Role of Coronary Artery Calcium Scoring in Detection of Coronary Artery Disease according to Framingham Risk Score in Populations with Low to Intermediate Risks

Current guidelines recommend that coronary artery calcium (CAC) screening should only be used for intermediate risk groups (Framingham risk score [FRS] of 10%-20%). The CAC distributions and coronary artery disease (CAD) prevalence in various FRS strata were determined. The benefit to lower risk populations of CAC score-based screening was also assessed. In total, 1,854 participants (aged 40-79 years) without history of CAD, stroke, or diabetes were enrolled. CAC scores of > 0, ≥ 100, and ≥ 300 were present in 33.8%, 8.2%, and 2.9% of the participants, respectively. The CAC scores rose significantly as the FRS grew more severe (P 20% strata were 3.4%, 6.7%, 9.0%, and 11.6% (P 20%; P < 0.05). In conclusion, the yield of screening for significant CAC and occult CAD is low in the very low risk population but it rises in low and intermediate risk populations.

Association of metabolic syndrome with coronary artery calcification

No abstract available.

Metabolic syndrome criteria as predictors of subclinical atherosclerosis based on the coronary calcium score

BACKGROUND/AIMS: The aim was to determine which of three sets of metabolic syndrome (MetS) criteria (International Diabetes Federation [IDF], National Cholesterol Education Program Adult Treatment Panel III [ATP III], and European Group for the Study of Insulin Resistance [EGIR]) best predicts the coronary artery calcification (CAC) score in a cross-sectional study. This has not been evaluated in previous studies. METHODS: A total of 24,060 subjects were screened for CAC by multi-detector computed tomography. The presence of CAC was defined as a CAC score > 0. The odds ratio for the presence of CAC was analyzed for three different sets of MetS criteria and according to number of MetS components. RESULTS: CAC was observed in 12.6% (3,037) of the subjects. Patients with MetS, as defined by the IDF, ATP III, and EGIR criteria, had a CAC rate of 23.0%, 25.1%, and 29.5%, respectively (p or = 3 (p for trend < 0.001). CONCLUSIONS: The presence of MetS was associated with the presence of CAC. There was no significant difference among the three sets of MetS criteria in terms of the ability to predict CAC. An increase in the number of MetS components was associated with an increased odds of CAC.

Coronary artery plaque burden and calcium scores in healthy men adhering to long-term wine drinking or alcohol abstinence

Observational studies suggest there are clinical benefits to moderate red wine (RW) consumption. However, the effects on coronary vasculature and overall lifestyle are unclear. We investigated whether a lifestyle of regular long-term RW consumption is associated with changes in coronary plaque burden, calcium score, carotid intima/media thickness, endothelial function, and metabolic variables, compared with alcohol abstinence. Healthy volunteers were evaluated by coronary computed tomography angiography (CTA) as well as carotid and brachial artery ultrasound. Nutritional status, psychological status, and metabolic variables were assessed. The study included 101 drinkers [aged 58.9±7.3 years (means±SD)], from wine brotherhoods, and 104 abstainers, from Anglican, Evangelical and Catholic churches both in the city of São Paulo, Brazil. No significant differences in demographics were noted. Lesion prevalence per patient assessed by coronary CTA and classified as absent (0), 1-25, 26-49, and ≥50% stenosis was similar between groups. When analyzed by individual arteries, i.e., left anterior descending, circumflex, and right coronary, prevalence was also not different. On the other hand, calcium scores were higher among drinkers than abstainers (144.4±362.2 vs 122.0±370.3; P<0.01). However, drinkers reported less history of diabetes and exercised more. RW drinkers consumed 2127.9±387.7 kcal/day while abstainers consumed 1836.0±305.0 (P<0.0001). HDL cholesterol was significantly higher among drinkers compared to abstainers (46.9±10.9 vs 39.5±9.0 mg/dL; P<0.001), while fasting plasma glucose was lower (97.6±18.2 vs 118.4±29.6 mg/dL; P<0.02). Liver enzymes were normal in both groups. In conclusion, long-term wine drinkers displayed a similar plaque burden but greater calcium score than abstainers, despite a more atherogenic diet, and the mechanisms for the increased calcium scores in the former remain speculative.

Significance of Microalbuminuria in Relation to Subclinical Coronary Atherosclerosis in Asymptomatic Nonhypertensive, Nondiabetic Subjects

We aimed to investigate the significance of microalbuminuria and its relationship with subclinical atherosclerosis in nonhypertensive and nondiabetic patients, by using coronary artery computed tomography (CT). A total of 1,318 nonhypertensive and nondiabetic subjects who had taken coronary artery CT and measured spot urine albumin to creatinine ratio (UACR) were evaluated. The atherosclerotic changes of coronary arteries were greater in subjects with microalbuminuria, reflected by coronary artery calcium score (CACS) and significant coronary artery stenosis (CACS > or = 100 in 15.3% vs 7.6% and stenosis > or = 50% in 11.5% vs 4.9% of patients with vs without microalbuminuria, P = 0.008 and P = 0.011, respectively). Among various parameters that are known as a risk factor or possible biomarkers of coronary artery disease, presence of microalbuminuria, age and Framingham risk score were significantly related to coronary artery stenosis. Among them the presence of microalbuminuria showed stronger correlation than others to the coronary artery stenosis detected by CT, even after adjusting confounding factors (OR 3.397, 95% confidence interval 1.138 to 10.140, P = 0.028). The presence of microalbuminuria by UACR was significantly associated with presence of coronary artery stenosis > or = 50% in asymptomatic, nonhypertensive and nondiabetic general population. Our study suggests that the presence of microalbuminuria may imply subclinical coronary artery disease, even in asymptomatic population.

