Measurement of pulse wave velocity: site matters

BACKGROUND: Aortic pulse wave velocity (PWV) predicts mortality from cardiovascular disease, ischaemic heart disease and stroke. However, a comparison of associations between PWV measured at different sites and atherosclerosis in coronary, carotid and femoral arteries has not been made. METHODS: In 159 men (ages 45-82 years) with and without known coronary artery disease, PWV measurements were made between carotid-femoral, carotid-radial and femoral-posterior tibial sites, using an ultrasound technique. Coronary artery calcification (CAC) scores were measured by multislice computed tomography. Carotid and femoral intima-media thickness (IMT) and presence of plaque were determined by ultrasound. Known coronary artery disease was confirmed by angiography. Participants were grouped into four categories of CAC score: 0-10, 11-100, 101-400, > 400 Hounsfield Units (HU). Measurements of blood pressure, heart rate and fasting bloods were made in all individuals. RESULTS: Carotid-femoral PWV correlated positively with CAC score and increased with incremental coronary calcification category (median carotid-femoral PWV 16.8 m/s in those with CAC score > 400 HU and 13.8 m/s in those with CAC score < 10 HU; P = 0.003). Carotid-femoral PWV also correlated with carotid and femoral IMT (P < 0.001, P = 0.004, respectively) and with carotid and femoral plaque (P = 0.001, P = 0.038, respectively). Increased carotid-femoral PWV also correlated with increasing age (P < 0.001), systolic blood pressure (P < 0.001), mean arterial pressure and pulse pressure (P < 0.001). Carotid-radial and femoral-posterior tibial PWV were not significantly associated with CAC score, carotid or femoral IMT or carotid plaque. CONCLUSIONS: Carotid-femoral PWV is a better indicator of atherosclerosis than either carotid-radial or femoral-posterior tibial PWV, and should be used preferentially in studies of atherosclerosis and in stratifying risk in clinical settings.     

The Relationship between coronary artery calcification as assessed by multi-detector computed tomography and arterial stiffness

Pulse wave analysis and intima-media thickness (IMT) of carotid artery are the non-invasive indicators of subclinical atherosclerosis. Coronary artery calcification (CAC) score measured by multi-detector computed tomography (MDCT) is well known as a predictor of coronary heart disease (CHD). We investigated the association between coronary calcification assessed by MDCT and extracoronary atherosclerosis measured by pulse wave analysis and IMT of carotid artery. Arterial stiffness and carotid IMT were measured consecutively in 133 patients who underwent their first coronary MDCT angiography due to chest pain. Patients were divided into three groups according to the CAC score (group 1, score = 0, n = 62; group 2, 0 < score < 400, n = 58; group 3, score ≥ 400, n = 13). The classification of CAC score was associated with age, prevalence of hypertension and dyslipidemia, systolic blood pressure, pulse pressure, brachial-ankle pulse wave velocity, percentage of brachial mean artery pressure, upstroke time (UT), augmentation index, and carotid IMT. In a multivariate analysis, age (P = .048), hypertension (P = .007), dyslipidemia (P = .24), and mean ankle UT (P = .038) were independent variables for the classification of CAC score. The UT of pulse wave was significantly associated with the CAC score. The increased UT of pulse wave might provide incremental risk prediction in addition to that defined by conventional CHD risk assessment.     

Interrelation between the extent of atherosclerosis in the thoracic aorta, carotid intima-media thickness and the extent of coronary artery disease

