Incidence of venous thromboembolism in the setting of hematopoietic cell transplantation.

ABSTRACT

The underlying risk of venous thromboembolism (VTE) is unclear in patients undergoing hematopoietic cell transplantation (HCT). As such, these patients should still be considered at risk for development of VTE due to factors such as their underlying malignancy and the marked inflammatory state that develops from treatment. The purpose of this study was to characterize the incidence of VTE in patients undergoing HCT. Retrospective chart review of patients from the Indiana University Stem Cell Transplant Unit treated between January 1, 2008, and May 24, 2011. Patients were older than 18 years and had undergone HCT. The primary objective was to analyze the incidence of VTE in patients undergoing autologous HCT versus allogeneic HCT. Secondary objectives included documentation of VTE treatment strategies and time to occurrence of VTE. Of the 567 patients who underwent autologous HCT, 14 developed VTE (2.5%), whereas 5 of the 180 patients who underwent allogeneic HCT developed VTE (2.8%; P = 1.000). The median time to development of VTE from admission for HCT was 12 days in the autologous HCT arm versus 19 days in the allogeneic HCT arm (P = 0.610). The most commonly used VTE treatment strategy was enoxaparin (12 out of 19 VTEs). This study illustrates that VTE does occur rarely in patients who have undergone HCT. The optimal treatment regimen in this population requires further evaluation. Until a reliable protocol for treatment and evidence for risk factors are established, providers should be vigilant for occurrence of VTE in these patients.