Coronary Artery Calcium Density Research Articles

CT-derived coronary artery calcium density is affected by regional lesion distribution and image reconstruction parameters

PurposeThe prognostic relevance of coronary artery calcium (CAC) density, assessed from cardiac CT scans, is established. However, the influence of CAC distribution, volume, image reconstruction, and clinical factors on CAC density warrants further examination. MethodsIn this study, 120 patients underwent non-contrast ECG-gated cardiac CT scans using a prospectively defined CAC scoring protocol with 1-, 3-, and 5-mm thick image reconstructions, both with and without a 20% image overlap. We segmented CAC in all reconstructions and assessed the relationship between CAC density, volume, and number of detected calcifications/patient. ResultsOverall, 75/120 (63%) patients (66% men, mean age 63 ± 11 years) presented CAC across 342 segments. CAC density, CAC volume, and the number of detected calcifications decreased with increasing slice thickness (p < 0.001 for all); these effects were slightly reduced by image overlap (p < 0.001 for all). Higher CAC density correlated with greater CAC volume (ρ = 0.62; p < 0.001) and more calcified segments per person (ρ = 0.32; p = 0.006). Higher CAC density was also associated with lower patient weight (beta: -0.6, 95%CI: −1.1–-0.1, p = 0.022) and increased high-density lipoprotein (HDL) levels (beta: 0.7, 95%CI: 0.0–1.4, p = 0.046). In a multivariable analysis adjusted for clinical covariates, lower CAC density was associated with broader CAC distribution (i.e., a higher number of calcified segments at a given CAC volume; beta-coefficient: -58.9; 95%CI: −84.7 to −33.1; p < 0.001). ConclusionCAC density is significantly impacted by regional CAC distribution and image reconstruction, potentially confounding its prognostic value. Accounting for these factors may improve patient risk assessment, management, and cardiovascular health outcomes.

Calcium scoring on coronary computed angiography tomography with photon-counting detector technology: Predictors of performance

IntroductionObtaining accurate coronary artery calcium (CAC) score measurements from CCTA datasets with virtual non-iodine (VNI) algorithms would reduce acquisition time and radiation dose. We aimed to assess the agreement of VNI-derived and conventional true non-contrast (TNC)-based CAC scores and to identify the predictors of accuracy. MethodsCCTA datasets were acquired with either 120 or 140 ​kVp. CAC scores and volumes were calculated from TNC and VNI images in 197 consecutive patients undergoing CCTA. CAC density score, mean volume/lesion, aortic Hounsfield units and standard deviations were then measured. Finally, percentage deviation (VNI - TNC/TNC∗100) of CTA-derived CAC scores from non-enhanced scans was calculated for each patient. Predictors (including anthropometric and acquisition parameters, as well as CAC characteristics) of the degree of discrepancy were evaluated using linear regression analysis. ResultsWhile the agreement between TNC and VNI was substantial (mean bias, 6.6; limits of agreement, 178.5/145.3), a non-negligible proportion of patients (36/197, 18.3%) were falsely reclassified as CAC score ​= ​0 on VNI. The use of higher tube voltage significantly decreased the percentage deviation relative to TNC-based values (β ​= ​−0.21 [95%CI: 0.38 to −0.03], p ​= ​0.020) and a higher CAC density score also proved to be an independent predictor of a smaller difference (β ​= ​−0.22 [95%CI: 0.37 to −0.07], p ​= ​0.006). ConclusionThe performance of VNI-based calcium scoring may be improved by increased tube voltage protocols, while the accuracy may be compromised for calcified lesions of lower density. The implementation of VNI in clinical routine, however, needs to be preceded by a solution for detecting smaller lesions as well.

Association of apolipoproteins C-I and C-II truncations with coronary heart disease and progression of coronary artery calcium: Multi-Ethnic Study of Atherosclerosis

