Relation between changes in red blood cell distribution width after coronary artery bypass grafting and early postoperative morbidity

Abstract

Background: Red blood cell distribution width (RDW) is highly associated with various clinical states. In the present study, we aimed to determine the natures of associations between RDW changes and early adverse events after isolated coronary artery bypass grafting (CABG). Methods: We retrospectively analyzed medical records of enrolled 117 patients. Patients were classified into two groups depending on early adverse events (No-event vs. Event). Delta RDW values were calculated (Delta RDW: Post-Peak RDW minus Pre-RDW). Patients were divided into tertiles based on Delta RDW. The Delta RDW cut-off point for an adverse event was determined by receiver operating characteristic curve analysis. In addition, logistic regression analysis was performed to identify independent factors of early adverse events. Results: Thirty eight patients experienced 53 early adverse events. Delta RDW and Delta C-reactive protein were significantly higher in the Events group than in the No-event group. Incidences of early adverse events increased significantly between Delta RDW tertiles (P<0.001). The ROC curve of Delta RDW showed that a Delta RDW of >= 1.45 had a sensitivity of 71.1 % and a specificity of 78.2% for predicting an early adverse event after CABG (P<0.001). Multivariable analysis showed Delta RDW (P=0.042) and length of ICU stay (P<0.001) independently predicted an adverse event. Conclusions: Delta RDW was identified to be an independent predictor of early adverse events, and a Delta RDW cut-off of 1.45 was found to predict early adverse events after CABG. Careful monitoring of RDW trends after isolated CABG provides a simple, inexpensive and objective means of predicting early adverse events.