Background: In severe chronic heart failure (CHF) elevated serum levels of uric acid (UA) predict poor survival. This study investigates whether hyperuricaemia (defined as serum UA level >= 6.5 mg/dL) extends its prognostic value on population with less advanced CHF. Methods: We studied 119 consecutive patients with stable, mild-moderate CHF (88 men, age: 64 +/- 11 years, NYHA class I/II/III: 9/65/45, LVEF: 32 +/- 8%). Results: Serum UA level (mean: 6.2 +/- 2.0 mg/dL, range: 2.0-16.2 mg/dL) increased in parallel to CHF severity expressed as NYHA class (4.9 +/- 1.1 vs. 5.7 +/- 1.5 vs. 7.2 +/- 2.4 mg/dL, NYHA I vs. II vs. III; NYHA I, II vs. III, p < 0.01), inversely correlated with peak oxygen consumption (r = 0.39, p < 0.01) and LVEF (r = -0.31, p < 0.01), but not with renal function (expressed as creatinine clearance calculated from Cockcroft-Gault formula; r = -0.14, p > 0.1), and predicted inflammatory status as evidenced by the correlation with C-reactive protein (r=0.31, p=0.003). Hyperuricaemia was detected in 48 (40%) patients. During follow-up (mean: 580 +/- 209 days, > 18 months in all survivors), 27 (23%) patients died. Hyperuricaemia was related to impaired survival in univariate (HR 2.8, 95%CI: 1.3-6.1, p=0.01) and multivariate analyses (adjusted for NYHA class and impaired renal function-the only mortality predictors in this population; p < 0.05). The 18-month survival for CHF patients with hyperuricaemia was 71% (95% CI: 58-84%) vs. 89% (95% CI: 81-96%) in those with normal UA level (p=0.01). Conclusion: In patients with mild-moderate CHF, hyperuricaemia predicts exercise intolerance and inflammatory activation and is strongly and independently related to poor prognosis. Whether elevated serum UA level may become a novel therapeutic target in CHF, deserves further studies. (c) 2006 Elsevier Ireland Ltd. All rights reserved.