Background and aimsHigher truncated-to-native proteoform ratios of apolipoproteins (apo) C-I (C-I’/C-I) and C-II (C-II’/C-II) are associated with less atherogenic lipid profiles. We examined prospective relationships of C-I’/C-II and C-II’/C-II with coronary heart disease (CHD) and coronary artery calcium (CAC). MethodsApoC-I and apoC-II proteoforms were measured by mass spectrometry immunoassay in 5790 MESA baseline plasma samples. CHD events (myocardial infarction, resuscitated cardiac arrest, fatal CHD, n = 434) were evaluated for up to 17 years. CAC was measured 1–4 times over 10 years for incident CAC (if baseline CAC = 0), and changes (follow-up adjusted for baseline) in CAC score and density (if baseline CAC>0). ResultsC-II’/C-II was inversely associated with CHD (n = 434 events) after adjusting for non-lipid cardiovascular risk factors (Hazard ratio: 0.89 [95% CI: 0.81–0.98] per SD), however, the association was attenuated after further adjustment for HDL levels (0.93 [0.83–1.03]). There was no association between C-I’/C-I and CHD (0.98 [0.88–1.08]). C-II’/C-II was positively associated with changes in CAC score (3.4% [95%CI: 0.6, 6.3]) and density (6.3% [0.3, 4.2]), while C-I’/C-I was inversely associated with incident CAC (Risk ratio: 0.89 [95% CI: 0.81, 0.98]) in fully adjusted models that included plasma lipids. Total apoC-I and apoC-II concentrations were not associated with CHD, incident CAC or change in CAC score. ConclusionsIncreased apoC-II truncation was associated with reduced CHD, possibly explained by differences in lipid metabolism. Increased apoC-I and apoC-II truncations were also associated with less CAC progression and/or development of denser coronary plaques.

Association Of Quantitative Coronary Artery Calcium Density Volume With Major Adverse Cardiovascular Events In A Wide Spectrum Of Patients Who Referred For Cardiac Imaging Testing

Association Of Quantitative Coronary Artery Calcium Density Volume With Major Adverse Cardiovascular Events In A Wide Spectrum Of Patients Who Referred For Cardiac Imaging Testing

Lipoprotein(a) and coronary artery calcium in comparison with other lipid biomarkers: The multi-ethnic study of atherosclerosis

Coronary artery calcium (CAC) scoring is often used for atherosclerotic cardiovascular disease (ASCVD) risk stratification in individuals with elevated lipoprotein(a) [Lp(a)]. To evaluate associations between Lp(a) and baseline CAC (volume/density) and CAC progression compared to other lipid biomarkers. We utilized data from the Multi-Ethnic Study of Atherosclerosis (MESA), a cohort study of individuals without clinical ASCVD, excluding statin users. We evaluated the associations between Lp(a), low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), triglycerides, total cholesterol, apolipoprotein B, and non-HDL-C with baseline CAC and annual CAC progression using multivariable ordinal regression with adjustment for ASCVD risk factors. Analyses were also stratified by median age. In 5,597 participants (2,726 at median 9.5-year follow-up), Lp(a) was not associated with baseline CAC volume or density and was modestly associated with volume progression (OR 1.11, 95% CI 1.03-1.21). However, other biomarkers were positively associated with baseline volume and volume progression (LDL-C: OR 1.26, 95% CI: 1.19-1.33 and OR 1.22, 95% CI: 1.15-1.30, respectively), except HDL-C which was inversely associated. LDL-C, total cholesterol and non-HDL-C were inversely associated with baseline density. In participants <62 years of age, Lp(a) was modestly associated with baseline CAC volume (OR 1.10, 95% CI: 1.00-1.20) and volume progression (OR 1.16 95% CI: 1.04-1.30). In contrast to other lipid biomarkers, Lp(a) was not associated with baseline CAC volume or density and was only modestly associated with volume progression. Our findings suggest that Lp(a) is not as robustly associated with CAC as other lipid biomarkers.

Radiation dose optimization for photon-counting CT coronary artery calcium scoring for different patient sizes: a dynamic phantom study

