Evaluation of venous thromboembolism prophylaxis protocol in hematopoietic cell transplant patients

Hematopoietic cell transplant (HCT) recipients are at risk for thromboembolic and bleeding complications. There is limited evidence regarding the optimal approach to managing venous thromboembolism (VTE) prophylaxis in hospitalized patients undergoing HCT. In this retrospective cohort study, we evaluated the incidence of bleeding and VTE events in hospitalized HCT patients who received VTE prophylaxis per our institution’s VTE Prophylaxis Protocol (VPP), with either enoxaparin 40 mg subcutaneously daily or heparin 5 000 units subcutaneously twice daily, compared to historical controls who did not receive VTE prophylaxis. The primary outcome was a composite of major bleeding events, clinically relevant non-major bleeding (CRNMB), and minor bleeding. The secondary outcome was a composite of VTE events. A total of 614 patients were evaluated, including 278 prior to and 336 after implementation of VPP. VTE prophylaxis resulted in no difference in bleeding events (15.1% in the pre-VPP group vs. 14.6% in the post-VPP group, p = 0.86) or composite of major and CRNMB events (0.72% vs. 0.30%, p = 0.59). There was a trend toward lower incidence of VTE events in the post-VPP group which did not reach statistical significance (8.6% vs. 6.0%, p = 0.20). We conclude that VTE prophylaxis does not pose additional bleeding risk in HCT patients.