Usefulness of carotid plaque (sum and maximum of plaque thickness) in combination with intima‐media thickness for the detection of coronary artery disease in asymptomatic patients with diabetes

AIMS/INTRODUCTION: The usefulness of markers of carotid plaque, such as sum (PS) and maximum (P‐max) of the plaque thickness, in combination with intima‐media thickness in the common carotid artery (CIMT) for the detection of obstructive coronary artery disease (CAD) was investigated in patients with type 2 diabetes without known CAD. MATERIALS AND METHODS: B‐mode ultrasonographic scanning of the carotid artery and multislice computed tomography coronary angiography were carried out in 332 asymptomatic patients with type 2 diabetes. RESULTS: For the presence of obstructive CAD when incorporating PS or P‐max to standard risk factors in a multiple logistic regression model, the classification ability in PS and P‐max increased greatly (area under the curve [AUC] 0.827 vs 0.720 [net reclassification index {NRI} = 0.652, P < 0.01] and AUC 0.820 vs 0.720 [NRI = 0.775, P < 0.01], respectively), and it in CIMT increased slightly (AUC 0.740 vs 0.720, NRI = 0.230, P = 0.041). Furthermore, the classification abilities for a model with interaction terms between PS* or P‐max* and CIMT were statistically larger than those for a model without interaction terms (AUC 0.833 vs 0.827 [NRI = 0.411, P < 0.01] and 0.823 vs 0.820 [NRI = 0.269, P < 0.05], respectively). Partitioning showed the patients in the values of the PS <2.6 mm and CIMT <0.725 mm (100%), or in P‐max <2.1 mm and CIMT <0.725 mm (95.4%), did not have obstructive CAD, whereas those in the values of PS [Formula: see text] 2.6 mm, presence of hyperlipidemia and CIMT [Formula: see text] 0.675 mm (84%) or those in the value of P‐max [Formula: see text] 2.1 mm and body mass index [Formula: see text] 24 (91.7%) had obstructive CAD. CONCLUSIONS: Although the P‐max and PS in the carotid artery were useful as detectors of CAD, combining them with CIMT provided a much superior first‐line screening method in detecting CAD in asymptomatic patients with diabetes.