Objective: The aim of this study was to evaluate the prognostic values of serum tenascin-C in patients with heart failure and ischaemic heart disease. Methods: Serum tenascin-C levels were assessed in 83 patients with heart failure and in 30 healthy subjects. The correlations between serum tenascin-C levels and left ventricular ejection fraction, serum B-type natriuretic peptide and procollagen III were analysed. Patients were followed up for 12 months, and the relations between the serum levels of tenascin-C and cardiac events (re-hospitalisation for worsening heart failure and mortality) were analysed. Results: Serum tenascin-C levels in patients with heart failure were higher than in healthy volunteers (72.24 +/- 11.02 vs. 22.78 +/- 2.51 mu g/L, p < 0.01). Serum tenascin-C levels in patients of NYHA class IV were higher than in patients with NYHA class II (88.56 +/- 3.73 vs. 64.88 +/- 3.15 mu g/L, p < 0.01). The levels of tenascin-C were negatively correlated with the left ventricular ejection fraction (r = -0.636, p < 0.01), but were positively correlated with serum B-type natriuretic peptide (r = 0.553, p < 0.01) or procollagen III levels (r = 0.665, p < 0.01). An increased level of tenascin-C was an independent predictor for combined re-hospitalisation and mortality (OR 1.22, 95% CI: 0.86-2.14). Conclusion: Serum tenascin-C levels were elevated in patients with heart failure. The levels of tenascin-C were associated with the severity of left ventricular dysfunction and 12-month major adverse cardiac events. (Heart, Lung and Circulation 2013;22:184-187) (C) 2012 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier Inc. All rights reserved.