Agatston Calcium Score Research Articles

The Utility of the Agatston Calcium Score in Predicting Carotid Plaque Vulnerability

The Utility of the Agatston Calcium Score in Predicting Carotid Plaque Vulnerability

Diagnostic accuracy of postmortem computed tomography, magnetic resonance imaging, and computed tomography-guided biopsies for the detection of ischaemic heart disease in a hospital setting.

The autopsy rate worldwide is alarmingly low (0-15%). Mortality statistics are important, and it is, therefore, essential to perform autopsies in a sufficient proportion of deaths. The imaging autopsy, non-invasive, or minimally invasive autopsy (MIA) can be used as an alternative to the conventional autopsy in an attempt to improve postmortem diagnostics by increasing the number of postmortem procedures. The aim of this study was to determine the diagnostic accuracy of postmortem magnetic resonance imaging (MRI), computed tomography (CT), and CT-guided biopsy for the detection of acute and chronic myocardial ischaemia. We included 100 consecutive adult patients who died in hospital, and for whom next-of-kin gave permission to perform both conventional autopsy and MIA. The MIA consists of unenhanced total-body MRI and CT followed by CT-guided biopsies. Conventional autopsy was used as reference standard. We calculated sensitivity and specificity and receiver operating characteristics curves for CT and MRI as the stand-alone test or combined with biopsy for detection of acute and chronic myocardial infarction (MI). Sensitivity and specificity of MRI with biopsies for acute MI was 0.97 and 0.95, respectively and 0.90 and 0.75, respectively for chronic MI. MRI without biopsies showed a high specificity (acute: 0.92; chronic: 1.00), but low sensitivity (acute: 0.50; chronic: 0.35). CT (total Agatston calcium score) had a good diagnostic value for chronic MI [area under curve (AUC) 0.74, 95% confidence interval (CI) 0.64-0.84], but not for acute MI (AUC 0.60, 95% CI 0.48-0.72). We found that the combination of MRI with biopsies had high sensitivity and specificity for the detection of acute and chronic myocardial ischaemia.

Prognostic Impact of Calcium Score after Transcatheter Aortic Valve Implantation Performed With New Generation Prosthesis

Calcium score (CS) is a well-known prognostic factor after transcatheter aortic valve implantation (TAVI) performed with first generation prosthesis but few data are available concerning new generation valves. The aim of this study was to evaluate if CS remains a prognostic factor after Sapien 3 and Evolut R valves implantation. Agatston CS was evaluated on multislice computed tomography before TAVI in 346 patients implanted with Sapien XT (n = 61), CoreValve (n = 57) devices, (group 1, n = 118), and with new generation Sapien 3 (n = 147), Evolut R (n = 81) prosthesis, (group 2, n = 228). Major adverse cardiovascular events and aortic regurgitation (AR) were evaluated at 1 month. The 2 groups were similar at baseline except for logistic Euroscore (20.1% in group 1 vs 15.0 % in group 2; p = 0.001), chronic renal failure (44.1% vs 37.2% respectively, p = 0.007) and preprocedural CS (4,092 ± 2,176 vs 3,682 ± 2,109 respectively, p = 0.022). In group 1, 28 patients (23.7%) had adverse clinical events vs 21 (9.2%) in group 2 (p <0.01). In multivariate analysis, a higher CS was predictive of adverse events in group 1 (5,785 ± 3,285 vs 3,565 ± 1,331 p <0.0001) but not in group 2 (p = 0.28). A higher CS was associated with AR in group 1 (6,234 ± 2711 vs 3,429 ± 1,505; p <0.001) and in patients implanted with an Evolut R device from group 2 (4,085 ± 3,645 vs 2,551 ± 1,356; p = 0.01). In conclusion, CS appears as an important prognostic factor of major events after TAVI with first generation valves but not with new generation devices. CS remains associated with AR only with new generation self-expandable Evolut R devices.

