Latest Review Date: May 2024

Category:  Medicine                                                              

POLICY:

Ultrasonographic measurement of carotid artery intimal-medial thickness (CIMT) as a technique for identifying subclinical atherosclerosis for use in the screening, diagnosis, or management of atherosclerosis is considered investigational.

DESCRIPTION OF PROCEDURE OR SERVICE:

Ultrasonographic measurement of carotid intima-medial (or intimal-media) thickness (CIMT) refers to the use of B-mode ultrasound to determine the thickness of the 2 innermost layers of the carotid artery wall, the intima and the media. Detection and monitoring of intima-medial thickening, which is a surrogate marker for atherosclerosis, may provide an opportunity to intervene earlier in atherogenic disease and/or monitor disease progression.

Coronary Heart Disease

Heart disease is the leading cause of mortality in the United States, accounting for more than half of all deaths. Coronary heart disease (CHD), also known as coronary artery disease, is the most common cause of heart disease. In a 2024 update on heart disease and stroke statistics from the American Heart Association, it was estimated that 720,000 Americans have a new coronary attack (first hospitalized myocardial infarction or CHD death) and 335,000 have a recurrent attack annually. An estimated 20.5 million Americans ≥20 years of age have CHD. 

Established major risk factors for CHD have been identified by the National Cholesterol Education Program (NCEP) Expert Panel.  These risk factors include elevated serum levels of low density lipoprotein (LDL) cholesterol, total cholesterol, and reduced levels of high-density lipoprotein (HDL) cholesterol.  Other risk factors include a history of cigarette smoking, hypertension, family history of premature CHD, and age. 

Diagnosis

The third report of the NCEP Adult Treatment Panel (ATP III) establishes various treatment strategies to modify the risk of CHD, with emphasis on target goals of LDL cholesterol.  Pathology studies have demonstrated that levels of traditional risk factors are associated with the extent and severity of atherosclerosis. ATP III recommended the use of the Framingham criteria to further stratify those patients with 2 or more risk factors for more intensive lipid management. However, at every level of risk factor exposure, there is substantial variation in the amount of atherosclerosis, presumably related to genetic susceptibility and the influence of other risk factors.  Therefore, there has been interest in identifying a technique that can improve the ability to diagnose those at risk of developing CHD, as well as measure disease progression, particularly for those at intermediate risk. 

The carotid arteries can be well-visualized by ultrasonography, and ultrasonographic measurement of the carotid intima-media thickness (CIMT) has been investigated as a technique to identify and monitor subclinical atherosclerosis. B-mode ultrasound is most commonly used to measure CIMT. CIMT is measured and averaged over several sites in each carotid artery. Imaging the far wall of each common carotid artery yields more accurate and reproducible CIMT measurements than imaging near wall. Two echogenic lines are produced, representing the lumen-intima interface and the media-adventitia interface. The distance between these 2 lines constitutes the CIMT.

KEY POINTS:

The most recent literature review was performed through March 18, 2024.

Summary of Evidence

For individuals who are undergoing cardiac risk assessment who receive ultrasonic measurement of carotid intima-media (or intimal-medial) thickness (CIMT), the evidence includes large cohort studies, case-control studies, and systematic reviews. Relevant outcomes are test accuracy and morbid events. Some studies have correlated increased CIMT with other commonly used markers for risk of coronary heart disease (CHD) and with risk for future cardiovascular (CV) events. Lorenz et al (2012) found in their meta-analysis that CIMT was associated with increased CV events, although CIMT progression overtime was not associated with increased CV event risk. Peters et al (2012) found that the added predictive value of CIMT was modest, and the ability to reclassify patients into clinically relevant categories was not demonstrated. The results from these reviews and other studies have demonstrated the predictive value of CIMT is uncertain and that the predictive ability for any level of population risk cannot be determined with precision. Also, available studies do not define how the use of CIMT in clinical practice improves outcomes. There is no scientific literature that directly tests the hypothesis that measurement of CIMT results in improved patient outcomes and no specific guidance on how measurements of CIMT should be incorporated into risk assessment and risk management. The objective of 1 study, however, was to define “normal” CIMT progression in low to moderate CV risk patients. Study results showed definite patterns related to various factors that could be used as a tool to earlier identify patients at increased CV risk, but patient outcomes were not assessed. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

Practice Guidelines and Position Statements

American College of Cardiology and American Heart Association

A 2013 guideline on the assessment of cardiovascular risk from the American College of Cardiology and the American Heart Association (ACC/AHA) does not recommend CIMT for routine risk assessment of a first atherosclerotic CVD event. (ACC/AHA Class III: no benefit, LOE: B). This differs from the previous 2010 version of the ACC/AHA guidelines for assessment of cardiovascular risk, which indicated CIMT might be reasonable for assessing CV risk in intermediate risk asymptomatic adults.

