Data and statistical analysis

All statistical analysis was performed with GraphPad Prism version 4.00 (GraphPad Software, San Diego California USA). We have previously reported [12] that Elafin had no effect on all outcome measures assessed and data from patients receiving placebo and active treatment arms were therefore aggregated. Plasma hs-cTnI, hs-CRP, IL-6, IL-8 and MPO concentrations at each time point were expressed as median [inter-quartile range], mean ± standard error of mean or mean (95% confidence intervals) as appropriate. Forty-eight hour area-under-the-curve (AUC) was calculated for plasma hs-cTnI, hsCRP and cytokines.

The change in mass of infarcted tissue was determined by the difference in LGE from the preoperative and first postoperative CMR scans. This was categorized as increased, no change or reduced according to detection threshold based on inter-observer variability and agreement between both independent analysers. The absolute change in ejection fraction from pre to post surgery was calculated and an arbitrary value of 5% change was used to categorize patients into increased, decreased or no change.

Categorical data were compared using the Pearson’s chi-square test. Non-parametric R2* data were analysed with the Mann-Whitney U-test. Multiple comparisons for USPIO uptake were compared using Kruskal-Wallis. If significant, Dunn’s multiple comparison post-test was performed comparing R2* value across groups. Statistical significance was defined as two-sided P < 0.05.