Serum Uric Acid as a Marker of Disease Severity and Short-Term Outcome in Chronic Heart Failure: A Case-Control Study

Introduction: Serum uric acid (SUA) has been investigated as a readily available marker of disease severity and prognosis in patients with heart failure. Increased SUA may reflect enhanced xanthine oxidase activity, tissue hypoxia, oxidative stress and impaired renal urate handling. Objectives: To assess SUA levels in patients with chronic heart failure compared with healthy controls and to evaluate their association with New York Heart Association (NYHA) functional class, left ventricular ejection fraction (LVEF) and short-term mortality. Methods: This case-control study was conducted in 80 patients with documented chronic heart failure and 40 age- and sex-matched healthy controls. Patients with gout receiving urate-lowering therapy, end-stage renal disease/hemodialysis, malignancy and drug-induced secondary hyperuricemia were excluded. Clinical assessment, NYHA functional classification, laboratory investigations and echocardiography were performed. SUA was measured using the uricase method. Patients were followed for 30 days for symptomatic improvement and mortality. Results: The mean age of patients was 50.7 ± 11.93 years and 48 (60%) patients being males. Mean SUA was significantly higher in patients with chronic heart failure than in controls (6.62 ± 2.41 vs 3.71 ± 0.51 mg/dL, p<0.05). SUA increased progressively with NYHA functional class: 4.85 ± 1.69 mg/dL in class II, 6.702 ± 1.905 mg/dL in class III and 9.570 ± 3.030 mg/dL in class IV (p<0.001). The most common cause of heart failure was ischemic cardiomyopathy (42.5%). Mean LVEF at baseline was 45.56 ± 7.03%. At 30 days follow-up, 68 patients remained alive; among these, mean SUA was 5.91 ± 1.96 mg/dL and mean LVEF was 48.38 ± 6.14%. Twelve patients died during follow-up. Mean baseline SUA was significantly higher (p<0.001) among those who died than among survivors (9.41 ± 3.01 vs 6.12 ± 1.93 mg/dL). Conclusion: SUA was significantly higher in patients with chronic heart failure than in healthy controls and increased with worsening NYHA functional class. Higher baseline SUA was also associated with 30 days mortality. SUA may therefore serve as an inexpensive adjunctive marker of disease severity and short-term prognosis in chronic heart failure. Larger prospective studies with longer follow-up and multivariable analysis are required to determine its independent prognostic value.