Equivocal tests after contrast stress-echocardiography compared with invasive coronary angiography or with CT angiography: CT calcium score in mildly positive tests may spare unnecessary coronary angiograms

BackgroundImaging stress tests are not ideally accurate to predict anatomically obstructive CAD, leading to a non-trivial rate of unnecessary iCA. This may depend on the threshold used to indicate iCA, and maybe CTA or, one step earlier, CT calcium score could spare most unnecessary iCA in only mildly positive cSE. We assessed the diagnostic accuracy of contrast stress-echocardiography (cSE) in comparison with invasive coronary angiography (iCA), and CT angiography (CTA) only in case of equivocal tests, to find hints helping reduce falsely positive cSE in the suspicion of coronary artery disease (CAD).MethodsPatients who were indicated cSE for suspected CAD between 2012 and 2016, who also underwent iCA were selected and diagnostic results compared. A second group, specifically with equivocal cSE who underwent CTA was also analyzed.Results137 subjects with equivocal cSE and CTA and 314 with cSE (any result) and iCA were selected. In the CTA-equivocal cSE group, an Agatston score < 105 and a coronary flow reserve (CFR-LAD) <1.7 had very high negative predictive value (99%, 92% respectively) to exclude obstructive CAD. The Agatston score was the most significant incremental predictor of CAD beyond clinical variables (chi square 31 to 47, p < 0.001). In the iCA group a more-than-mild reversible wall motion abnormality (WMA) demonstrated high positive predictive value for CAD (89%), while CFR-LAD appeared less useful. More-than-mild reversible WMA was the most significant predictor of CAD beyond clinical variables (chi square 37.5 to 56, p < 0.001).ConclusionsOur data suggest iCA should be indicated only for more-than-mild reversible WMA at cSE, due to the very high positive predictive value for CAD of this finding, while mildly positive tests should be shifted to non-invasive CT, with CTA performed only for coronary calcium Agatston score > 100, since lower scores demonstrated very high negative predictive value for CAD, not justifying proceeding to CTA and even less to iCA.

Enhanced coronary calcium visualization and detection from dual energy chest x-rays with sliding organ registration

We have developed a technique to image coronary calcium, an excellent biomarker for atherosclerotic disease, using low cost, low radiation dual energy (DE) chest radiography, with potential for widespread screening from an already ordered exam. Our dual energy coronary calcium (DECC) processing method included automatic heart silhouette segmentation, sliding organ registration and scatter removal to create a bone-image-like, coronary calcium image with significant reduction in motion artifacts and improved calcium conspicuity compared to standard, clinically available DE processing. Experiments with a physical dynamic cardiac phantom showed that DECC processing reduced 73% of misregistration error caused by cardiac motion over a wide range of heart rates and x-ray radiation exposures. Using the functional measurement test (FMT), we determined significant image quality improvement in clinical images with DECC processing (p < 0.0001), where DECC images were chosen best in 94% of human readings. Comparing DECC images to registered and projected CT calcium images, we found good correspondence between the size and location of calcification signals. In a very preliminary coronary calcium ROC study, we used CT Agatston calcium score >50 as the gold standard for an actual positive test result. AUC performance was significantly improved from 0.73 ± 0.14 with standard DE to 0.87 ± 0.10 with DECC (p = 0.0095) for this limited set of surgical patient data biased towards heavy calcifications. The proposed DECC processing shows good potential for coronary calcium detection in DE chest radiography, giving impetus for a larger clinical evaluation.

Calcification of coronary arteries in early rheumatoid arthritis prior to anti-rheumatic therapy.

