EuroSCORE and neutrophil adhesion molecules predict outcome post-cardiac surgery

Abstract

This study tested the hypothesis that surgical stress and the host response to this trauma trigger an inflammatory cascade in which the neutrophil plays a central role. We hypothesised that pre-operative neutrophil migratory responses will correlate with post-operative clinical outcome in our shock model of open-heart surgery patients. We also tested the hypothesis that surface expression of adhesion molecules involved in the migratory process - CD11b, CD47 and CD99 - could be used to predict outcome. We believe that combining neutrophil migratory response, CD11b, CD47 and CD99 with the logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) will strengthen the power of the EuroSCORE not only in predicting post-operative mortality but also other clinical endpoints. Neutrophils were isolated pre-operatively from n = 31 patients undergoing open-heart surgery and allowed to migrate across endothelial monolayers in response to N-formyl-methionine-leucine-phenylalanine (fMLP). Isolated neutrophils were also assessed for surface expression of CD11b, CD47 and CD99 in response to fMLP by flow cytometry. Post-operative clinical parameters collected included days 1-5 white cell count and creatinine levels as well as intensive care unit (ICU) and post-operative hospital stay. Pre-operative surface expression of CD99 and CD47 correlates with post-operative creatinine levels (P < 0·05), a measurement of renal injury. We also show that while the logistic EuroSCORE alone can be used as a predictor of ICU stay, when combined with pre-operative CD99 surface expression, it improves its AUC value (0·794). Immunological markers, specifically the ability of the neutrophil to migrate, combined with the logistic EuroSCORE lead to improved sensitivity and specificity to predict patient outcome.