Warfarin therapy does not increase bleeding in patients undergoing heart transplantation

Abstract

Background. Historically, warfarin has been discontinued or rapidly reversed with fresh frozen plasma in patients awaiting heart transplantation because of concerns regarding excessive bleeding. Because preoperative warfarin may have effects on bleeding after cardiac operations, we reviewed our experience to determine the risks in patients undergoing heart transplantation while maintained on warfarin. Methods. The records of consecutive adult patients undergoing heart transplantation from January 1996 to December 1998 were reviewed. Preoperative and 24-hour postoperative data were obtained, including patient demographics; hematologic laboratory values; medication use; repeat or primary sternotomy data; allogeneic blood product administration; and chest tube drainage. Multivariate linear and logistic regression analyses were performed using these variables to determine risk factors for bleeding after heart transplantation. Results. Ninety adult patients, mean age 50 years, underwent orthotopic heart transplantation during the 36-month period. No relationships existed between preoperative international normalized ratio (INR, mean = 1.83 ± 0.1, p = 0.84) or postoperative INR (mean = 2.2 ± 0.9, p = 0.63) and chest tube drainage (mean = 721 ± 63 mL). Relationships were observed between total blood product administration and preoperative INR (partial r = 0.30, p = 0.01) and postoperative INR (partial r = −0.37, p = 0.002); however, preoperative INR did not correlate ( p = 0.29) when perioperative use of fresh frozen plasma was factored as a covariate. Inverse relationships were evident between postoperative INR and total blood product exposures, as well as transfusions of platelets (partial r = −0.26, p = 0.03), fresh frozen plasma (partial r = −0.28, p = 0.02), and red cells (partial r = −0.25, p = 0.04). Conclusions. Although we noted no correlations between INR and chest tube output, inverse relationships were observed with transfusion requirements in the first 24 hours after transplantation. Preoperative warfarin may be safely continued in patients awaiting heart transplantation.