Coronary calcium measurements: effect of CT scanner type and calcium measure on rescan reproducibility--MESA study

Automated AI-based coronary calcium scoring using retrospective CT data from SCAPIS is accurate and correlates with expert scoring

OBJECTIVES

Evaluation of the correlation and agreement between AI and semi-automatic evaluations of calcium scoring CT (CSCT) examinations using extensive data from the Swedish CardioPulmonary bio-Image study (SCAPIS).

MATERIALS AND METHODS

In total, 5057 CSCT examinations were performed on one CT system at Linköping University Hospital between October 8, 2015, and June 12, 2018. AI evaluations were compared to semi-automatic CSCT results from expert reader evaluations rendered within SCAPIS. Pearson correlation, intraclass correlation coefficients (ICC), and Bland-Altman analysis were applied for Agatston (AS), volume (VS), mass scores (MS), number of lesions and lesion location. Agreement of Agatston score classifications into cardiovascular (CV) risk categories was evaluated with weighted kappa analysis.

RESULTS

The evaluation included 4567 subjects, 2229 (48.8%) male, 2338 (51.2%) female, 50-64 years of age (mean 57.3 ± 4.4). The AS ranged from 0 to 2871 in the cohort, with 2846 subjects having an AS of 0. Mean and median AS were 51.4 and 0.0, respectively. Total AS, VS, MS and number of lesions ICCs were 0.994, 0.994, 0.994, 0.960 (p < 0.001), respectively. Bland-Altman analyses rendered mean differences ± 1.96 SD upper and lower limits of agreement for AS -0.04, -52.5 to 52.4, VS -0.44, -46.51 to 45.63, and MS -0.07, -9.62 to 9.48. Weighted kappa analysis for CV risk category classifications was 0.913, and overall accuracy was 91.2%.

CONCLUSION

There was excellent correlation and agreement between AI and semi-automatic evaluations for all calcium scores, number of lesions and lesion location. High degrees of agreement and accuracy were found for the CV risk categorization.

KEY POINTS

Question Can AI function as a tool for enhancing the efficiency and accuracy of Coronary Artery Calcium Score (CACS) evaluations in clinical radiology practice? Findings This study confirms the robustness of AI-derived CACS results across extensive datasets, though its generalizability is limited by data acquisition from a single CT system. Clinical relevance This study suggests that AI holds significant promise as a tool for enhancing the efficiency and accuracy of CACS evaluations, with implications for improving patient diagnostics and reducing radiologist workload in clinical practice.

Correlation Between Calcium Scoring and Abdominal Aortic Aneurysm Endovascular Repair Outcomes

OBJECTIVES

Endovascular aneurysm repair, though minimally invasive and has the benefit of relatively low perioperative complication rates, it is associated with significant long term reintervention rates related to endoleaks. Several variables have been studied to predict the outcomes of endovascular aneurysm repair, 1 of which is the calcium burden of the vasculature. This prompted us to study the association between calcium burden measured by the standardized Agatston scoring system and the outcomes of Endovascular aneurysm repair.

METHODS

This is a retrospective study of patients who underwent Endovascular aneurysm repair from 2008 to 2020 at our institution and who had a non-contrast computerized tomography scan preoperatively, accounting for 87 patients. The calcium burden of the vasculature was measured by the Agatston scoring system allowing for better reproducibility, and the outcome variables included mortality and endoleaks.

RESULTS

Patients with higher median total calcium scores (≥12966.9) had significantly lesser survival (79.8% vs 52.3% (P = .002) at five years compared to patients with lower median total calcium score (<12966.9). Also, patients with type 2 endoleaks had higher calcium scores in above the aneurysm level ((1591.2 vs 688.2), P = .05)) compared to patients with no type 2 endoleaks.

CONCLUSION

Calcium score assigned using a standardized Agatston scoring system can be used as a predictor of mortality risk assisting in deciding the treatment of choice for patients.

AI-enabled Cardiac Chambers Volumetry and Calcified Plaque Characterization in Coronary Artery Calcium (CAC) Scans (AI-CAC) Significantly Improves on Agatston CAC Score for Predicting All Cardiovascular Events: The Multi-Ethnic Study of Atherosclerosis

Background

Coronary artery calcium (CAC) scans contain valuable information beyond the Agatston Score which is currently reported for predicting coronary heart disease (CHD) only. We examined whether new artificial intelligence (AI) algorithms applied to CAC scans may provide significant improvement in prediction of all cardiovascular disease (CVD) events in addition to CHD, including heart failure, atrial fibrillation, stroke, resuscitated cardiac arrest, and all CVD-related deaths.

Methods

We applied AI-enabled automated cardiac chambers volumetry and automated calcified plaque characterization to CAC scans (AI-CAC) of 5830 individuals (52.2% women, age 61.7±10.2 years) without known CVD that were previously obtained for CAC scoring at the baseline examination of the Multi-Ethnic Study of Atherosclerosis (MESA). We used 15-year outcomes data and assessed discrimination using the time-dependent area under the curve (AUC) for AI-CAC versus the Agatston Score.

Results

During 15 years of follow-up, 1773 CVD events accrued. The AUC at 1-, 5-, 10-, and 15-year follow up for AI-CAC vs Agatston Score was (0.784 vs 0.701), (0.771 vs. 0.709), (0.789 vs.0.712) and (0.816 vs. 0.729) (p<0.0001 for all), respectively. The category-free Net Reclassification Index of AI-CAC vs. Agatston Score at 1-, 5-, 10-, and 15-year follow up was 0.31, 0.24, 0.29 and 0.29 (p<.0001 for all), respectively. AI-CAC plaque characteristics including number, location, and density of plaque plus number of vessels significantly improved NRI for CAC 1-100 cohort vs. Agatston Score (0.342).

Conclusion

In this multi-ethnic longitudinal population study, AI-CAC significantly and consistently improved the prediction of all CVD events over 15 years compared with the Agatston score.

Intraindividual Comparison of Dose Reduction and Coronary Calcium Scoring Accuracy Using Kilovolt-independent and Tin Filtration CT Protocols

Purpose To investigate the ability of kilovolt-independent (hereafter, kV-independent) and tin filter spectral shaping to accurately quantify the coronary artery calcium score (CACS) and radiation dose reductions compared with the standard 120-kV CT protocol. Materials and Methods This prospective, blinded reader study included 201 participants (mean age, 60 years ± 9.8 [SD]; 119 female, 82 male) who underwent standard 120-kV CT and additional kV-independent and tin filter research CT scans from October 2020 to July 2021. Scans were reconstructed using a Qr36f kernel for standard scans and an Sa36f kernel for research scans simulating artificial 120-kV images. CACS, risk categorization, and radiation doses were compared by analyzing data with analysis of variance, Kruskal-Wallis test, Mann-Whitney test, Bland-Altman analysis, Pearson correlations, and κ analysis for agreement. Results There was no evidence of differences in CACS across standard 120-kV, kV-independent, and tin filter scans, with median CACS values of 1 (IQR, 0-48), 0.6 (IQR, 0-58), and 0 (IQR, 0-51), respectively (P = .85). Compared with standard 120-kV scans, kV-independent and tin filter scans showed excellent correlation in CACS values (r = 0.993 and r = 0.999, respectively), with high agreement in CACS risk categorization (κ = 0.95 and κ = 0.93, respectively). Standard 120-kV scans had a mean radiation dose of 2.09 mSv ± 0.84, while kV-independent and tin filter scans reduced it to 1.21 mSv ± 0.85 and 0.26 mSv ± 0.11, cutting doses by 42% and 87%, respectively (P < .001). Conclusion The kV-independent and tin filter research CT acquisition techniques showed excellent agreement and high accuracy in CACS estimation compared with standard 120-kV scans, with large reductions in radiation dose. Keywords: CT, Cardiac, Coronary Arteries, Radiation Safety, Coronary Artery Calcium Score, Radiation Dose Reduction, Low-Dose CT Scan, Tin Filter, kV-Independent Supplemental material is available for this article. © RSNA, 2024.

