Hyperuricemia reflects global Fontan pathophysiology and associates with morbidity and mortality in patients after the Fontan operation

Abstract

BackgroundSerum uric acid (UA, mg/dl) levels associate with the pathophysiology and prognosis in patients with chronic heart failure. PurposeTo clarify the clinical significance of hyperuricemia (HUA, UA>7.0) in Fontan patients. Methods and resultsWe prospectively measured UA in 197 child and 102 adult Fontan patients and compared the results with the clinical variables, including hemodynamics, exercise capacity, and plasma levels of norepinephrine (NE) and brain natriuretic peptide, and unscheduled hospitalization (USH), including all-cause mortality. The mean UA was 5.8±1.7 and 66 patients (22%, 34% in the adults) showed HUA. HUA was associated with lower peak oxygen uptake only in adults (r=−0.35, p<0.0001). In children the use of diuretics, central venous pressure, liver enzymes, NE, and plasma creatinine (Cr) independently associated with UA. Of those, in addition to hypoxia, the use of diuretics and Cr independently predicted HUA (p<0.05–0.001). In adults, hypoxia, plasma levels of sodium and Cr independently determined UA. Of those, hypoxia and hyponatremia independently predicted HUA (p<0.05–0.001). During a follow-up of 49±27months, 67 USH, including 17 deaths, occurred. In all patients, on univariate analysis, HUA predicted mortality (hazard ratio: 3.2, 95% confidence interval: 1.2–8.6, p=0.0193). HUA predicted USH in all, adult and child Fontan patients (p<0.05–0.0001), however, these prognostic values, including for mortality, were not independent in the multivariate analyses. ConclusionsUA reflects global postoperative Fontan pathophysiology, including the prognosis, with some differences between child and adult patients. However, the prognostic value of HUA may be limited in multivariate models in this particular cohort.