Effect of Heart Rate and Body Mass Index on the Interscan and Interobserver Variability of Coronary Artery Calcium Scoring at Prospective ECG-Triggered 64-Slice CT

OBJECTIVE: To test the effects of heart rate, body mass index (BMI) and noise level on interscan and interobserver variability of coronary artery calcium (CAC) scoring on a prospective electrocardiogram (ECG)-triggered 64-slice CT. MATERIALS AND METHODS:One hundred and ten patients (76 patients with CAC) were scanned twice on prospective ECG-triggered scans. The scan parameters included 120 kV, 82 mAs, a 2.5 mm thickness, and an acquisition center at 45% of the RR interval. The interscan and interobserver variability on the CAC scores (Agatston, volume, and mass) was calculated. The factors affecting the variability were determined by plotting it against heart rate, BMI, and noise level (defined as the standard deviation: SD). RESULTS: The estimated effective dose was 1.5 +/- 0.2 mSv. The mean heart rate was 63 +/- 12 bpm (range, 44-101 bpm). The patient BMIs were 24.5 +/- 4.5 kg/m2 (range, 15.5-42.3 kg/m2). The mean and median interscan variabilities were 11% and 6%, respectively by volume, and 11% and 6%, respectively, by mass. Moreover, the mean and median of the algorithms were lower than the Agatston algorithm (16% and 9%, respectively). The mean and median interobserver variability was 10% and 4%, respectively (average of algorithms). The mean noise levels were 15 +/- 4 Hounsfield unit (HU) (range, 8-25 HU). The interscan and interobserver variability was not correlated with heart rate, BMI, or noise level. CONCLUSION: The interscan and interobserver variability of CAC on a prospective ECG-triggered 64-slice CT with high image quality and 45% of RR acquisition is not significantly affected by heart rate, BMI, or noise level. The volume or mass algorithms show reduced interscan variability compared to the Agatston scoring (p < 0.05).

Puntuación de calcio en arterias coronarias y presencia de estenosis angiográficamente significativas / Calcium scoring in coronary arteries and presence of angiographically significant stenosis

La presencia de calcio en las arterias coronarias es patognomónica de aterosclerosis. Agatston diseñó un método para cuantificar el puntaje de calcio coronario mediante la tomografía para determinar la asociación entre el grado de calcificación en las arterias coronarias determinado por tomografía de 64 cortes y la presencia de estenosis coronarias significativas (ECS) diagnosticadas por coronariografía invasiva (CI). Se estudiaron 153 pacientes, los cuales estaban programados para CI. Previo a la CI se les cuantificó el puntaje de calcio por arteria y por paciente. El 91,7 por ciento de los pacientes con puntaje ≤ 10 UA (unidades Agatston) no presentó ECS contra 8,3 por ciento con puntaje ≥ 401 UA (p < ,0001). El 2,4 por ciento con puntaje ≤ 10 UA en el tronco de la coronaria izquierda presentó ECS contra el 75 por ciento con puntaje ≥ 401 UA (p< 0,0001). El 5,5 por ciento con puntaje ≤ 10 UA en la arteria descendente anterior tenía ECS contra el 87,5 por ciento con puntaje ≥ 401 UA (p< 0,0001). Similar comportamiento se observó en las demás arterias. Se concluyó que existía asociación entre el grado de puntaje de calcio en las arterias coronarias diagnosticado por tomografía y la presencia de ECS diagnosticadas por CI.

The presence of calcium in the coronary arteries is pathognomonic of atherosclerosis. Agatston designed a method to quantify the coronary calcium scoring by tomography to determine the association between the degree of calcification in the coronary arteries by 64-slice computed tomography and the presence of significant coronary stenosis (SCS) diagnosed by invasive coronariography (IC). 153 patients that were scheduled for IC were studied. The calcium scoring was quantified by patient and by artery before performing the IC. 91.7 percent of the patients with scoring £10 UA (Agatston units) did not present SCS versus 8.3 percent with scoring ³ 401 UA (p< .0001). 2.4 percent with scoring 10 UA in the trunk of the left coronary presented SCS versus 75 percent with scoring 401 UA (p < 0.0001). 5.5 percent with scoring 10 UA in the anterior descending artery has SCS versus 87.5 percent with scoring 401 UA (p < 0.0001). Similar behavior was observed in the rest of the arteries. It was concluded that there was association between the calcium degree scoring in the coronary arteries diagnosed by computed tomography and the presence of SCS diagnosed by IC.

