Venous Thromboembolism Post-allogeneic Hematopoietic Cell Transplant: Risk Factors, Incidence, and Outcomes

Area of Science:

• Hematology
• Transplant Medicine
• Oncology

Background:

• Venous thromboembolism (VTE) is a known complication in malignancy patients.
• Data on VTE incidence and impact in allogeneic hematopoietic cell transplant (HCT) recipients are limited.
• This study investigates VTE in a contemporary HCT cohort.

Purpose of the Study:

• To determine the incidence of VTE after allogeneic HCT.
• To identify risk factors associated with post-HCT VTE.
• To evaluate the impact of VTE on transplant outcomes, including nonrelapse mortality (NRM) and overall survival (OS).

Main Methods:

• Retrospective review of patients undergoing allogeneic HCT from January 2014 to August 2019.
• Identification of patients who developed post-HCT VTE.
• Competing risk analysis to investigate patient, disease, and transplant-related risk factors for VTE.

Main Results:

• The study included 431 patients; 14.8% developed VTE.
• Cumulative incidence of VTE reached 13.8% by 36 months post-HCT.
• Independent risk factors for VTE included older age, prior VTE history, and grade 2-4 acute graft-versus-host disease (GVHD).
• VTE was associated with significantly increased NRM (HR: 4.09) and decreased OS (HR: 2.19).

Conclusions:

• VTE is a critical complication following allogeneic HCT.
• VTE significantly increases the risk of nonrelapse mortality and decreases overall survival.
• Older age, prior VTE, and acute GVHD are key risk factors for developing VTE post-HCT.