Intima-media thickness (IMT) of the common carotid artery and atherosclerosis of the thoracic aorta have been shown to correlate with coronary artery disease (CAD). This study compares the relation between wall changes in the thoracic aorta and the carotid arteries and the angiographic severity and extent of atherosclerotic lesions in the coronary arteries in patients with verified CAD. Atherosclerotic wall changes in the carotid arteries and the thoracic aorta were measured by B-mode ultrasonography and transesophageal echocardiography (TEE), respectively, in 37 subjects aged 65+/-10 years with angiographically verified CAD. The mean value of the common carotid IMT of the right and left sides was 0.87+/-0.21 mm. All subjects had carotid plaques. TEE detected grades II-IV atherosclerotic plaques in the thoracic aorta in 32 of the 37 (86%) patients. A significant correlation was seen between the extent of coronary artery stenosis and aortic plaques score (r=0.46, p=0.008). Mean carotid IMT was also significantly correlated with coronary artery stenosis extent score (r=0.44, p=0.007). Moreover, a significant correlation was seen between the aortic plaque score and the mean carotid IMT (r=0.39, p=0.02). In conclusion, we found a clear and significant relationship between wall changes in the thoracic aorta, common carotid IMT and the angiographic extent of coronary artery stenosis in patients with severe CAD. These findings indicate a potential of B-mode ultrasonography of the carotid arteries and transesophageal echocardiographic aortic examination in the diagnostic and prognostic evaluation of patients with suspected CAD.     

The Relationship between Coronary Artery Calcification as Assessed by Multi-Detector Computed Tomography and Arterial Stiffness

Pulse wave analysis and intima-media thickness (IMT) of carotid artery are the non-invasive indicators of subclinical atherosclerosis. Coronary artery calcification (CAC) score measured by multi-detector computed tomography (MDCT) is well known as a predictor of coronary heart disease (CHD). We investigated the association between coronary calcification assessed by MDCT and extracoronary atherosclerosis measured by pulse wave analysis and IMT of carotid artery. Arterial stiffness and carotid IMT were measured consecutively in 133 patients who underwent their first coronary MDCT angiography due to chest pain. Patients were divided into three groups according to the CAC score (group 1, score = 0, n = 62; group 2, 0 < score < 400, n = 58; group 3, score ≥ 400, n = 13). The classification of CAC score was associated with age, prevalence of hypertension and dyslipidemia, systolic blood pressure, pulse pressure, brachial-ankle pulse wave velocity, percentage of brachial mean artery pressure, upstroke time (UT), augmentation index, and carotid IMT. In a multivariate analysis, age (P = .048), hypertension (P = .007), dyslipidemia (P = .24), and mean ankle UT (P = .038) were independent variables for the classification of CAC score. The UT of pulse wave was significantly associated with the CAC score. The increased UT of pulse wave might provide incremental risk prediction in addition to that defined by conventional CHD risk assessment.     

Diagnostic accuracy of carotid ultrasonography in screening for coronary artery disease

OBJECTIVES: This study investigated the diagnostic accuracy of carotid ultrasonography in screening for significant coronary artery disease (% diameter stenosis > or = 75%). METHODS: Five hundred sixty patients (342 males, 218 females, mean age 66.4 years) underwent both coronary angiography and carotid ultrasonography. Gensini's coronary score was calculated as a quantitative parameter of coronary atherosclerosis. The most hypertrophic intimal-medial complex thickness (IMT) of the bilateral common carotid arteries (distal and proximal to the echo probe in each artery) was measured within 2 or 3 cm from the carotid bifurcation. The mean IMT (mean of these 4 sites), the maximum IMT (maximum of these 4 sites), and number of plaques (localized hypertrophy of IMT > or = 1.1 mm) were calculated as a quantitative parameter of carotid atherosclerosis. RESULTS: The screening parameters were determined as 0.85 mm mean IMT, 1.1 mm maximum IMT, and at least 2 sites of plaque. The sensitivity, specificity and accuracy rate for the detection of coronary artery disease were 57.3%, 61.6% and 59.6% for mean IMT, 43.5%, 71.1% and 58.6% for maximum IMT, and 60.8%, 70.5% and 66.1% for number of plaques. Furthermore, the overall results (except maximum IMT) were 73.3%, 49.2% and 60.2%. CONCLUSIONS: These results suggest that carotid ultrasonography is useful as a non-invasive and easy screening method for coronary artery disease. Furthermore, carotid ultrasonography will allow routine observations to follow the progression of coronary atherosclerosis.     

