Hyperuricaemia predicts poor outcome in patients with mild to moderate chronic heart failure

Abstract 

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.

Keywords: Chronic heart failure, Uric acid, Prognosis