PB1437 - Reduced- versus full-dose anticoagulants for the extended treatment of cancer associated venous thromboembolism

Background: Reduced-dose anticoagulant therapy in the treatment of cancer associated venous thromboembolism (VTE) has been used to avoid bleeding. However, it may increase the risk of recurrent VTE.

Aims: To study the rate of recurrent VTE and bleeding complications in patients with cancer associated VTE who were treated with reduced- or full--dose anticoagulants.

Methods: A retrospective study was conducted in a single center academic hospital. Patients with cancer associated VTE who received anticoagulants for at least 6 months were evaluated. Reduced-dose anticoagulant was defined as a dose that did not meet the recommended dosage. Electronic medical records were reviewed. The primary outcome was recurrent VTE. The secondary outcomes were major bleeding and clinically relevant non major bleeding.

Results: A total of 229 patients were included. The median age was 65 (IQR 54-72) years. In the reduced-dose group, age and history of previous bleeding were higher than in the full-dose group (table1). Lung and gynecological cancers were the most prevalent. There were 169 (74%) patients and 60 (36%) patients who received full- and reduced- dose anticoagulants. The median time to reduce the dose was 3.6 (interquartile range [IQR] 0.7- 5.5) months. Of a total of 7 (3.1%) recurrent VTE, 4 (2.4%) occurred in the full-dose and 3 (5.0%) in the reduced-dose groups (p=0.40), respectively. The median time to recurrent VTE was 7.2 (IQR 3.5-12.4) months. There were 8 (3.5%) bleeding events, 6 (3.5%) and 2 (3.4%) in the full- and reduced-dose anticoagulant groups (p=0.82), respectively (table2). The median follow-up time was 1.5 years (IQR 1-3.1).

Conclusion(s): Older age and history of previous bleedings were associated with the use of reduced-dose anticoagulants. Patients with cancer associated VTE receiving reduced-dose anticoagulants had a two-fold increased risk of recurrent VTE compared with those receiving full-dose anticoagulants while the bleeding risk was not different.