Evaluation of extended direct oral anticoagulant dosing strategies in patients with and without cancer from a prospective observational registry

Abstract

Background

Low-dose direct oral anticoagulants (DOACs) have been studied in randomized controlled trials for extended prevention of venous thromboembolism (VTE) after 6 months at therapeutic doses.

Objectives

This study examined the effectiveness, safety, and utilization of low-dose DOACs in a real-world cohort with dedicated analysis of cancer patients.

Methods

Consecutive patients enrolled in the Mayo Clinic VTE Registry from March 1, 2013, to December 31, 2022, were followed prospectively for VTE recurrence, major bleeding (MB), and clinically relevant non-MB (CRNMB). Patients with events during the first 3 months were excluded. After anticoagulation for 3 months with either rivaroxaban or apixaban, characteristics and outcomes of patients continuing anticoagulation were evaluated by Cox regression and a nested case-control study.

Results

In total, 466 patients (71% apixaban and 29% rivaroxaban) were identified on low-dose DOACs and 2273 in the full-dose group. Demographics between groups were mostly similar. Patients with active cancer as a provoking factor were less common in the overall low-dose DOAC group. In Cox regression analysis, VTE recurrence was not different between any groups. In noncancer patients, CRNMB but not MB was decreased in the low-dose group (hazard ratio [HR], 4.97; P < .001). In patients with cancer, low-dose DOACs were protective for MB (HR, 4.48; P = .001) and CRNMB (HR, 6.81; P < .001). Bleeding outcomes were the same in nested case-control analysis as well.

Conclusion

Dose reduction maintains low recurrence rates but also decreases bleeding, with the most pronounced effect in the cancer population.