VTE prophylaxis for Haematology Patients:

Current guidelines

• Based on RCT that exclude subjects with a potentially high bleeding risk (including platelet count
• No recommendations/ algorithms for prophylaxis in pateints with thrombocytopaenia

Not even in allogeneic transplant

• Current BCSH/BSBMT do not recommend heparin (unfractionated or low molecular weight) for prophylaxis of veno-occlusive disease (sinusoidal obstruction syndrome) in allogeneic bone marrow transplants

How common a problem is it?

• In acute leukaemia rate is 3.7 per 100 person years
• In acute lymphoblastic leukaemia 4.2 per 100 person years
• In acute myeloid leukaemia 3.4 per 100 person years

Where to go from here...

Bleeding is a major concern

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Is thrombocytopenia protective?

Platelet count at the time of VTE diagnosis ALL

Platelet count at the time of VTE diagnosis: AML

Does increased risk of VTE matter?

Does increased risk of VTE matter?

• Hazard ratio for death in the presence of VTE
• AML: 1.0 (95%CI 0.8-1.2; p value 0.99)
• ALL: 1.4 (95% CI 1.0-2.0; p value 0.3)

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Better risk stratification?

Risk Factors for VTE

• Previous VTE
• Chemotherapy (especially aspariginase)
• Central venous catheter
• Comorbid conditions
• Body mass index >30
• Immobolity
• Use of eythopoiesis--stimulating agent

In ALL patients Risk Factors

• Baseline platelet count 50-99x10^9/L (aOR 3.7)
• Philadelphia chromasome positivity (aOR 2.8)
• Age >40yo (aOR 2.7)
• presence of additional haematologic malignancy (myeloma, lymphoma; aOR 8.3)
• In women, hormonal therapy (aOR 2.4)

Risk Factors in AML

• Male (aOR 1.9)
• Liver disease (aOR 3.7)
• Use of Erythroid Stimulating Agent (aOR 2.4)
• Women, hormonal therapy (aOR 2.6)

How to implement risk stratification?

Conclusion

• While there is an increased risk of VTE the routine use of chemical prophylaxis confers an increased risk of bleeding
• No conclusive evidence about what to use and when to withold
• VTE is not associated with increased mortality in AML (and probably not ALL either)

Reference

• Vu, K. et al. A retrospective study of venothromboembolism in acute leukaemia patients treated at the University of Texas MD Anderson Cancer Center. Cancer Medicine. 2015; 4(1)27-35
• Tufano, A. et al. Prevention of Venous thromboembolism in Medical patients with Thrombocytopaenia or Platelet dysfunction: A review of literatures. Seminars in thrombosis and Haemostasis. 2011. 37(3):267-273
• Grace, H K. Venous thromboembolism in patient with with acute leukaemia: incidence, risk factors and effect on survival. Blood. 2009. 113(17):3911-3917
• Crowther, M. Bleeding risk and the management of bleeding complications in patients undergoing anticoagulant therapy: focus on new anticoagulant agents. Blood. 2008. 111(10): 4871 - 4879