Coronary and peripheral artery remodeling in patients undergoing PTCA: An intracoronary and transcutaneous ultrasound study.

The aim of this study was to assess the relationship between the plaque burden of nonstenotic coronary artery segments and the wall thickness of peripheral arteries using intracoronary and transcutaneous ultrasound imaging, respectively. Intracoronary ultrasound (CVIS, 3.5 Fr) was performed in 27 patients undergoing percutaneous transluminal coronary angioplasty. Carotid arteries were imaged by B-mode ultrasound with semiautomatic edge detection and radial arteries by high resolution A-mode echotracking (NIUS 2). Quantitative measurements included coronary artery intima-media cross-sectional area (IM(CSA)) and cross-sectional narrowing (CSN), as well as intima-media thickness (IMT) and lumen radius (r) of the common carotid and the radial arteries. Intima-media thickness was increased in coronary, carotid, and radial arteries. Coronary arteries had an IM(CSA) of 7.7 +/- 2.5 mm(2) and a CSN of 24% +/- 8%. Despite this moderate plaque burden, lumen area was preserved (12.3 +/- 4.2 mm(2)) because of compensatory enlargement of coronary arteries. Right and left carotid and right radial arteries had an IMT of 575 +/- 78 microm, 570 +/- 129 microm, and 328 +/- 61 microm, respectively. There was no correlation between coronary IM(CSA) and carotid IMT (r = 0.07) or radial IMT (r = 0.02), and there was no correlation between coronary CSN and carotid IMT/r (r = 0.12), or radial IMT/r (r = 0.25). In conclusion, in these patients with symptomatic ischemic disease no relationship between IMT of the coronary arteries and IMT of carotid or radial arteries was found. Although increasingly popular, IMT of peripheral arteries may be of limited value as surrogate marker for the severity of coronary artery disease. Cathet. Cardiovasc. Intervent. 48:12-17, 1999.     

Atherosclerotic changes of extracoronary arteries are associated with the extent of coronary atherosclerosis

The aim of the present study was to examine the association between carotid and femoral artery intima media thickness (IMT) and the extent and severity of coronary artery disease (CAD) as well as the effects of traditional vascular risk factors on the atherosclerotic changes in the carotid and femoral arteries. Two hundred twenty-four patients who underwent coronary angiography for suspected CAD were evaluated by B-mode ultrasound imaging of the common carotid, internal carotid, carotid bifurcation, and femoral artery for measurement of IMT; traditional vascular risk factors were also evaluated in these patients. CAD extent was evaluated by the number of diseased vessels and by Gensini score. Age, male gender, and diabetes were common risk factors for higher CAD extent and higher carotid and femoral IMT. Insulin levels were correlated with femoral IMT and CAD extent, whereas blood lipids were correlated predominantly with carotid IMT. IMT from carotid and femoral arteries increased significantly with an increase in CAD extent. Using multiple stepwise regression analysis, the following parameters were found to be independent predictors of CAD extent: male gender (p<0.0001), common femoral artery IMT (p = 0.0028), common carotid artery IMT (p = 0.015), age (p = 0.02), diabetes mellitus (p = 0.035), and carotid artery bulb IMT (p = 0.04). Common femoral IMT was the only independent parameter for predicting Gensini score (p<0.0001). In conclusion, there are territorial differences in the various arterial beds regarding their response to risk factors. Femoral artery and carotid bulb are independent predictors of CAD extent and the inclusion of these measurements would add information to that provided by the common carotid artery.     

Comparative performance of subclinical atherosclerosis tests in predicting coronary heart disease in asymptomatic individuals.