Impact of optimal cholesterol levels on subclinical atherosclerosis in the absence of risk factors in young adults

BACKGROUND AND AIMS

We aimed to assess the association of blood lipids with the prevalence, incidence, and progression of subclinical atherosclerosis among young individuals without dyslipidemia and other traditional cardiovascular risk factors (CVRFs).

METHODS

A total of 1270 participants from the Coronary Artery Risk Development in Young Adults (CARDIA) study aged 32-46 years free of cardiovascular disease, diabetes, hypertension, current smoking, and dyslipidemia (total cholesterol [TC] ≥ 240 mg/dL, triglycerides [TG] ≥ 150 mg/dL, low-density lipoprotein cholesterol [LDL-C] ≥ 160 mg/dL, high-density lipoprotein cholesterol [HDL-C] < 40 mg/dL, or taking lipid-lowering medications) were included. A subgroup with optimal lipids within the low-CVRF group was defined with TC < 200 mg/dL, LDL-C < 100 mg/dL, non-HDL-C < 130 mg/dL, and women with HDL-C ≥ 50 mg/dL.

RESULTS

1-SD higher TC (25.9 mg/dL), LDL-C (24.7 mg/dL), and non-HDL-C (26.6 mg/dL) were associated with a greater risk of presence (hazard ratios: 1.30-1.36), incidence (1.30-1.32), and progression (1.31-1.35) of coronary artery calcium (CAC) and a 42-44% greater odds of composite mean carotid intima-media thickness (CIMT) ≥ 75th percentile [780 μm] (p < 0.05). Repeating the analyses in a subset of participants with a CAC score of zero did not alter the association of TC, LDL-C, and non-HDL-C with CIMT. In the subgroup with optimal lipids, these lipid indices remained associated with an increased risk of presence and incidence of CAC and greater CIMT measures.

CONCLUSIONS

Among adults aged 32-46 years, in the absence of traditional CVRFs, elevated cholesterol levels, even within what is considered optimal, are associated with atherosclerosis and arteriopathy.

Associations of Abdominal Muscle Density and Area and Incident Cardiovascular Disease, Coronary Heart Disease, and Stroke: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Muscle density is inversely associated with all-cause mortality, but associations with cardiovascular disease (CVD) risk are not well understood. This study evaluated the association between muscle density and muscle area and incident total CVD, coronary heart disease (CHD), and stroke in diverse men and women.

METHODS AND RESULTS

Adult participants (N=1869) in the Multi-Ethnic Study of Atherosclerosis Ancillary Body Composition Study underwent computer tomography scans of the L2-L4 region of the abdomen. Muscle was quantified by density (Hounsfield units) and area in cm2. Sex-stratified Cox proportional hazard models assessed associations between incident total CVD, incident CHD, and incident stroke across sex-specific percentiles of muscle area and density, which were entered simultaneously into the model. Mean age for men and women at baseline were 64.1 and 65.1 years, respectively, and median follow-up time was 10.3 years. For men, associations between muscle density and incident CVD were inverse but not significant in fully adjusted models (P trend=0.15). However, there was an inverse association between density and CHD (P trend=0.02; HR, 0.26 for 95th versus 10th percentile), and no association with stroke (P trend=0.78). Conversely, for men, there was a strong positive association between muscle area and incident CVD (HR, 4.19 for 95th versus 10th percentile; P trend<0.001). Associations were stronger for CHD (HR, 6.18 for 95th versus 10th percentile; P trend<0.001), and null for stroke (P trend=0.67). Associations for women were mostly null.

CONCLUSIONS

For men, abdominal muscle density is associated with lower CHD risk, whereas greater muscle area is associated with markedly increased risk of CHD.

Coronary artery calcium scoring assessment in ultra-low-dose chest computed tomography

OBJECTIVES

To investigate the effect of non-electrocardiogram (ECG) -triggered ultra-low-dose CT (ULD-CT) with different reconstruction protocols on coronary artery calcium (CAC) scoring assessment, compared with ECG-triggered CAC CT (CAC-CT).

METHODS

This prospective study included 115 patients who underwent CAC-CT and ULD-CT scans under the same topogram images. CAC-CT adopted a prospective ECG-triggered sequential acquisition with a tube potential of 120 kV, and the reconstruction protocol was standard Qr36 + slice 3 mm (CACQr-3mm group). ULD-CT adopted a non-ECG-triggered high-pitch acquisition with a tube potential of Sn100 kV, and four groups of images (named ULDQr-3mm, ULDSa-3mm, ULDQr-1.5mm, and ULDSa-1.5mm) were reconstructed using different reconstruction algorithms (standard Qr36, kV-independent Sa36) and slice thicknesses (3 mm, 1.5 mm). The accuracy of CAC detection by ULD-CT was calculated. The agreement of the CAC score between ULD-CT and CAC-CT scans was assessed using intraclass correlation coefficients (ICC) and Bland-Altman plot, and the agreement of risk categorization was assessed using weighted kappa.

RESULTS

The sensitivity and specificity of the ULDSa-1.5mm group for detecting positive CAC were 100% and 97.4%, respectively (k = 0.980). The CAC score for the ULDSa-3mm and ULDSa-1.5mm groups demonstrated excellent agreement with the CACQr-3mm group (ICC = 0.992, 0.990, respectively), with a mean difference of -12.3 and - 12.4. The agreement of risk categorization based on absolute and percentile CAC score between the ULDSa-1.5mm and CACQr-3mm groups was excellent (weighted k = 0.954, 0.983, respectively), and risk reclassification rates were low (3.5%, 2.8%, respectively). The effective dose was reduced by approximately 77.2% for the ULD-CT compared to the CAC-CT (0.18 mSv vs. 0.79 mSv, p < 0.001).

CONCLUSION

Reconstruction with a 1.5-mm slice thickness and kV-independent iterative algorithmic protocol in ULD-CT yielded excellent agreement in CAC score quantification and risk categorization compared with ECG-triggered CAC-CT.