American Association of Clinical Endocrinologists 

The American Association of Clinical Endocrinologists and American College of Endocrinology published 2017 guidelines stating that CIMT could be applied as a risk stratification tool in determining the need for more aggressive preventive strategies against CVD (Grade B; BEL 2)—but that it should not be performed routinely.

American Society of Echocardiography

In 2008, the American Society of Echocardiography (ASE) consensus statement, endorsed by the Society for Vascular Medicine, stated that CIMT is a feature of arterial wall aging "that is not synonymous with atherosclerosis, particularly in the absence of plaque." The statement recommended measurement of both CIMT and carotid plaque by ultrasound "for refining CVD [cardiovascular disease] risk assessment in patients at intermediate cardiovascular disease risk (Framingham Risk Score 6%-20%) without established CHD [coronary heart disease], peripheral arterial disease, cerebrovascular disease, diabetes mellitus, or abdominal aortic aneurysm." However, the Society acknowledged that "More research is needed to determine whether improved risk prediction observed with CIMT or carotid plaque imaging translates into improved patient outcomes." The recommendations made in the 2008 consensus statement were endorsed in ASE's 2020 guideline– Recommendations for the Assessment of Carotid Arterial Plaque by Ultrasound for the Characterization of Atherosclerosis and Evaluation of Cardiovascular Risk. Authors of the 2020 guideline also note the following: "Since the largest portion of CIMT (approximately 99% in healthy individuals and approximately 80% when diseased) consists of the medial layer, CIMT has not been shown to consistently add to CVD risk prediction."

U.S. Preventive Services Task Force Recommendations

In 2009, the U.S. Preventive Services Task Force (USPSTF) published a systematic review of CIMT within the scope of a larger recommendation on the use of nontraditional risk factors in coronary heart disease risk assessment. USPSTF could not draw conclusions on the applicability of CIMT to the intermediate-risk population at large outside the research setting. The USPSTF summary of recommendation specific to CIMT stated that: “… the current evidence is insufficient to assess the balance of benefits and harms of using … [CIMT] … to screen asymptomatic men and women with no history of CHD to prevent CHD events.” USPSTF identified the following research need: “The predictive value … of carotid IMT … should be examined in conjunction with traditional Framingham risk factors for predicting CHD events and death.”

In 2018, the USPSTF published a recommendation statement on using nontraditional risk factors to assess risk of CVD; CIMT was not mentioned in this recommendation.

KEY WORDS:

Carotid intimal medial thickness (CIMT), B-mode ultrasound, intimal medial thickness, IMT, atherosclerosis, ultrasonographic measurement, SonoCalc®, Cardioscan

APPROVED BY GOVERNING BODIES:

In February 2003, SonoCalc® (Sonosite) was cleared for marketing by the FDA through the 510(k) process.  The FDA determined that this software was substantially equivalent to existing image display products for use in the automatic measurement of the intima media thickness of the carotid artery from images obtained from ultrasound systems.  Subsequently, several other devices have been approved through the 510(k) process.

BENEFIT APPLICATION:

Coverage is subject to member’s specific benefits.  Group-specific policy will supersede this policy when applicable.

ITS: Home Policy provisions apply

FEP contracts: Special benefit consideration may apply.  Refer to member’s benefit plan. 

CURRENT CODING: 

CPT code:

It is possible that providers may incorrectly use the following CPT code:

REFERENCES:

