Plasma and Cardiac Galectin-3 in Patients With Heart Failure Reflects Both Inflammation and Fibrosis

Background-Galectin (Gal)-3 is a beta-galactoside-binding lectin and currently intensely studied as a biomarker in heart failure. Gal-3 also exerts proinflammatory effects, at least in extracardiac tissues. Objective of this study was to characterize the relationship of plasma and myocardial Gal-3 levels with cardiac fibrosis and inflammation in patients with nonischemic dilated cardiomyopathy and inflammatory cardiomyopathy (iCMP). Methods and Results-Endomyocardial biopsies and blood samples were obtained from patients with newly diagnosed cardiomyopathy and clinical suspicion of myocarditis. According to histopathologic findings, patients were classified as having dilated cardiomyopathy (n= 40) or iCMP (n= 75). Cardiac fibrosis was assessed histologically on endomyocardial biopsy sections. In patients with iCMP, myocardial Gal-3 expression significantly correlated with inflammatory cell count on endomyocardial biopsy (r= 0.56; P < 0.05). In contrast, an inverse association was observed between myocardial Gal-3 expression and cardiac fibrosis in patients with iCMP (r=-0.59; P < 0.05). In patients with dilated cardiomyopathy, myocardial Gal-3 expression correlated with cardiac fibrosis on left ventricular biopsy (P= 0.63; P < 0.01). Of note, in both groups, plasma Gal-3 levels did not correlate with myocardial Gal-3 levels or left ventricular fibrosis, whereas a positive correlation between plasma Gal-3 levels and inflammatory cell count on endomyocardial biopsy was observed in patients with iCMP. Conclusions-The present study suggests that myocardial Gal-3 can be considered as a possible marker for both cardiac inflammation and fibrosis, depending on the pathogenesis of heart failure. However, circulating concentrations of Gal-3 do not seem to reflect endomyocardial Gal-3 levels or cardiac fibrosis.