Analysis of anticoagulation strategies for venous thromboembolism during severe thrombocytopenia in patients with hematologic malignancies: a retrospective cohort.

The safety and efficacy of anticoagulation for venous thromboembolism (VTE) at times of severe thrombocytopenia is unclear. In this retrospective study, we evaluated patients with hematologic malignancy and either (1) acute or chronic VTE on anticoagulation before platelet count dropped below 50 × 109/L or (2) acute VTE occurring while platelets were <50 × 109/L. In 78 eligible patients, the primary outcomes of time to recurrent VTE or clinically significant bleeding within 100 d were compared by management strategy. Bleeding occurred in 27% of patients receiving anticoagulation versus 3% when anticoagulation was held (IRR 10.1, 95% CI 1.5-432.6). Recurrent VTE occurred in 2% of patients receiving anticoagulation versus 15% when anticoagulation was held (IRR 0.17, 95% CI 0.0-1.51). Most bleeding occurred before day 31(11/13), but recurrent VTE mostly occurred after day 40 (5/6). Our findings suggest that temporarily withholding anticoagulation for VTE during severe thrombocytopenia in patients with hematologic malignancies might reduce adverse outcomes.