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 ≧2.6 mm, presence of hyperlipidemia and CIMT ≧0.675 mm (84%) or those in the value of P-max ≧2.1 mm and body mass index ≧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.