1. Baber U, Mehran R, Sartori S, et al. Prevalence, impact, and predictive value of detecting subclinical coronary and carotid atherosclerosis in asymptomatic adults: the BioImage study. J Am Coll Cardiol. Mar 24 2015;65(11):1065-1074.
2. Blaha MJ, Rivera JJ, Budoff MJ et al. Association between Obesity, High-Sensitivity C-Reactive Protein >=2 mg/L, and Subclinical Atherosclerosis: Implications of JUPITER from the Multi-Ethnic Study of Atherosclerosis. Arterioscler Thromb Vasc Biol 2011; 31(6):1430-8.
3. Blue Cross Blue Shield Association. Ultrasonographic measurement of carotid intimal-medial thickness as an assessment of subclinical atherosclerosis. Medical Policy Reference Manual, July 2010.
4. Bytyci I, Shenouda R, Wester P, et al. Carotid Atherosclerosis in Predicting Coronary Artery Disease: A Systematic Review and Meta-Analysis. Arterioscler Thromb Vasc Biol. Apr 2021; 41(4): e224-e237.
5. Calonge N, Petitti DB, DeWitt TG, et al. Using nontraditional risk factors in coronary heart disease risk assessment: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. Oct 06 2009; 151(7): 474-82.
6. Camhi SM, Katzmarzyk PT, Broyles ST et al. Subclinical atherosclerosis and metabolic risk: role of body mass index and waist circumference. Metab Syndr Relat Disord 2011; 9(2):119-25.
7. Curry SJ, Krist AH, Owens DK, et al. Risk Assessment for Cardiovascular Disease with Nontraditional Risk Factors: US Preventive Services Task Force Recommendation Statement. JAMA. Jul 17 2018; 320(3): 272-280.
8. Den Ruijter HM, Peters SA, Anderson TJ et al. Common carotid intima-media thickness measurements in cardiovascular risk prediction: a meta-analysis. JAMA 2012; 308(8):796-803.
9. Geisel MH, Bauer M, Hennig F, et al. Comparison of coronary artery calcification, carotid intima-media thickness and ankle-brachial index for predicting 10-year incident cardiovascular events in the general population. Eur Heart J. Jun 14 2017;38(23):1815-1822.
10. Goff DC, Jr, Lloyd-Jones DM, Bennett G et al. 2013 ACC/AHA Guideline on the Assessment of Cardiovascular Risk: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation 2013.
11. Green D, Foiles N, Chan C et al. An association between clotting factor VII and carotid intima-media thickness: the CARDIA study. Stroke 2010; 41(7):1417-22.
12. Greenland P, Alpert JS, Beller GA et al. 2010 ACCF/AHA guideline for assessment of cardiovascular risk in asymptomatic adults: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol 2010; 56(25):e50-103.
13. IOM (Institute of Medicine). 2011. Clinical Practice Guidelines We Can Trust. Washington, DC: The National Academies Press.
14. Jellinger PS, Handelsman Y, Rosenblit PD, et al. American Association of Clinical Endocrinologists and American College of Endocrinology Guidelines for Management of Dyslipidemia and Prevention of Cardiovascular Disease - Executive Summary. Complete Appendix to Guidelines available at http://journals.aace.com. Endocr Pract. Apr 2 2017;23(4):479-497.
15. Johnson HM, Turke TL, Grossklaus M et al. Effects of an office-based carotid ultrasound screening intervention. J Am Soc Echocardiogr 2011; 24(7):738-47.
16. Johri AM, Nambi V, Naqvi TZ, et al. Recommendations for the Assessment of Carotid Arterial Plaque by Ultrasound for the Characterization of Atherosclerosis and Evaluation of Cardiovascular Risk: From the American Society of Echocardiography. J Am Soc Echocardiogr. Aug 2020; 33(8): 917-933.
17. Keo HH, Baumgartner I, Hirsch AT et al. Carotid plaque and intima-media thickness and the incidence of ischemic events in patients with atherosclerotic vascular disease. Vasc Med 2011; 16(5):323-30.
18. Lorenz MW, Polak JF, Kavousi M et al. Carotid intima-media thickness progression to predict cardiovascular events in the general population (the PROG-IMT collaborative project): a meta-analysis of individual participant data. Lancet 2012; 379(9831):2053-62.
19. Lorenz MW, Schaefer C, et al. Is carotid intima media thickness useful for individual prediction of cardiovascular risk? Ten-year results from the Carotid Atherosclerosis Progression Study (CAPS). Eur Heart J, June 2010. [Epub ahead of print].