Assessment of Subclinical Atherosclerosis in Asymptomatic People In Vivo: Measurements Suitable for Biomarker and Mendelian Randomization Studies

BACKGROUND

One strategy to reduce the burden of cardiovascular disease is the early detection and treatment of atherosclerosis. This has led to significant interest in studies of subclinical atherosclerosis, using different phenotypes, not all of which are accurate reflections of the presence of asymptomatic atherosclerotic plaques. The aim of part 2 of this series is to provide a review of the existing literature on purported measures of subclinical disease and recommendations concerning which tests may be appropriate in the prevention of incident cardiovascular disease.

METHODS

We conducted a critical review of measurements used to infer the presence of subclinical atherosclerosis in the major conduit arteries and focused on the predictive value of these tests for future cardiovascular events, independent of conventional cardiovascular risk factors, in asymptomatic people. The emphasis was on studies with >10 000 person-years of follow-up, with meta-analysis of results reporting adjusted hazard ratios (HRs) with 95% CIs. The arterial territories were limited to carotid, coronary, aorta, and lower limb arteries.

RESULTS

In the carotid arteries, the presence of plaque (8 studies) was independently associated with future stroke (pooled HR, 1.89 [1.04-3.44]) and cardiac events (7 studies), with a pooled HR, 1.77 (1.19-2.62). Increased coronary artery calcium (5 studies) was associated with the risk of coronary heart disease events, pooled HR, 1.54 (1.07-2.07) and increasing severity of calcification (by Agaston score) was associated with escalation of risk (13 studies). An ankle/brachial index (ABI) of <0.9, the pooled HR for cardiovascular death from 7 studies was 2.01 (1.43-2.81). There were insufficient studies of either, thoracic or aortic calcium, aortic diameter, or femoral plaque to synthesize the data based on consistent reporting of these measures.

CONCLUSIONS

The presence of carotid plaque, coronary artery calcium, or abnormal ankle pressures seems to be a valid indicator of the presence of subclinical atherosclerosis and may be considered for use in biomarker, Mendelian randomization and similar studies.

Cumulative Blood Pressure in Early Adulthood and Coronary Artery Calcium and Carotid Intima-Media Thickness in Middle Age Among Adults With Maintained Blood Pressure of <130/80 mm Hg: A Post Hoc Analysis

BACKGROUND

To examine the association of blood pressure (BP) levels with coronary artery calcium and carotid intima-media thickness (CIMT) in people with maintained BP below the hypertension range based on current definitions.

METHODS AND RESULTS

In this post hoc analysis of the CARDIA (Coronary Artery Risk Development in Young Adults) prospective observational cohort study conducted in 4 US cities, we examined 1233 study participants (mean [SD] age at year 20 examination was 45.3 [3.5] years; 65.4% women). Participants with BP assessments across 20 years and untreated BP of <130/80 mm Hg were included. Multivariable logistic or linear regression models, adjusted for age, sex, race, education, diabetes, body mass index, serum creatinine, smoking, alcohol intake, physical activity, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides, were used to examine the associations between cumulative BP measures with coronary artery calcium and CIMT. Higher long-term cumulative systolic BP and pulse pressure across early adulthood were associated with higher CIMT (both P<0.001) but not coronary artery calcium in the multivariable-adjusted model. The associations remained significant even after adjustment for a single BP measurement at year 0 or year 20. The odds ratio (OR) of a maximal CIMT >1.01 mm was ≈50% higher per 1-SD increase in systolic BP (OR, 1.50 [95% CI, 1.19-1.88]) and pulse pressure (OR, 1.46 [95% CI, 1.19-1.79]). Similar findings for CIMT were observed among individuals with a coronary artery calcium score of 0 as well as those with maintained BP of <120/80 mm Hg throughout young adulthood.

CONCLUSIONS

Long-term cumulative systolic BP and pulse pressure across early adulthood within the nonhypertensive range were associated with adverse midlife alterations in CIMT.

Fusion Modeling: Combining Clinical and Imaging Data to Advance Cardiac Care

In addition to the traditional clinical risk factors, an increasing amount of imaging biomarkers have shown value for cardiovascular risk prediction. Clinical and imaging data are captured from a variety of data sources during multiple patient encounters and are often analyzed independently. Initial studies showed that fusion of both clinical and imaging features results in superior prognostic performance compared with traditional scores. There are different approaches to fusion modeling, combining multiple data resources to optimize predictions, each with its own advantages and disadvantages. However, manual extraction of clinical and imaging data is time and labor intensive and often not feasible in clinical practice. An automated approach for clinical and imaging data extraction is highly desirable. Convolutional neural networks and natural language processing can be utilized for the extraction of electronic medical record data, imaging studies, and free-text data. This review outlines the current status of cardiovascular risk prediction and fusion modeling; and in addition gives an overview of different artificial intelligence approaches to automatically extract data from images and electronic medical records for this purpose.

Interpreting the Coronary Artery Calcium Score - Critical Information for the Practicing Physician

Coronary artery calcium scanning is a routine test for assessing the severity of atherosclerosis in asymptomatic individuals. This inexpensive, noninvasive test quantifies the calcium deposition in the 4 principal coronary arteries. Correct interpretation is important to the physician (for recommending therapy) and to the patient (for determining his or her lifetime risk of a cardiovascular event). A score of 0 indicates that a cardiovascular event is extremely unlikely in the next 5 years. In contrast, a score greater than 0 portends a coronary event. The higher the score, the greater the risk. Both the arterial location of the calcium and the number of coronary arteries involved alter the interpretation of the calcium score. At any given age, females have significantly lower scores than males. One-third of individuals with scores greater than 1000 will have a cardiovascular event within 3 years. For all elevated calcium scores, aggressive treatment is warranted, including significant lifestyle changes and medications to reduce low-density lipoprotein cholesterol. Understanding the importance of the coronary artery calcium score will result in improved therapy and patient compliance.

Distribution and determinants of coronary artery calcium score in asymptomatic patients with Type-2 diabetes: The French-CAC100 score

BACKGROUND

Coronary artery calcium score (CACS) refines the cardiovascular disease (CVD) risk prediction in patients with Type-2 diabetes (T2D). We aimed to identify the determinants for high CACS in CVD-free patients with T2D.

METHODS

We studied 796 patients with T2D with CACS measured in three centers: two in continental France and a third in the Reunion Island. To predict a CACS ≥ 100, we derived a risk score in patients in continental France, and validated it in those in the Reunion Island.

RESULTS

The distributions of CACS distributions were similar among patients in continental France and Reunion Island. The French-CAC100 score included 5 parameters (age, sex, diabetes duration, non-CV end-organ damage and presence of ≥ 2 other CVD risk factors), ranging from 0 to 22 points. Similar areas under the curves were found for the risk score in both settings (0.80 vs. 0.73, p = 0.10). A French-CAC100 score < 10 excluded the odds for CACS ≥ 100 and CACS ≥ 400 with negative predictive values of 90% and 97% respectively, avoiding 58% of CT-scans.

CONCLUSION

Regardless of the geographic area, patients with T2D share similar risk factors for high CACS. The French-CAC100 score allows the identification of those at higher risk of elevated CACS.