Accelerated coronary atherosclerosis is common in patients with rheumatoid arthritis (RA). To examine coronary artery calcification (CAC) frequency and severity, its correlation with traditional risk factors (TRF) of cardiovascular diseases (CVD) and inflammatory markers in patients with early RA prior to anti-rheumatic therapy. RA adult patients (ACR/EULAR criteria, 2010, duration ≤12months, without prior administration of disease-modifying anti-rheumatic drugs, glucocorticoids) underwent 32-row scanning for CAC scoring. Agatston, volume and mass calcium scores were calculated. Additionally, we used calculators on the website of the Multi-Ethnic Study of Atherosclerosis. 74 RA patients (women n=54 (73%), median age 56years, median RA duration 6months) with moderate/high RA activity (median DAS28 [ESR] 5.4) were enrolled within the framework of the observational study. Most of the patients had multiple TRFs of CVD and subclinical organ damage. CAC has been detected in 34 (46%) early RA patients. Calcification severity was significantly higher in men and in patients with ischemic heart disease (IHD). In patients younger than 45years (n=16) CAC was not detected. Among patients older than 45years (n=58), the frequency of CAC was 59%: asymptomatic patients-n=46 (48%), IHD patients-n=12 (100%). Among asymptomatic patients the presence of CAC associated with a significantly higher frequency of arterial hypertension (1.6 fold) compared with cases without CAC. Coronary age in asymptomatic patients with CAC and IHD patients was significantly greater than their actual age. More than half of early RA patients older 45years had CAC. The presence and severity of CAC correlated positively with TRFs, but not with lipid levels and RA activity.

Gender differences in the association of epicardial adipose tissue and coronary artery calcification: EPICHEART study: EAT and coronary calcification by gender

BackgroundThe association of epicardial adipose tissue (EAT) and coronary artery calcification (CAC) seems to differ by gender. However, few studies have controlled for body size, and the ideal method for body size indexing has not been explored. ObjectivesTo analyse the effect of gender related-body size and-body fat differences on the association of EAT with CAC. MethodsThis was a prospective cohort of 371 severe aortic stenosis patients (77±8.5year-old, 51% females) referred to cardiac surgery. Agatston calcium score, EAT volume and visceral abdominal fat (VAF) were obtained by computed tomography. Body composition was determined using bioelectrical impedance analysis. Body weight and height were measured to derive body mass index (BMI), body surface area (BSA), and body surface index (BSI). EAT volume was normalized for BSA, weight and height. ResultsMedian CAC score was higher in men (887; IQR: 2010) than in women (279: IQR: 145) (p<0.01). Similarly, men had higher volume of EAT than women (137±65.6 vs. 106±65.6mL, p<0.01), even when BSA- or height-indexed, but not if weight-indexed. EAT volume was associated with CAC adjusting for adiposity (BMI or BSI and VAF, or fat mass), but not with further adjustment for gender. In a stratified analysis, absolute- and indexed-volumes of EAT were independently associated with CAC in men while no association was found in women (gender-interaction p<0.05). ConclusionsIn these high-risk patients, we demonstrated that EAT was associated with CAC score irrespective of body size, body fat and cardiovascular risk factors in men but not in women.

Differential Expression of microRNAs in Severely Calcified Carotid Plaques

We investigated whether microRNA (miRNA) alteration is related to the presence of calcification in carotid plaques. We classified 10 plaques from carotid endarterectomy patients into high- and low-calcified plaques based on Agatston calcium scores. A microarray analysis for miRNA profiles was performed, with validation by a miRNA quantitative real-time polymerase chain reaction (qRT-PCR). The miRNA microarray identified 697 probes; 657 of them were downregulated. We selected the genes that satisfied total gene signal (TGS) >50, |Log2 ratio| > 1 and ≥1 of the following: (1) false discovery rate (FDR) <.05 in the comparison of mean values of logarithmic transformed signals between the groups; (2) .05 ≤ FDR < .1 and showing either high or median for context score+ in miRSearch among the 72 carefully selected genes related to angiogenesis or calcification; and (3) FDR<.1 in the comparison of 10 individual sets of high- and low-calcified plaques. The expression of miRNA validated by qRT-PCR revealed a significant downregulation of hsa-miR-4530, hsa-miR133b, and hsa-miR-1-3p. A Spearman's rank correlation analysis revealed that the logarithmic TGSs for the microarray of hsa-miR-4530 and hsa-miR-133b were significantly inversely correlated with the carotid plaques' calcium scores, and the delta Cq values for the qRT-PCR showed a direct association. In high-calcified carotid plaques, a specific profile for miRNA may be identified, and the expressions of hsa-miR-4530 and hsa-miR-133b had inverse correlations with the calcium score in the plaques, suggesting that miRNAs may play a modulating role in calcified plaques and plaque stability.

