Uric acid in chronic heart failure; correlation with prognostic markers

Abstract

Background: Chronic heart failure (CHF) is a leading cause of both morbidity and mortality worldwide. The pathophysiologic understanding of chronic heart failure (CHF) has shifted from a mere hemodynamic disorder to a much more complex approach including changes and imbalances in neurohormonal, immune, and metabolic functions. Hyperuricemia is a constant finding in CHF. Aim: To estimate the level of uric acid (UA) in patients with CHF, and to explore the possible relationship with established prognostic markers in these patients. Patients and Methods: Ninety-five patients with CHF were studied. Detailed clinical assessment, ECG, laboratory investigations and echocardiography were performed for all patients. Serum UA level >7.0 mg/dl was considered high. Results: The age range of patients was 28-85 years (median age 67). Of this group, 54 were males. The duration of the disease ranged from 113 years. In addition, 56% of patients were diabetic, 64% were hypertensive, and 74% had ischemic heart disease. 41 patients were class III New York Heart Association (NYHA) functional calcification, whereas 34 patients and 12 patients were in class II & IV respectively. The following diagnostic information was obtained: 1) blood pressure readings were 60 -123mmHg (mean=87.9±14.4). 2) atrial fibrillation (AF) was noted in 36 patients (38%) 3) left ventricular ejection fraction (EF%) was 13-68% (mean=37.9±20.1) 4) blood urea ranged from 13-197 mg/dl (mean=64.7±42.6) 5) serum creatinine was 0.4-5.5mg/dl (mean=1.4±0.9) 6) serum sodium was 119-148 (mean=134.2±5.9) 7) Elevated serum uric acid levels were found in 73% of our patients. We found a significant inverse correlation between serum uric acid level and mean arterial blood pressure (r = -0.42, p = 0.019) and with left ventricular ejection fraction (EF%) (r = -0.31, p = 0.003). We also demonstrated a direct correlation between serum UA and blood urea (r= +0.21, p= .042), serum Cr (r= +0.21, p= 0.051) and age (r=+0.37, p= 0.034). No significant differences were noted in serum UA level in different (NYHA) functional subgroups. Conclusions: High serum UA was observed in 73% of patients with CHF. The observed significant correlation between UA level and some established prognostic markers in these patients may indicate that serum UA could provide additional prognostic information in this population. We propose that such a simple marker that can be measured anywhere at a low cost to help identify high-risk patients with CHF.