Association of Coronary Artery Calcium Density and Volume With Predicted Atherosclerotic Cardiovascular Disease Risk and Cardiometabolic Risk Factors in South Asians: The Mediators of Atherosclerosis in South Asians Living in America (MASALA) Study

Individuals of South Asian (SA) ancestry are predisposed to a higher risk of atherosclerotic cardiovascular disease (ASCVD). Coronary artery calcium (CAC) volume and density can identify coronary plaque characteristics unique to SA that may provide important prognostic information to identify high risk individuals beyond traditional CAC scores. We used data from the Mediators of Atherosclerosis in South Asians Living in America (MASALA). CAC density and volume were assessed according to established protocols. ASCVD risk was estimated using the pooled cohort equations (PCE). Multivariable-adjusted linear regression models were used to study the association between the PCE and advanced CAC measures, and between cardiovascular risk factors and CAC density and volume. Our analyses included 1,155 participants (mean age 57 (SD 9) years, 52% men) with information on advanced CAC measures. After multivariable-adjustment, the PCE was associated with both CAC density (β 0.24, 95% CI 0.12,0.35) and CAC volume (β 0.43, 95% CI 0.38,0.48). High-density lipoprotein cholesterol was directly associated with CAC density while waist circumference was inversely associated with it. Body mass index, hypertension status, statin use, diabetes, and HOMA-IR were all directly associated with CAC volume. Estimated ASCVD risk was associated with both CAC volume and density. Different cardiometabolic risk factors are associated with CAC density and volume. Future longitudinal studies are required to demonstrate the interrelationship of advanced CAC measures and cardiovascular risk factors with incident ASCVD outcomes.

Association between coronary artery calcium and thoracic spine bone mineral density: Multiethnic Study of Atherosclerosis (MESA)

BACKGROUND AND AIMS

Previously, osteoporosis and coronary artery disease were considered unrelated. However, beyond age, these two conditions appear to share common etiologies that are not yet fully understood. We examined the relationship between thoracic spine bone mineral density (BMD) and severity of coronary artery calcium (CAC) score.

METHODS AND RESULTS

MESA is a prospective cohort study of 6814 men and women between the ages of 45 and 84 years, without clinical cardiovascular disease. This study included participants who underwent non-contrast chest CT scans to determine CAC score and thoracic spine BMD. The thoracic spine BMD was categorized into osteoporosis (defined as T score: ≤ -2.5), osteopenia (T-score between: -2.5 and -1) and normal BMD (T-score ≥ -1). There were 3392 subjects who had CAC >0 at baseline. The prevalence of CAC >0 was 36% in normal BMD group, 49% in the osteopenia and 68% in osteoporosis group. After adjusting for risk factors of atherosclerosis, in multivariate regression models we found a significant association between CAC and osteoporosis (OR: 1.40, 95% CI 1.16-1.69, p value < 0.0004). Furthermore, we stratified our results by gender and found a statistically significant association in both men and women.

CONCLUSION

Results from this cross-sectional analysis of a large population based ethnically diverse cohort indicate a significant inverse relationship between thoracic BMD and CAC in both genders independent of other cardiovascular risk factors. Future studies need to explore the underlying pathophysiological mechanisms relating BMD and coronary artery calcification.

Diagnostic Cardiac CT for the Improvement of Cardiovascular Event Prediction

BACKGROUND

The aim of the long-term Heinz Nixdorf Recall Study (observation period 20 years) was to establish the extent to which computed tomography (CT) improves the predictability of cardiovascular events relative to determination of risk factors alone.

METHODS

In the period 2000-2003, study staff examined 4355 probands (53% of them female) aged 45-75 years with no signs of cardiovascular disease. The Atherosclerotic Cardiovascular Disease (ASCVD) score was calculated on the basis of demographic data and cardiovascular risk factors. Cardiac CT was carried out over the same period and coronary artery calcification (CAC) was graded according to the Agatston score.

RESULTS

The median duration of follow-up was 18.2 years for men and 17.8 years for women. Myocardial infarction or stroke occurred in 458 (11%) of the 4154 participants with complete data. Overall, estimation of risk using a combination of ASCVD score and CAC grade was superior to the ASCVD score alone-even after 10 and 20 years. Classification into established risk categories improved by 12.2% (95% confidence interval: [5.3%; 18.1%]). In the highest ASCVD risk category, we observed occurrence of a cardiovascular event over 20 years for 14% [5.0%; 23.1%] of probands with a CAC score = 0 but for 34.2% [27.5%; 41.4%] of those with a CAC score ≥ 400. In the lowest ASCVD risk category, an event occurred in 2.4% [1.4%; 3.7%] of probands with a CAC score = 0 and in 23.5% [2.3%; 35.8%] of those with a CAC score ≥ 400.

CONCLUSION

Even after 20 years, individual risk prediction is improved by addition of CT-based determination of coronary artery calcification to the ASCVD score. Therefore, assessment of ASCVD risk factors should be complemented more widely by cardiac CT in the primary prevention of cardiovascular disease.

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

Background: 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. Methods: 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. Results: 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 < 0.001). Mean CAC density increased from 228.8 ± 35.4 HU to 232.6 ± 37.0 HU (p < 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 (<median: 2.0 ± 24.3 HU, ≥median: 3.6 ± 21.9 HU, p = 0.34), Agatston score at baseline (<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. 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.

Relationship of fibroblast growth factor 21 with the prevalence and progression of vascular and valvular calcification: Multi-ethnic study of atherosclerosis

BACKGROUND

Elevated circulating levels of fibroblast growth factor 21 (FGF21) are associated with cardiovascular disease (CVD). Therefore, we investigated the relationship of plasma FGF21 with calcification at different vascular and valvular sites.

METHODS

A total of 5786 participants, free of clinically apparent CVD at baseline and with valid data on plasma FGF21 and calcification (Agatston score, volume and density) at coronary arteries, thoracic arteries, mitral and aortic valves, and aortic valve ring, were included in the analysis. Vascular calcification was measured at 2-3 follow-up visits.

RESULTS

At baseline, higher FGF21 levels were associated with prevalent descending thoracic aortic calcification (DTAC) (prevalence ratio = 1.06 [95% CI 1.01-1.11] per SD increase in log-transformed unit, P = 0.016). Among participants without prevalent calcification, higher FGF21 levels were associated with incident DTAC (relative risk [RR] = 1.13 [95% CI 1.04-1.22], P = 0.002). Among all participants, higher FGF21 levels were also associated with the progression of DTAC score and volume (RR = 1.07 [95% CI 1.03-1.12] and 1.08 [95% CI 1.03-1.12] respectively, both P < 0.01). No significant association of FGF21 was found for prevalence (prevalence ratio = 0.89-1.05), incidence (RR = 0.97-1.16) and progression of calcification (RR = 0.94-1.14) at the other sites.

CONCLUSION

Higher FGF21 levels were associated with the presence, incidence and progression of DTAC. However, the magnitude of this association was similar to those of the non-significant associations of FGF21 levels with calcifications at other sites. Further research is needed to assess the potential of FGF21 as a biomarker for vascular calcification.

