Determining the Optimal Parameters for Scoring Systems to Predict Postoperative Bleeding After Diabetic Coronary Artery Bypass Surgery

INTRODUCTION: Postoperative bleeding increases morbidity and mortality. We aimed to review the scoring systems used to predict massive bleeding after isolated coronary artery bypass grafting in diabetic patients and determine the parameters of the new scoring system - the Optimum Risk Score for Bleeding (ORS). METHODS: Two hundred ninety-seven diabetic patients who underwent isolated coronary artery bypass operation between 2017 and 2019 were reviewed. The patients were grouped according to amount of drainage (> 850 mL/day) and the European Multicenter Study on Coronary Artery Bypass Grafting (E-CABG) bleeding severity grade. Previously identified risk factors and scoring systems (Papworth, WILL-BLEED, Association of Cardiothoracic Anesthetists perioperative risk of blood transfusion [ACTA-PORT], Transfusion Risk and Clinical Knowledge [TRACK], and Transfusion Risk Understanding Scoring Tool [TRUST]) were analyzed. RESULTS: Papworth was better predictive for E-CABG bleeding grades 2 - 3. WILL-BLEED, ACTA-PORT, TRACK, and TRUST had no discriminatory value in terms of E-CABG bleeding grades 2 - 3. Among the parameters in the scoring systems, gender, preoperative hemoglobin (or hematocrit) value, preoperative platelet count, use of antiplatelets until less than five days prior to the operation, and preoperative creatinine (or estimated glomerular filtration rate) values should be included in the scoring system we aim to establish in the future, the ORS. CONCLUSION: The current scoring systems do not provide satisfactory results in predicting postoperative bleeding. Female gender, lower body mass index, and preoperative platelet count were associated with increased postoperative bleeding. There is a need for an ORS which gives more precise results in predicting postoperative bleeding.