Galectin-3: a novel blood test for the evaluation and management of patients with heart failure.

Replacement of functional myocytes with crosslinked collagen as a result of tissue fibrosis is a final common pathway that is central to the progression of heart failure (HF), irrespective of etiology. In response to a variety of mechanical and neurohormonal stimuli, macrophages secrete galectin-3, which works as a paracrine and endocrine factor to stimulate additional macrophages, pericytes, myofibroblasts, and fibroblasts. The response to this signal is cellular proliferation and secretion of procollagen I. This protein is then irreversibly crosslinked to form collagen and result in cardiac fibrosis. With a commercially available assay, galectin-3 can now be measured in blood and has been found to aid in the prognosis of both systolic and nonsystolic HF. Measurement of galectin-3 before hospital discharge, on outpatient evaluation for suspected HF, and approximately twice per year for those with stable symptoms is supported by the evidence available at this time. Levels > 25.9 ng/mL, independent of symptoms, clinical findings, and other laboratory measures, predict a patient who is likely to have rapid progression of HF, resulting in hospitalization and death. In addition, a doubling in galectin-3 level over the course of 6 months, irrespective of baseline value, identifies a high-risk patient in whom additional care management efforts and advanced therapies could be warranted.