Evaluation of Carotid Plaque Using Ultrasound Imaging

Ex-vivo atherosclerotic plaque characterization using spectral photon-counting CT: Comparing material quantification to histology

BACKGROUND AND AIMS

Atherosclerotic plaques are characterized as being vulnerable to rupture based on a series of histologically defined features, including a lipid-rich necrotic core, spotty calcification and ulceration. Existing imaging modalities have limitations in their ability to distinguish between different materials and structural features. We examined whether X-ray spectral photon-counting computer tomography (SPCCT) images were able to distinguish key plaque features in a surgically excised specimen from the carotid artery with comparison to histological images.

METHODS

An excised carotid plaque was imaged in the diagnostic X-ray energy range of 30-120 keV using a small-bore SPCCT scanner equipped with a Medipix3RX photon-counting spectral X-ray detector with a cadmium telluride (CdTe) sensor. Material identification and quantification (MIQ) images of the carotid plaque were generated using proprietary MIQ software at 0.09 mm volumetric pixels (voxels). The plaque was sectioned, stained and photographed at high resolution for comparison.

RESULTS

A lipid-rich core with spotty calcification was identified in the MIQ images and confirmed by histology. MIQ showed a core region containing lipid, with a mean concentration of 260 mg lipid/ml corresponding to a mean value of -22HU. MIQ showed calcified regions with mean concentration of 41 mg Ca/ml corresponded to a mean value of 123HU. An ulceration of the carotid wall at the bifurcation was identified to be lipid-lined, with a small calcification identified near the breach of the artery wall.

CONCLUSIONS

SPCCT derived material identification and quantification images showed hallmarks of vulnerable plaque including a lipid-rich necrotic core, spotty calcifications and ulcerations.

Asymptomatic retinal emboli and current practice guidelines: a review

Asymptomatic retinal emboli are found in 1-3% of patients on routine fundus examination. As the use of teleretinal imaging for diabetic patients and ocular photography continues to increase, the number of asymptomatic retinal emboli found will also increase. This article will discuss the different aetiologies of retinal emboli and will present an overview of the recommended referrals for further systemic testing and treatment. It is important to communicate well with the primary care physician when asymptomatic retinal emboli are detected to ensure the appropriate investigations are undertaken.

Subclinical cardiovascular disease and utility of coronary artery calcium score

ASCVD are the leading causes of mortality and morbidity among Globe. Evaluation of patients' comprehensive and personalized risk provides risk management strategies and preventive interventions to achieve gain for patients. Framingham Risk Score (FRS) and Systemic Coronary Risk Evaluation Score (SCORE) are two well studied risk scoring models, however, can miss some (20-35%) of future cardiovascular events. To obtain more accurate risk assessment recalibrating risk models through utilizing novel risk markers have been studied in last 3 decades and both ESC and AHA recommends assessing Family History, hs-CRP, CACS, ABI, and CIMT. Subclinical Cardiovascular Disease (SCVD) has been conceptually developed for investigating gradually progressing asymptomatic development of atherosclerosis and among these novel risk markers it has been well established by literature that CACS having highest improvement in risk assessment. This review study mainly selectively discussing studies with CACS measurement. A CACS = 0 can down-stratify risk of patients otherwise treated or treatment eligible before test and can reduce unnecessary interventions and cost, whereas CACS ≥ 100 is equivalent to statin treatment threshold of ≥ 7.5% risk level otherwise statin ineligible before test. Since inflammation, insulin resistance, oxidative stress, dyslipidemia and ongoing endothelial damage due to hypertension could lead to CAC, ASCVD linked with comorbidities. Recent cohort studies have shown a CACS 100-300 as a sign of increased cancer risk. Physical activity, dietary factors, cigarette use, alcohol consumption, metabolic health, family history of CHD, aging, exposures of neighborhood environment and non-cardiovascular comorbidities can determine CACs changes.

Vulnerable Plaque Is More Prevalent in Male Individuals at High Risk of Stroke: A Propensity Score-Matched Study

OBJECTIVES

To assess the gender differences in the prevalence of carotid vulnerable plaques in high-risk individuals for stroke in a multicenter, cross-sectional study.

METHODS

In the year 2015, 18595 residents who were at the age of 40 or older participated in a face-to-face study in eight communities in southwestern China. Totally 2,644 participants at high risk of stroke were enrolled. Before and after propensity score matching (PSM), the prevalence of carotid plaques and vulnerable plaques were compared between men and women. Multivariate analyses were applied to explore the association between the gender and carotid plaques. Stratified analyses and interaction tests were performed to identify factors that might modify the association between the gender and carotid plaques.

