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Richard K. Brantley, MD
Internal Medicine
Dr. Brantley has been practicing on the staff of Martha Jefferson Hospital since 2004. Prior to that, he served on the General Medicine faculty at UVA. He completed his residency at UVA in 2000 and prior to that received his MD from Vanderbilt. He and his wife, Gretchen Wasserstrom, have 2 children.
However, intensive glycemic control in diabetics, weight loss and use of medications such as statins and glitazones can slow progression or even cause regression of IMT. IMT has become an accepted endpoint for clinical trials of efficacy of lipid-lowering medications.
What data suggest the utility of CIMT for non-invasive risk stratification? A large, well designed trial of over 4,400 older subjects without clinical cardiovascular disease
followed for a mean of six years concluded that the intima-media thickness of the common and internal carotid artery is strongly associated with the risk of myocardial infarction and stroke. CIMT retained predictive power for new cardiovascular events even after traditional risk factors for cardiovascular events have been taken into consideration; moreover, such measurements seem more powerful
predictors than these same risk factors (OÌLeary et al.,1999, NEJM 340:14-22). Data from the Framingham Offspring Study demonstrated that subclinical atherosclerosis, assessed by CIMT, is more prevalent in individuals with a family history of CHD, even after adjusting for traditional cardiac risk factors. Early-onset parental CHD identified offspring with a strong familial predisposition to
atherosclerosis and elevated CIMT. Finally, a 2005 prospective study in Type 2 diabetics (Bernard et al., Diabetes Care 2005, 28:1158-1162) with at least one other cardiac risk factor found that carotid IMT provides a similar predictive value for coronary events as the Framingham score, and suggested that the combination of these two indexes
significantly improved risk prediction for these patients.
In conclusion, CIMT is a non-invasive, easy, and relatively inexpensive measure of atherosclerotic burden. It has been used extensively in this role as a research tool as a surrogate endpoint in research on risk reduction of cardiovascular disease. It is appealing because it quantifies a final endpoint, which is the result of both pathogenic and protective factors. It is strongly correlated with subsequent cardiovascular disease in asymptomatic individuals. One clinical niche might be to use CIMT as an additional tool for risk stratification in the intermediate risk patient. It could also prove useful in the office to visually demonstrate active vascular disease to the asymptomatic, high-risk patient who has not grasped the importance of needed lifestyle changes and/or pharmacotherapy. A normal thickness might be reassuring to a patient who is statistically low risk but is anxious nonetheless. According to the NCEP/ATP-III report, cost, standardization issues, and lack of availability in the community of CIMT precluded a current recommendation for Ïroutine use.Ó However, the report noted that Ïif carried out under proper conditions, CIMT could be used to identify persons at higher risk than that revealed by the major risk factors alone.Ó There is not yet data that identifying such individuals by carotid ultrasonography improves outcomes in clinical practice, but hopefully such trials will be forthcoming.
In conclusion, CIMT is a non-invasive, easy, and relatively inexpensive measure of atherosclerotic burden. It has been used extensively in this role as a research tool as a surrogate endpoint in research on risk reduction of cardiovascular disease. It is appealing because it quantifies a final endpoint, which is the result of both pathogenic and protective factors. It is strongly correlated with subsequent cardiovascular disease in asymptomatic individuals. One clinical niche might be to use CIMT as an additional tool for risk stratification in the intermediate risk patient. It could also prove useful in the office to visually demonstrate active vascular disease to the asymptomatic, high-risk patient who has not grasped the importance of needed lifestyle changes and/or pharmacotherapy. A normal thickness might be reassuring to a patient who is statistically low risk but is anxious nonetheless. According to the NCEP/ATP-III report, cost, standardization issues, and lack of availability in the community of CIMT precluded a current recommendation for Ïroutine use.Ó However, the report noted that Ïif carried out under proper conditions, CIMT could be used to identify persons at higher risk than that revealed by the major risk factors alone.Ó There is not yet data that identifying such individuals by carotid ultrasonography improves outcomes in clinical practice, but hopefully such trials will be forthcoming.
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