Intraoperative transfusion and an increased preoperative C-reactive protein level are associated with higher mortality after off-pump coronary artery bypass grafting

Objective: The effects of transfusion on clinical outcomes after cardiac surgery remain inconclusive. We hypothesized that the risk of postoperative cumulative long-term, all-cause mortality after transfusion in patients undergoing cardiac surgery would differ by individual inflammatory status reflected by C-reactive protein level; thus, we performed a retrospective study. Methods: All patients who underwent isolated off-pump coronary artery bypass grafting between October 2004 and October 2015 were retrospectively included. Patients were divided into 4 categories according to whether the preoperative C-reactive protein level was greater than or less than 1 mg/dL and whether red cells were transfused intraoperatively. The 4 categories were as follows: low C-reactive protein without transfusion; low C-reactive protein with transfusion; high C-reactive protein without transfusion; and high C-reactive protein with transfusion. A multivariable Cox regression was then performed. Sensitivity analysis in subgroup (<3 units of red cells transfused) was also performed. Results: A total of 1636 patients were analyzed. Of the 4 categories, patients in the high C-reactive protein with transfusion group were at significantly higher risk of mortality than the low C-reactive protein without transfusion (hazard ratio, 1.86; 95% confidence interval, 1.24-2.79) or with transfusion group (hazard ratio, 1.47; 95% confidence interval, 1.13-1.93). A sensitivity analysis of patients who received only 1 or 2 units of red cells showed similar results. Conclusions: Intraoperative red blood cell transfusion in patients with increased C-reactive protein level was significantly related to the risk of mortality after off-pump coronary artery bypass grafting.