Relation of Serum Uric Acid Levels and Outcomes Among Patients Hospitalized for Worsening Heart Failure With Reduced Ejection Fraction (from the Efficacy of Vasopressin Antagonism in Heart Failure Outcome Study With Tolvaptan Trial)

Abstract

We investigated the clinical profiles associated with serum uric acid (sUA) levels in a large cohort of patients hospitalized for worsening chronic heart failure with ejection fraction (EF) ≤40%, with specific focus on gender, race, and renal function based interactions. In 3,955 of 4,133 patients (96%) with baseline sUA data, clinical characteristics and outcomes were compared across sUA quartiles. The primary end points were all-cause mortality and a composite of cardiovascular mortality or heart failure hospitalization. Interaction analyses were performed for gender, race, and baseline renal function. Median follow-up was 9.9 months. Mean sUA was 9.1 ± 2.8 mg/dl and was higher in men than in women (9.3 ± 2.7 vs 8.7 ± 3.0 mg/dl, p <0.001) and in blacks than in whites (10.0 ± 2.7 vs 9.0 ± 2.8 mg/dl, p <0.001). Higher sUA was associated with lower systolic blood pressure and EF, higher natriuretic peptides, and more impaired renal function. After accounting for 24 baseline covariates, in patients with enrollment estimated glomerular filtration rate ≥30 ml/min/1.73 m(2), sUA was strongly associated with increased all-cause mortality (hazard ratio 1.44, 95% confidence interval 1.22 to 1.69, p <0.001) and the composite end point (hazard ratio 1.44, 95% confidence interval 1.26 to 1.64, p <0.001). However, in patients with estimated glomerular filtration rate <30 ml/min/1.73 m(2), sUA was not related with either end point (both p >0.4). Adjusted interaction analyses for gender, race, and admission allopurinol use were not significant. In conclusion, sUA is commonly elevated in patients hospitalized for worsening chronic heart failure and reduced EF, especially in men and blacks. The prognostic use of sUA differs by baseline renal function, suggesting different biologic and pathophysiologic significance of sUA among those with and without significant renal dysfunction.