Risk factors and utility of maximum carotid intima-media thickness as a surrogate marker for coronary artery stenosis

Abstract

Background: This study investigated the factors associated with coronary artery stenosis in outpatients. Furthermore, the usefulness of maximum carotid intima-media thickness (maximum-IMT) as a surrogate marker of coronary artery stenosis was evaluated.

Methods: We conducted a single-center retrospective study. A total of 601 outpatients (338 males; 263 females; mean age, 69.8±10.0 years) who underwent coronary computed tomography angiography between April 2006 and March 2012 were analyzed. The associations between coronary artery stenosis (≥75%) as determined by coronary computed tomography angiography and clinical and laboratory parameters were evaluated by multivariate logistic regression. Validation of maximum-IMT as measured by ultrasonography as a surrogate marker of coronary artery stenosis was analyzed by receiver operating characteristic (ROC) curve analysis.

Results: The estimated glomerular filtration rate (eGFR: mL/min/1.73 m²) (odds ratio [OR] 0.985, p<0.01), diabetes mellitus (OR 1.98, p<0.05), and maximum-IMT (mm) (OR 1.76, p<0.01) were significantly associated with coronary artery stenosis (≥75%). In analysis of each group categorized by identified factors, such as renal impairment (eGFR <60 mL/min/1.73 m²) and diabetes mellitus, the ROC curve of maximum-IMT was significant in the group of patients with diabetes mellitus without renal impairment (p<0.01) (cutoff value of maximum-IMT, 2.0 mm; sensitivity, 0.74; and specificity, 0.54) but not in other groups.

Conclusion: Renal impairment, diabetes mellitus, and increased maximum-IMT may be significant risk factors of coronary artery stenosis. Maximum-IMT as measured by ultrasonography may be a useful surrogate marker for coronary artery stenosis in patients with diabetes mellitus without renal impairment but not in other patients.

Keywords: coronary artery stenosis; diabetes mellitus; maximum intima–media thickness; renal impairment.

Figure 1

Visual quantitative grading of coronary artery stenosis using coronary computed tomography angiography. The severity of coronary artery stenosis (arrows) was visually categorized as no stenosis, 1%–24% stenosis, 25%–49% stenosis, 50%–74% stenosis, and ≥75% stenosis. Patients with at least one coronary artery stenotic lesion ≥75% were considered to have significant coronary artery stenosis.

Figure 2

Longitudinal B-mode ultrasound image of the common carotid artery. Notes: IMT was measured as the distance between the lumen–intima (black arrow) and media–adventitia (gray arrow) (A). Maximum-IMT was measured as the thickest IMT value recorded in either the right or left side of the common carotid artery, carotid bulb, and internal carotid artery (double arrow) (B). Abbreviation: IMT, intima–media thickness.

Figure 3

Flow diagram of the analyzed patients. Abbreviation: IMT, intima–media thickness.

Figure 4

Associations between the degree of maximum-IMT and the prevalence of coronary artery stenosis (≥75%) as determined with coronary computed tomography angiography in each group categorized by the presence or absence of diabetes mellitus and renal impairment. Notes: (A) The group of patients with diabetes mellitus (−)/renal impairment (−). (B) The group of patients with diabetes mellitus (+)/renal impairment (−). (C) The group of patients with diabetes mellitus (−)/renal impairment (+). (D) The group of patients with diabetes mellitus (+)/renal impairment (+). Abbreviation: IMT, intima–media thickness.

Figure 5

ROC analysis for predicting coronary artery stenosis of ≥75% for each group categorized by the presence or absence of diabetes mellitus and renal impairment. Notes: (A) The group of patients with diabetes mellitus (−)/renal impairment (−). (B) The group of patients with diabetes mellitus (+)/renal impairment (−). (C) The group of patients with diabetes mellitus (−)/renal impairment (+). (D) The group of patients with diabetes mellitus (+)/renal impairment (+). Abbreviations: AUC, area under the curve; ROC, receiver operating characteristic.