment in patients with cancer-associated VTEs and chronic kidney disease (CKD) is scarce, although it is of relevance in establishing better tailored management strategies in these patients.
Objectives: We compared risks of recurrent VTEs and major bleeds in cancer-associated VTE patients with and without CKD.
Methods: A total of 1684 patients diagnosed with a cancer-associated VTE between 2001 and 2011 were followed for 180 days after VTE diagnosis. Patients were treated mainly with low-molecular-weight heparin (LMWH) or vitamin-K antagonists (VKA). Primary outcomes were recurrent VTE and major bleeding. Secondary outcome was fatal bleeding.
Results: Recurrent VTEs occurred in 15.9/100 patient years (py) in patients without CKD (eGFR > 60 mL min(-1) ), 19.5/100 py in those with CKD stage 3A (eGFR 45-60 mL min(-1) ), 14.9/100 py in those with CKD 3B (eGFR 30-45 mL min(-1) ), and 6.8/100 py in patients with CKD 4-5 (eGFR < 30 mL min(-1) ). Major bleeding occurred in 11.4/100 py in patients without CKD, 18.5/100 py in those with CKD stage 3A, 16.0/100 py in those with CKD 3B, and 40.8/100 py in patients with CKD 4-5. Fatal bleeding occurred in 1.1/100 py, 3.4/100 py, 6.3/100 py and 15.7/100 py, respectively. These increased bleeding risks in CKD patients were mainly observed in those on LMWH treatment, not VKA.
Conclusions: The risk of major bleeding was increased in CKD patients with VTE and cancer, and was most prominent in those treated with LMWH and an eGFR < 30 mL min(-1) . These results indicate that LMWH should be used with caution in this specific population.
(© 2013 International Society on Thrombosis and Haemostasis.)