The association between uric acid levels and different clinical manifestations of coronary artery disease.

Abstract

Uric acid (UA) has been associated with the presence and severity of coronary artery disease. To further assess the role of UA role in coronary artery disease, we investigated UA levels in both healthy asymptomatic middle-aged individuals and in different subgroups of hospitalized patients with suspected or definite myocardial infarction (MI). The severity of coronary artery calcification (CAC) was examined in asymptomatic individuals (n=1039) using a noncontrast computed tomography scan. Hospitalized patients with suspected acute MI (n=772) were grouped according to troponin I (TnI) concentrations: (i) elevated TnI concentrations (>0.03 µg/l) with subdivision according to the type of MI and other clinical conditions associated with myocardial injury, or (ii) nonelevated TnI concentrations (≤0.03 µg/l). UA was not associated with the severity of CAC in asymptomatic individuals when adjusting for relevant risk factors. Patients with type 2 MI and patients with myocardial injury associated with conditions of myocardial ischemia showed significantly higher UA levels (0.390 mmol/l, P=0.002 and 0.400 mmol/l, P=0.001, respectively) than patients with type 1 MI (0.329 mmol/l), after adjusting for other risk factors. UA was not correlated with the severity of CAC in asymptomatic middle-aged individuals, and patients with type 2 MI or ischemic myocardial injury were shown to have higher UA levels than type 1 MI patients. This observation is concordant with the hypothesis that UA might be involved in the pathophysiological mechanisms leading to an imbalance in the oxygen supply/demand ratio in type 2 MI and ischemic myocardial injury.