Oral β-glucan reduces infarction size and improves regional contractile function in a porcine ischaemia/reperfusion model

Abstract

Objectives: We previously reported a cardioprotective effect of oral β-glucan in patients who underwent coronary artery bypass grafting. The present study was conducted to determine whether oral β-glucan could reduce myocardial infarction size and whether these changes would be reflected by better preservation of contractile indices measured by speckle tracking echocardiography (STE). Methods: Fourteen pigs were randomized to receive oral β-glucan 50 mg/kg (n = 7) or placebo (control, n = 7) 10 days before they were anaesthetized and subjected to 1 h clamping of the left anterior descending coronary artery followed by reperfusion for 3 h. Longitudinal strain, circumferential strain and radial strain were assessed by STE after 3 h of reperfusion. Infarction size and area at risk were determined by Evans blue and 2,3,5-triphenyltetrazolium chloride staining. Results: Pretreatment with β-glucan reduced the infarct area/area at risk ratio by 36% (P < 0.05) and the total necrotic area of the left ventricle by 37% (P < 0.05) compared with controls. Viable myocardium at risk was 30% higher in the β-glucan vs. control group (P < 0.05). Anterior apical strain values for β-glucan vs. control were -4.7 ± 9.4 vs. 5.9 ± 6.1% (P < 0.05) for longitudinal strain, -14.7 ± 6.6 vs. -7.7 ± 4.3 (P < 0.05) for circumferential strain, 15.1 ± 7.7 vs. 7.1 ± 11.8 (ns) for radial strain. Conclusions: Oral β-glucan pretreatment reduces infarction size and improves regional contractile function in a porcine ischaemia/reperfusion model. © The Author 2012. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.