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 >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.

Association of Cardiovascular Health Through Young Adulthood With Genome-Wide DNA Methylation Patterns in Midlife: The CARDIA Study

BACKGROUND

Cardiovascular health (CVH) from young adulthood is strongly associated with an individual's future risk of cardiovascular disease (CVD) and total mortality. Defining epigenomic biomarkers of lifelong CVH exposure and understanding their roles in CVD development may help develop preventive and therapeutic strategies for CVD.

METHODS

In 1085 CARDIA study (Coronary Artery Risk Development in Young Adults) participants, we defined a clinical cumulative CVH score that combines body mass index, blood pressure, total cholesterol, and fasting glucose measured longitudinally from young adulthood through middle age over 20 years (mean age, 25-45). Blood DNA methylation at >840 000 methylation markers was measured twice over 5 years (mean age, 40 and 45). Epigenome-wide association analyses on the cumulative CVH score were performed in CARDIA and compared in the FHS (Framingham Heart Study). We used penalized regression to build a methylation-based risk score to evaluate the risk of incident coronary artery calcification and clinical CVD events.

RESULTS

We identified 45 methylation markers associated with cumulative CVH at false discovery rate <0.01 (P=4.7E-7-5.8E-17) in CARDIA and replicated in FHS. These associations were more pronounced with methylation measured at an older age. CPT1A, ABCG1, and SREBF1 appeared as the most prominent genes. The 45 methylation markers were mostly located in transcriptionally active chromatin and involved lipid metabolism, insulin secretion, and cytokine production pathways. Three methylation markers located in genes SARS1, SOCS3, and LINC-PINT statistically mediated 20.4% of the total effect between CVH and risk of incident coronary artery calcification. The methylation risk score added information and significantly (P=0.004) improved the discrimination capacity of coronary artery calcification status versus CVH score alone and showed association with risk of incident coronary artery calcification 5 to 10 years later independent of cumulative CVH score (odds ratio, 1.87; P=9.66E-09). The methylation risk score was also associated with incident clinical CVD in FHS (hazard ratio, 1.28; P=1.22E-05).

CONCLUSIONS

Cumulative CVH from young adulthood contributes to midlife epigenetic programming over time. Our findings demonstrate the role of epigenetic markers in response to CVH changes and highlight the potential of epigenomic markers for precision CVD prevention, and earlier detection of subclinical CVD, as well.

Generative models for reproducible coronary calcium scoring

Purpose: Coronary artery calcium (CAC) score, i.e., the amount of CAC quantified in CT, is a strong and independent predictor of coronary heart disease (CHD) events. However, CAC scoring suffers from limited interscan reproducibility, which is mainly due to the clinical definition requiring application of a fixed intensity level threshold for segmentation of calcifications. This limitation is especially pronounced in non-electrocardiogram-synchronized computed tomography (CT) where lesions are more impacted by cardiac motion and partial volume effects. Therefore, we propose a CAC quantification method that does not require a threshold for segmentation of CAC. Approach: Our method utilizes a generative adversarial network (GAN) where a CT with CAC is decomposed into an image without CAC and an image showing only CAC. The method, using a cycle-consistent GAN, was trained using 626 low-dose chest CTs and 514 radiotherapy treatment planning (RTP) CTs. Interscan reproducibility was compared to clinical calcium scoring in RTP CTs of 1662 patients, each having two scans. Results: A lower relative interscan difference in CAC mass was achieved by the proposed method: 47% compared to 89% manual clinical calcium scoring. The intraclass correlation coefficient of Agatston scores was 0.96 for the proposed method compared to 0.91 for automatic clinical calcium scoring. Conclusions: The increased interscan reproducibility achieved by our method may lead to increased reliability of CHD risk categorization and improved accuracy of CHD event prediction.

Low-dose coronary calcium scoring CT using a dedicated reconstruction filter for kV-independent calcium measurements

In this prospective, pilot study, we tested a kV-independent coronary artery calcium scoring CT protocol, using a novel reconstruction kernel (Sa36f). From December 2018 to November 2019, we performed an additional research scan in 61 patients undergoing clinical calcium scanning. For the standard protocol (120 kVp), images were reconstructed with a standard, medium-sharp kernel (Qr36d). For the research protocol (automated kVp selection), images were reconstructed with a novel kernel (Sa36f). Research scans were sequentially performed using a higher (cohort A, n = 31) and a lower (cohort B, n = 30) dose optimizer setting within the automatic system with customizable kV selection. Agatston scores, coronary calcium volumes, and radiation exposure of the standard and research protocol were compared. A phantom study was conducted to determine inter-scan variability. There was excellent correlation for the Agatston score between the two protocols (r = 0.99); however, the standard protocol resulted in slightly higher Agatston scores (29.4 [0-139.0] vs 17.4 [0-158.2], p = 0.028). The median calcium volumes were similar (11.5 [0-109.2] vs 11.2 [0-118.0] mm3; p = 0.176), and the number of calcified lesions was not significantly different (p = 0.092). One patient was reclassified to another risk category. The research protocol could be performed at a lower kV and resulted in a substantially lower radiation exposure, with a median volumetric CT dose index of 4.1 vs 5.2 mGy, respectively (p < 0.001). Our results showed that a consistent coronary calcium scoring can be achieved using a kV-independent protocol that lowers radiation doses compared to the standard protocol. KEY POINTS: • The Sa36f kernel enables kV-independent Agatston scoring without changing the original Agatston weighting threshold. • Agatston scores and calcium volumes of the standard and research protocols showed an excellent correlation. • The research protocol resulted in a significant reduction in radiation exposure with a mean reduction of 22% in DLP and 25% in CTDIvol.

Asymptomatic coronary artery disease assessed by coronary computed tomography in patients with systemic lupus erythematosus: A systematic review and meta-analysis

BACKGROUND

Coronary artery disease (CAD) assessed by coronary computed tomography (CT) in patients with systemic lupus erythematosus (SLE) has been investigated in several studies, but with conflicting results. The aim of this systematic review and meta-analysis of the literature was synthesize the evidence on this topic.

METHODS

The relevant literature was identified and evaluated from inception until January 2021 in PubMed, Embase, Web of Science and Cochrane library. Studies reporting coronary artery calcification (CAC), and its prevalence and extent using the coronary calcium score (CCS) were included. Data extracted from eligible studies were used to calculate effect estimates (ESs) and 95% confidence intervals (95%CI) and weighted mean differences (WMD) with 95%CI.

RESULTS

Twenty-four studies were eligible for inclusion. For the CAC prevalence, 11 studies were included (918 SLE patients and 3952 controls) and the pooled prevalence for the random effect was 29.8% (95%CI 25.7-32.9%) for SLE patients and 11.8% (95%CI 16.2-20.4%) in controls (RR 2.22, 95%CI 1.42 to 3.48; p= 0.0005) and no significant increase in the WMD for CCS (MD= 0.32, 95%CI -5.55 to 6.20, p= 0.91) compared with controls in seven studies. Greater organ damage and glucocorticoid use has been associated with a higher CCS. According to two studies, the coronary CT angiography calcified and non-calcified plaque burden were increased in SLE patients compared with controls.

