Automated Border Detection for Assessing the Mechanical Properties of the Carotid Arteries: Comparison with Carotid Intima–Media Thickness

Healthy aging and carotid performance: strain measures and β-stiffness index

Arterial stiffness is related to the risk of cardiovascular disease (CVD) and increases with aging. Functional impairment of the arterial wall can occur before structural changes and can be detectable before CVD symptoms. The elastic properties of the carotid arterial wall during the cardiac cycle can be evaluated by standard 2-dimensional (2D) ultrasound longitudinal or circumferential imaging of vascular deformation (strain) using speckle tracking. The purpose of this study was to compare standard 2D ultrasound circumferential and longitudinal images of vascular tissue motion and strain using speckle tracking in young and older individuals. Participants underwent recording of 2D ultrasound circumferential and longitudinal images of the common carotid artery. Circumferential carotid strain (CS) and CS rate were obtained and analyzed via speckle tracking software. Following the strain analysis, the circumferential strain β-stiffness (C-β) was calculated. Conventional longitudinal β-stiffness (L-β) was calculated and non-invasive blood pressure measurements were obtained from carotid artery pressure measurements in a resting supine position using applanation tonometry. C-β was significantly higher than L-β, and the association with age was greater (r = .824 vs. r = .547). CS and CS rate were significantly higher in the young compared to the older group. L-β does not explain as much of the age-dependent differences in the carotid artery compared with C-β. This is possibly due to the inclusion of whole arterial wall motion and deformation observed in the CS image. The ability of C-β to accurately predict the future risk of CVD independent of age still needs further investigation.

Peripheral vascular stiffness, assessed with two-dimensional speckle tracking versus the degree of coronary artery calcification, evaluated by tomographic coronary artery calcification index

INTRODUCTION

Even in asymptomatic patients, the result of atherosclerosis progression is deterioration of the function and morphology of the artery wall. Two-dimensional speckle-tracking (2DST) is a sonographic technique that allows for precise evaluation of arterial wall compliance. Together with measurement of intima-media thickness (IMT), it can be applied for quick and non-invasive assessment of the progression of peripheral artery atherosclerosis.

MATERIAL AND METHODS

Fifty-eight patients of mean age 61 years (SD 10.6) underwent cardiac computed tomography (CT) and subsequent ultrasonographic evaluation of the left common carotid artery. The calcium score was calculated according to the Agatston method and compared with IMT, circumferential strain variables assessed by 2DST, conventional arterial stiffness parameters (β-stiffness index and elastic modulus) and clinical data. Intra-observer and inter-observer agreement was evaluated.

RESULTS

Strain variables and IMT differed significantly in patients with calcium score (CS) > 0 and CS = 0. Moreover, they correlated with CS, systolic blood pressure and age of patients. Conventional stiffness parameters were not able to identify the group of patients with calcifications present in the coronary arteries. For the 2DST technique, interclass and intraclass agreements were 84.83% and 94.42% respectively.

CONCLUSIONS

Circumferential strain variables assessed by 2DST and measurement of IMT can be used for evaluation of peripheral artery deterioration in patients until the 6(th) decade of life. These parameters reflect the development of calcifications in coronary arteries and, more importantly, can be used for a more detailed estimation of the atherosclerosis risk in patients with CS = 0.

Increased carotid arterial stiffness in subclinical hypothyroidism

OBJECTIVE

Arterial stiffness is involved in the pathophysiology of cardiovascular disease, and subclinical hypothyroidism (SCH) is associated with increased risk of atherosclerosis. The present study was designed to examine whether SCH is associated with an increase in carotid arterial stiffness.

METHODS

The carotid arterial stiffness parameter in 93 patients with SCH and 90 sex- and age-matched euthyroid volunteers was evaluated using a color Doppler ultrasound machine implemented with a high-resolution echo-tracking system.

RESULTS

The participants with SCH had higher total cholesterol, LDL-cholesterol and highly sensitive C-reactive protein (hsCRP) levels than those who were euthyroid. Furthermore, carotid arterial stiffness β (β index) was significantly higher in SCH patients than in normal controls, and β index was significantly positively correlated with age, smoking index, diastolic blood pressure, systolic blood pressure, TSH and hsCRP and significantly negatively correlated with pulse rate in subclinical hypothyroid patients.

CONCLUSIONS

Subclinical hypothyroidism is associated with preclinical vascular alteration, characterized by increased carotid arterial stiffness values, which have been shown to be related to the hsCRP and TSH.