Reduced- versus full-dose anticoagulants for the extended treatment of cancer-associated venous thromboembolism in Thai patients

Abstract

Background: Reduced-dose anticoagulant therapy for extended treatment of cancer-associated venous thromboembolism (VTE) has been used to avoid bleeding. However, it may increase the risk of recurrent VTE. Objectives: To study the rate of recurrent VTE and bleeding complications in Thai patients with cancer-associated VTE who were treated with full-dos/e or reduced-dose anticoagulants. Methods: A retrospective cohort study was conducted in a single-center academic hospital. Electronic medical records were reviewed from 2016-2023. Patients with cancer-associated VTE who received anticoagulants for at least 3 months were evaluated. Reduced-dose anticoagulant was defined as a dose that was lower than the recommended standard dosage. The primary outcome was recurrent VTE. The secondary outcomes were major bleeding and clinically relevant nonmajor bleeding. Results: A total of 229 patients were included. The median age was 65 years (IQR, 54-72). In the reduced-dose group, age and history of previous bleeding were higher than in the full-dose group. There were 169 (74%) patients and 60 (26%) patients who received full- and reduced-dose anticoagulants. The median time to reduce the dose was 3.6 months (IQR, 0.7-5.5). Of a total of 7 (3.1%) recurrent VTEs, 4 (2.4%) occurred in the full-dose and 3 (5.0%) in the reduced-dose groups (P = .4), respectively. The median time to recurrent VTE was 7.2 months (IQR, 3.5-12.4). There were 8 (3.5%) bleeding events, 7 (4.1%) and 1 (1.7%) in the full and reduced-dose anticoagulant groups (P = .35), respectively. The median follow-up time was 1.5 years (IQR, 1-3.1). Conclusion: Older age and a history of previous bleeding were associated with the use of reduced-dose anticoagulants. Patients with cancer-associated VTE receiving reduced-dose anticoagulants had a numerically higher risk of recurrent VTE and lower bleeding outcomes compared with those receiving full-dose anticoagulants.