Correlation between Uric Acid Level and the Severity of Coronary Atherosclerosis and Plaque Composition Detected by Multi-Detector Computed Tomography

Abstract

SUMMARY I n the evaluation of patients with suspected coronary artery disease (CAD), the role of non-invasive imaging has increased exponentially over the past decades, particularly in patients with an intermediate likelihood of CAD. Multi-detector computed tomography (MDCT) has emerged as a powerful tool for accurate non-invasive assessment of CAD whenever “appropriate”. It has a high sensitivity and specificity for diagnosis and risk assessment of CAD if used appropriately and with proper patient selection. MDCT allows assessment of CAD by two methods, namely calcium screening and CT angiography. The recent developments expanded the scope of cardiac CT to allow, not just visualization of the coronary artery lumen and detection of stenosis, but also detection and quantification of different types of atherosclerotic plaques, which was shown to have a prognostic value by determining the “vulnerable” plaques which are more liable to cause acute coronary syndromes (ACS), and thus associated with increased mortality. Meanwhile, preventive cardiology has emerged as a promising branch in recent decades. It focuses mainly on determining the risk factors for CAD and dealing with the “modifiable” risk factors to decrease the burden of CAD. Smoking, obesity, diabetes, hypertension and dyslipidemia are among the well-known modifiable CV risk factors. Since the beginning of the 20th century, uric acid (UA) has been suggested as a CV risk factor, and numerous studies were conducted to determine its actual relationship to CAD, which is still in fact a matter of debate. On one hand, many authors believe that the association between CAD and elevated UA levels is merely because of the link between UA and other established CV risk factors. Also, being a powerful anti-oxidant, increased UA levels might just be a compensatory mechanism to counteract the oxidative stress induced in CAD. On the other hand, some studies have shown that the association between UA and CAD remains significant even after adjustment for concomitant risk factors, suggesting that UA is an independent risk factor for CAD. Other studies even failed to show any association between CAD and UA at all. Our study aimed at assessing whether UA is an independent risk factor for CAD, and whether it had any predictive value on the significance of CAD, or the type of atherosclerotic plaque detected by MDCT. The study included 122 adult symptomatic subjects without a previous history of CAD, presenting to Ain-Shams University hospitals between January 2015 and June 2016 to undergo MDCT upon suspicion of CAD.