Intima–media thickness: a new tool for diagnosis and treatment of cardiovascular risk

Abstract

Increased intima-media thickness (IMT) is a non-invasive marker of early arterial wall alteration, which is easily assessed in the carotid artery by B-mode ultrasound, and more and more widely used in clinical research. Methods of IMT measurement can be categorized by two approaches: (i) measurement at multiple extracranial carotid sites in near and far walls and (ii) computerized measurement restricted to the far wall of the distal common carotid artery. Because IMT reflects global cardiovascular risk, its normal value might be better defined in terms of increased risk rather than in terms of statistical distribution within a healthy population. The available epidemiological data indicate that increased IMT (at or above 1 mm) represents a risk of myocardial infarction and/or cerebrovascular disease. Close relationships have been shown between: (i) most traditional cardiovascular risk factors; (ii) certain emerging risk factors such as lipoproteins, psychosocial status, plasma viscosity, or hyperhomocysteinemia; and (iii) various cardiovascular or organ damages such as white matter lesion of the brain, left ventricular hypertrophy, microalbuminuria or decreased ankle to brachial systolic pressure index. Thus, IMT gives a comprehensive picture of the alterations caused by multiple risk factors over time on arterial walls. Prospective primary and secondary prevention studies have also shown that increased IMT is a powerful predictor of coronary and cerebrovascular complications (risk ratio from 2 to 6) with a higher predictive value when IMT is measured at multiple extracranial carotid sites than solely in the distal common carotid artery. Therapeutic double-blind trials have shown that lipid-lowering drugs, such as resin and overall statines, and to a lesser extent antihypertensive drugs, such as calcium antagonists, may have a beneficial effect on IMT progression in asymptomatic or in coronary patients. However, methodological standardization of IMT measurement still needs to be implemented before routine measurement of IMT can be proposed in clinical practice as a diagnostic tool for stratifying cardiovascular risk in primary prevention and for aggressive treatment decision. It can be anticipated however, that the presence of increased carotid IMT in one individual with intermediate cardiovascular risk would lead to his classification into the high-risk category and thus influence the aggressiveness of risk factor modifications.

Análise estrutural e funcional carotídea em familiares de pacientes com diabete melito tipo 2

“…In several observational and clinical studies, except one which demonstrated a weak correlation, the IMT has been a marker of subclinical vascular cardiac disease, in association with traditional risk factors for coronary heart disease (according to our findings: CRP, LDL-cholesterol and DBP) and the coronary atheroma load, being a predictor of subsequent cardiovascular events and an early indicator of atherosclerosis, besides being a valuable risk marker in noninvasive assessments [5][6][7][10][11]14,[20][21][22][23][24][25][26][27] . With regard to carotid structural properties, no comparison with previous studies with the same group profiles could be conducted because none was found in the medical literature.…”

“…The presence of atherosclerosis is pronounced even before the clinical event, and much research has been conducted on early detection of atherosclerosis, both in DM2 and non-DM2 patients, over the last two decades 4,5 .…”

“…This method allows both structural (for example, intima-media thickness, which is considered a subclinical cardiovascular disease surrogate marker and a strong predictor of future vascular events) and functional (elasticity) vessel analysis 5,[7][8][9][10][11][12][13][14][15][16] . Therefore, since a family history of diabetes, even in nondiabetics subjects with no known cardiovascular risk factors, is regarded as an increased coronary heart disease risk, per se, carotid ultrasonic measurements can be an important early atherosclerosis marker.…”

The clinical significance of carotid intima-media thickness in cardiovascular diseases: a survey in Beijing

“…CIMT plays a role in predicting the risk of cardiovascular diseases and in turn provides information on relevant therapeutic strategies, making it a surrogate marker or an intermediate end point for observational studies and interventional therapy. 2,[4][5][6][7] Although it is clear that CIMT is a good predictor of subsequent cardiovascular diseases, it is important to establish whether the incremental information obtained by carotid ultrasound further defines an individual's risk profile, which is still in controversy 8 and data to indicate that measurement of CIMT may be useful in symptomatic patients to further distinguish patients into higher-risk or lower-risk group are presently not available. 5 Since measurement of arterial wall IMT made with B-ultrasound used in 1986, great developments had been achieved.…”

“…The establishment of a standardized method of measuring CIMT is critical for further utilization and in urgent need. 4,8 The purpose of this study is to investigate the relationships between cardiovascular events (MI, stroke and peripheral arterial disease (PAD)) and CIMT in middle-aged and older adults in Beijing, China; to assess which of the indexes, IMT in the CCA, internal carotid artery (ICA) and carotid bifurcation (CB) separately or in combination, is a better correlate.…”