CONCLUSIONS

In SLE, asymptomatic CAD by CAC is more prevalent and there is more multivessel disease compared with controls without lupus. However, the extent of CAC was not increased in SLE patients.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021228710.

Quantification of Calcium in Peripheral Arteries of the Lower Extremities: Comparison of Different CT Scanners and Scoring Platforms

OBJECTIVES

The aim of this study was to investigate the interscanner and interscoring platform variability of calcium quantification in peripheral arteries of the lower extremities.

MATERIALS AND METHODS

Twenty human fresh-frozen legs were scanned using 3 different computed tomography (CT) scanners. The radiation dose (CTDIvol) was kept similar for all scanners. The calcium scores (Agatston and volume scores) were quantified using 4 semiautomatic scoring platforms. Comparative analysis of the calcium scores between scanners and scoring platforms was performed by using the Friedman test; post hoc analysis was performed by using the Wilcoxon signed rank test with Bonferroni correction.

RESULTS

Sixteen legs had calcifications and were used for data analysis. Agatston and volume scores ranged from 12.1 to 6580 Agatston units and 18.2 to 5579 mm3. Calcium scores differed significantly between Philips IQon and Philips Brilliance 64 (Agatston: 19.5% [P = 0.001]; volume: 14.5% [P = 0.001]) and Siemens Somatom Force (Agatston: 18.1% [P = 0.001]; volume: 17.5% [P = 0.001]). The difference between Brilliance 64 and Somatom Force was smaller (Agatston: 5.6% [P = 0.778]; volume: 7.7% [P = 0.003]). With respect to the interscoring platform variability, OsiriX produced significantly different Agatston scores compared with the other 3 scoring platforms (OsiriX vs IntelliSpace: 14.8% [P = 0.001] vs Syngo CaScore: 13.9% [P = 0.001] vs iX viewer: 13.2% [P < 0.001]). For the volume score, the differences between all scoring platforms were small ranging from 2.9% to 4.0%. Post hoc analysis showed a significant difference between OsiriX and IntelliSpace (3.8% [P = 0.001]).

CONCLUSIONS

The use of different CT scanners resulted in notably different Agatston and volume scores, whereas the use of different scoring platforms resulted in limited variability especially for the volume score. In conclusion, the variability in calcium quantification was most evident between different CT scanners and for the Agatston score.

Coronary calcium scores on dual-source photon-counting computed tomography: an adapted Agatston methodology aimed at radiation dose reduction

Objectives

The aim of this study was to determine mono-energetic (monoE) level–specific photon-counting CT (PCCT) Agatston thresholds, to yield monoE level independent Agatston scores validated with a dynamic cardiac phantom. Also, we examined the potential of dose reduction for PCCT coronary artery calcium (CAC) studies, when reconstructed at low monoE levels.

Methods

Theoretical CAC monoE thresholds were calculated with data from the National Institute of Standards and Technology (NIST) database. Artificial CAC with three densities were moved in an anthropomorphic thorax phantom at 0 and 60–75 bpm, and scanned at full and 50% dose on a first-generation dual-source PCCT. For all densities, Agatston scores and maximum CT numbers were determined. Agatston scores were compared with the reference at full dose and 70 keV monoE level; deviations (95% confidence interval) < 10% were deemed to be clinically not-relevant.

Results

Averaged over all monoE levels, measured CT numbers deviated from theoretical CT numbers by 6%, 13%, and − 4% for low-, medium-, and high-density CAC, respectively. At 50% reduced dose and 60–75 bpm, Agatston score deviations were non-relevant for 60 to 100 keV and 60 to 120 keV for medium- and high-density CAC, respectively.

Conclusion

MonoE level–specific Agatston score thresholds resulted in similar scores as in standard reconstructions at 70 keV. PCCT allows for a potential dose reduction of 50% for CAC scoring using low monoE reconstructions for medium- and high-density CAC.

Key Points

• Mono-energy level–specific Agatston thresholds allow for reproducible coronary artery calcium quantification on mono-energetic images.

• Increased calcium contrast-to-noise ratio at reduced mono-energy levels allows for coronary artery calcium quantification at 50% reduced radiation dose for medium- and high-density calcifications.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-022-08642-5.

Plasma lipid profiles in early adulthood are associated with epigenetic aging in the Coronary Artery Risk Development in Young Adults (CARDIA) Study

Background

GrimAge acceleration (GAA), an epigenetic marker that represents physiologic aging, is associated with atherosclerotic cardiovascular disease. However, the associations between early adulthood lipid levels and GAA in midlife are unknown. Also, it is unknown whether GAA mediates the associations between lipid levels in young adults and subclinical atherosclerosis in midlife.

Results

We estimated measures of epigenetic age acceleration in 1118 White and Black participants from the Coronary Artery Risk Development in Young Adults (CARDIA) Study at examination years (Y) 15 and 20. We used multivariable regression models to examine associations of Y15 and Y20 GAA estimates with plasma lipid levels measured at prior examination years (Y0, Y5, and Y10) and concurrently: triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) levels. Mediation analysis was used to assess the extent to which GAA may mediate associations between plasma lipids and coronary artery calcification (CAC). In our study each 1-SD higher cumulative TG level was associated with an average 0.73 ± 0.12 years older GAA. Each 1-SD higher cumulative HDL-C level was associated with an average 0.57 ± 0.17 years younger GAA. Stratified analyses showed that the associations between TG and GAA were stronger among female and Black participants and the associations between HDL-C and GAA were stronger among female and White participants. GAA statistically mediated 17.4% of the association of cumulative TG with CAC.

Conclusions

High TG and low HDL-C in early adulthood are associated with accelerated epigenetic aging by midlife. Increased epigenetic age acceleration may partially mediate the associations between high TG levels and the presence of subclinical atherosclerosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01222-2.

Evolution of Coronary Calcium Screening for Assessment of Atherosclerotic Cardiovascular Disease Risk and Role in Preventive Cardiology

PURPOSE OF REVIEW

Coronary artery calcium (CAC) is an important measure of subclinical atherosclerosis and strongly predicts atherosclerotic cardiovascular disease (ASCVD) outcomes. The purpose of this review is to discuss the key studies that have helped to establish its role as an important screening tool and its place in preventive cardiology.

RECENT FINDINGS

Epidemiologic studies document a strong relation of age, race/ethnicity, and risk factors with the prevalence and extent of CAC. Large-scale registry and prospective investigations show CAC to be the strongest subclinical disease predictor of ASCVD outcomes, with higher CAC scores associated with successively higher risks and those with a CAC score of 0 having a long-term "warranty" against having events. Moreover, CAC is associated with greater initiation of preventive health behaviors and therapy. Current US guidelines utilize CAC to inform the treatment decision for statin therapy. Further study is underway to document whether CAC screening will ultimately improve clinical outcomes. CAC is well established as the most important subclinical cardiovascular disease measure for prediction of future ASCVD outcomes and can be used for informing the treatment decision for preventive therapies.