Relation between serum levels of chemotaxis-related factors and the presence of coronary artery calcification as expression of subclinical atherosclerosis

BackgroundAtherosclerotic plaque formation is characterized by recruitment of monocytes/macrophages, which contributes to its calcification by releasing pro-osteogenic cytokines. Chemotaxis-related proteins, including netrin-1, gremlin-1 and macrophage inflammatory protein-1β (MIP-1β), regulate immune cell migration. However, their relation with the presence of subclinical atherosclerosis, assessed by measures of coronary artery calcifications (CAC) in patients without known coronary artery disease (CAD), remains unclear. AimsTo examine whether these chemoattractant-related proteins are associated with the presence of CAC in patients without known CAD. MethodsA retrospective case-control observational study was conducted in 120 outpatients without CAD, undergoing a CAC evaluation by computed tomography with the Agatston Calcium score, categorized as CAC− (none) and CAC+ (≥1). Serum biomarkers were quantified by ELISA. ResultsLpa, dyslipidaemia and smoking were significantly higher (p=0.006, p≤0.0001 and p=0.001, respectively) in CAC+ patients. Serum netrin-1 levels were lower in CAC+ than in CAC− patients (196.8±127.8pg/ml versus 748.3±103.2pg/ml, p≤0.0001), and a similar pattern was found for gremlin-1 (1.14±0.39ng/ml versus 4.33±1.20ng/ml, p≤0.0001). However, TNFα and MIP-1β were strongly upregulated in CAC+ patients (447.56±74pg/ml versus 1104±144pg/ml and 402.00±94pg/ml versus 905.0±101.6pg/ml, respectively, p≤0.001). Multivariate analyses revealed that low netrin-1 and gremlin-1 levels and high TNFα and MIP-1β amounts were associated with CAC presence, after adjustment for clinical and biochemical variables. ConclusionsWe found a netrin-1 and gremlin-1 deficiency and a TNFα and MIP-1β overproduction in CAC+ patients' serum. These proteins may be used to identify individuals with subclinical atherosclerosis. Further research is warranted in a larger cohort of patients to establish these chemotactic-related proteins as biomarkers that improve CAD risk stratification.

CT angiography to evaluate coronary artery disease and revascularization requirement before trans-catheter aortic valve replacement

BackgroundCoronary artery disease (CAD) and aortic stenosis share pathophysiological mechanisms and risk factors. We evaluated the clinical utility of coronary computed tomography angiography (CTA) to identify CAD and revascularization requirement in patients with severe aortic stenosis considered for transcatheter aortic valve replacement (TAVR). MethodsConsecutive patients without known CAD underwent calcium scoring, CTA and invasive coronary angiography (ICA). A second-generation dual-source CT scanner was used. ICA-quantitative coronary angiography (QCA) served as reference standard. CAD was reported using a lenient threshold of ≥50% and a stricter threshold of ≥70% diameter reduction. Findings of ≥70% diameter reduction and of high-risk CAD were used to predict revascularization. ResultsThe study included 140 patients [68 males; 82.3 (7.7) years]. CAD defined by the 50% threshold on ICA was found in 58/140 (41%) patients. CAD by the 70% threshold was found in 23/140 (16%) patients. High-risk CAD was found in 16/140 (11%) patients. CTA and ICA had similar odd-ratios of 3.22 (1.26–8.23) and 4.62 (1.64–13.05), respectively, in predicting revascularization. Forty-two/140 (30%) patients had <400 Agatston calcium score, 98/140 (70%) patients had ≥400 calcium score. The diagnostic performance of CTA in the low calcium score group was better than the high calcium score group (AUC 0.81 vs. 0.63). ConclusionCTA remained questionable to rule-out CAD as gatekeeper to ICA in TAVR candidates who had severe coronary calcifications. In patients with less severe coronary calcifications, accounting for 30% of participants in this study, CTA may play a clinical role.

