Segment Involvement Score Research Articles

Body mass index as a predictor of the presence but not the severity of coronary artery disease evaluated by cardiac computed tomography

The relation between body mass index (BMI) and coronary artery disease (CAD) extension remains controversial. The aim of this study was to evaluate the correlation between BMI and CAD extension documented by coronary computed tomography angiography (CCTA). Prospective registry including 1706 consecutive stable patients that performed CCTA (dual source scanner) for the evaluation of CAD. The population was stratified by BMI: normal 530 (31.1%), overweight 802 (47.0%) and obesity 374 (21.9%). BMI was significantly higher in patients with CAD (27.7 ± 4.3 vs 26.8 ± 4.3 kg/m(2), p < 0.001); these patients were also older, more often male and had higher prevalence of diabetes, hypertension and dyslipidemia. By multivariate analysis (logistic regression) BMI remains an independent predictor of CAD (odds ratio (OR) 1.03, 95% confidence interval (CI) 1.01-1.06; p = 0.012). Regarding the severity of CAD, BMI was not significantly different among patients with and without obstructive CAD (27.7 ± 4.3 vs 27.2 ± 4.3 kg/m(2), p = 0.120). In 319 patients (4516 segments; 4077 evaluable), a detailed atherosclerotic burden was evaluated and compared among BMI classes, defined according to the presence of plaque and the degree of stenosis. Obstructive CAD was identified in 16.9% of the patients and 45.1% had non-obstructive CAD. The discriminative threshold for high burden, established by the segment involvement score (SIS), was >5 segments with plaque (15.4% patients). The prevalence of SIS >5 among the BMI classes was: 18.7%, 13.7% and 13.6% for normal, overweight and obesity respectively (p values for the specific classes versus all other patients: 0.241, 0.450 and 0.663). In this population of stable patients undergoing CCTA for suspected CAD, BMI was an independent predictor of its presence, but was not correlated with the coronary disease severity.

THU0057 Differential impact of traditional cardiac risk factors on coronary plaque prevalence in coronary artery disease (CAD)-naïve subjects with rheumatoid arthritis compared to controls

BackgroundTraditional cardiac risk factors (CRFs) are associated with cardiovascular outcomes in both Rheumatoid arthritis (RA) and the general population. Their distribution in RA approximates that in controls. However, their relative...

Progression of Arterial Stiffness and Coronary Atherosclerosis: Longitudinal Evaluation by Cardiac CT

We sought to use cardiac CT angiography (CTA) to longitudinally examine the relationship between changes in aortic stiffness and of the atherosclerotic burden over time. One hundred sixty-four patients with suspected coronary artery disease underwent two retrospectively ECG-gated cardiac CTA studies an average of 12 ± 10 months apart. Arterial stiffness was represented by the aortic distensibility index (ADI) and atherosclerosis by segment involvement score (SIS) (defined as the number of coronary artery segments per patient displaying atherosclerotic plaque). Changes in ADI and SIS between the studies were compared using linear and logistic regression accounting for differences in clinical and demographic baseline characteristics. Age (p = 0.004), time between studies (p = 0.02), and increase in SIS (p < 0.001) were associated with a decrease in ADI on univariate analysis. Increase in SIS remained a significant independent predictor of decreased ADI on both multivariate logistic regression (with change in ADI represented categorically) and multivariate linear regression (both p < 0.001). On longitudinal evaluation with cardiac CTA, the progression of aortic stiffness is associated with the progression of coronary atherosclerosis. Although outcome studies are needed, a comprehensive assessment of vascular health with cardiac CTA, including both indexes of arterial stiffness and atherosclerotic burden, may improve risk stratification and therapy monitoring.

