Presentation Highlights

During Tuesday’s Abstract Symposia, Travis Cox, M.D. presented his work evaluating the effect of anticoagulation on survival in patients with venous thromboembolism (VTE) in the setting of acute leukemia and thrombocytopenia.

  • Patients with acute leukemia and VTE were assigned to one of three treatment groups: anticoagulation, inferior vena cava filter (IVCF), or observation.
  • Patients who received anticoagulation had increased survival with no increase in clinically relevant bleeding (CRB).
  • IVCF had no statistically significant benefit compared with observation alone, but there were no major IVCF-related complications.

The incidence of venous thromboembolism (VTE) is increased in patients with cancer, with VTE being the second most common cause of death in these patients. The highest rate of VTE is associated with hematological malignancies, and it appears to be a poor prognostic factor. There is, however, a paucity of high-quality evidence in leukemia-associated thrombosis complicated by thrombocytopenia. The ISTH SSC 2013 guidance statement does not recommend anticoagulation for patients with platelets <50,000/µL.

The aim of the study was to delineate the treatment outcomes and modifying factors in this complex subset of patients. The study was a 14-year, retrospective review of 2873 adult patients with acute leukemia and acute proximal lower extremity DVT/ PE and platelet count <50,000/μL. Patients who were anticoagulated for other indications, and those who had been treated with both IVCF and anticoagulation, were excluded.

Patients were assigned to one of three groups based on treatment: anticoagulation, IVCF, or observation. They were evaluated for recurrence of VTE by 6 months, clinically relevant bleeding (CRB), IVCF complications, and cause of death (COD). Bleeding was considered major if the patient had a hemoglobin decrease of ≥2 g/dL, required transfusion, occurred in a critical organ, or resulted in death.

The overall survival (OS) hazard ratio for anticoagulation vs. observation was 0.29 (p=0.0004), and for IVCF vs. observation was 0.66 (p=0.1858). For those with a history of VTE, the OS hazard ratio was 1.77 (p=0.0467). Overall survival was 10 months for the patients who received anticoagulation compared with 1.8 months with IVCF, and 1.3 months with observation only. This represents a significant survival advantage for those receiving anticoagulation.

There was no significant difference in CRB among groups. Major bleeding occurred in 17.4%, 38.1%, and 23.3% of patients in the anticoagulation, IVCF, and observation groups, respectively. Intracranial hemorrhage was highest in the IVCF group (19%) vs. the anticoagulation (4%) or observation groups (7%). Causes of death were primary disease and infection; cause did not vary among groups.

Overall, anticoagulation was associated with prolonged survival compared with the other groups, with no increase in CRB. In contrast, the use of IVCF did not provide a survival advantage compared with observation alone. These results are important, as they indicate that anticoagulation should be considered for VTE in the setting of acute leukemia, even when thrombocytopenia is present.

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