Equivalent thrombotic risk with Warfarin, Dabigatran, or Enoxaparin after failure of initial direct oral anticoagulation (DOAC) therapy.

Abstract

The direct oral anticoagulants (DOACs) are now commonly regarded as first line anticoagulants in most cases of venous thromboembolism (VTE). However, the optimal choice of subsequent anticoagulant in instances of first line DOAC failure is unclear. To describe and compare outcomes with second line anticoagulants used after DOAC failure. Patients seen at an urban hospital system for an episode of acute VTE initially treated with either apixaban or rivaroxaban who experienced a subsequent recurrent thrombosis while on anticoagulation (1st recurrent thrombosis) were included. In total, 166 patients after apixaban or rivaroxaban failure were included. Following DOAC failure (1st recurrent thrombosis), the subsequent anticoagulant was warfarin in 60 patients (36%), dabigatran in 42 patients (25%), and enoxaparin in 64 patients (39%). Enoxaparin was preferentially prescribed in patients with a malignancy-associated etiology for 1st recurrent thrombosis (p < 0.01). The median follow-up time in our cohort was 16 months. There was no difference in 2nd recurrent thrombosis-free survival (p = 0.72) or risk for major bleeding event (p = 0.30) among patients treated with dabigatran, warfarin, or enoxaparin. In this retrospective analysis of patients failing first line DOAC therapy, rates of 2nd recurrent thrombosis and bleeding did not differ among subsequently chosen anticoagulants. Our study provides evidence that the optimal 2nd anticoagulant is not clear, and the choice of 2nd anticoagulant should continue to balance patient preference, cost, and provider experience.