Evolving risk for thromboembolism in spinal cord injury (SPIRATE study)

Objective: To compare the frequency of venous thromboembolism (VTE) in patients examined during 1992-1995 with those examined during 1999-2003. Design: A comprehensive review of the charts of all patients admitted between late 1999 and early 2003 for rehabilitation after spinal cord injury. Only records, including evidence for objective testing for VTE (ultrasound, venography, lung scanning) were included, and patients having inferior vena cava filter placement or previous VTE were excluded. Analysis variables included type and location of spinal cord injury, American Spinal Injury Association classification, concomitant injuries, surgical procedures, complications, preexisting illnesses, and use of antithrombotic prophylaxis. Using univariate optimal discriminant analysis, data from the current group of patients were compared with a previous study of 243 subjects examined between 1992 and 1995. Results: The current sample consisted of 76 persons with acute spinal cord injury, of whom six had VTE (7.9%). As compared with the frequency of VTE in the previous patient sample (21%), this represented a significant decrease (P < 0.01). The major differences between the current and previous patient samples were a decrease in the use of unfractionated heparin (15.8% vs. 56.8%, P < 0.0001) and an increase in the use of low molecular weight heparin (81.6% vs. 59.7%, P < 0.0001). Conclusions: VTE has been a common and occasionally lethal complication in persons with spinal cord injury. The recent switch from unfractionated heparin to low molecular weight heparin for the prevention of VTE has coincided with a decrease in the frequency of this complication in patients with spinal cord injury.