PurposeTo systematically assess the radiation dose reduction potential of coronary artery calcium (CAC) assessments with photon-counting computed tomography (PCCT) by changing the tube potential for different patient sizes with a dynamic phantom.MethodsA hollow artery, containing three calcifications of different densities, was translated at velocities corresponding to 0, < 60, 60–75, and > 75 beats per minute within an anthropomorphic phantom. Extension rings were used to simulate average- and large -sized patients. PCCT scans were made with the reference clinical protocol (tube potential of 120 kilovolt (kV)), and with 70, 90, Sn100, Sn140, and 140 kV at identical image quality levels. All acquisitions were reconstructed at a virtual monoenergetic energy level of 70 keV. For each calcification, Agatston scores and contrast-to-noise ratios (CNR) were determined, and compared to the reference with Wilcoxon signed-rank tests, with p < 0.05 indicating significant differences.ResultsA decrease in radiation dose (22%) was achieved at Sn100 kV for the average-sized phantom. For the large phantom, Sn100 and Sn140 kV resulted in a decrease in radiation doses of 19% and 3%, respectively. Irrespective of CAC density, Sn100 and 140 kVp did not result in significantly different CNR. Only at Sn100 kV were there no significant differences in Agatston scores for all CAC densities, heart rates, and phantom sizes.ConclusionPCCT at tube voltage of 100 kV with added tin filtration and reconstructed at 70 keV enables a ≥ 19% dose reduction compared to 120 kV, independent of phantom size, CAC density, and heart rate.Key Points• Photon-counting CT allows for reduced radiation dose acquisitions (up to 19%) for coronary calcium assessment by reducing tube voltage while reconstructing at a normal monoE level of 70 keV.• Tube voltage reduction is possible for medium and large patient sizes, without affecting the Agatston score outcome.

Coronary Artery Calcium Density and Cardiovascular Events by Volume Level: The MESA.

The Agatston coronary artery calcium (CAC) score provides robust cardiovascular disease risk prediction but upweights plaque area by a density factor. Density, however, has been shown to be inversely associated with events. Using CAC volume and density separately improves risk prediction, but it is unclear how to apply this method clinically. We aimed to evaluate the association between CAC density and cardiovascular disease across the spectrum of CAC volume to better understand how to incorporate these metrics into a single score. We performed an analysis of MESA (Multi-Ethnic Study of Atherosclerosis) participants with detectable CAC to evaluate the association between CAC density and events by level of CAC volume using multivariable Cox regression models. In a cohort of 3316 participants, there was a significant interaction (P<0.001) between CAC volume and density for coronary heart disease (CHD) risk (myocardial infarction, CHD death, resuscitated cardiac arrest). Models using CAC volume and density resulted in improvement in the C-index (0.703, SE 0.012 versus 0.687, SE 0.013) and a significant net reclassification improvement (0.208 [95% CI, 0.102-0.306]) compared with the Agatston score for CHD risk prediction. Density was significantly associated with lower CHD risk at volumes ≤130 mm3 (hazard ratio, 0.57 per unit of density [95% CI, 0.43-0.75]), but the inverse association at volumes >130 mm3 was not significant (hazard ratio, 0.82 per unit of density [95% CI, 0.55-1.22]). The lower risk for CHD associated with higher CAC density varied by level of volume, and volume ≤130 mm3 is a potentially clinically useful cut point. Further study is needed to integrate these findings into a unified CAC scoring method.

Coronary Artery Calcium Dispersion and Cause-Specific Mortality

Coronary artery calcium (CAC) measures subclinical atherosclerosis and improves risk stratification. CAC characteristics-including vessel(s) involved, number of vessels, volume, and density-have been shown to differentially impact risk. We assessed how dispersion-either the number of calcified vessels or CAC phenotype (diffuse, normal, and concentrated)-impacted cause-specific mortality. The CAC Consortium is a retrospective cohort of 66,636 participants without coronary heart disease (CHD) who underwent CAC scoring. This study included patients with CAC >0 (n=28,147). CAC area, CAC density, and CAC phenotypes (derived from the index of diffusion=1 - [CAC in most concentrated vessel/total Agatston score]) were calculated. The associations between CAC characteristics and cause-specific mortality were assessed. The participant details included (n=28,147): mean age 58.3 years, 25% female, 89.6% White, and 66% had 2+ calcified vessels. Diabetes, hypertension, and hyperlipidemia were predictors of multivessel involvement (p <0.001). After controlling for the overall CAC score, those with 4-vessel CAC involvement had more CAC area and less dense calcifications than those with 1-vessel. There was a graded increase in all-cause and cardiovascular disease (CVD)- and CHD-specific mortality as the number of calcified vessels increased. Among those with ≥2 vessels involved (n=18,516), a diffuse phenotype was associated with a higher CVD-specific mortality and had a trend toward higher all-cause and CHD-specific mortality than a concentrated CAC phenotype. Diffuse CAC involvement was characterized by less dense calcification, more CAC area, multiple coronary vessel involvement, and presence of certain traditional risk factors. There is a graded increase in all-cause and CVD- and CHD-specific mortality with increasing CAC dispersion.

High- vs. Low-Intensity Statin Therapy and Changes in Coronary Artery Calcification Density after One Year.

