Uric acid renal excretion and renal insufficiency in decompensated severe heart failure

To evaluate uric acid renal excretion, hyperuricemia, renal dysfunction, and prognosis in patients with decompensated severe heart failure, as there are few data available.

One hundred and twenty-two patients, hospitalized for heart failure decompensation, in NYHA class IV, were classified into 3 groups as follows. Pilot group [ejection fraction (EF)0.45 and valvular dysfunction, n=16). The patients in groups 1 and 2 underwent assessment of creatinine and uric acid clearance before and after pyrazinamide, to estimate uric acid tubular secretion. Uric acid clearance <6.8 mL/min and secretion <170 microg/min were considered reduced. In groups 1 and pilot (n=106), mortality was analyzed by Cox regression model, and the prognostic value of hyperuricemia was assessed by ROC curve.

In groups 1 and 2, respectively, serum uric acid was 511.7 and 422.5 micromol/L, and creatinine clearance was 46.7 and 61.4 mL/min. Uric acid clearance (3.2 vs. 3.9 mL/min) and tubular secretion (116 vs. 128 microg/min) were not different, but lower than normal values. In groups 1 and pilot, the 12-month mortality was 46.4% (CI 95%: 36.7%-56.0%). At end of follow-up, mortality was associated with impaired creatinine clearance (p<0.001), but not with hyperuricemia (p=0.236).

In patients with decompensated severe heart failure, the tubular secretion and the clearance of uric acid were reduced. Renal dysfunction was associated with mortality, but hyperuricemia was not.