Association of Abdominal Aorta Calcium and Coronary Artery Calcium with Incident Cardiovascular and Coronary Heart Disease Events in Black and White Middle-Aged People: The Coronary Artery Risk Development in Young Adults Study

Background Assessing coronary artery calcium (CAC) is among AHA/ACC prevention guidelines for people at least 40 years old at intermediate risk for coronary heart disease (CHD). To study enhanced risk stratification, we investigated the predictive value of abdominal aorta calcium (AAC) relative to CAC for cardiovascular disease (CVD) and CHD events in Black and White early middle-aged participants, initially free of overt CVD. Methods and Results In the CARDIA (Coronary Artery Risk Development in Young Adults) study, a multi-center, community-based, longitudinal cohort study of CVD risk, the CAC and AAC scores were assessed in 3011 participants in 2010-2011 with follow-up until 2019 for incident CVD and CHD events. Distributions and predictions, overall and by race, were computed. During the 8-year follow-up, 106 incident CVD events (55 were CHD) occurred. AAC scores tended to be much higher than CAC scores. AAC scores were higher in Black women than in White women. CAC predicted CVD with HR 1.77 (1.52-2.06) and similarly for AAC, while only CAC predicted CHD. After adjustment for risk factors and calcium in the other arterial bed, the association of CAC with CVD was independent of risk factors and AAC, while the association of AAC with CVD was greatly attenuated. However, AAC predicted incident CVD when CAC was 0. Prediction did not vary by race. Conclusions AAC predicted CVD nearly as strongly as CAC and could be especially useful as a diagnostic tool when it is an incidental finding or when no CAC is found.

Dose Reduction in Coronary Artery Calcium Scoring Using Mono-Energetic Images from Reduced Tube Voltage Dual-Source Photon-Counting CT Data: A Dynamic Phantom Study

In order to assess coronary artery calcium (CAC) quantification reproducibility for photon-counting computed tomography (PCCT) at reduced tube potential, an anthropomorphic thorax phantom with low-, medium-, and high-density CAC inserts was scanned with PCCT (NAEOTOM Alpha, Siemens Healthineers) at two heart rates: 0 and 60-75 beats per minute (bpm). Five imaging protocols were used: 120 kVp standard dose (IQ level 16, reference), 90 kVp at standard (IQ level 16), 75% and 45% dose and tin-filtered 100 kVp at standard dose (IQ level 16). Each scan was repeated five times. Images were reconstructed using monoE reconstruction at 70 keV. For each heart rate, CAC values, quantified as Agatston scores, were compared with the reference, whereby deviations >10% were deemed clinically relevant. Reference protocol radiation dose (as volumetric CT dose index) was 4.06 mGy. Radiation dose was reduced by 27%, 44%, 67%, and 46% for the 90 kVp standard dose, 90 kVp 75% dose, 90 kVp 45% dose, and Sn100 standard dose protocol, respectively. For the low-density CAC, all reduced tube current protocols resulted in clinically relevant differences with the reference. For the medium- and high-density CAC, the implemented 90 kVp protocols and heart rates revealed no clinically relevant differences in Agatston score based on 95% confidence intervals. In conclusion, PCCT allows for reproducible Agatston scores at a reduced tube voltage of 90 kVp with radiation dose reductions up to 67% for medium- and high-density CAC.

Calcium Identification and Scoring Based on Echocardiography. An Exploratory Study on Aortic Valve Stenosis

Currently, an echocardiography expert is needed to identify calcium in the aortic valve, and a cardiac CT-Scan image is needed for calcium quantification. When performing a CT-scan, the patient is subject to radiation, and therefore the number of CT-scans that can be performed should be limited, restricting the patient's monitoring. Computer Vision (CV) has opened new opportunities for improved efficiency when extracting knowledge from an image. Applying CV techniques on echocardiography imaging may reduce the medical workload for identifying the calcium and quantifying it, helping doctors to maintain a better tracking of their patients. In our approach, a simple technique to identify and extract the calcium pixel count from echocardiography imaging, was developed by using CV. Based on anonymized real patient echocardiographic images, this approach enables semi-automatic calcium identification. As the brightness of echocardiography images (with the highest intensity corresponding to calcium) vary depending on the acquisition settings, echocardiographic adaptive image binarization has been performed. Given that blood maintains the same intensity on echocardiographic images-being always the darker region-blood areas in the image were used to create an adaptive threshold for binarization. After binarization, the region of interest (ROI) with calcium, was interactively selected by an echocardiography expert and extracted, allowing us to compute a calcium pixel count, corresponding to the spatial amount of calcium. The results obtained from these experiments are encouraging. With this technique, from echocardiographic images collected for the same patient with different acquisition settings and different brightness, obtaining a calcium pixel count, where pixel values show an absolute pixel value margin of error of 3 (on a scale from 0 to 255), achieving a Pearson Correlation of 0.92 indicating a strong correlation with the human expert assessment of calcium area for the same images.

Evaluating a calcium-aware kernel for CT CAC scoring with varying surrounding materials and heart rates: a dynamic phantom study

OBJECTIVES

The purpose of this study was twofold. First, the influence of a novel calcium-aware (Ca-aware) computed tomography (CT) reconstruction technique on coronary artery calcium (CAC) scores surrounded by a variety of tissues was assessed. Second, the performance of the Ca-aware reconstruction technique on moving CAC was evaluated with a dynamic phantom.

METHODS

An artificial coronary artery, containing two CAC of equal size and different densities (196 ± 3, 380 ± 2 mg hydroxyapatite cm^-3), was moved in the center compartment of an anthropomorphic thorax phantom at different heart rates. The center compartment was filled with mixtures, which resembled fat, water, and soft tissue equivalent CT numbers. Raw data was acquired with a routine clinical CAC protocol, at 120 peak kilovolt (kVp). Subsequently, reduced tube voltage (100 kVp) and tin-filtration (150Sn kVp) acquisitions were performed. Raw data was reconstructed with a standard and a novel Ca-aware reconstruction technique. Agatston scores of all reconstructions were compared with the reference (120 kVp) and standard reconstruction technique, with relevant deviations defined as > 10%.

RESULTS

For all heart rates, Agatston scores for CAC submerged in fat were comparable to the reference, for the reduced-kVp acquisition with Ca-aware reconstruction kernel. For water and soft tissue, medium-density Agatston scores were again comparable to the reference for all heart rates. Low-density Agatston scores showed relevant deviations, up to 15% and 23% for water and soft tissue, respectively.

CONCLUSION

CT CAC scoring with varying surrounding materials and heart rates is feasible at patient-specific tube voltages with the novel Ca-aware reconstruction technique.

KEY POINTS

• A dedicated calcium-aware reconstruction kernel results in similar Agatston scores for CAC surrounded by fatty materials regardless of CAC density and heart rate. • Application of a dedicated calcium-aware reconstruction kernel allows for radiation dose reduction. • Mass scores determined with CT underestimated physical mass.

