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

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.