The prognostic performance of subclinical atherosclerosis in predicting coronary heart disease (CHD) needs to be clarified because of the existence of many non-invasive tests available for its detection in the clinical setting: ultrasound measurement of carotid intima-media thickness (IMT) and plaque, cardiac computed tomography assessment of coronary artery calcium, Doppler stethoscope measurement of ankle-arm index pressure (AAI), and mechanographic or Doppler determination of aortic pulse wave velocity (PWV). Data analysis of the main prospective studies in asymptomatic populations allows the establishment of a dose-response relationship between subclinical atherosclerosis burden and cumulative incidence of future CHD event (absolute risk). Negative subclinical atherosclerosis testing conveys a low 10-year CHD risk inferior to 10% whatever the test considered, i.e. IMT less than the 1st tertile or 1st quintile, AAI > or = 0.90, PWV less than the first tertile, no discernible carotid plaque, or zero coronary calcium score. Positive testing for IMT (>95th percentile or 5th quintile), AAI (<0.90), or PWV (>3rd tertile) conveys a moderately high 10-year CHD risk between 10 and 20%. Positive testing for carotid plaque (focal protrusion >1.5 mm or mineralization) or coronary calcium (total score >300 or 400 units) conveys a high 10-year CHD risk superior to 20%. Therefore, positive subclinical atherosclerosis measurement seems to have its place in the context of existing prediction models, namely for intermediate risk classification. It also remains to be established whether individuals with negative subclinical atherosclerosis may be considered at low CHD risk and receive conservative management.     

Association of coronary artery calcium with severity of myocardial ischemia in left anterior descending, left circumflex, and right coronary artery territories

Background:

An increasing coronary artery calcium score is associated with a higher likelihood of myocardial ischemia.

Hypothesis:

The association of the coronary calcium score with myocardial ischemia in different coronary arteries needed to be investigated.

Methods:

We correlated the coronary artery calcium (CAC) score with the severity of myocardial ischemia diagnosed by myocardial perfusion imaging in the left anterior descending (LAD), left circumflex (LCX), and right coronary artery (RCA) territories in 206 patients, mean age 66 years, without cardiac stents or coronary artery surgery.

Results:

The mean CAC score in the LAD coronary artery was 160 ± 218 in patients with no or mild ischemia and 336 ± 379 in patients with moderate or severe ischemia (P = 0.039). The mean CAC score in the LCX coronary artery was 57 ± 117 in patients with no or mild ischemia and 161 ± 191 in patients with moderate or severe ischemia (P = 0.018). The mean CAC score in the RCA was 114 ± 237 in patients with no or mild ischemia and 261 ± 321 in patients with moderate or severe ischemia (P = 0.045). Stepwise linear regression analysis showed that male gender (P < 0.0001), age (P < 0.0001), and moderate or severe ischemia (P = 0.023) were significantly associated with high LAD coronary artery CAC scores. Male gender (P < 0.0001), age (P = 0.0002), and moderate or severe ischemia (P = 0.006) were significantly associated with high LCX coronary artery CAC scores. Male gender (P < 0.0001) and age (P < 0.0001) were significantly associated with high RCA CAC scores.

Conclusions:

Higher CAC scores are significantly associated with moderate or severe ischemia in the LAD and LCX coronary arteries. © 2011 Wiley Periodicals, Inc. The authors have no funding, financial relationships, or conflicts of interest to disclose.     

Comparison of coronary calcium and stress myocardial perfusion imaging in apparently healthy siblings of individuals with premature coronary artery disease

Detection of subclinical coronary atherosclerosis is possible using exercise myocardial perfusion imaging for inducible ischemia or multidetector computed tomography for coronary artery calcium (CAC), which is used to detect subclinical coronary atherosclerosis. The extent to which these screening tests converge in an asymptomatic population that is at increased risk for coronary artery disease remains unknown. We compared the concordance of findings in 260 asymptomatic middle-age siblings of hospitalized index patients <60 years of age with documented coronary artery disease. All subjects underwent maximal exercise testing with postexercise and delayed attenuation-corrected thallium single-photon emission computed tomography and multidetector computed tomography for CAC. An abnormal exercise single-photon emission computed tomographic (SPECT) result occurred in >50% of subjects with a CAC score >100, but also in 12% with no CAC, 9% with CAC scores of 1 to 10, and 20% with CAC scores of 11 to 100. In subjects with an abnormal exercise SPECT result, 59% had CAC scores < or =100. Overall, there was only a modest agreement between an abnormal exercise SPECT result and high CAC scores. In conclusion, although moderate or severe CAC is often associated with inducible ischemia, the absence of CAC or the presence of only mild CAC by no means precludes inducible myocardial ischemia. These screening tests may reflect different aspects or stages of coronary disease in an asymptomatic middle-age population.     

