Objective: Patients with active cancer and venous thromboembolism (VTE) have elevated risk of recurrent VTE (rVTE) and major bleeding (MB). The risk is even higher within those with a prior bleeding event or renal disease. There is a need to understand the risk of rVTE and MB of commonly used anticoagulants among these high-risk patients.
Methods: VTE patients with active cancer and treated with apixaban, warfarin, or low molecular weight heparin (LMWH) within 30 days of VTE were identified from five claims databases in the United States. Inverse probability of treatment weighting (IPTW) was used to balance patient characteristics. The post-IPTW population was stratified by prior bleed or renal disease status. Cox proportional hazards models were used to evaluate interactions between treatment and prior bleed or renal disease on risk of rVTE and MB, with p value <.1 considered significant.
Results: Study criteria were met by 30,586 VTE cancer patients: 35.0% had prior bleed and 29.0% had renal disease. For apixaban, LMWH, and warfarin cohorts, the incidence (events per 100 person-years) of MB was higher in patients with prior bleed (17.48 vs 7.58, 25.61 vs 13.11, and 20.38 vs 8.97) or renal disease (15.79 vs 8.71, 22.11 vs 15.90, and 18.49 vs 10.39) vs those without the conditions. Generally, there were no significant interactions between anticoagulant use and prior bleed or renal disease on rVTE and MB (p for interaction >.1).
Conclusion: The incidence of MB was higher among those with prior bleed or renal disease. Effects of apixaban, warfarin, or LMWH were generally consistent regardless of prior bleed or renal disease status.
Keywords: VTE; anticoagulant; cancer; prior bleed; renal disease.