Background

Obesity is considered a challenging public problem, which has been proven to be closely associated with coronary artery disease (CAD). Each risk factor of CAD has been separately studied many times in the past, but very few have comprehensively and quantitatively evaluated the relationship between the abdominal fat-related parameters and severity of CAD. The aim of this study was to analyze whether the abdominal fat-related parameters were associated with severity of CAD using abdominal non-enhanced computed tomography (NECT).

Methods

Patients who went through both abdominal NECT and invasive coronary angiography (ICA) were included and retrospectively analyzed. The abdominal fat-related parameters [the ratio of visceral adipose tissue to subcutaneous adipose tissue (VAT/SAT ratio)] and traditional cardiovascular risk factors were evaluated in the participants with or without obstructive CAD. The correlations between the abdominal fat-related parameters and severity of CAD were assessed, and the multivariable logistic regression analysis was performed to investigate the parameters that could be used to predict the severity of CAD.

Results

A total of 223 consecutive subjects (obstructive CAD group, n= 117; non-obstructive CAD group, n= 106) were analyzed. The VAT/SAT ratio was significantly higher (0.95±0.33 vs. 0.70±0.25, P< 0.001) in obstructive CAD (O-CAD) patients than that in non-obstructive CAD (NO-CAD) patients. There was a trend to having nonalcoholic fatty liver disease (NAFLD) in the O-CAD patients than that of NO-CAD (P= 0.002); the abdominal aortic calcification (AAC) score in O-CAD patients were higher than that in NO-CAD patients (P< 0.001). The multivariable logistic regression analysis demonstrated that VAT/SAT ratio, NAFLD, and AAC score were independent predictors of O-CAD after adjusting the traditional cardiovascular risk factors. The area under the curve (AUC) of the combination of the above risk factors is 0.85, which leads to an increase in AUC than each risk factor alone in differentiating patients with or without O-CAD.

Conclusions

VAT/SAT ratio, NAFLD, and AAC score are correlated with the severity of CAD, indicating their characteristics of being independent risk factors for O-CAD, irrespective of the traditional cardiovascular risk factors. Those CT-derived parameters may make positive contributions to the differentiation of the patients with increased risk of O-CAD.