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INTRODUCTION: Historically, warfarin has been discontinued in status I patients awaiting heart transplantation (Htx) due to concerns regarding excessive bleeding. Our clinical practice has been to maintain patients on warfarin regardless of status with a target international normalized ratio (INR) of 2.0 until Htx. Therefore, we reviewed our experience to determine the risk of bleeding and transfusion requirements in patients undergoing Htx while maintained on warfarin anticoagulation.
METHODS: We retrospectively reviewed the medical records on consecutive patients undergoing Htx from 1/96-11/98. Preoperative prothrombin time, INR, platelet count, total bilirubin, creatinine, aspirin and/or warfarin use, cardiopulmonary bypass (CPB) time, aprotinin or epsilon aminocaproic acid (EACA) administration, heparin and protamine dose, redo or primary sternotomy information, blood product administration and chest tube drainage in the first 24 hours were obtained.
RESULTS: A total of 91 adult patients underwent Htx including 1 heterotopic, 3 heart/kidney, and 7 redo Htx. Thirty-four patients had repeat sternotomies. The age was 50 + 10 years (mean + standard deviation) with a range of 21-64 years. The INR for all patients was 1.8 + 0.7 with a range of 0.9-3.5. The blood products transfused for all patients at 24 hours (hr) included 2.9 + 2.8 units packed red blood cells, 0.6 + 1.0 units of platelets, 2.1 + 2.7 units of fresh frozen plasma, and 0.3 + 0.6 units of cryoprecipitate. The 24 hr chest tube drainage was 762 + 599 ml. There was no correlation between preoperative INR and 24 hr chest tube drainage (p=0.3) or blood products transfused (p=0.9). Only 5 patients had to be reexplored for excessive bleeding.
DISCUSSION: Despite the perception that preoperative warfarin increases bleeding, we noted no correlation between prolongation of INR and chest tube drainage or transfusion requirements in our patient population. One postulated mechanism for this lack of bleeding is that patients receiving warfarin undergo less hemostatic activation during CPB with better preservation of coagulation. Further, the majority of our patients also received pharmacologic interventions with either aprotinin or EACA. We conclude that preoperative warfarin use does not increase the risk of bleeding in patients undergoing Htx, and the cessation of warfarin in status I patients is not warranted.