Preoperative neutrophil response as a predictive marker of clinical outcome following open heart surgery and the impact of leukocyte filtration.

Abstract

Open heart surgery is associated with a massive systemic inflammatory response. Neutrophils, are the main mediator of this response. We hypothesised that the degree of neutrophil activation and inflammatory response to open heart surgery varies individually and correlates with clinical outcome. The aim of this study was to determine if individual clinical outcome can be predicted preoperatively through assessment of in-vitro stimulated neutrophil responses. Following that, the effects of neutrophil depletion through leukocyte filters are examined.

Neutrophil responses were assessed preoperatively (n=40) through change in neutrophil adhesion molecule [CD11b, CD62L and P Selectin Glycoprotein-1 (PSGL-1)] expression before and after in-vitro stimulation with Phorbol 12-myristate 13-acetate, PMA (1 ng/ml), lipopolysaccharide, LPS (1 μg/ml) and N-Formyl-Met-Leu-Phe, fMLP (1 ng/ml). Stimulated neutrophil responses were then correlated with postoperative clinical outcome. Patients were then randomised to leukocyte filtration (n=20) and a control group (n=20) and the effect of leukocyte filtration on neutrophil response and clinical outcome were investigated.

An individual variation in in-vitro stimulated neutrophil responses was demonstrated. Significant correlations were shown between neutrophil responses and maximum serum creatinine change, CKMB-fraction, adrenaline requirement, noradrenaline requirement, duration of adrenaline required and time to extubation. White cell count and percentage neutrophils were lower in the LD group (P=0.05). CD11b expression (P=0.005) and PSGL-1 expression (P=0.043) across leukocyte filters were also increased. However, no significant difference was detected in clinical outcome between the LD and control groups.

Preoperative neutrophil responses to in-vitro stimuli can predict clinical outcome following open heart surgery. However, leukocyte filtration did not offer significant benefit in clinical outcome in our study.