Association of uric acid with mortality in patients with stable coronary artery disease

Abstract

Objective: The association between uric acid and cardiovascular disease is poorly studied. We undertook this study to assess whether uric acid level predicts clinical outcome in patients with stable coronary artery disease (CAD) treated with percutaneous coronary intervention (PCI).

Materials/methods: This study included 8149 patients with stable CAD who underwent PCI. Uric acid was measured before angiography. The primary end point was 1-year mortality. Quartiles of quartiles of uric acid were: 1.49 to <5.49 mg/dl (1st quartile; n=2032 patients), 5.49 to <6.40 mg/dl (2nd quartile; n=1981 patients), 6.40 to <7.50 mg/dl (3rd quartile; n=2093 patients) and 7.50 to 21.90 mg/dl (4th quartile; n=2043 patients).

Results: There were 196 deaths during the 1-year follow-up. The numbers of deaths (Kaplan-Meier estimates) according to uric acid quartiles were: 35 deaths (1.8%) in the 1st quartile, 30 deaths (1.6%) in the 2nd quartile, 45 deaths (2.2%) in the 3rd quartile and 86 deaths (4.3%) in the 4th quartile (unadjusted hazard ratio [HR]=1.60, 95% confidence interval [CI] 1.38-1.86, P<0.001 for each standard deviation [SD] increase in the logarithmic scale). After adjustment for traditional cardiovascular risk factors, renal function and inflammatory status, the association between uric acid and 1-year mortality remained significant (adjusted HR=1.26, 95% CI 1.07-1.48; P=0.005 for each standard deviation increase in the logarithmic scale). Uric acid improved predictivity of the multivariable model regarding mortality (P=0.040).

Conclusions: Elevated level of uric acid is an independent predictor of 1-year mortality in patients with stable CAD treated with PCI.