Comparative Effectiveness and Safety of Direct-acting Oral Anticoagulants and Warfarin in Patients with Venous Thromboembolism and Active Cancer: An Observational Analysis

Abstract

Purpose: There is limited evidence to support the use of direct-acting oral anticoagulants (DOACs) in patients with venous thromboembolism (VTE) and active cancer. This study aimed to assess the effectiveness of DOACs versus warfarin for the prevention of recurrent VTE and major bleeding events in patients with VTE and active cancer.

Methods: We identified patients with incident VTE and active cancer who newly initiated treatment with DOACs or warfarin from Truven Health MarketScan Commercial Claims and Medicare supplemental databases. Patients were followed up from treatment initiation (index date) until the occurrence of >7-day gap in treatment, the start of the study comparator, an outcome of interest (recurrent VTE or major bleeding), inpatient death, disenrollment, or end of the study period, whichever occurred first. We controlled for confounders via propensity score matching and estimated the hazard ratios (HRs) using Cox proportional hazards regression models.

Findings: A total of 9952 patients were included in the matched cohort (4976 DOACs users and 4976 warfarin users). Patient characteristics were well balanced after matching. We observed a lower incidence of recurrent VTE (3 vs 5 per 100 person-years) and major bleeding events (2 vs 3 per 100 person-years) in the DOAC group compared to warfarin group, respectively. In Cox regression models, use of DOACs (vs warfarin) was associated with a lower risk of recurrent VTE (hazard ratio (HR), 0.59; 95% CI, 0.42-0.82) and major bleeding events (HR, 0.64; 95% CI, 0.44-0.94).

Implications: On the basis of our findings, among patients with VTE and active cancer, DOACs offer superior effectiveness with a lower risk of bleeding when compared with warfarin for the secondary prevention of VTE.

Keywords: DOACs; cancer; safety; thrombosis; venous thromboembolism; warfarin.