Dalteparin versus enoxaparin for venous thromboembolism prophylaxis in acute spinal cord injury and major orthopedic trauma patients: 'DETECT' trial

Background: To compare the impact of switching from enoxaparin 30 mg subcutaneously (SC) twice daily to dalteparin 5,000 units SC once daily for venous thromboembolism (VTE) prophylaxis in critically-ill major orthopedic trauma and/or acute spinal cord injury (SCI) patients. Methods: DETECT was a retrospective, cohort study at a tertiary care referral teaching center-phase I from December 1, 2002 to November 30, 2003 (enoxaparin); and phase 2 from January 1, 2004 to December 31, 2004 (dalteparin). Major orthopedic trauma patients with pelvic, femoral shaft, or complex lower extremity fractures, and/or acute SCI patients admitted to the intensive care unit and who received a low-molecular-weight heparin (LMWH) for VTE prophylaxis were included. Results: DETECT reviewed 135 patients (63 enoxaparin, 72 dalteparin), with similar baseline demographics, clinical characteristics, injuries, severity of illness, and risk factors for VTE. Clinically symptomatic proximal deep vein thrombosis (DVT) or pulmonary embolism (PE) rates were 1.6% with enoxaparin and 9.7% with dalteparin (p = 0.103, absolute risk increase [ARI] of 8.1% [-0.6% to 15.6%]), with no differences in major bleeding (6.4% versus 6.9%) or minor bleeding (64% versus 69%), or mortality (4.8 % versus 6.9 %). Switching from enoxaparin to dalteparin was associated with $12,485 (CAD) in LMWH acquisition cost savings. Conclusions: DETECT raises the hypothesis that dalteparin 5,000 units SC daily may not be clinically noninferior to enoxaparin 30 mg SC twice daily for VTE prophylaxis in this high-risk population. Until an adequately-powered, prospective noninferiority trial is performed, enoxaparin is supported by level 1 evidence and should be the prophylactic agent of choice.