Warfarin therapy and perioperative transfusion requirement with bleeding amount in patients undergoing cardiac surgery with cardiopulmonary bypass: a retrospective study.

SUMMARY Objectives The study was designed to evaluate the effect of warfarin on perioperative transfusion, bleeding and coagulation status in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). Background There were controversy about the effect of warfarin on perioperative transfusion and bleeding. Methods/Materials Medical records from 107 consecutive patients with atrial fibrillation (AF) on warfarin therapy undergoing cardiac surgery with cardiopulmonary bypass (CPB) from 2008 to 2013 at a single university teaching hospital were retrospectively reviewed to compare the patients on to those not on warfarin therapy in terms of perioperative transfusion requirement, postoperative 24-h bleeding amount, and coagulation status assessment using prothrombin time (PT), international normalised ratio (INR) and rotational thromboelastometry (ROTEM®). Results Although PT/INR was significantly prolonged both before and after surgery in patients on warfarin therapy, ROTEM® data, perioperative transfusion requirement and postoperative 24-h bleeding amount (785 ± 331 vs 676 ± 303 mL, P = 0·089, respectively) were not significantly different between the patients on and those not on warfarin therapy. Conclusion In patients on warfarin therapy undergoing cardiac surgery with CPB, warfarin therapy did not significantly increase perioperative transfusion requirement and bleeding.