The role of ultrasonography of the peripheral arteries in diagnosing coronary artery disease

Atherosclerosis develops simultaneously in multiple arterial beds, that creates opportunity to diagnose of coronary artery disease. Aim of the study was the evaluation of association between atherosclerotic involvement of peripheral arteries assessed by ultrasound and significant coronary artery disease revealed by angiography. Study included 410 patients, (73% males), mean age 56.0 +/- 9.5 year scheduled for coronary angiography. During ultrasound examination of common carotid and common femoral arteries arterial wall intima-media (IMT) thickness and atherosclerotic plaques presence were assessed. Significant coronary artery disease (CAD) was diagnosed with coronary angiography as diameter stenosis > 50%. Intimo-media thickness (IMT) of common carotid arteries did not differ between groups with and without significant coronary artery disease (right 6.6 vs 6.4 mm, p = ns, left 6.9 vs 6.6 mm, p = ns) but in common femoral arterial was greater in patients with coronary artery disease (right 8.2 vs 7.1 mm, p < 0.005, left 7.9 vs 7.1 mm, p = 0.03). Atherosclerotic plaques in carotid and femoral arteries was detected more often in CAD patients (90.1% vs 34.6%, p < 0.0001). Positive predictive value for CAD diagnosis with detection of plaque in carotid or femoral artery was 93% and negative prognostic value for exclusion CAD after plaque exclusion in all arteries was 61%. Search for atherosclerotic plaques in ultrasound examination of peripheral arteries may facilitate CAD diagnosis in selected patients groups.     

Carotid and femoral atherosclerotic lesions in patients with coronary heart disease confirmed by angiography

INTRODUCTION: Clinically evident atherosclerosis is preceded by preclinical changes in the arterial wall. These changes are characterised by increased thickness of the intima-media complex (IMT). AIMS: A complex ultrasound assessment of the peripheral vessels as well as an attempt to find ultrasound parameters correlating with the burden of atherosclerotic lesions of the coronary arteries. METHODS: 231 patients who underwent both coronary angiography and ultrasound examination of the following arteries: common carotid artery (CCA), carotid bulb and common femoral artery (CFA) were enrolled. The IMT value, presence of plaque and Doppler blood flow parameters were evaluated. Selected clinical and biochemical risk factors of atherosclerosis were assessed. Two groups of patients were analysed: 200 patients with coronary artery disease confirmed by angiography (study group), and 31 patients with normal coronary arteries (control group). RESULTS: Significantly higher values of the IMT in the peripheral arteries were observed in patients with coronary artery lesions than in those without (CCA - 0.91 vs 0.61 mm, carotid bulb -- 1.31 vs 0.67 mm, CFA -- 1.38 vs 0.63 respectively, p<0.0001). Atherosclerotic plaques were present only in patients with coronary artery disease. Additionally, IMT values of the CCA, carotid bulb and CFA were significantly higher in patients with severe coronary artery disease (three vessel disease) than in patients with lesions in one or two coronary arteries. CONCLUSIONS: Patients with coronary lesions present with increased IMT values and higher plaque occurrence. Complex ultrasound evaluation of different peripheral arteries (CCA, carotid bulb and CFA) may be used as part of the cardiovascular risk stratification.     

Clinical significance of the coronary calcification score by multidetector row computed tomography for the evaluation of coronary stenosis in Japanese patients.

