The prognostic impact of uric acid in acute heart failure according to coexistence of diabetes mellitus

ABSTRACT BACKGROUND AND AIMS Increased uric acid levels predict higher mortality in heart failure (HF) patients. Patients with diabetes mellitus (DM) appear to have increased xanthine oxidase activity. We aimed to study if the association between uric acid and mortality in acute HF was different according to the coexistence of DM. METHODS AND RESULTS We studied a cohort of patients hospitalized due to acute HF in 2009-2010. Patients with no uric acid measurement upon admission were excluded from the analysis. Follow-up: 2 years; endpoint: all-cause mortality. Patients with elevated uric acid (>80.0mg/L) were compared with those with lower values. We used a multivariate Cox-regression analysis to assess the prognostic impact of uric acid (both continuous and categorical variable: cut-off 80.0mg/L). The analysis was stratified according to coexistence of DM. We studied 569 acute HF patients, 44.6%male, mean age 76 years, 290 were diabetic. Median admission uric acid: 81.2mg/L and 52.2%had uric acid >80.0mg/L. Elevated uric acid predicted all-cause mortality in acute HF only in patients with DM. The multivariate-adjusted HR of 2-year mortality was 1.68 (95% CI 1.15-2.46) for diabetic HF patients with uric acid>80.0mg/L compared to those with lower levels (p=0.008) and 1.10 (95% CI: 1.03-1.18) per each 10mg/L increase in uric acid (p=0.007). In non-diabetic HF patients, uric acid was not associated with mortality. CONCLUSIONS Increased uric acid predicts ominous outcome in acute HF patients with diabetes, however, it is not prognostic associated in non-diabetics. Uric acid may play a different role in acute HF depending on DM status.