RESULTS

Among 2644 high-risk individuals enrolled, there were 1,202 (45.5%) men and 1442 (54.5%) women. Carotid plaques were detected in 904 (34.2%) participants, while vulnerable plaques were found in 425 (16.1%) participants. Before PSM, carotid plaques were more prevalent in male individuals than the female (36.7% vs. 32.1%, p = 0.01), as well as vulnerable plaque (20.0% vs. 12.8%, p < 0.01). Men tend to have a higher prevalence of vulnerable plaques in multivariate analyses (adjusted OR 1.70, 95% CI 1.10-2.62, p = 0.02). Stratified analyses and interaction tests demonstrated that the association between male sex and vulnerable carotid plaque did not change by age, family history of stroke, histories of chronic disease, smoking status, drinking status, physical activity, and BMI (all p for interaction > 0.05). After PSM, vulnerable plaques were still more prevalent in male individuals than the female (17.03% vs. 12.07%, p = 0.032).

CONCLUSION

Male individuals had a higher risk of vulnerable carotid plaque independent of classical vascular risk factors. Whether there is a gender-specific association between variations in genes related to inflammation, lipid metabolis, and endothelial function and plaque vulnerability needs to be further studied.

Point-of-Care Ultrasound (POCUS) in the Field of Diabetology

Ultrasound is increasingly used in daily clinical practice to improve the efficiency of the clinical examination. In this article, we reviewed its various possible uses in the field of diabetology. The ultrasonic evaluation of the carotid arteries (plaques and intima media thickness) allows improving the assessment of the cardiovascular risk. Steatosis can be detected relatively easily on liver ultrasound. Ultrasound also allows a more sensitive detection of lipohypertrophy resulting in glycemic fluctuations and thus increasing the risk of hypoglycemia than the clinical examination. Finally, muscle ultrasound appears to be a promising tool to assess the nutritional status and its consequences (e.g., falls).

Is the intima-media thickness of temporal and axillary arteries influenced by cardiovascular risk?

Objectives

To measure with US the intima-media thickness (IMT) of temporal (superficial, parietal and frontal branches) and axillary arteries in subjects without a diagnosis of GCA and/or PMR with different cardiovascular (CV) risk; and to assess the performance of previously proposed cut-off values for normal IMT.

Methods

Subjects ≥ 50 years without a diagnosis of GCA or PMR were included. Bilateral US of the temporal arteries, including the frontal and parietal branches, and axillary arteries was performed by two sonographers using a 10–22 MHz and 6–18 MHz probe. The following previously proposed cut-offs were considered: superficial temporal artery: 0.42 mm; frontal branch: 0.34 mm; parietal branch: 0.29 mm; axillary artery: 1.0 mm.

Results

A total of 808 arteries in 101 subjects were evaluated; of these, 31 (30.7%) were classified as very high CV risk, seven (6.9%) as high, 34 (33.7%) as moderate and 29 (28.7%) as low risk. Subjects with very high or high risk showed higher IMT than those with moderate or low risk in the superficial temporal arteries [0.23 (s.d. 0.07) vs 0.20 (s.d. 0.04), P &lt; 0.01] and in the axillary arteries [0.54 (s.d. 0.17) vs 0.48 (s.d. 0.10), P = 0.002]. The IMT was higher than the reference cut-off in 13/808 (1.6%) arteries, in ≥1 artery in 10/101 subjects (10.1%). Of these 10 subjects, 8 (80%) were classified as having very high or high risk.

Conclusion

Our results suggest that CV risk might influence the US-determined IMT of the temporal and axillary arteries in subjects without GCA. Therefore, in patients with suspected GCA, particular attention should be paid when measuring the IMT in those patients with very high/high CV risk.

Relative Estimate of Revised Cardiovascular Risk Combining Traditional and Non-traditional Image-based CV Markers: A Kerala Based Study

BACKGROUND

Non-traditional image markers can improve the traditional cardiovascular risk estimation, is untested in Kerala based participants.

OBJECTIVE

To identify the relationship between the 'Modified CV risk' categories with traditional and non-traditional image-based risk markers. The correlation and improvement in reclassification, achieved by pooling atherosclerotic non-traditional markers with Intermediate (≥7.5% and <20%) and High (≥20%) 10-year participants is evaluated.