Abstract 18744: Peripheral Blood Gene Expression Reflects Differences Between Coronary Artery Calcification and Stenosis as Assessed by Coronary Artery Calcium Scanning and Ct Angiogaphy

Background. We previously validated a composite peripheral blood gene expression score (GES) based on age, sex and 23 genes to detect obstructive coronary artery disease (CAD), using invasive coronary angiography as gold standard (≥50% diameter stenosis). Plaque and stenosis can also be assessed by cardiovascular CT. Methods. 614 symptomatic patients with no known CAD or diabetes from the COMPASS and PREDICT studies underwent CAC and CTA by institutional protocols and GES was measured according to Corus® CAD protocols in the CardioDx CLIA laboratory (Palo Alto, CA). CAC was expressed as Agatston score. For qualitative analysis, each of the 17 segments was graded for stenosis as 0: none, 1: minimal, 2: mild, 3: moderate and 4: severe; segment involvement score (SIS) was calculated by adding all segments with any plaque and segment stenosis score (SSS) by summing individual segment scores. Patients from COMPASS (N=394) also underwent quantitative measurements of calcified, high-density and low-density non-calcified plaque, as previously described. Expression levels of the 23 genes were analyzed by age and sex-adjusted logistic regression. Results. In the 614 patients, mean age was 57±10; 50% were men. Overall GES was significantly correlated with CAC (r=0.35) and MPS (r=0.41), both p&lt;0.001. Individual gene expression level analysis showed that genes from the myeloid lineage, including S100A12/8, were significantly increased and T cell genes decreased with increasing MPS, whereas only innate immunity (myeloid and NK, S100A12/8, SLAMF7) genes were significantly increased with increasing calcification. In the quantitative analysis set (N=394, mean age: 55±12, 50% men) a similar pattern was observed with only neutrophil genes significantly upregulated with calcification, whereas both B and T cell genes were downregulated with increasing MPS. Conclusions. Gene expression and qualitative and quantitative cardiac CT data showed that peripheral blood gene expression changes for overall maximum percent stenosis and calcification differ. MPS was associated with increased expression of innate immune genes and decreased lymphocyte gene expression, while calcification was associated with increases in innate immune gene expression.

Differences in Coronary Atherosclerotic Plaque Burden and Composition According to Increasing Age on Computed Tomography Angiography

Few data were available regarding the underlying burden of specific plaque types with increasing ages. The aim of this study was to assess the relationship of coronary artery calcium (CAC) score with total coronary plaque burden and the difference of underlying coronary plaque composition across differing aging groups using 64-slice multidetector computed tomography. Multidetector computed tomographic images of 781 consecutive patients were evaluated using a 15-coronary segment model. Segment involvement score (the total number of segments with any plaque), segment stenosis score (the sum of maximal stenosis score per segment), total plaque score (the sum of the plaque amount per segment), and plaque composition were measured to compare with total CAC scores stratified by age tertile (lowest [n = 274], <55 years; middle [n = 242], 55-65 years; highest [n = 265], >65 years). The mean age of the study population was 59 ± 13 years (481 men [62%]). With increasing age, higher segment involvement scores, segment stenosis scores, and total plaque scores were noted. Plaque burden was correlated significantly with total CAC scores in all tertiles. The percentage of partially calcified (P < .001) and calcified (P < .001) plaque increased with age, and in the highest age tertile, 87% of plaque contained calcium (calcified or mixed), compared to only 63% in the younger patients (P < .001). Those aged >65 years were highly unlikely to have isolated noncalcified plaque (in the setting of a calcium score of 0). Younger patients were 10 times more likely to have isolated noncalcified plaque (P < .001). The absence of CAC strongly excludes obstructive disease, and CAC predicts the presence of coronary atherosclerotic plaque. However, the absence of any CAC does not exclude the presence of coronary atherosclerotic plaque, especially in patients aged <55 years. Plaque composition shifted from noncalcified to calcified plaque with increasing age, which may affect the vulnerability of these lesions over time.

