Did blood transfusion increase mortality in patients with diabetes undergoing isolated coronary artery bypass graft surgery? A propensity score-matched analysis of 816 patients

Background: The aim of this study was to compare clinical outcomes of blood transfusion in patients with diabetes mellitus undergoing isolated on-pump coronary artery bypass grafting. Methods: The medical records of a total of 1,912 patients (1,300 males, 612 females; mean age 60.7 +/- 10.0) with diabetes who underwent isolated on-pump coronary artery bypass grafting between January 1999 and June 2019 were retrospectively analyzed. The patients were divided into two groups as patients with and without blood transfusions. The mortality rates were compared between the two groups. Results: The mortality rate was 14 times higher in the patients receiving blood transfusion (odds ratio: 14.80; 95% confidence interval 5.05 to 43.34; p<0.001). However, in the multivariate logistic regression analysis, there were no statistically significant difference in mortality between the patient groups, when diabetes mellitus was a covariate factor (Odds ratio: 8.34; 95% confidence interval 3.94 to 17.66 vs. odds ratio 8.36; 95% confidence interval 3.95 to 17.70). Conclusion: The propensity score-matched analysis of patients with diabetes showed that clinical outcomes were more severely affected by blood transfusion.