20. Martin SS, Aday AW, Almarzooq ZI, et al. 2024 Heart Disease and Stroke Statistics: A Report of US and Global Data Fromthe American Heart Association. Circulation. Feb 20 2024; 149(8): e347-e913.
21. Mookadam F, Moustafa SE, Lester SJ et al. Subclinical atherosclerosis: evolving role of carotid intima-media thickness. Prev Cardiol 2010; 13(4):186-97.
22. Mozaffarian D, Benjamin EJ, et al. Heart disease and stroke statistics-2016 update: a report from the American Heart Association. Circulation. Jan 26 2016;133(4):e38-360.
23. Nambi V, Chambless L, He M et al. Common carotid artery intima-media thickness is as good as carotid intima-media thickness of all carotid artery segments in improving prediction of coronary heart disease risk in the Atherosclerosis Risk in Communities (ARIC) study. Eur Heart J 2012; 33(2):183-90.
24. National Cholesterol Education Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults, www.nhlbi.nih.gov/guidelines/cholesterol/atp3xsum.pdf.
25. Olmastroni E, Baragetti A, Casula M, et al. Multilevel Models to Estimate Carotid Intima-Media Thickness Curves for Individual Cardiovascular Risk Evaluation. Stroke. Jul 2019; 50(7): 1758-1765.
26. Paramsothy P, Knopp RH, Bertoni AG et al. Association of combinations of lipid parameters with carotid intima-media thickness and coronary artery calcium in the MESA (Multi-Ethnic Study of Atherosclerosis). J Am Coll Cardiol 2010; 56(13):1034-41.
27. Patel J, Al Rifai M, Blaha MJ, et al. Coronary artery calcium improves risk assessment in adults with a family history of premature coronary heart disease: results from Multiethnic Study of Atherosclerosis. Circ Cardiovasc Imaging. Jun 2015;8(6):e003186.
28. Peters SA, den Ruijter HM, Bots ML et al. Improvements in risk stratification for the occurrence of cardiovascular disease by imaging subclinical atherosclerosis: a systematic review. Heart 2012; 98(3):177-84.
29. Plichart M, Celermajer DS, Zureik M et al. Carotid intima-media thickness in plaque-free site, carotid plaques and coronary heart disease risk prediction in older adults. The Three-City Study. Atherosclerosis 2011; 219(2):917-24.
30. Raiko JR, Magnussen CG, Kivimaki M et al. Cardiovascular risk scores in the prediction of subclinical atherosclerosis in young adults: evidence from the cardiovascular risk in a young Finns study. Eur J Cardiovasc Prev Rehabil 2010; 17(5):549-55.
31. Stein JH, Korcarz CE, Hurst RT, et al. Use of carotid ultrasound to identify subclinical vascular disease and evaluate cardiovascular disease risk: a consensus statement from the American Society of Echocardiography Carotid Intima-Media Thickness Task Force. Endorsed by the Society for Vascular Medicine. J Am Soc Echocardiogr. Feb 2008; 21(2): 93-111;quiz 189-90.
32. Tsao CW, Aday AW, Almarzooq ZI, et al. Heart Disease and Stroke Statistics-2023 Update: A Report from the American Heart Association. Circulation. Feb 21 2023; 147(8): e93-e621.
33. Tschiderer L, Klingenschmid G, Seekircher L, et al. Carotid intima-media thickness predicts carotid plaque development: Meta-analysis of seven studies involving 9341 participants. Eur J Clin Invest. Apr 2020; 50(4): e13217.
34. van den Oord SC, Sijbrands EJ, ten Kate GL et al. Carotid intima-media thickness for cardiovascular risk assessment: systematic review and meta-analysis. Atherosclerosis 2013; 228(1): 1-11.
35. Villines TC, Hsu LL, Blackshear C, et al. Relation of carotid intima-media thickness to cardiovascular events in Black Americans (From the Jackson Heart Study). Am J Cardiol. Nov 1 2017;120(9):1528-1532.
36. Virani SS, Alonso A, Benjamin EJ, et al. Heart Disease and Stroke Statistics-2020 Update: A Report from the American Heart Association. Circulation. Mar 03 2020; 141(9): e139-e596.
37. Xie W, Liang L, Zhao L et al. Combination of carotid intima-media thickness and plaque for better predicting risk of ischaemic cardiovascular events. Heart 2011; 97(16):1326-31.

