Relationships between circulating galectin-3, extracellular matrix fibrosis and outcomes in dilated cardiomyopathy

BACKGROUND Galectin-3 is an emerging biomarker in cardiovascular disease. Myocardial galectin-3 is involved in the pathology of cardiac fibrosis; however, the role of circulating galectin-3 is not yet established. OBJECTIVES To assess the relationships between circulating galectin-3, fibrosis and outcomes in dilated cardiomyopathy (DCM). MATERIAL AND METHODS We included 70 patients (age: 48 ±12.1 years, ejection fraction (EF) 24.4 ±7.4%) with new-onset DCM (n = 35, ≤6 months). Galectin-3 and procollagen type I and III (PICP, PINP, PIIICP, and PIIINP), transforming growth factor β (TGF-β), connective tissue growth factor (CTGF), osteopontin (OPN), matrix metalloproteinases (MMP-2 and -9), and tissue inhibitor (TIMP-1) were determined in serum at baseline and after 3 and 12 months. Patients underwent endomyocardial biopsy. The endpoint was a combination of death and urgent hospitalization at 12 months. RESULTS Galectin-3 did not correlate with biopsy-determined fibrosis. Baseline galectin-3 correlated with OPN,, TIMP-1, PIIICP, and MMP-2. In new-onset DCM, galectin-3 levels at baseline were higher than at 3 and 12 months, whereas in chronic DCM there was no difference. Galectin-3 was a predictor of the endpoint (hazard ratio (HR) = 1.115; 95% confidence interval (95% CI) = 1.009-1.231; p < 0.05). The best cut-off value was 14.54 ng/mL (area under the curve (AUC) = 0.67). Patients with galectin-3 ≥14.54 ng/mL had an increased risk of events (HR = 2.569; 95% CI = 1.098-6.009; p < 0.05). CONCLUSIONS Circulating galectin-3 is unrelated to fibrosis. Serial measurements of galectin-3 correlated with markers of fibrosis, including markers of collagen synthesis and OPN. Circulating galectin-3 was independently associated with cardiovascular (CV) outcomes in DCM.