Nonalcoholic Fatty Liver Disease May Be Associated With Coronary Artery Disease Complexity

We read the article ‘‘Association between nonalcoholic fatty liver disease and coronary artery disease complexity in patients with acute coronary syndrome: a pilot study’’ by Agaç et al. The authors assessed the relationship between nonalcoholic fatty liver disease (NAFLD) and SYNTAX score (SS) in patients who presented with acute coronary syndrome (ACS). They concluded that the presence of NAFLD is associated with higher SS in these patients. Serum alanine transaminase and aspartate transaminase activities are independently positively associated with the risk and severity of premature coronary artery disease (CAD), suggesting that these enzymes could serve as surrogate markers for cardiovascular (CV) risk in this specific group of patients. Serumg-glutamyltransferase activity is also an indicator of oxidative stress and is associated with CV disease. These associations can be partly attributed to NAFLD and insulin resistance, but there may be additional underlying mechanisms that contribute to the increased CV risk (eg, inflammation and oxidative stress). The NAFLD is a hepatic manifestation of metabolic syndrome (MetS). The MetS is a clinical entity comprising risk factors such as hypertension, glucose intolerance, atherogenic lipid profile, abdominal obesity, lack of physical activity, and increased inflammatory state. Most of the recent studies demonstrated that there was a correlation between the inflammatory mediators and the components of MetS. Elevated inflammatory mediators are a common indicator of atherosclerotic involvement of the vascular structure indicating CAD, cerebrovascular disease, peripheral arterial disease, and chronic inflammatory disease. Inflammatory mediators can also be affected by atherosclerotic risk factors such as smoking, alcohol consumption, hypercholesterolemia, and hypothyroidism. In this context, the authors did not mention some of the factors affecting these markers, including alcohol consumption, insulin resistance, hypercholesterolemia, hypothyroidism, heart failure, cerebrovascular disease, peripheral arterial disease, and chronic inflammatory disease in their study. Obstructive sleep apnoea syndrome (OSAS) and NAFLD are common conditions in clinical practice. Patients with OSAS should be screened for the presence and severity of NAFLD. It would be useful if the authors provided information about these factors. In a previous study, the presence of diabetes mellitus, lower values of high-density lipoprotein cholesterol, left ventricular ejection fraction (LVEF), and estimated glomerular filtration rate were independent predictors of CAD complexity. The SS was developed for the grading of coronary complexity based on angiographic visual assessment. The addition of clinical risk factors to the SS may further enhance its usefulness to objectively evaluate the patients. The Logistic Clinical SS consisting of 4 continuous variables (SS, age, creatinine clearance, and LVEF) substantially enhances the risk stratification of patients with CAD for the outcome of 1-year all-cause death compared with the SS alone. The Logistic Clinical SS was able to accurately distinguish patients with or without a clinical outcome and could accurately predict individual patient risk without underor overestimating the risk. Renal dysfunction included in this score may predict CAD and could estimate the risk of mortality and morbidity. Also, we believe that it would be useful to provide interobserver and intraobserver variability for CAD severity assessment in the Agaç et al study. In conclusion, NAFLD is associated with higher SS in patients who presented with ACS in the Agaç et al study. However, the reasons for higher SS are very complex, and the roles of the risk factors discussed above deserve further largescale prospective randomized clinical trials.