Relation between calcium burden, echocardiographic stent frame eccentricity and paravalvular leakage after corevalve transcatheter aortic valve implantation.

Paravalvular aortic leakage (PVL) after transcatheter aortic valve implantation (TAVI) is a complication with potentially severe consequences. The relation between native aortic root calcium burden, stent frame eccentricity and PVL was not studied before. Two-hundred-and-twenty-three consecutive patients with severe aortic stenosis who underwent TAVI with a Medtronic CoreValve System© and who had available pre-discharge transthoracic echocardiography were studied. Echocardiographic stent inflow frame eccentricity was defined as major-minor diameter in a short-axis view >2 mm. PVL was scored according to the updated Valve Academic Research Consortium (VARC-2) recommendations. In a subgroup of 162 (73%) patients, the calcium Agatston score was available. Stent frame eccentricity was seen in 77 (35%) of patients. The correlation between the Agatston score and stent frame eccentricity was significant (ρ = 0.241, P = 0.003). Paravalvular leakage was absent in 91 cases (41%), mild in 67 (30%), moderate in 51 (23%), and severe in 14 (6%) cases. The correlation between stent frame eccentricity and PVL severity was significant (ρ = 0.525, P < 0.0001). There was a relation between particular eccentric stent frame shapes and the site of PVL. Calcification of the aortic annulus is associated with a subsequent eccentric shape of the CoreValve prosthesis. This eccentric shape results in more PVL, with the localization of PVL related to the shape of stent frame eccentricity.

CT myocardial perfusion imaging: current status and future perspectives.

Computed tomography myocardial perfusion (CTP) combined with coronary computed tomography angiography (CCTA) may constitute a "1-stop shop" for the noninvasive diagnosis of hemodynamically significant coronary stenosis during a single CT examination. CTP shows high diagnostic performance and provides incremental value over CCTA for the detection of hemodynamically significant coronary stenosis in patients with a high Agatston calcium score or coronary artery stents. Future studies should determine the optimal protocol and clinical value of CTP for guiding revascularization strategy and prognostication. In this article, we review the current status and future perspectives of CTP, focusing on technical considerations, clinical applications, and future research topics.

Abstract P362: Significant Positive Association Between Alcohol Consumption and Advanced Aortic Calcification in an International Multiethnic Cohort of 1335 Men Aged 40-49 Years: The ERA JUMP Study

Introduction: Aortic calcification (AC) is a less widely used measure of atherosclerosis, has been linked to cardiovascular (CV) morbidity and mortality. A J-shaped association of alcohol consumption with CHD has been consistently reported in epidemiological studies. However, scanty literature is available describing the association of alcohol consumption and AC. Hypothesis: We hypothesized that alcohol consumption has a J-shaped association with advanced AC. Method: ERA JUMP is a population-based study of subclinical atherosclerosis in 1335 men aged 40-49 years without CVD (310 European American, 107 African American, 303 Japanese American, 313 Japanese in Japan and 308 Korean in South Korea). Participants were examined for AC, alcohol consumption, CV risk and other factors in 2002-07 with rigorous standardization. AC was assessed by electron-beam CT and quantified using the Agatston method. Advanced AC was defined as Agatston calcium score ≥300. Alcohol consumption was categorized into four groups: 0 (non-drinkers), &lt;1 (light drinkers), &gt; 1 to &lt; 3 (moderate drinkers) and &gt;3 drinks per day (heavy drinkers) (1 drink=12.5 grams of ethanol). Multivariable logistic regression was used to assess the relationship between AC with alcohol consumption adjusting for age, race, CV risk and other factors. Results: Among 1299 studied participants, after excluding participants with missing values for AC (n=36), 70.3% (913 of 1299) were current drinkers and 10.9% (142 of 1299) had advanced AC. Prevalence of advanced AC among non, light, moderate, and heavy drinkers was 7.25% (28 of 386), 10.89% (43 of 395), 9.06% (28 of 309), and 20.57% (43 of 209) respectively. Alcohol consumption had a positive association with advanced AC with a significant cubic trend (p&lt;0.01). There was no significant interaction on advanced AC between race and alcohol consumption. Conclusion: A significant positive association between alcohol consumption and advanced AC was observed in this cross-sectional study of an international multi-ethnic cohort.