Relation of aortic calcification, wall thickness, and distensibility with severity of coronary artery disease: evaluation with coronary CT angiography

Three known risk factors for aortic atherosclerosis predict the severity of coronary artery disease (CAD): aortic calcification (AC), aortic wall thickness (AWT), and aortic distensibility (AD). To determine the relationship of AC, AWT, and AD with the severity of CAD. A total of 104 patients who underwent both coronary CT angiography (CCTA) and invasive coronary angiography were enrolled. The severity of CAD was assessed by three methods: the segment involvement score (SIS), the segment stenosis score (SSS), and the modified Gensini score (mG). We quantified AC using the Agatston method on low-dose ungated chest CT (LDCT). We measured AWT at the thickest portion of the descending thoracic aorta on CCTA. AD was calculated as the difference between the maximum and minimum areas of the ascending aorta and the pulse pressure. The relationships between the severity of CAD and the three aortic factors were assessed. The AC and AWT of the thoracic aorta were significantly higher in the occlusive CAD (OCAD) group (1984.21 ± 2986.10 vs. 733.00 ± 1648.71, P = 0.01; 4.13 ± 1.48 vs. 3.40 ± 1.01, P = 0.22). Patients with OCAD had more than one epicardial coronary artery with >50% luminal stenosis. The AC (r = 0.453 with SIS; r = 0.454 with SSS; r = 0.427 with mG) and the AWT (r = 0.279 with SIS; r = 0.324 with SSS; r = 0.304 with mG) were significantly correlated with all three methods, and the AD was negatively correlated with the SIS (r = - 0.221, P < 0.05, respectively) in the unadjusted model. After adjustment for cardiovascular risk factors, only the correlations between AC and all three methods assessing CAD remained significant. There are significant relationships between AC, AWT and AD and severity of CAD. In particular, AC measured on LDCT is the most consistent predictor of severity of CAD.

Correlation between Acute Coronary Syndrome Classification and Multi-detector CT Characterization of Plaque

To determine if multi-detector CT (MDCT) characterization of plaque is correlated with the classification of acute coronary syndrome (ACS). Altogether 1900 patients were examined by MDCT from December 2007 to May 2009, of whom 95 patients fulfilled the criteria of ACS. Those patients were divided into the discrete plaque group ( n=61) and diffuse plaque group ( n=34) based on the findings in MDCT. The clinical diagnosis of ACS and CT results were analyzed, including segment stenosis score, segment involvement score, 3-vessel plaque score, left main score, calcification score, and remodeling index. The incidences of major adverse cardiac events in follow-up period were also recorded. The patients of the diffuse plaque group were older than those of the discrete plaque group ( Pü0.0001). The diffuse plaque group presented more cases of hypertension, peripheral artery disease, diabetes, and heart failure than discrete plaque group (all P<0.05). All the 5 patients with ST-segment elevation myocardial infarction were found in discrete plaque group. The segment stenosis score of the discrete plaque group was lower than that of the diffuse plaque group(5.15±3.55 vs. 14.91±5.37, Pü0.001). The other four scores demonstrated significant inter-group difference as well (all P<0.05). The remodeling index of thediscrete plaque group was higher (1.12±0.16 vs.0.97±0.20, Pü0.05). Follow-up data showed that major adverse cardiac events occurred more frequently in diffuse plaque group than in discrete group (29.41% vs. 11.48%, P=0.0288). Characteristics of discrete and diffuse plaques may be significantly different among different classes of ACS. The diffuse plaque may present higher risk, correlated to higher mortality. The diagnosis of discrete and diffuse plaques by MDCT would provide a new insight into the prognosis and treatment of ACS.