METHODS

The cross-sectional study with 594 participants has the ultrasound measurements recorded from the medical archives of clinical locations at Ernakulum district, Kerala. With carotid Intima-Media Thickness (cIMT) measurement, the Plaque (cP) complexity was computed using selected plaque characteristics to compute the carotid Total Plaque Risk Score (cTPRS) for superior risk tagging. Statistical analysis was done using RStudio, the classification accuracy was verified using the decision tree algorithm.

RESULTS

The mean age of the participants was (58.14±10.05) years. The mean cIMT was (0.956±0.302) mm, with 65.6% plaque incidence. With 94.90% variability around its mean, the Multinomial Logistic Regression model identifies cIMT and cTPRS, age, diabetics, Familial Hypercholesterolemia (FH), Hypertension treatment, the presence of Rheumatoid Arthritis (RA), Chronic Kidney Disease (CKD) as significant (p<0.05). cIMT and cP were found significant for 'Intermediate High', 'High' and 'Very High' 'Modified CV risk' categories. However, age, diabetes, gender and use of hypertension treatment are significant for the 'Intermediate' 'Modified CV risk' category. The overall performance of the MLR model was 80.5%. The classification accuracy verified using the decision tree algorithm has 78.7% accuracy.

CONCLUSION

The use of atherosclerotic markers shows a significant correlation suitable for a nextlevel reclassification of the traditional CV risk.

High-Frequency Ultrasound of Multiple Arterial Areas Reveals Increased Intima Media Thickness, Vessel Wall Appearance, and Atherosclerotic Plaques in Systemic Lupus Erythematosus

Introduction: Despite improved therapies and management, patients with systemic lupus erythematosus (SLE) still have increased risks of cerebrovascular and cardiovascular disease. High-frequency ultrasound (US) provides an opportunity to distinguish atherosclerosis from inflammation in the vessels. We hypothesized that an extended US protocol may add information regarding vascular affection in SLE.

Methods: Sixty patients (52 women, 8 men; mean age 43.2 ± 11.3 years) with SLE characterized by either lupus nephritis (LN; n = 20), antiphospholipid syndrome (APS; n = 20), or skin and joint involvement (n = 20) as well as matched healthy controls (n = 60) were included. Intima-media thickness (IMT), assessment of vessel walls, and plaque occurrence were recorded using high-frequency US (GE Logic E9) in common carotid, internal carotid, brachiocephalic, subclavian, axillary, common femoral, and proximal superficial femoral arteries as well as in the aortic arch.

Results: For the entire SLE group, IMT was increased in the internal carotid artery (0.52 ± 0.17 vs. 0.45 ± 0.09 mm, p = 0.004), the common femoral artery (0.57 ± 0.23 vs. 0.49 ± 0.11 mm, p < 0.01), the subclavian artery (0.58 ± 0.19 vs. 0.53 ± 0.13 mm, p = 0.02), and the aortic arch (1.21 ± 0.63 vs. 0.98 ± 0.25 mm, p = 0.002) compared to controls. These differences were primarily observed in the APS and LN groups compared to controls. Vessels with increased IMT ≥0.9 mm had a smooth, medium echogenic appearance in areas free of atherosclerotic plaques. Atherosclerotic plaques were detected in 15/60 patients (25%) as compared to 2/60 of the controls (3%). Plaques were predominantly (67%) located in the carotid bifurcation. Multivariate analysis revealed influence of age on IMT in all vessel areas. Furthermore, in the common femoral artery, sagittal abdominal diameter, diastolic blood pressure, and cholesterol all showed association with increased IMT. In the internal carotid artery, male sex and presence of Raynaud phenomenon influenced IMT.

Conclusion: Among SLE patients without presence of plaques, an extended US protocol revealed increased wall thickness with predominantly medium echogenic appearance highlighting possibly inflammation or early atherosclerosis. The appearance of vessel walls has not previously been studied in detail. An increased number of plaques were found in SLE compared to age- and sex-matched healthy controls. We found similar risk factors for increased IMT and occurrence of plaques, possibly indicating atherosclerotic mechanisms rather than inflammation.

The Role of Carotid and Femoral Plaque Burden in the Diagnosis of Coronary Artery Disease

PURPOSE OF REVIEW

With limitations of cardiovascular disease risk stratification by traditional risk factors, the role of noninvasive imaging techniques, such as vascular ultrasound, has emerged as a prominent utility for decision-making in coronary artery disease. A review of current guidelines and contemporary approaches for carotid and femoral plaque assessment is needed to better inform the diagnosis, management, and treatment of atherosclerosis in clinical practice.