Coronary fat content evaluated by morphometry in patients with severe atherosclerosis has no relation with serum lipid levels

The relationship between lipid serum levels and coronary atherosclerotic plaque fat content was studied in 51 necropsy patients. Serum lipids were measured by standard techniques, during life, in the absence of lipid-lowering drugs. Intima, intimal fat and media areas were measured using a computerized system in cryosections of the odd segments of the right, anterior descending and circumflex coronary arteries stained with Sudan-IV. Mean intimal and lipid areas were 5.74 ± 1.98 and 1.22 ± 0.55 mm² (22.12 ± 8.48 percent) in 26 cases with high cholesterol (³200 mg/dL) and 4.98 ± 1.94 and 1.16 ± 0.66 mm² (22.75 ± 9.06 percent) in 25 cases with normal cholesterol (<200 mg/dL; P > 0.05). Patients with high levels of low-density lipoprotein (³130 mg/dL, N = 15) had a higher intima/media area ratio than those with normal levels of low-density lipoprotein (<130 mg/dL, N = 13, P < 0.01). No significant difference in the morphometrical variables was found in groups with high or low serum levels of triglycerides (³200 mg/dL, N = 13 vs <200 mg/dL, N = 36) or high-density lipoprotein (³35 mg/dL, N = 11 vs <35 mg/dL, N = 17). The association between the morphological measurements and serum levels of cholesterol, its fractions, and triglycerides was also tested and the correlation coefficients were low. Although high cholesterol is a risk factor, we show here that in patients with severe atherosclerosis blood cholesterol and triglyceride levels seem to have little influence on coronary lipid content, indicating that other factors may contribute to arterial lipid deposition and plaque formation.

Escore de cálcio na avaliação cardiovascular do paciente com diabetes / Calcium score in the cardiovascular evaluation of the diabetic patient

A presença de cálcio nas artérias coronárias é um marcador específico de aterosclerose, independentemente de sua etiologia. A quantificação do cálcio coronariano através da tomografia computadorizada é um método não-invasivo cuja principal indicação clínica atual é a estratificação de risco para doença coronariana, complementando a estratificação convencional principalmente naqueles pacientes de risco intermediário. Pela classificação atual de fatores de risco da maioria das sociedades, o paciente diabético é categorizado como equivalente de doença coronariana, sendo portanto um paciente de alto risco. Assim sendo, a quantificação do cálcio coronariano não teria indicação para esses pacientes com esta finalidade. No entanto, estudos com pequenos grupos mostram evidências de que, mesmo nesses pacientes, este teste teria um poder discriminatório em termos de prognóstico. Esta pode ser uma aplicação clínica potencial desse método, dependendo da validação desses dados e de estudos futuros. Existem outras aplicações potenciais para esse método, que necessitam de validação e que podem ser úteis para os diabéticos, como o estudo da progressão do cálcio avaliando a eficácia da terapêutica. Neste artigo revisamos o método e as principais indicações da quantificação do escore de cálcio coronariano.

Coronary artery calcium (CAC) is a specific marker of atherosclerosis, independent of its etiology. Quantification of CAC by computed tomography (CT) is a non-invasive test recommended mainly for risk stratification for coronary heart disease, in addition to the conventional stratification, especially in intermediate risk patients. Currently, a diabetic patient is classified as a coronary heart disease equivalent, therefore a high-risk patient according to most societies. For that matter calcium score is not currently recommended for diabetic patients. Although quantification of CAC by computed tomography (CT) is not yet supported by strong evidence in diabetes, small studies showed evidence that this test could have a discriminatory power in terms of prognosis within this group of patients. That could be a future clinical application, depending on the validation of these data and the results of future studies. There are some other potential applications for this method that could be useful for diabetic patients as well, but haven't been extensively validated, like the assessment of progression of coronary artery calcium as a form of evaluating effectiveness of medical therapy. In this article we review the method and current indications for the quantification of CAC by computed tomography.

Expression of osteopontin in calcified coronary atherosclerotic plaques

Advanced atherosclerosis is often associated with dystrophic calcification and remodeling of extracellular matrix of vascular wall. Recently many studies have documented a general relationship between calcification and severity of coronary disease, and discussed the feasibility of electron beam computed tomography for detecting and quantifying the coronary artery calcification in the patients. The present study investigated the expression and the localization of osteopontin, one of noncollagenous bone matrix protein, within the calcified coronary arteries. Autopsy-derived coronary artery specimens were scanned and reconstructed to visualize the pattern of coronary calcification using a novel microscopic computed tomography technique. The localization of the osteopontin were evaluated by immunohistochemial stain with LF7. The present study showed that the pattern of coronary calcification is variable and the expression of osteopontin is localized mainly to calcified lesion. The smooth muscle cells in addition to macrophage expressed osteopontin protein in human coronary atherosclerotic plaques. Soluble osteopontin released near to the sites of vascular calcification may represent an adaptive mechanism aimed at regulating the process of vascular calcification.