Statin therapy promotes the progression of coronary artery calcification (CAC). Comparing patients on high (HIST) vs. low-to-intermediate intensity statin therapy (LIST), randomized controlled trials with a one-year follow-up failed to document a relevant difference in the Agatston score and CAC volume. We evaluated whether statin intensity modifies CAC density at one year. We performed a pooled analysis of two randomized-controlled trials (BELLES, EBEAT), comparing the effects of HIST (Atorvastatin 80 mg) vs. LIST (Pravastatin 40 mg, Atorvastatin 10 mg) on CAC measures after one year. The differences in CAC density and its change were compared using the two-sided t-test. Data from 852 patients (66.7% female) with available baseline and follow-up CT were evaluated from both trials. HIST vs. LIST more effectively reduced LDL-cholesterol (annualized change: -45.8 ± 38.5 vs. -72.9 ± 46.0 mg/dL, p &lt; 0.001). Mean CAC density increased from 228.8 ± 35.4 HU to 232.6 ± 37.0 HU (p &lt; 0.0001) at one-year follow-up. Comparing patients on HIST vs. LIST, CAC density at follow-up (HIST: 231.9 ± 36.1 HU vs. LIST: 233.3 ± 37.7 HU, p = 0.59) and its change from baseline (HIST: 4.0 ± 19.1 HU vs. LIST: 3.6 ± 19.6 HU, p = 0.73) did not differ. Subgroup analyses, stratifying by LDL reduction (&lt;median: 2.0 ± 24.3 HU, ≥median: 3.6 ± 21.9 HU, p = 0.34), Agatston score at baseline (&lt;100: 2.6 ± 22.5 HU vs. 3.2 ± 25.6 HU, p = 0.82; ≥100: 4.8 ± 17.0 HU vs. 3.8 ± 16.6 HU, p = 0.44, for HIST vs. LIST; respectively), and equal number of lesions in both CT scans (3.7 ± 20.3 HU vs. 7.0 ± 22.2 HU, p = 0.24) showed similar results. HIST vs. LIST leads to a higher reduction in cholesterol levels, which does not translate into relevant differences in the change of CAC density at one-year follow-up.

Mortality impact of low CAC density predominantly occurs in early atherosclerosis: explainable ML in the CAC consortium

BackgroundMachine learning (ML) models of risk prediction with coronary artery calcium (CAC) and CAC characteristics exhibit high performance, but are not inherently interpretable. ObjectivesTo determine the direction and magnitude of impact of CAC characteristics on 10-year all-cause mortality (ACM) with explainable ML. MethodsWe analyzed asymptomatic subjects in the CAC consortium. We trained ML models on 80% and tested on 20% of the data with XGBoost, using clinical characteristics ​+ ​CAC (ML 1) and additional CAC characteristics of CAC density and number of calcified vessels (ML 2). We applied SHAP, an explainable ML tool, to explore the relationship of CAC and CAC characteristics with 10-year all-cause and CV mortality. Results2376 deaths occurred among 63,215 patients [68% male, median age 54 (IQR 47–61), CAC 3 (IQR 0–94.3)]. ML2 was similar to ML1 to predict all-cause mortality (Area Under the Curve (AUC) 0.819 vs 0.821, p ​= ​0.23), but superior for CV mortality (0.847 vs 0.845, p ​= ​0.03).Low CAC density increased mortality impact, particularly ≤0.75. Very low CAC density ≤0.75 was present in only 4.3% of the patients with measurable density, and 75% occurred in CAC1-100. The number of diseased vessels did not increase mortality overall when simultaneously accounting for CAC and CAC density. ConclusionCAC density contributes to mortality risk primarily when it is very low ≤0.75, which is primarily observed in CAC 1–100. CAC and CAC density are more important for mortality prediction than the number of diseased vessels, and improve prediction of CV but not all-cause mortality. Explainable ML techniques are useful to describe granular relationships in otherwise opaque prediction models.