Residential proximity to major roads, exposure to fine particulate matter and aortic calcium: the Framingham Heart Study, a cohort study

ObjectivesTraffic and ambient air pollution exposure are positively associated with cardiovascular disease, potentially through atherosclerosis promotion. Few studies have assessed associations of these exposures with thoracic aortic calcium Agatston score...

Residential Proximity to Major Roads, Exposure to Fine Particulate Matter, and Coronary Artery Calcium: The Framingham Heart Study.

Long-term exposure to traffic and particulate matter air pollution is associated with a higher risk of cardiovascular disease, potentially via atherosclerosis promotion. Prior research on associations of traffic and particulate matter with coronary artery calcium Agatston score (CAC), an atherosclerosis correlate, has yielded inconsistent findings. Given this background, we assessed whether residential proximity to major roadway or fine particulate matter were associated with CAC in a Northeastern US study. We measured CAC ≤2 times from 2002 to 2005 and 2008 to 2011 among Framingham Offspring or Third-Generation Cohort participants. We assessed associations of residential distance to major roadway and residential fine particulate matter (2003 average; spatiotemporal model) with detectable CAC, using generalized estimating equation regression. We used linear mixed effects models to assess associations with loge(CAC). We also assessed associations with CAC progression. Models were adjusted for demographic variables, socioeconomic position markers, and time. Among 3399 participants, 51% had CAC measured twice. CAC was detectable in 47% of observations. At first scan, mean age was 52.2 years (standard deviation 11.7); 51% male. There were no consistent associations with detectable CAC, continuous CAC, or CAC progression. We observed heterogeneous associations of distance to major roadway with odds of detectable CAC by hypertensive status; interpretation of these findings is questionable. Our findings add to prior work and support evidence against strong associations of traffic or fine particulate matter with the presence, extent, or progression of CAC in a region with relatively low levels of and little variation in fine particulate matter.

Preoperative Image-Based Simulation of Carotid Artery Stenting Considering Agatston Score of Calcified Plaques

The role of calcification inside fibroatheroma during carotid artery stenting operation is controversial. Cardiologists face a major problem in placing stents: “plaque protrusion” i.e. elastic fibrous caps containing early calcifications that penetrate inside the stent. The aim of this work is to assess the contribution of calcification to plaque vulnerability by using image-based models of carotid artery stenting. Technically, Finite Element Analysis was used to simulate the balloon and stent expansion as a preoperative virtual framework. A nonlinear static structural analysis was performed on 20 image-based models of patients reconstructed from Multidetector Computer Tomography (CT) angiography acquisitions. Subject-specific local Elastic Modulus (EM) of calcified plaques was estimated using the Agatston Calcium (Ca) score, as obtained from CT images. The main findings from the personalized simulations are that maximum values of von Mises stress of 102kPa and 329kPa are obtained on calcified plaques when patient-specific balloon pressure expansion and stent self-expansion, respectively, are modeled. In modeling stent expansion procedure, it is observed a statistically significant positive correlation for EM of calcification with maximum stress (R=0.55; p=0.013) and Plaque Wall Stress (PWS) (R=0.47; p=0.038), while no significant correlation is observed for Ca score with maximum stress (R=0.28; p=0.23) and PWS (R=0.27; p=0.26), this last result suggesting a moderate impact of Ca score in plaque rupture. The approach proposed here could enrich the arsenal of tools available for pre-operative prediction of carotid artery stenting procedure in the presence of calcified plaques. Keywords: Atherosclerotic calcification, calcified plaques, carotid artery stenting, finite element analysis, plaque mechanics, subject-specific model.

