Increased carotid artery intimal-medial thickness: risk factor for exercise-induced myocardial ischemia in asymptomatic older individuals

Abstract

Asymptomatic coronary artery disease (CAD) is prevalent in the general population and has been associated with an increased risk for symptomatic CAD. Although the diagnosis of asymptomatic CAD is currently dependent on exercise testing and coronary angiography, other vascular diagnostic techniques could potentially be of aid in the assessment. Increased intimal-medial thickness (IMT) of the common carotid artery as assessed by B-mode ultrasonography is a purported index of atherosclerosis, and is associated with symptomatic CAD. Based on a recent report, this article will focus on the relationship between IMT and asymptomatic CAD as evidenced by exercise ECG, and in combination with exercise thallium scintigraphy. It was found that exercise-induced ST segment depression was associated with increased IMT independent of age, coronary risk factors and manifest CAD. After adjustment for age, IMT progressively increased from healthy subjects to asymptomatic subjects with positive exercise ECG alone, to those with concordant positive ECG and thallium scintigraphic findings who had IMT virtually identical to that in subjects with manifest CAD. Each 0.1 mm increase in IMT was associated with a 1.91-fold (95% CI 1.46-2.50) increased risk for concordant positive exercise tests or manifest CAD, independent of other coronary risk factors. These findings and the review of the literature suggest the potential utility of carotid ultrasonography in identifying asymptomatic individuals at higher risk for CAD.

Arterial stiffness: a brief review

“…In the specific context of the aorta, the vessel stiffens as well as dilates with age[14]. In addition, the thickness of the aortic wall increases even in the absence of atherosclerotic disease and is largely due to intimal thickening[ 15, 16]. Vascular aging is strongly associated with elastin depletion and fragmentation, as well as collagen deposition[ 17–19].…”

“…In addition, increased luminal pressure (such as in hypertension) also tends to favor collagen production at the expense of elastin[29]. Indeed, histological examination of arterial tissue post-mortem appears to confirm that between the ages of 20 and 90 (the widest range of human longevity), there is doubling or tripling of the thickness of the tunica media[15, 30]. When stiffened vessels are examined microscopically, a striking array of histological changes are observed.…”

Correlation of Carotid Intimomedial Thickness with Coronary Risk Factors in Type 2 Diabetic Patients

“…Chen et 22 al investigated the association of fasting and postprandial triglyceride levels with CIMT among type 2 diabetic patients in Southeast China. The CIMT in patients with postprandial HTG was significantly greater than that in patients with postprandial 23 normo-triglyceridaemia (p<0.05). Nagai et al, in 1998, compared CIMT in asymptomatic older subjects with exerciseinduced myocardial ischaemia.…”

Arterial Stiffness and Functional Outcome in Acute Ischemic Stroke

“…One of the inevitable conditions of an aging vascular system is the presence of atherosclerosis 33)39). In addition, intimal change thickens the aortic wall even without atherosclerotic disease 21)34). The elastin fibers are depleted and fragmented by the aging process,9)24)27) leadings to vessel wall toughening and thus increasing the central pressure 9)22).…”