Abstract 9971: Distribution of Coronary Artery Calcium and Risk for Cardiovascular Disease: The Multi-Ethnic Study of Atherosclerosis

Introduction: We tested the hypothesis that specific arteries with coronary artery calcium (CAC) would be associated with higher risk for incident cardiovascular disease (CVD) outcomes, even after accounting for traditional risk factors, and that adding this metric to current risk scores would improve event prediction. Methods: We analyzed data from 3,255 MESA participants with baseline CAC and event follow-up. Cox proportional hazards models assessed the independent associations between CAC presence in each of the main coronary arteries and incident myocardial infarction (MI), hard coronary artery disease (CHD), and hard CVD, adjusting for the ASCVD risk score and CAC volume and density. Area under the receiver operating characteristic curve (AUC) analyses assessed for risk discrimination by adding CAC distribution to existing risk models. Results: At baseline [mean age 66 years (SD 9.6); 1,893 female (58%)], 2,909 (89%) participants had CAC in the left anterior descending (LAD), 1,871 (58%) in the left circumflex (LCx), 1,691 (52%) in the right coronary artery (RCA), and 693 (21%) in the left main (LM). Over a median of 15.5 years, 275 developed MI, 408 CHD, and 598 CVD. After adjustment for the ASCVD risk score and CAC volume and density, only the RCA remained significant for MI and CHD, and was borderline for CVD (Table). AUC increased after adding RCA CAC presence to the ASCVD risk score for MI (0.5992 to 0.6660; 95% CI 0.031-0.102) and CHD (0.6483 to 0.6818; 95% CI, 0.003-0.064), but not for CVD, and there was no significant increase for any endpoints when added to models accounting for CAC volume and density. Conclusion: Prevalent CAC was most common in the LAD, followed by the LCx and RCA. Accounting for risk factors and CAC measures, the RCA was the only artery independently associated with additional MI and CHD risk. Moreover, MI and CHD risk prediction were improved with the addition of CAC distribution to the ASCVD score but not when also accounting for CAC volume and density.

Abstract 9969: Number of Calcified Coronary Arteries and Prediction of Cardiovascular Outcomes: The Multi-Ethnic Study of Atherosclerosis

Introduction: Current coronary artery calcium (CAC) scoring methods do not account for the number of vessels affected. We assessed the hypothesis that the number of vessels with CAC would be associated with higher risk for incident cardiovascular disease (CVD) outcomes, even after accounting for traditional risk factors, and that adding this metric to current risk scores would improve event prediction. Methods: We analyzed data from 3,255 MESA participants with baseline CAC and event follow-up. Cox proportional hazard regression analyses evaluated the association between number of affected vessels and incident myocardial infarction (MI), hard coronary artery disease (CHD), and hard CVD, adjusting for the ASCVD score and CAC volume and density. Area under the receiver operator curves (AUC) assessed event discrimination by adding number of vessels with CAC to current risk models. Results: At baseline [mean age 66 years (SD 9.6); 1,893 female (58%)], 1,086 participants (33%) had CAC in 1 vessel, 832 in 2 (26%), 987 in 3 (30%), and 385 in 4 (12%). Over a median of 15.5 years, 275 developed MI, 408 CHD, and 598 CVD. Multivariable-adjusted risk was higher with CAC in 3-4 vs 1 vessel for all outcomes (Table) and with 3-4 vs 2-vessels for CHD and CVD (HR 1.36, 95% CI 1.0-1.8 and HR 1.30, 95% CI 1.0-1.6). AUC increased after adding the number of vessels with CAC to the ASCVD score for MI (0.5992 to 0.6645, p=0.002), but not for CHD or CVD, and there was no significant increase for any endpoint when added to models already accounting for CAC volume and density. Conclusions: In a cohort free of baseline CVD, CAC had similar prevalence in 1, 2, and 3 vessels. After accounting for the ASCVD score and CAC volume and density, CAC in 3-4 vessels still conferred a significantly higher risk for adverse CVD outcomes compared to CAC in 1-2 vessels. Moreover, MI risk prediction was improved with adding the number of vessels with CAC to the ASCVD score, but not when also accounting for CAC volume and density.

High- vs. low-intensity statin therapy and changes in coronary artery calcification density after one year