Asociación entre el calcio de la aorta torácica y la geometría de esta en una cohorte de sujetos asintomáticos con riesgo cardiovascular aumentado

Introduction and objectivesThoracic aorta calcium detection is known to improve cardiovascular risk prediction for cardiac and noncardiac events beyond traditional risk factors. We investigated the influence of thoracic aorta morphometry on the presence and extent of aortic calcifications. MethodsNonenhanced computed tomography heart scans were performed in 970 asymptomatic participants at increased cardiovascular risk. An automated algorithm estimated the geometry of the entire thoracic aorta and quantified the aortic calcium Agatston score. A nonparametric model was used to analyze the percentiles of calcium score by age. Logistic regression models were calculated to identify anatomical associations with calcium levels. ResultsCalcifications were concentrated in the aortic arch and descending portions. Higher amounts of calcium were associated with an enlarged, unfolded, less tapered and more tortuous aorta. The size of the ascending aorta was not correlated with aortic calcium score, whereas enlargement of the descending aorta had the strongest association: the risk of having a global calcium score > 90th percentile was 3.62 times higher (confidence interval, 2.30-5.91; P < .001) for each 2.5-mm increase in descending aorta diameter. Vessel taper, tortuosity, unfolding and aortic arch and descending volumes were also correlated with higher amounts of calcium. ConclusionsThoracic aorta calcium was predominantly found at the arch and descending aorta and was positively associated with the size of the descending aorta and the aortic arch, but not with the size of the ascending aorta. These findings suggest that aortic dilatation may have different mechanisms and may consequently require different preventive strategies according to the considered segments.Full English text available from: www.revespcardiol.org/en

Association Between Thoracic Aorta Calcium and Thoracic Aorta Geometry in a Cohort of Asymptomatic Participants at Increased Cardiovascular Risk

Introduction and objectivesThoracic aorta calcium detection is known to improve cardiovascular risk prediction for cardiac and noncardiac events beyond traditional risk factors. We investigated the influence of thoracic aorta morphometry on the presence and extent of aortic calcifications. MethodsNonenhanced computed tomography heart scans were performed in 970 asymptomatic participants at increased cardiovascular risk. An automated algorithm estimated the geometry of the entire thoracic aorta and quantified the aortic calcium Agatston score. A nonparametric model was used to analyze the percentiles of calcium score by age. Logistic regression models were calculated to identify anatomical associations with calcium levels. ResultsCalcifications were concentrated in the aortic arch and descending portions. Higher amounts of calcium were associated with an enlarged, unfolded, less tapered and more tortuous aorta. The size of the ascending aorta was not correlated with aortic calcium score, whereas enlargement of the descending aorta had the strongest association: the risk of having a global calcium score > 90th percentile was 3.62 times higher (confidence interval, 2.30-5.91; P < .001) for each 2.5-mm increase in descending aorta diameter. Vessel taper, tortuosity, unfolding and aortic arch and descending volumes were also correlated with higher amounts of calcium. ConclusionsThoracic aorta calcium was predominantly found at the arch and descending aorta and was positively associated with the size of the descending aorta and the aortic arch, but not with the size of the ascending aorta. These findings suggest that aortic dilatation may have different mechanisms and may consequently require different preventive strategies according to the considered segments.

