Venous Thromboembolism in Patients With Thrombocytopenia: Risk Factors, Treatment, and Outcome

Venous thromboembolism (VTE) is a frequent and potentially lethal condition. Venous thrombi are mainly constituted of fibrin and red blood cells, but platelets also play an important role in VTE formation. Information about VTE in patients with thrombocytopenia is, however, missing.

To identify VTE risk factors and describe treatment and outcome (bleeding episodes and mortality) in patients with thrombocytopenia.

Patients with thrombocytopenia (platelet count <100 × 10⁹/L) admitted to Odense University Hospital, Denmark, between April 2000 and April 2012 were included. Fifty cases had experienced VTE. Controls without VTE were matched 3:1 with cases on sex and hospital department. Medical records were examined, and data were analyzed using conditional logistic regression.

In multivariate analysis, platelet count <50 × 10⁹/L (odds ratio [OR] 0.22, P < .05) and chronic liver disease (OR 0.05, 95% confidence interval [CI] 0.01-0.58) reduced the risk of VTE. Surgery (OR 6.44, 95% CI 1.37-30.20) and previous thromboembolism (OR 6.16, 95% CI 1.21-31.41) were associated with an increased VTE risk. Ninety-two percent of cases were treated with anticoagulants. There was no difference in bleeding incidence between cases and controls.

Several known VTE risk factors also seems to apply in patients with thrombocytopenia. Also, patients with thrombocytopenia may be VTE risk stratified based on platelet count and comorbidities. Finally, patients having thrombocytopenia with VTE seem to be safely treated with anticoagulants without increased occurrence of bleeding.