BACKGROUND: The coronary artery calcification (CAC) score measured by multidetector row computed tomography (MDCT) has emerged as a marker for predicting coronary artery disease (CAD). To evaluate the clinical significance of the CAC score, coronary artery stenosis as assessed by coronary angiography (CAG) was compared with the CAC score determined by MDCT, risk factors and medications. METHODS AND RESULTS: Subjects included 374 consecutive patients who underwent ECG-gate CT angiography using MDCT. The accuracy in patients with a CAC score >or=400 was 84%, and significantly lower than that in patients with a CAC score =0. In addition 92 patients (68 males, 24 females; mean age, 63+/-11 years) who underwent both MDCT and CAG within a 1-month period were selected for further investigation. Patients with significant coronary stenosis had a significantly higher CAC score than those without stenosis. In addition, a higher number of stenosed vessels was associated with a higher CAC score. The subjects were divided into 3 groups according to the CAC score: low (0-12), intermediate (13-444) and high (>or=445). The CAC score was significantly associated with age, and plasma levels of total cholesterol and hemoglobinA1c, and logistic regression analysis revealed that significant coronary stenosis as assessed by CAG was most closely correlated with the CAC score (p=0.03). CONCLUSIONS: The CAC score determined by MDCT can predict CAD independent of other factors, such as age, metabolic diseases and medications, when coronary stenosis can not be diagnosed because of severe calcification.     

Impact of multiple coronary risk factors on the intima-media thickness of different segments of carotid artery in healthy young adults (The Bogalusa Heart Study)

Although risk factors for coronary artery disease are also associated with increased carotid artery intima-media thickness (IMT) as measured by B-mode ultrasonography in middle-aged and older persons, information on the impact of multiple risk factors on the IMT of different segments of the carotid artery in young adults is limited. This relation was examined in a sample of 518 black and white subjects (mean age 32 years; 71% white, 39% male) enrolled in the Bogalusa Heart Study. IMT was thicker and more skewed in the bulb compared with other carotid segments. Race differences (blacks more than whites) were noted for the common carotid (p <0.001) and carotid bulb (bifurcation) IMT (women only, p <0.001). Men had a greater IMT in the common carotid (p <0.05), internal carotid (p <0.05), and carotid bulb (whites only, p <0.001). In a multivariate analysis, systolic blood pressure, race, age, low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein (HDL) cholesterol weree entered into a model in that order and accounted for the 16.7% variance in the common carotid IMT; age, systolic blood pressure, HDL cholesterol, LDL cholesterol, race, and insulin levels explained the 19.4% variance in the carotid bulb IMT. Gender and body mass index (BMI) accounted for the 4.7% variance in the internal carotid IMT. Increases in IMT with increasing number of risk factors (cigarette smoking, higher total cholesterol to HDL cholesterol ratio, higher systolic blood pressure, greater waist circumference, and higher insulin level) were noted for the common carotid and carotid bulb segments (p for trend <0.001 for both). The observed deleterious trend of increasing IMT at different carotid segments with increasing number of risk factors in free-living, asymptomatic young subjects underscores the importance of profiling multiple risk factors early in life. Ultrasonography of carotid arteries, especially at the bifurcation, may be helpful along with measurements of risk factors for evaluation of asymptomatic atherosclerotic disease.     

Age and the power of zero CAC in cardiac risk assessment: overview of the literature and a cautionary case