Abstract Introduction High-dose statin therapy (HIST) halts coronary plaque progression and reduces the risk of cardiovascular events by increasing atheroma calcification. The Agatston score is well established in the clinical routine for assessment of coronary artery calcification using non-contrast computed tomography. However, randomized controlled trials failed to detect an influence of HIST vs. low-to-intermediate statin therapy (LIST) on the Agatston and CAC volume score after one year. Coronary plaques with lower density including spotty calcifications may represent dynamic and early stages of atherosclerosis. We evaluated whether CAC density differentiates in HIST- vs. LIST-treated patients after one year. Methods The meta-analysis contains data from two prospective, randomized, double-blind studies (BELLES, EBEAT) that were designed to detect CAC changes after one year comparing HIST vs. LIST. In both studies, patient's coronary calcification burden was measured at baseline and one-year follow-up using electron beam computed tomography (EBCT). Patients data were pooled and stratified by intensity of statin therapy. Furthermore, the cohort was divided into several subgroup analyses, accounting for LDL-Cholesterol reduction, initial Agatston score and a consistent number of lesions. Results Data from 852 patients, 66% female were included. The amount of CAC overall increased after 1 year [Agatston score: 169.3 (80.0, 377.1) vs. 214.9 (95.4, 450.0); p&amp;lt;0.0001NP; volume score: 292.1±445.4 vs. 355.5±482.4; p&amp;lt;0.0001; number of lesions: 6 (3,10) vs. 7 (4,12); p&amp;lt;0.0001NP, at baseline and follow-up, respectively]. Likewise, the average CAC density was higher at follow-up [CAC density: 228.8±35.4 vs. 232.6±37.0; p&amp;lt;0.0001]. HIST vs. LIST more effectively reduced LDL-cholesterol (annualized change: −58.6±50.9 vs. −44.4±43.7 mg/dL, p=0.005). Comparing patients on HIST vs. LIST, CAC density at follow-up (231.9±36.1 HU vs. 233.3±37.7, p=0.59) and its change from baseline (4.0±19.1 HU vs. 3.6±19.6 HU, p=0.73) did not differ. Subgroup analyses, stratifying by LDL-reduction ( Conclusion HIST vs. LIST leads to a higher reduction in cholesterol levels, which does not translate into relevant differences in the change of CAC density at one-year follow-up. Funding Acknowledgement Type of funding sources: None.

Cholesterol mass efflux capacity and coronary artery calcium: The Multi-Ethnic Study of Atherosclerosis

We assessed the cross-sectional and longitudinal relationships of high-density lipoprotein (HDL)-mediated cholesterol mass efflux capacity (CMEC) with coronary artery calcium (CAC) score and CAC density. CMEC was measured in 1626 Multi-Ethnic Study of Atherosclerosis (MESA) participants in samples obtained between 2000 and 2002 as part of two nested case-control studies, one with cases of incident cardiovascular disease and the other with cases of carotid plaque progression by ultrasound. Cardiac CT examinations for the presence of CAC were performed at baseline and at two additional examinations. CAC scores (Agatston and volume) and density scores (for those with positive CAC) were calculated. Multivariable linear regression modeling per SD increment of CMEC was used to estimate the associations of CMEC with each of these CAC measures. We found no association between higher CMEC and either lower CAC scores or a higher CAC density. We also found no association between higher CMEC and progression of any of these CAC measures. These findings suggest that HDL-mediated cholesterol efflux may be associated with cardiovascular risk via mechanisms unrelated to burden of calcified plaque.

Density of Calcified Coronary Artery Plaque and Risk of Incident Atrial Fibrillation (from the Multiethnic Study of Atherosclerosis)

Elevated coronary artery calcium (CAC) score, as assessed by the Agatston method, is associated with incident atrial fibrillation (AF). We aimed to evaluate the associations of CAC volume and density with incident AF. Participants from the Multiethnic Study of Atherosclerosis without baseline AF and CAC &amp;amp;gt;0 were included. The associations between baseline and progression (average annual change) of CAC measures and incident AF were evaluated using Cox proportional hazards models. CAC volume and Agatston scores were natural log (ln)-transformed, and hazard ratios (HRs) were calculated per standard deviation increment. The baseline analysis included 3,332 participants; 2,643 were included in the progression analysis. In multivariable models adjusted for cardiovascular risk factors, volume (HR 1.24, 95% confidence interval [CI] 1.14 to 1.36), density (HR 1.14, 95% CI 1.05 to 1.25), and Agatston score (HR 1.24, 95% CI 1.14 to 1.35) were associated with increased risk of incident AF. In models including both volume and density, the magnitude of association between volume and incident AF was unchanged, whereas the density association was eliminated (HR 0.99, 95% CI 0.89 to 1.11). Median time to follow-up CAC assessment was 1.9 (interquartile range 1.3, 3.0) years. Similar results were observed for the association of incident AF with annual change in volume and Agatston score. CAC volume, but not density, is associated with risk for incident AF when adjusting for both. In conclusion, our findings suggest that, although CAC may be a risk marker for AF, the association between CAC and AF appears to be independent of plaque density.

