Warfarin for venous thromboembolism prophylaxis in lung transplant recipients: A quality improvement project

Lung transplant recipients have a high risk of developing venous thromboembolism (VTE) and increased mortality from VTE due to lack of bronchial circulation after transplant. Increased risk of VTE is also observed in patients taking sirolimus as part of their immunosuppression regimen. Currently, there is no guideline on long-term VTE prophylaxis in this patient population. A protocol was developed at a single lung transplant center where 1 mg warfarin was used in lung transplant recipients who take sirolimus to reduce the risk of VTE. This project was a retrospective chart review study to compare the VTE rate in patients who were treated with 1mg warfarin and those who were not. The study found a VTE rate of 27.2 % in lung transplant recipients taking sirolimus at this transplant center. There was no reduction in VTE with the use of 1mg warfarin. Male gender was found to be an independent risk factor for VTE development. Hospitalization, surgery, and central line placement were found to be associated with significant increased risk for VTE. Limitations of the study include retrospective design, selection and recall bias, confounding bias, and small sample size. More aggressive measures are warranted to prevent VTE in patients with multiple risk factors. The results from the study can be used to guide further research and practice in this perspective.