Predictors of disagreement between prospectively ECG-triggered dual-source coronary computed tomography angiography and conventional coronary angiography

AimsTo identify causes of misinterpretation in second generation, dual-source coronary computed tomography angiography (CCTA). MethodsA retrospective re-interpretation was performed on 100 consecutive CCTA studies, previously performed with a 2×128 slice dual-source CT. Results were compared with coronary angiography (CA). CCTA and CA images were interpreted by 2 independent readers. At CCTA vessel diameter, image quality, plaque characteristics and localization (bifurcation vs. non) were described for all segments. Finally, aortic contrast-to-noise ratio (CNR) and the total Agatston calcium score were quantified. Agreement between CCTA and CA was assessed with the Kappa statistic after categorizing the stenosis severity at significant (≥50%) and critical (≥70%) cut-offs, and independent predictors of disagreement were determined by multivariable logistic regression, including patient characteristics such as body mass index (BMI), heart rate (HR), age and gender. ResultsPer-segment sensitivity and specificity at ≥50% and ≥70% stenosis was of 83–95%, and 73–97%, respectively. There was a substantial agreement between CCTA and CA (kappa-50%=0.78, SE=0.03; kappa-70%=0.72, SE=0.03). Worse motion-related quality score, smaller vessel diameter, calcification within the segment of interest and LAD location were independent predictors of disagreement at 50% stenosis. The same factors, excluded LAD location, in addition to bifurcation-location of the coronary lesion predicted misdiagnosis at 70% stenosis. HR per se and BMI did not predict disagreement. ConclusionAccording to the literature a substantial agreement between CCTA and CA was found. However, discrepancies exist and are mainly related with motion-related degradation of image quality, specific vessel anatomy and plaque characteristics. Awareness of such potential limitations may help guiding interpretation of CCTA.

0486: Aortic valve calcium score evaluated with CT scan predicts outcome after TAVI

The clinical risk scores usually used for surgical valve replacement failed to accurately predict outcomes after TAVI and alternative risk parameters are lacking. We proposed to determine the prognostic value of aortic valve calcifications evaluated with CT-scan on outcome after TAVI. This prospective monocentric study included 118 patients referred for TAVI for severe symptomatic aortic stenosis. The procedure was performed via transfemoral route using a balloon expandable (n=61) or a self expandable (n=57) valve. Pre-intervention non enhanced, ECG-gated, multislice CT-scan was done in all patients. Aortic valve calcifications were evaluated using the Agatston calcium score (CS). Procedure-related complications were evaluated and clinical outcome was analysed using a composite criteria (mortality, stroke, myocardial infarction, heart failure) at 30-day follow-up. Mean CS was 4092±2176. At 30-day follow-up, mortality was 6.8% (n=8) and 28 patients (23%) have presented the composite criteria. On univariate analysis (table), CS appears to be the best predictor of adverse outcome after TAVI, significantly higher in patients who have presented the composite criteria (5785 vs 3565 p<0,001). A CS threshold of 6000 allowed to define patients at risk of adverse outcome with a sensitivity of 50% and a specificity of 97%. On multivariate analysis, the only predictors of adverse outcome were dislipidemia (OR 12; IC95 2,7–54,7), BMI (OR 0,8; IC95 0,7-0,95) and CS>6000 (OR 106; IC95 15,5-727,6). During the follow-up, the 5 patients who have developped a moderate to severe aortic regurgitation had a significantly higher CS than those who developped none or mild regurgitation (10121 vs 3809, p<0,001). High degree of calcification of aortic valve, easily quantifiable on the pre-operative CT-scan appears to be an important prognostic parameter which should be considered by the Heart Team in the decision making. Abstract 0486 – Table: Predictors of adverse outcome after TAVI Presence of composite criteria n=28 Absence of composite criteria n=90 p EuroScore 1 (%) 24,96±11,48 18,55±10,99 0,013 Dislipidemia n(%) 12 (43) 23 (26) 0,08 Body mass index (BMI) n(%) 24,21±4,01 27,33±5,51 0,01 CoreValve prothesis n(%) 18 (64) 39 (43) 0,056 Calcium score 5875,71±3285,84 3565,78±1331,18 <0,001