Coronary artery calcium and cardiovascular disease prediction by scanner type: the multi-ethnic study of atherosclerosis

To evaluate the predictive value of coronary artery calcium (CAC) scoring methods across cardiac computed tomography (CT) scanner types. CAC was measured in participants from the MESA (Multi-Ethnic Study of Atherosclerosis), a prospective cohort study of participants free of baseline cardiovascular disease (CVD), using either EBCT (electron beam CT) or MDCT (multidetector CT). The risks for incident coronary heart disease (CHD) and CVD events were compared for CAC scores per SD using Cox proportional hazards models with multivariable adjustment in 3,362 MESA participants with detectable CAC. Using the Agatston score, the hazard ratio (HR) and 95% confidence interval (CI) for CHD was 1.50 (1.27,1.78) for EBCT and 1.60 (1.37,1.87) for MDCT. Using volume and density scores, the HR for CHD was 2.14 (1.71,2.68) for volume and 0.61 (0.48,0.76) for density on EBCT and 1.73 (1.42,2.11) for volume and 0.88 (0.71,1.10) for density on MDCT. Similar results were seen for CVD risk and in analyses stratified by sex, body mass index (BMI), and age. The volume and density score model demonstrated higher areas under the curve (AUC) for CHD than the Agatston score with EBCT (0.702, 95% CI: 0.666,0.738 versus 0.677, 95% CI: 0.638,0.715, p<0.001) and MDCT (0.669, 95% CI: 0.632,0.705 versus 0.660, 95% CI: 0.622,0.697, p=0.216). The CAC volume and density scores provide better risk prediction than the Agatston score for CHD and CVD events, regardless of CT scanner type. CAC density was strongly and inversely associated with CHD risk. Both density and volume score prediction were stronger for EBCT than MDCT.

Coronary artery calcium incidence and changes using direct plaque measurements: The MASALA study

Background and aimsWe aimed to identify predictors of change in direct measures of coronary artery calcium (CAC) volume and density in South Asian participants. MethodsWe used data from participants in the Mediators of Atherosclerosis in South Asians Living in America (MASALA) study with prevalent CAC and direct measures of CAC by serial computed tomography (CT) exams (2010–2013, 2016–2018). We examined the distribution of incident CAC volume and peak density, as well as progression and identified risk factors for progression of change in volume and density in multivariable models. ResultsThe study cohort consisted of 102 participants with incident CAC and 285 with CAC progression. CAC volume and density were highest, and incident CAC was most common in the left anterior descending artery (LAD). The greatest progression in volume was in the right coronary artery and the greatest change in density was in the left main. In linear regression models for CAC progression adjusted for baseline density, volume, risk factors, smoking (β +190.1, p = 0.02), baseline volume (β +0.24 per mm3, p < 0.01), and scan interval (β +0.15 per day, p = 0.01) were associated with change in total volume whereas Lp(a) (β +0.81 per mg/dL, p = 0.03), exercise (β +0.19 per 10 MET-min/week, p = 0.01), and baseline volume (β +0.15 per mm3, p < 0.01) and density (β −0.55 per unit, p < 0.01) were associated with change in total density. ConclusionsIn this South Asian cohort, smoking was associated with CAC volume progression, while Lp(a) and exercise were associated with progression of peak CAC density.

Joint Associations of Obesity and Cardiorespiratory Fitness With Coronary Artery Calcium Composition: IS THERE EVIDENCE FOR FAT-BUT-FIT?

The purpose of this study was to examine the individual and joint associations of obesity and cardiorespiratory fitness (CRF) with indices of coronary artery calcification (CAC) in 2090 middle-aged men. Obesity was defined as a body mass index (BMI) ≥25 kg/m2 and a waist circumference (WC) ≥90 cm. Cardiorespiratory fitness was operationally defined as peak oxygen uptake (V˙o2peak) directly measured using gas analysis. Participants were then divided into unfit and fit categories based on age-specific V˙o2peak percentiles. Agatston scores >100 and volume and density scores >75th percentile were defined as indices of CAC, signifying advanced subclinical atherosclerosis. Obese men had increased CAC Agatston, volume, and density scores, while higher CRF was associated with lower Agatston and volume scores after adjusting for potential confounders. In the joint analysis, unfit-obese men had higher CAC Agatston and CAC volume. The fit-obesity category was not associated with CAC Agatston (OR = 0.91: 95% CI, 0.66-1.25, for BMI and OR = 1.21: 95% CI, 0.86-1.70, for WC) and CAC volume (OR = 1.14: 95% CI, 0.85-1.53, for BMI and OR = 1.23: 95% CI, 0.90-1.69, for WC), which were similar to estimates for the fit-normal weight category. These findings demonstrate that while obesity is positively associated with the prevalence of moderate to severe CAC scores, CRF is inversely associated with the prevalence of moderate to severe CAC scores. Additionally, the combination of being fit and obese was not associated with CAC scores, which could potentially reinforce the fat-but-fit paradigm.