The coronary artery calcium (CAC) score is a marker of advanced coronary atherosclerosis. Numerous prospective cohorts have validated CAC as an independent marker that improves prognostication in atherosclerotic cardiovascular disease (ASCVD) beyond traditional risk factors. Accordingly, CAC is now incorporated into international cardiovascular guidelines as a tool to inform medical decision-making. Particular interest concerns the significance of zero CAC score (CAC=0). While many studies report CAC=0 to virtually exclude obstructive coronary artery disease (CAD), non-negligible rates of obstructive CAD despite CAC=0 are reported in certain populations. Overall, the current literature supports the power of zero CAC as a strong downward risk classifier in older patients, whose CAD burden predominantly involves calcified plaque. However, with their higher burden of non-calcified plaque, CAC=0 does not reliably exclude obstructive CAD in patients under 40 years. Illustrating this point, we present a cautionary case of a 31-year-old patient found to have severe two-vessel CAD despite CAC=0. We highlight the value of coronary computed tomography angiography (CCTA) as the gold-standard non-invasive imaging modality when the diagnosis of obstructive CAD is in question.Key words: calcium score, coronary artery calcium, coronary computed tomography angiography (CCTA), heart disease risk factors     

Gender differences in carotid intima-media thickness in patients with suspected coronary artery disease

Selecting patients who have suspected coronary artery disease (CAD) for coronary angiography remains difficult in some subgroups (e.g., women have often atypical symptoms and false-positive findings on noninvasive tests). This study evaluated gender differences and the clinical value of carotid intima-media thickness (IMT) in predicting CAD. We evaluated 558 patients who had symptoms and underwent coronary angiography: 91 women (61.2 +/- 9.5 years of age) had CAD (> or =1 lesion with a decrease >50% in luminal diameter of a coronary artery), 29 women (57.9 +/- 7.0 years of age) did not have CAD, 372 men (58.9 +/- 9.2 years of age) had CAD, and 66 men (54.6 +/- 8.7 years of age) did not have CAD. Maximal IMT was assessed bilaterally at the common carotid, bulb, and internal carotid arteries and expressed as mean IMT for each patient. Among patients who did not have CAD, women had lower mean IMT values than men (0.93 +/- 0.15 vs 1.05 +/- 0.19, p < 0.001). This gender difference was not seen in patients who had CAD (1.3 +/- 0.31 vs 1.31 +/- 0.31, p = 0.92). Among women and men, those with CAD had larger IMT values than those without CAD. Multivariable regression analysis showed that age, CAD, hypertension, smoking, and diabetes had the strongest effect on IMT values in women and men. Receiver-operator characteristic analysis showed that women had a significantly lower IMT threshold for likelihood of CAD (p < 0.001) and that a mean IMT of 1.069 mm was highly predictive of concomitant CAD (sensitivity 79%, specificity 90%, positive predictive value 96%); for men, the mean IMT threshold was 1.153 mm (sensitivity 66%, specificity 74%, positive predictive value 93%). In conclusion, carotid IMT assessment may be a valuable tool in selecting patients for coronary angiography to predict the likelihood of CAD. This particularly concerns women in whom sensitivity and specificity of mean IMT are high.     

Coronary calcification is more predictive of carotid intimal medial thickness in black compared to white middle aged men

BackgroundRace-specific data for the association between coronary artery calcification (CAC) and carotid intimal medial thickness (IMT) are limited. We sought to compare black-white specific associations of these two measures.MethodsWe conducted a population-based study of 379 randomly selected men aged 40–49 years (84 black and 295 white) from Allegheny County, US (2004–2006). Agatston CAC score was evaluated by electron-beam tomography and carotid IMT was evaluated by ultrasonography.ResultsCompared to white men, black men had similar prevalence of CAC (p = 0.56) and higher total carotid IMT (p < 0.001). In black and white men, CAC score had significant positive correlations with total carotid IMT (r = 0.47 and r = 0.24, respectively, p < 0.001 for both) as well as the IMT for the common carotid artery (CCA), internal carotid artery and carotid bulb. The associations of CAC with total and CCA IMT were significantly stronger in black (β = 0.07 and β = 0.05, respectively) than white men (β = 0.03 and β = 0.01, respectively) after adjustment for traditional coronary risk factors (p = 0.046 and p = 0.036, respectively).ConclusionsIn black and white middle aged men, CAC score had significant positive correlations with total and segmental carotid IMT. CAC was more predictive of total and CCA IMT in black than white men independent of coronary risk factors.     

