Carotid intima-media thickness: knowledge and application to everyday practice

Heart disease is the primary cause of death in the United States. Fortunately, intervention measures can reduce the risk of cardiovascular disease (CVD) after a patient has been accurately assessed. Atherosclerotic disease, one of the driving forces behind CVD, is not always detected by traditional risk assessment. Carotid intima-media thickness (CIMT), as measured by B-mode ultrasound, is a surrogate marker for atherosclerosis and can be used to detect an accelerated disease process and subclinical disease. Advantages of CIMT are that it is noninvasive, relatively inexpensive, and can be repeatedly performed with no adverse effects on the patient. Carotid intima-media thickness is associated with CVD and is an independent predictor of stroke and myocardial infarction. Therefore, CIMT is valuable for clarifying CVD risk, particularly for patients with intermediate risk by conventional risk assessment. Screening for subclinical disease even in low-risk patients may have benefit, especially for those with a family history of premature CVD or those with any of the National Cholesterol Education Program risk factors. The detection of subclinical atherosclerosis allows the physician to implement prevention efforts prior to a devastating CVD event and to investigate possible reasons for increased arterial thickening, such as an occult underlying insulin-resistant condition or residual lipid risk markers. Treatment with several types of drugs has been demonstrated to halt the progression or even reduce CIMT. Carotid intima-media thickness is currently limited by the lack of standardized protocols that may affect reproducibility from measure to measure. Efforts to draft a standardized protocol are underway by the Society of Atherosclerosis Imaging and Prevention that will address this issue. Carotid intima-media thickness provides a valuable tool for physicians to clarify the CVD risk of their patients. Practical implications of CIMT for everyday clinical practice are addressed.