Preoperative platelet inhibition with ASA does not influence postoperative blood loss following coronary artery bypass grafting

INTRODUCTION: Platelet inhibition is thought to increase perioperative blood loss in patients with planned coronary artery bypass grafting (CABG). This retrospective study reviews the results of over 10 000 patients with CABG, comparing continued platelet inhibition with preoperative disruption of this therapy.

PATIENTS AND METHODS: From 1995 to 2007, 12 023 patients underwent isolated CABG and were included in this study. The data were evaluated with regard to preoperative aspirin therapy, EuroScore relevant risk factors, and the operative results. Parameters of the operative outcome were in-hospital mortality, perioperative infarctions, reexploration rate, strokes, pericardial tamponade, blood transfusions, and perioperative drainage loss.

RESULTS: The patients were divided into two groups: group A (continuous aspirin therapy till surgery [n = 2519]), and group B (patients with preoperative interruption of their aspirin therapy for at least five days [n = 9504]). There was no difference between the groups with regard to age, EuroScore (4.3 +/- 2.8 vs. 4.2 +/- 2.9), emergency cases (8.8 % vs. 8.7 %), left main stenoses (17.9 % vs. 17.6 %), duration of surgery (198 +/- 53 vs. 198 +/- 52 min.) and sex distribution. The postoperative drainage loss did not differ between groups A and B (834 +/- 781 ml vs. 902 +/- 811 ml), nor did the number of postoperatively administered red cell packages (0.88 +/- 2.7 vs. 1.01 +/- 2.9). When analyzing the three subgroups "on-pump primary CABG", "OPCAB procedures", and "redo CABG", again no difference was found in the main outcome parameters. Only the redo CABG of group B had a higher reexploration rate compared to group A (5 % vs. 3.3 %, P < 0.05).

CONCLUSION: Preoperative aspirin therapy does not seem to influence the operative outcome of isolated CABG. Therefore, the often given recommendation to stop this therapy prior to elective CABG procedures should be abandoned.