EFFECTS OF PREOPERATIVE ENOXAPARIN ON BLEEDING AFTER CORONARY ARTERY BYPASS SURGERY

Low molecular weight heparins are replacing unfractionated heparin in practice prior to cardiac surgery. This study examines postoperative (post-op) bleeding indicators in patients who received enoxaparin and underwent elective isolated first time coronary artery bypass graft.

A total of 125 consecutive patients who underwent this procedure between 2009 and 2011 at one tertiary center were reviewed and divided into three groups: Group A (n = 50) received the last dose of enoxaparin between 12 and 24 hours before surgery, Group B (n = 25) received the last dose before 24 hours and Group C (n = 50) did not receive enoxaparin. Perioperative bleeding indicators and transfusion rates were compared.

Preoperative patients' characteristics were comparable between the three groups. There were no perioperative deaths, return to the operating room for any reason, nor major bleeding. Post-op bleeding indicators were similar in the three groups. The average chest tube drainage at 24 hours post-op was 880 mL, 695 mL and 830 mL in Group A, B and C respectively (p = 0.71). Transfusion rates of red blood cells were not statistically different (Group A 56%, B 64% & C 62%; p = 0.747). In multivariate analysis, female gender, older age, and preoperative clopidogrel intake (stopped 5 days prior to surgery) were associated with higher transfusion rates.

In elective first time coronary artery bypass graft patients who had no aspirin or clopidogrel intake 5 days prior to surgery, the use of enoxaparin up to 12 hours prior to skin incision does not increase the risk of post-op bleeding.