Reproducibility of coronary artery calcium quantification on dual-source CT and dual-source photon-counting CT: a dynamic phantom study

To systematically compare coronary artery calcium (CAC) quantification between conventional computed tomography (CT) and photon-counting CT (PCCT) at different virtual monoenergetic (monoE) levels for different heart rates. A dynamic (heart rates of 0, < 60, 60–75, and > 75 bpm) anthropomorphic phantom with three calcification densities was scanned using routine clinical CAC protocols with CT and PCCT. In addition to the standard clinical protocol of 70 keV, PCCT images were reconstructed at monoE levels of 72, 74, and 76 keV. CAC was quantified using Agatston, volume, and mass scores. Agatston scores 95% confidence intervals (CI) were calculated and compared between PCCT and CT. Volume and mass scores were compared with physical quantities. For all CAC densities, routine clinical protocol Agatston scores of static CAC were higher for PCCT compared to CT. At < 60 bpm, Agatston scores at 74 and 76 keV reconstructions were reproducible (overlapping CI) for PCCT and CT. Increased heart rates yielded different Agatston scores for PCCT in comparison with CT, for all monoE levels. Low density CAC volume scores showed the largest deviation from physical volume, with mean deviations of 59% and 77% for CT and PCCT, respectively. Overall, mass scores underestimated physical mass by 10%, 38%, and 59% for low, medium, and high density CAC, respectively. PCCT allows for reproducible Agatston scores for dynamic CAC (< 60 bpm) when reconstructed at monoE levels of 74 or 76 keV, regardless of CAC density. Deviations from physical volume and mass were, in general, large for both CT and PCCT.

Abstract 9425: Coronary Artery Calcium Measurement and Prediction of Cardiovascular Disease by Different Ct Scanner Types: The Multi-Ethnic Study of Atherosclerosis

Introduction: Coronary artery calcium (CAC) scoring is a powerful tool for cardiovascular disease (CVD) risk prediction. The Agatston score weighs lesion area upward for density, and is consistent across computed tomography (CT) scanner type. Considering volume and density separately improves risk prediction, but has not been evaluated by CT scanner type. Hypothesis: Our hypothesis was that the predictive value of volume and density scoring would be superior to the Agatston score across CT scanner types. Methods: We used data from MESA (Multi-Ethnic Study of Atherosclerosis), a prospective cohort study of participants free of baseline clinical cardiovascular disease. CAC was measured using either EBCT (electron beam CT) or MDCT (multi-detector CT). We compared risk prediction for coronary heart disease (CHD) and CVD events using the Agatston method and the volume and density scores by scanner type using Cox proportional hazards models with multivariable adjustment among those with baseline CAC &gt; 0. HRs are presented as per standard deviation. Results: The 3,362 MESA participants with CAC &gt;0 were studied. Using the Agatston method, the HR [95% CI] for CHD was 1.28 [1.16-1.42] for EBCT and 1.22 [1.12-1.34] for MDCT. Using the volume score adjusted for density, the HR for CHD was 2.11 [1.70-2.63] for EBCT and 1.71 [1.41-2.07] for MDCT. Density was strongly and inversely associated with CHD. Similar results were seen for CVD risk and in analyses stratified by sex, BMI, age, and baseline statin use. The volume score demonstrated higher areas under the curve (AUC) than the Agatston score with EBCT (0.702, 95% CI 0.665-0.738 vs 0.677, 95% CI 0.638-0.715, p=0.013) and MDCT (0.669, 95% CI 0.632-0.705 vs 0.653, 95% CI 0.616-0.690, p=0.107). Conclusions: Compared with the Agatston score, the CAC volume score, adjusted for density, provides better risk prediction for CHD and CVD events, regardless of CT scanner type. CAC density was strongly and inversely associated with CVD risk.