POLICY HISTORY:

Medical Policy Group, August 2005 (3)

Medical Policy Administration Committee, August 2005

Available for comment August 27-October 10, 2005

Medical Policy Group, August 2006 (1)

Medical Policy Group, August 2007(1)

Medical Policy Group, March 2009 (4)

Medical Policy Group, July 2009 (3)

Medical Policy Group, July 2010 (1): Policy updated, no coverage change

Medical Policy Group, July 2011 (1): Update to Description, Key Points and References

Medical Policy Group, July 2012 (1): Update to Key Points and References related to MPP update; no change to policy statement

Medical Policy Group, July 2013 (4): 2013 Update to Key Points and References related to Diagnostic Utility

Medical Policy Panel, July 2014

Medical Policy Group, July 2014 (4): Updated Key Points, Practice Guidelines and References. No change to policy statement at this time.

Medical Policy Group, November 2014: 2015 Annual Coding update. Added code 93895 to current coding

Medical Policy Panel, July 2015

Medical Policy Group, July 2015 (4): Updates to Description, Key Points, Key Words, Coding, and References. No change to policy statement. Moved CPT 93799 to previous coding section

Medical Policy Group, January 2016 (4): Added CPT code 93880 to Coding section.

Medical Policy Group, April 2016 (4): Added the statement “It is possible that providers may incorrectly use the following CPT code”.

Medical Policy Panel, January 2017

Medical Policy Group, January 2017(4): Updates to Description, Key Points, and References. No change to policy statement.

Medical Policy Group, October 2017 (4): Added Key Word Cardioscan.

Medical Policy Panel, May 2018

Medical Policy Group, May 2018 (4): Updates to Description, Key Points, and References. No change to policy statement.

Medical Policy Panel, May 2019

Medical Policy Group, May 2019 (4): Updates to Description, Key Points, and Coding. Removed Previous coding section with code 93799.

Medical Policy Panel, May 2020

Medical Policy Group, May 2020 (4): Updates to Key Points and References. No change to policy statement.

Medical Policy Panel, November 2020: 2021 Annual Coding Update.  Added CPT code 93998 to Current Coding.  Moved deleted CPT code 0126T to Previous coding section.

Medical Policy Panel, May 2021

Medical Policy Group, May 2021 (4): Updates to Description, Key Points, Practice Guidelines, Governing Bodies and References. Policy statement updated to remove “not medically necessary,” no change to policy intent.

Medical Policy Panel, May 2022

Medical Policy Group, May 2022 (4): Updates to Description, Key Points and References.

Medical Policy Panel, May 2023

Medical Policy Group, May 2023 (4): Updates to Description, Key Points, Benefit Application, Current Coding and References.

Medical Policy Panel, May 2024

Medical Policy Group, May 2024 (4): Updates to Description, Key Points, and References.  No change to policy statements.

This medical policy is not an authorization, certification, explanation of benefits, or a contract. Eligibility and benefits are determined on a case-by-case basis according to the terms of the member’s plan in effect as of the date services are rendered. All medical policies are based on (i) research of current medical literature and (ii) review of common medical practices in the treatment and diagnosis of disease as of the date hereof. Physicians and other providers are solely responsible for all aspects of medical care and treatment, including the type, quality, and levels of care and treatment.

This policy is intended to be used for adjudication of claims (including pre-admission certification, pre-determinations, and pre-procedure review) in Blue Cross and Blue Shield’s administration of plan contracts.

The plan does not approve or deny procedures, services, testing, or equipment for our members. Our decisions concern coverage only. The decision of whether or not to have a certain test, treatment or procedure is one made between the physician and his/her patient. The plan administers benefits based on the member’s contract and corporate medical policies. Physicians should always exercise their best medical judgment in providing the care they feel is most appropriate for their patients. Needed care should not be delayed or refused because of a coverage determination.

As a general rule, benefits are payable under health plans only in cases of medical necessity and only if services or supplies are not investigational, provided the customer group contracts have such coverage.

The following Association Technology Evaluation Criteria must be met for a service/supply to be considered for coverage:

1. The technology must have final approval from the appropriate government regulatory bodies;

2. The scientific evidence must permit conclusions concerning the effect of the technology on health outcomes;

3. The technology must improve the net health outcome;

4. The technology must be as beneficial as any established alternatives;

5. The improvement must be attainable outside the investigational setting.

Medical Necessity means that health care services (e.g., procedures, treatments, supplies, devices, equipment, facilities or drugs) that a physician, exercising prudent clinical judgment, would provide to a patient for the purpose of preventing, evaluating, diagnosing or treating an illness, injury or disease or its symptoms, and that are:

1. In accordance with generally accepted standards of medical practice; and

2. Clinically appropriate in terms of type, frequency, extent, site and duration and considered effective for the patient’s illness, injury or disease; and

3. Not primarily for the convenience of the patient, physician or other health care provider; and

4. Not more costly than an alternative service or sequence of services at least as likely to produce equivalent therapeutic or diagnostic results as to the diagnosis or treatment of that patient’s illness, injury or disease.