RECENT FINDINGS

The recent consensus-based guidelines for carotid plaque assessment in coronary artery disease have been established, supported by some outcomes-based research. Currently, there is a gap of evidence on the use of femoral ultrasound to detect atherosclerosis, as well as predict adverse cardiovascular outcomes. The quantification and characterization of individualized plaque burden are important to stratify risk in asymptomatic or symptomatic atherosclerosis patients. Standardized quantification guidelines, supported by further outcomes-based research, are required to assess disease severity and progression.

Associations of Endogenous Sex Hormones with Carotid Plaque Burden and Characteristics in Midlife Women

CONTEXT

Endogenous sex hormones may be involved in the pathogenesis of cardiovascular disease (CVD) in women. Carotid plaque characteristics, such as echogenicity, an ultrasound measure that reflects plaque composition, may identify unstable plaques that are more likely to rupture, precipitating a CVD event. However, few studies have considered sex steroids in relation to carotid plaque and its characteristics.

OBJECTIVE

To evaluate estrone (E1), estradiol (E2), testosterone (T), sex hormone binding globulin (SHBG), and free T (FT) in relation to carotid plaque in women.

DESIGN, SETTING, AND PARTICIPANTS

In MsHeart, a cross-sectional study of 304 women aged 40 to 60 years, participants underwent a carotid artery ultrasound assessment. The current analysis included MsHeart participants with carotid plaque (n = 141, 46%). E1, E2, and T were assayed using liquid chromatography-tandem mass spectrometry; FT was estimated using ensemble allostery models. Regression models were adjusted for sociodemographic characteristics and CVD risk factors.

MAIN OUTCOMES

Carotid plaque burden (number of plaques, total plaque area [TPA]) and characteristics (calcification, echogenicity) were determined using semi-automated software.

RESULTS

SHBG was inversely related to TPA (odds ratio [OR] 0.39; 95% confidence interval [CI] 0.21, 0.74; multivariable) and higher FTs were associated with greater TPA (OR 2.89; 95% CI 1.31, 6.37; multivariable). Higher E1 was related to echogenicity (OR 2.31; 95% CI 1.26, 4.33; multivariable), characteristic of more stable plaque.

CONCLUSIONS

SHBG and FT are related to TPA while E1 is related to plaque echogenicity, suggesting these hormones have different roles in the development of carotid plaque. Our findings highlight the importance of sex hormones in the development of carotid plaque in midlife women.

Carotid ultrasound investigation as a prognostic tool for patients with diabetes mellitus

BACKGROUND

Experimental and clinical data indicate a major influence of diabetes on atherogenesis. We aimed to assess whether the effect of diabetes on long-term mortality in asymptomatic patient with carotid stenosis is contingent upon the degree of the carotid atherosclerotic burden.

METHODS

1065 patients with neurological asymptomatic carotid atherosclerosis as evaluated by duplex sonography were prospectively followed for cause-specific mortality.

RESULTS

During a median of 11.8 years, a total of 549 deaths, including 362 cardiovascular deaths, were recorded. Diabetes and glycohemoglobin A1c (Hba1c) levels were significantly associated with mortality. Diabetes displayed an independent risk for all-cause (adjusted HR 1.62; 95% CI 1.35-1.94) and cardiovascular death (adjusted HR 1.75, 95% CI 1.40-2.19). The adjusted hazard ratio per increase of 1% of Hba1c levels was 1.21 (P < 0.01) for all-cause and 1.31 (P < 0.01) for cardiovascular mortality, respectively. Patients with diabetes mellitus and a higher degree of carotid stenosis and were at great risk of adverse outcome. Only 21% of the asymptomatic diabetic patients with carotid narrowing over 50% survived, whereas 62% of the patients without diabetes and with carotid atherosclerosis below 50% were still alive after 12-years of follow-up. The high risk for all-cause and cardiovascular death of these patients remained significant after adjustment for various established cardiovascular risk factors in multivariable regression analysis (adjusted hazard ratio 2.4, P < 0.001; compared to patients without diabetes and < 50% carotid atherosclerosis).

CONCLUSION

Diabetic patients with carotid stenosis ≥ 50% are at exceptional high risk for all-cause and cardiovascular death. Thus, routinely ultrasound investigation of the carotid arteries might be a valuable prognostic tool for patients with diabetes mellitus.