MESA: The NIH-Sponsored Study That Validates Atherosclerosis Imaging for Primary Prevention

Coronary artery calcium (CAC) score correlates strongly with the burden of atherosclerotic plaques in the coronary arteries. It is the strongest predictor of future coronary events in asymptomatic individuals, being stronger than all traditional risk factors combined. It is also a better predictor of future events than carotid intima-media thickness (CIMT) measurement for the prediction of coronary artery disease but slightly weaker than CIMT for the prediction of cerebrovascular events such as stroke. These findings have been validated by the Multi-Ethnic Study of Atherosclerosis (MESA), a prospective epidemiologic study sponsored by the National Institutes of Health (NIH) investigating the prevalence, correlates, and progression of atherosclerosis in an asymptomatic, ethnically diverse population. That is why the US national guidelines have recently elevated their recommendation levels to Class IIa for use of CAC and CIMT in risk stratification of the asymptomatic intermediate-risk population.     

The prevalence of coronary artery calcium among diabetic individuals without known coronary artery disease

OBJECTIVES: We sought to examine the age and gender distribution of coronary artery calcium (CAC) by diabetes status in a large cohort of asymptomatic individuals. BACKGROUND: Among individuals with diabetes, coronary artery disease (CAD) is a major cause of morbidity and mortality. Electron-beam tomography (EBT) quantifies CAC, a marker for atherosclerosis. METHODS: Screening for CAC by EBT was performed in 30,904 asymptomatic individuals stratified by their self-reported diabetes status, gender, and age. The distribution of CAC across the strata and the association between diabetes and CAC were examined. RESULTS: Compared with nondiabetic individuals (n = 29,829), those with diabetes (n = 1,075) had higher median CAC scores across all but two age groups (women 40 to 44 years old and men and women > or =70 years old). Overall, the likelihood of having a CAC score in the highest age/gender quartile was 70% greater for diabetic individuals than for their nondiabetic counterparts. CONCLUSIONS: Younger diabetic individuals appear to have calcified plaque burden comparable to that of older individuals without diabetes. These findings call for future research to determine if EBT-CAC screening has an incremental value over the current CAD risk assessment of individuals with diabetes.     

Effect of parental coronary artery disease on adverse effects of the metabolic syndrome and aging on carotid artery intima-media thickness (from the Bogalusa Heart Study)

Genetic susceptibility is considered an important predictor of coronary artery disease (CAD) and its risk factors. This study was conducted to assess the hypothesis that parental CAD, a surrogate measure of genetic susceptibility, increases the vulnerability of the arterial wall to adverse effects of the metabolic syndrome and the aging process in asymptomatic young adults. The study cohort consisted of 1,073 black and white subjects (29.1% black, 43.7% male) aged 25 to 44 years. Carotid intima-media thickness (IMT) of the common carotid, carotid bulb, and internal carotid segments was measured using B-mode ultrasound. Subjects with parental CAD had greater composite (average of 3 segments) carotid IMT (0.839 vs 0.802 mm, p = 0.04) and a higher prevalence of the metabolic syndrome (20.7% vs 13.3%, p <0.01) compared with those without such a history. Furthermore, the association of the metabolic syndrome with composite, carotid bulb, and internal carotid IMT was significantly stronger in subjects with parental CAD than those without such a history (p = 0.022, p = 0.032, and p = 0.035 for comparison of slopes, respectively). After adjusting for race, gender, and the metabolic syndrome components, only internal carotid IMT showed significantly more increase with age in subjects with parental CAD compared with those without such a history (regression coefficient: beta = 0.014 vs beta = 0.006, p = 0.010 for comparison of slopes). In conclusion, parental CAD amplifies the adverse effects of the metabolic syndrome and aging on carotid artery IMT, especially internal carotid IMT, in asymptomatic young adults. These findings reinforce the value of using family history of CAD in risk assessment algorithm.