Serum uric acid, renal function and prognosis in patients with chronic heart failure and reduced ejection fraction. Insights from the Italian Network on Heart Failure

Background: The role of hyperuricemia on short-term clinical prognosis in outpatients with heart failure and reduced ejection fraction (HFrEF) has few investigations and inconclusive results. We evaluated the prognostic impact of serum uric acid (SUA) on short-term clinical outcome among ambulatory patients with chronic HFrEF enrolled in a nationwide cardiology registry, stratified by the presence of chronic renal dysfunction (CKD).

Methods: 2246 outpatients with LVEF ≤40 %, vital status at 1-year follow-up known, and with SUA and creatinine available were stratified accordingly to SUA tertiles (≤5.6 5.7-7.3, >7.3 mg/dl) and by CKD as defined by an estimated glomerular filtration rate < 60 ml/min/1.73m².

Results: Patients in the 2nd and 3rd SUA tertile were older, more symptomatic (NYHA class III-IV), with a lower EF, higher creatinine and heart rate. They had more commonly atrial fibrillation and CKD. At 1-year follow-up, patients in the 2nd and 3rd SUA levels tertile had an increased risk of cardiovascular death and/or HF hospitalization than those in the first tertile (HR 1.72 95 % CI 1.26-2.35, and HR 2.20 95 % CI 1.63-2.97, respectively). After multivariable adjustment, SUA was no longer associated with adverse outcome in the overall cohort. When the multivariable analysis was separately performed in patients with or without CKD, SUA was independently associated with cardiovascular death/HF hospitalization (p = 0.02) only in the latter group.

Conclusions: Mildly to moderately elevated SUA levels are associated to one-year survival in outpatients with HFrEF, but hyperuricemia resulted an independent marker of outcome only in patients without CKD.