A Special Report on Changing Trends in Preventive Stroke/Cardiovascular Risk Assessment Via B-Mode Ultrasonography

PURPOSE OF REVIEW

Cardiovascular disease (CVD) and stroke risk assessment have been largely based on the success of traditional statistically derived risk calculators such as Pooled Cohort Risk Score or Framingham Risk Score. However, over the last decade, automated computational paradigms such as machine learning (ML) and deep learning (DL) techniques have penetrated into a variety of medical domains including CVD/stroke risk assessment. This review is mainly focused on the changing trends in CVD/stroke risk assessment and its stratification from statistical-based models to ML-based paradigms using non-invasive carotid ultrasonography.

RECENT FINDINGS

In this review, ML-based strategies are categorized into two types: non-image (or conventional ML-based) and image-based (or integrated ML-based). The success of conventional (non-image-based) ML-based algorithms lies in the different data-driven patterns or features which are used to train the ML systems. Typically these features are the patients' demographics, serum biomarkers, and multiple clinical parameters. The integrated (image-based) ML-based algorithms integrate the features derived from the ultrasound scans of the arterial walls (such as morphological measurements) with conventional risk factors in ML frameworks. Even though the review covers ML-based system designs for carotid and coronary ultrasonography, the main focus of the review is on CVD/stroke risk scores based on carotid ultrasound. There are two key conclusions from this review: (i) fusion of image-based features with conventional cardiovascular risk factors can lead to more accurate CVD/stroke risk stratification; (ii) the ability to handle multiple sources of information in big data framework using artificial intelligence-based paradigms (such as ML and DL) is likely to be the future in preventive CVD/stroke risk assessment.

Receive Beam-Steering and Clutter Reduction for Imaging the Speed-of-Sound Inside the Carotid Artery

Handheld imaging of the tissue’s speed-of-sound (SoS) is a promising multimodal addition to diagnostic ultrasonography for the examination of tissue composition. Computed ultrasound tomography in echo mode (CUTE) probes the spatial distribution of SoS, conventionally via scanning the tissue under a varying angle of ultrasound transmission, and quantifying—in a spatially resolved way—phase variations of the beamformed echoes. So far, this technique is not applicable to imaging the lumen of vessels, where blood flow and tissue clutter inhibit phase tracking of the blood echoes. With the goal to enable the assessment of atherosclerotic plaque composition inside the carotid artery, we propose two modifications to CUTE: (a) use receive (Rx) beam-steering as opposed to transmit (Tx) beam-steering to increase acquisition speed and to reduce flow-related phase decorrelation, and (b) conduct pairwise subtraction of data obtained from repetitions of the scan sequence, to highlight blood echoes relative to static echo clutter and thus enable the phase tracking of blood echoes. These modifications were tested in a phantom study, where the echogenicity of the vessel lumen was chosen to be similar to the one of the background medium, which allows a direct comparison of SoS images obtained with the different techniques. Our results demonstrate that the combination of Rx-steering with the subtraction technique results in an SoS image of the same quality as obtained with conventional Tx-steering. Together with the improved acquisition speed, this makes the proposed technique a key step towards successful imaging of the SoS inside the carotid artery.

Ultrasound carotid plaque features, cardiovascular disease risk factors and events: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND AND AIMS

It is not known if ultrasound carotid plaque features are associated with cardiovascular disease (CVD) risk factors or if they predict future CVD events.

METHODS

We measured total carotid plaque area (TPA) and grayscale plaque features (grayscale median, black areas, and discrete white areas) by B-mode carotid ultrasound among 2205 participants who participated in the first (baseline) visit of the Multi-Ethnic Study of Atherosclerosis. Multivariable linear regression was used to examine relationships between ultrasound plaque features and CVD risk factors at baseline. Cox proportional hazards models were used to assess if TPA, grayscale features, and carotid plaque score (number of arterial segments with a plaque) could predict incident coronary heart disease and cerebrovascular disease events over a mean follow-up of 13.3 years.

RESULTS

Participants were mean (standard deviation [SD]) 65.4 (9.6) years, 49% male, 39% White, 11% Chinese, 28% Black, and 22% Hispanic. Mean TPA 27.7 (24.7) mm2, but no grayscale plaque features, was associated with CVD risk factors. In fully adjusted models, TPA but no grayscale features predicted incident coronary heart disease (CHD) events (HR 1.23; 95%CI 1.11-1.36; p<0.001), however, C-statistics for CHD were similar to carotid plaque score but less than for coronary artery calcium (CAC) scoring. Neither TPA nor grayscale features independently predicted cerebrovascular events.

