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Poster Networking

Venous Thromboembolism

PB1460 - Anti-Xa level monitoring of low-molecular-weight heparin in patients with thrombosis and cancer

Tuesday, June 25, 2024
13:45 – 14:45 ICT
Room: Exhibition Hall
Background: Low-molecular-weight heparin is the standard treatment for cancer-associated thrombosis (CAT). The benefits of monitoring level of anticoagulation of low molecular weight heparins (LMWH) by determining anti-FXa activity in patients with oncological disease is controversial.

Aims: To assess the efficacy of LMWH anticoagulation by monitoring anti-Xa activity in patients with oncological disease.

Methods: Observational, descriptive, longitudinal and retrospective study. Results of anti-Xa activity determinations in our center were evaluated from 2018 to June 2023. The results of the anti-Xa activity, bleeding and rethrombosis events throughout the follow-up were included. Comparison between thrombosis and bleeding events with the different types of LMWH was drawn using Fisher's exact test.

Results: 447 results of anti-Xa activity from 50 patients were analyzed. 108 anti-Xa activity results (24.1%) were in the supratherapeutic range and 34 (7.6%) were infratherapeutic. A result out the therapeutic range in 21 anti-Xa determinations (34.2%) led to modification of the LMWH regimen. Six VTE events were detected in 6 patients, 4 pulmonary thromboembolisms (PE), one deep vein thrombosis (DVT) and one catheter-related thrombosis (CRT). Six bleeding episodes were recorded in six patients, with anti-Xa activity being supratherapeutic in two patients at the time of bleeding. No statistically significant differences were observed between bemiparin and enoxaparin and tinzaparin for thrombosis and bleeding events.

Conclusion(s): Monitoring anticoagulation using anti-Xa levels may be useful in some patients with oncological diseases receiving therapeutic doses of LMWH. Our results in relation to efficacy and safety were similar to published using different monitoring protocols of LMWH. Checking levels of anti-Xa activity when the determination is outside the range allows the LMWH dose not to be modified in cases of errors in the pre-analysis.