Factor V Leiden does not affect bleeding in aprotinin recipients after cardiopulmonary bypass

BACKGROUND: Carriers of the factor V Leiden mutation (FVL) are resistant to activated protein C proteolysis. Therefore, they are at increased risk of thromboembolic events. Aprotinin is an unspecific proteinase inhibitor frequently used during cardiac surgery procedures to reduce bleeding. However, aprotinin may cause thromboembolic complications after cardiopulmonary bypass (CPB). The primary endpoint of this study was the amount of blood loss after CPB in aprotinin recipients, and secondary endpoints were thromboembolic complications. METHODS: A total of 1,447 consecutive patients who underwent cardiac surgery with CPB were prospectively enrolled. All patients were screened for FVL by a fluorescence-based polymerase chain reaction method. Linear and logistic regression analyses were performed to assess associations of FVL on bleeding and thromboembolic complications. RESULTS: One hundred seven individuals (7.4%) were heterozygous FVL carriers. No difference was found between FVL carriers and noncarriers regarding age, sex, CPB, type of operation, EuroSCORE, antiplatelet treatment, and reoperation. FVL was not significantly associated with postoperative blood loss, whereas a significant influence was found for female sex (P < 0.0001), duration of CPB (P < 0.0001), reoperation (P = 0.001), and preoperative antiplatelet treatment (P < 0.002). Multiple linear regression analysis for total blood loss had an observed power of at least 99%. FVL carriers faced the same risk for postoperative transfusion (P = 0.391), reoperation (P = 0.675), myocardial infarction (P = 0.44), stroke (P = 0.701), and 30-day mortality (P = 0.4) as did noncarriers. CONCLUSIONS: These data suggest that FVL carriers do not have reduced blood loss compared with noncarriers. Furthermore, the combination of aprotinin and FVL does not enhance the risk for thromboembolic complications.