CONCLUSIONS

In middle-aged adults free of known cardiovascular disease, TPA but not grayscale plaque features was associated with CVD risk factors and predicted incident CHD events. For CHD, prediction indices for TPA were similar to carotid plaque score but less than for CAC.

Joint Effect of Carotid Plaque and C-Reactive Protein on First-Ever Ischemic Stroke and Myocardial Infarction?

Background

The joint effect of atherosclerosis and CRP (C‐reactive protein) on risk of ischemic stroke (IS) and myocardial infarction (MI) has been sparsely studied. The aim of this study was to explore whether CRP mediates the risk of events in subjects with prevalent carotid plaque, examine synergism, and test whether CRP and carotid plaque add to risk prediction beyond traditional risk factors.

Methods and Results

CRP and carotid total plaque area (TPA) were measured in 10 109 participants in the Tromsø Study from 1994 to 2008. Incident IS (n=671) and MI (n=1079) were registered until December 31, 2013. We calculated hazard ratios (HRs) of MI and IS according to categories of CRP (<1, 1–3, and >3 mg/L) and plaque status (no plaque and TPA below and above median) in Cox proportional hazard models with time‐varying covariates. Multivariable‐adjusted CRP >3 versus <1 mg/L was associated with risk of IS (HR, 1.84; 95% confidence interval, 1.49–2.26) and MI (HR, 1.46; 95% confidence interval, 1.23–1.73). TPA above median versus no plaque was associated with risk for IS (HR, 1.65; 95% confidence interval, 1.36–2.01) and MI (HR, 1.64; 95% confidence interval, 1.41–1.92). In participants with plaque, adjustment for CRP minimally attenuated the risk estimates. The highest incidence rates for MI and IS were seen in the group with both CRP >3 mg/L and TPA is above the median. TPA and CRP combined added to risk prediction beyond traditional risk factors.

Conclusions

The simultaneous presence of subclinical atherosclerosis and elevated CRP was associated with increased risk of IS and MI. The combined assessment of subclinical atherosclerosis and inflammatory biomarkers may improve cardiovascular disease risk stratification.

[TIMMA: Ultrasonographic scale of carotid atherosclerosis by vascular neurologists]

BACKGROUND

Carotid atherosclerosis is a powerful predictive factor of vascular risk at the individual patient level. Ultrasonography is a reference technique for the evaluation of this condition. However, its use in common practice remains difficult due to a lack of standardization and inter-operator variability. We present a new and simple technique for the assessment of carotid atherosclerosis; and evaluate the ability of vascular neurologists to obtain results consistent with those of an expert in vascular ultrasound.

MATERIAL AND METHODS

The TIMMA scale is an acronym for the five classes of carotid atherosclerosis in French, VIMMA in English: very important, important, moderate, minimal and absent. Combined, the first two classes make up the group "significant atheroma" and the last three classes make up the group "no significant atheroma". This scale was evaluated in 38 patients (76 carotid arteries) suffering from ischemic stroke or transient ischemic attack by five operators who are competent in carotid echocardiography: one TIMMA-trained (40 hours of training) vascular neurologist physician (VNP), three VNPs informed on the measurement method (1 hour of information) and one specialized vascular physician (SVP) who was considered to be the reference examiner. We evaluated the concordance between the VNPs and the SVP in classifying patients, firstly into the significant or not atheroma group and, secondly, into the five TIMMA classes.

RESULTS

The evaluation of the two-group clustering scale found a concordance between the informed VNPs and the SVP on 76 carotid arteries of 86% (kappa=0.7) and between the trained VNP and the SVP on 58 carotid arteries of 90% (kappa=0.8). The positive and negative predictive values for significant atheroma diagnosis were 100% and 81%, respectively, for the informed VNPs, and 100% and 80% for the trained VNP. The evaluation of the Five-Class Scale showed a concordance between the informed VNPs and the SVP of 46% (kappa=0.3), and between the trained VNP and the SVP of 74% (kappa=0.7).

CONCLUSION

TIMMA allows VNPs who are competent in carotid ultrasonography to reproducibly identify subjects with significant carotid atheroma. The contribution of this scale to the determination of cardiovascular risk should be evaluated.