Reproducibility of coronary plaque detection and characterization using low radiation dose coronary computed tomographic angiography in patients with intermediate likelihood of coronary artery disease (ReSCAN study)

The purpose of this study is to evaluate the interscan, interobserver and intraobserver agreement for coronary plaque detection, and characterization using low radiation dose high-pitch spiral acquisition coronary CT angiography (CTA). Two experienced observers independently evaluated coronary CTA datasets from 50 consecutive patients undergoing two 128-slice dual source CT scans within 12 days. Mean (±SD) estimated radiation exposure was 1.5 ± 0.2 mSv per scan. Observers recorded the presence and characterization of coronary plaques as non-calcified or calcified. A "segment involvement score" (SIS) was computed by summing the numbers of segments with any coronary plaque per patient. Reproducibility was assessed using kappa (κ) statistics, paired t test and Bland-Altman analyses. Interscan, interobserver, and intraobserver agreement (κ-values) for detection of any or calcified plaques were 83-94% (κ-values 0.57-0.85), and 67-84% (0.31-0.67) for non-calcified plaques on a patient level. No significant difference was observed in mean interscan or interobserver SIS. Mean (95% CI) intraobserver SIS difference was -0.88 (-1.25; -0.51), P < 0.001, with limits of agreement from -4.7 to 2.9. Low radiation dose high-pitch coronary CTA permits detection of any or calcified plaques with high interscan, interobserver, intraobserver agreement. However, variability for the detection of non-calcified plaque is substantial.

One size does not fit all: getting drug doses right for children

<h3>Objective</h3> Low association between cardiac symptoms and coronary artery disease (CAD) in patients with inflammatory joint diseases (IJD) demands for objective markers to improve cardiovascular risk stratification. Our main aim...

Multidetector computed tomography coronary artery plaque predictors of stress-induced myocardial ischemia by SPECT

BackgroundAtherosclerosis imaging by multidetector computed tomography (MDCT) detects coronary artery plaque extent, distribution, location and composition. In contrast, functional imaging by single-photon emission computed tomography (SPECT) identifies perfusion defects known to predict prognosis of coronary heart disease (CHD). We sought to determine whether anatomic measures of plaque by MDCT predict functional measures of CHD by SPECT and thus, serve as measures of adverse cardiovascular prognosis. Methods and resultsConsecutive low-to-intermediate risk symptomatic patients without known CHD (n=163) underwent both stress SPECT and MDCT. MDCT plaque extent and distribution were graded by a segment stenosis score (summation of luminal obstruction in all coronary segments) and segment involvement score (summation of segments exhibiting any plaque), respectively. Plaque location was assessed with a segments-at-risk score (plaque extent weighted by proximity) and a modified Duke CAD index. Plaque composition was graded as non-calcified, calcified and mixed. SPECT findings—summed stress (SSS), rest (SRS) and difference (SDS) scores—were compared to MDCT plaque scores.In univariate analyses, segment stenosis score (p=0.006), segments-at-risk score (p=0.002), Duke CAD index (p=0.02), and mixed plaque score (p=0.01) predicted severely abnormal SPECT. Highest compared to lowest quartile mixed plaque scores were predictive of higher SSS (8.1±10.3 versus 3.5±5.7, p<0.001), SRS (3.2±7.7 versus 0.9±3.1, p=0.008), and SDS (4.9±6.4 versus 2.6±3.9, p=0.012). In contrast, higher segment involvement scores, calcified and non-calcified plaque scores did not predict higher SPECT measures of ischemia. In multivariable analyses, comparing highest to lowest quartiles, individuals with high segment stenosis scores [odds ratio (OR) 1.97 (1.22–3.39), p=0.008], segments-at-risk scores [OR 1.71 (1.24–2.58), p=0.005], highest risk Duke CAD index category [OR 2.25 (1.12–4.41), p=0.02], and mixed plaque scores [OR 1.64 (1.10–2.43), p=0.01] had more severely abnormal SPECT scans. ConclusionsIn low-to-intermediate risk patients without known CHD, MDCT coronary artery plaque assessment successfully identify patients at higher risk of increased extent, severity and reversibility of myocardial perfusion defects by SPECT. Anatomic MDCT findings, including plaque extent, location and composition, are independent predictors of functional ischemia and severe CHD by SPECT and thus, represent markers of adverse cardiovascular prognosis prior to the occurrence of clinical cardiovascular events.