Quantitative CT histogram indices for abdominal muscles are associated with coronary artery disease severity

Abstract

Aim

To explore the relationship between quantitative CT histogram indices of abdominal muscles and coronary artery disease (CAD) severity.

Materials and methods

CAD patients and controls who received chest CT covering the L1-L2 intervertebral disc were enrolled. Abdominal muscles at the L1-L2 level, including the abdominal wall muscles, the psoas major muscles and the paraspinal muscles, were segmented. Six histogram indices, covering area, average and median attenuation, skewness, kurtosis and standard deviation (SD) of attenuation, were measured and compared with controls. Associations between histogram indices and coronary artery calcium score (CACS) and total coronary plaque burden were then assessed using multivariate regression analysis.

Results

Two hundred ninety male and 165 female CAD patients were enrolled. Compared with controls, both sexes of CAD patients had a broader, platykurtic and right-skewed distribution in the psoas major muscles and female CAD patients had a leptokurtic and left-skewed distribution in the abdominal wall muscles additionally. After adjusting for cardiovascular risk factors, BMI, liver fat fraction, visceral adipose tissue and subcutaneous adipose tissue, the SD in the psoas major muscles was positively associated with CACS in male CAD patients (β=0.13; 95% CI: 0.02 to 0.23; P=0.02), and kurtosis in the abdominal wall muscles was positively associated with total plaque burden in female CAD patients (β=0.15; 95% CI, 0.01 to 0.29; P=0.03).

Conclusion

The histogram indices for abdominal wall muscles were independently associated with CAD severity in CAD patients, and the relationships were different between the two sexes.