Pharmacogenetic association of diabetes-associated genetic risk score with rapid progression of coronary artery calcification following treatment with HMG-CoA-reductase inhibitors -results of the Heinz Nixdorf Recall Study

HMG-CoA-Reductase inhibitors (HMGRIs) are currently the most widely used group of drugs in patients with coronary artery disease (CAD) and are given preemptively to patients with high levels of cholesterol, including those with diabetes mellitus (DM). However, intake of HMGRIs also increases the progression of coronary artery calcification (CAC) and the risk of developing DM. This study aimed to investigate whether HMGRI intake interacts with the diabetes-associated genetic risk score (GRS) to affect CAC progression using data from the population-based Heinz Nixdorf Recall (HNR) study. CAC was measured in 3157 participants using electron-beam computed tomography twice, at baseline (CAC_b) and 5 years later (CAC_5y). CAC progression was classified as slow, expected, or rapid based on predicted values. Weighted DM GRS was constructed using 100 diabetes mellitus-associated single nucleotide polymorphisms (SNPs). We used log-linear regression to evaluate the interaction of HMGRI intake with diabetes-associated GRS and individual SNPs on CAC progression (rapid vs. expected/slow), adjusting for age, sex, and log(CAC_b + 1). The prevalence of rapid CAC progression in the HNR study was 19.6%. We did not observe any association of the weighted diabetes mellitus GRS with the rapid progression of CAC (relative risk (RR) [95% confidence interval (95% CI)]: 1.01 [0.94; 1.10]). Furthermore, no indication of an interaction between GRS and HMGRI intake was observed (1.08 [0.83; 1.41]). Our analyses showed no indication that the impact of HMGRIs on CAC progression is significantly more severe in patients with a high genetic risk of developing DM than in those with a low GRS.

Very High Coronary Artery Calcium (≥1000) and Association With Cardiovascular Disease Events, Non-Cardiovascular Disease Outcomes, and Mortality: Results From MESA

BACKGROUND

There are limited data on the unique cardiovascular disease (CVD), non-CVD, and mortality risks of primary prevention individuals with very high coronary artery calcium (CAC; ≥1000), especially compared with rates observed in secondary prevention populations.

METHODS

Our study population consisted of 6814 ethnically diverse individuals 45 to 84 years of age who were free of known CVD from MESA (Multi-Ethnic Study of Atherosclerosis), a prospective, observational, community-based cohort. Mean follow-up time was 13.6±4.4 years. Hazard ratios of CAC ≥1000 were compared with both CAC 0 and CAC 400 to 999 for CVD, non-CVD, and mortality outcomes with the use of Cox proportional hazards regression adjusted for age, sex, and traditional risk factors. Using a sex-adjusted logarithmic model, we calculated event rates in MESA as a function of CAC and compared them with those observed in the placebo group of stable secondary prevention patients in the FOURIER clinical trial (Further Cardiovascular Outcomes Research With PCSK9 Inhibition in Subjects With Elevated Risk).

RESULTS

Compared with CAC 400 to 999, those with CAC ≥1000 (n=257) had a greater mean number of coronary vessels with CAC (3.4±0.5), greater total area of CAC (586.5±275.2 mm²), similar CAC density, and more extensive extracoronary calcification. After full adjustment, CAC ≥1000 demonstrated a 4.71- (3.63-6.11), 7.57- (5.50-10.42), 4.86-(3.32-7.11), and 1.94-fold (1.57-2.41) increased risk for all CVD events, all coronary heart disease events, hard coronary heart disease events, and all-cause mortality, respectively, compared with CAC 0 and a 1.65- (1.25-2.16), 1.66- (1.22-2.25), 1.51- (1.03-2.23), and 1.34-fold (1.05-1.71) increased risk compared with CAC 400 to 999. With increasing CAC, hazard ratios increased for all event types, with no apparent upper CAC threshold. CAC ≥1000 was associated with a 1.95- (1.57-2.41) and 1.43-fold (1.12-1.83) increased risk for a first non-CVD event compared with CAC 0 and CAC 400 to 999, respectively. CAC 1000 corresponded to an annualized 3-point major adverse cardiovascular event rate of 3.4 per 100 person-years, similar to that of the total FOURIER population (3.3) and higher than those of the lower-risk FOURIER subgroups.

CONCLUSIONS

Individuals with very high CAC (≥1000) are a unique population at substantially higher risk for CVD events, non-CVD outcomes, and mortality than those with lower CAC, with 3-point major adverse cardiovascular event rates similar to those of a stable treated secondary prevention population. Future guidelines should consider a less distinct stratification algorithm between primary and secondary prevention patients in guiding aggressive preventive pharmacotherapy.

Association of Coronary Calcium, Carotid Wall Thickness, and Carotid Plaque Progression With Low-Density Lipoprotein and High-Density Lipoprotein Particle Concentration Measured by Ion Mobility (From Multiethnic Study of Atherosclerosis [MESA])

Current risk stratification strategies do not fully explain cardiovascular disease (CVD) risk. We aimed to evaluate the association of low-density lipoprotein (LDL-P) and high-density lipoprotein (HDL-P) particles with progression of coronary artery calcium and carotid wall injury. All participants in the Multi-Ethnic Study Atherosclerosis (MESA) with LDL-P and HDL-P measured by ion mobility, coronary artery calcium score (CAC), carotid intima-media thickness (IMT), and carotid plaque data available at Exam 1 and 5 were included in the study. CAC progression was annualized and treated as a categorical or continuous variable. Carotid IMT and plaque progression were treated as continuous variables. Fully adjusted regression models included established CVD risk factors, as well as traditional lipids. Mean (±SD) follow-up duration was 9.6 ± 0.6 years. All LDL-P subclasses as well as large HDL-P at baseline were positively and significantly associated with annualized CAC progression, however, after adjustment for established risk factors and traditional lipids, only the association with medium and very small LDL-P remained significant (β -0.02, p = 0.019 and β 0.01, p = 0.003, per 1 nmol/l increase, respectively). Carotid plaque score progression was positively associated with small and very small LDL-P (p <0.01 for all) and non-HDL-P (p = 0.013). Only the association with very small LDL-P remained significant in a fully adjusted model (p = 0.035). Mean IMT progression was not associated with any of the lipid particles. In conclusion, in the MESA cohort, LDL-P measured by ion mobility was significantly associated with CAC progression as well as carotid plaque progression beyond the effect of traditional lipids.

Distribution of calcium volume, density, number, and type of coronary vessel with calcified plaque in South Asians in the US and other race/ethnic groups: The MASALA and MESA studies

BACKGROUND AND AIMS

South Asians (SA) experience disproportionately higher rates of atherosclerotic cardiovascular disease (ASCVD) events than non-Hispanic whites (NHW) and several other Asian groups. The coronary artery calcium (CAC) Agatston score may not capture the unique characteristics of coronary plaque in SA. We therefore evaluated the prevalence and patterns of advanced CAC measures (specific coronary vessel involvement, CAC volume and density) in SA versus other race/ethnicities.

METHODS

We combined data from the Mediators of Atherosclerosis in South Asians Living in America (MASALA) and Multi-Ethnic Study of Atherosclerosis (MESA) cohorts. We used multivariable-adjusted linear regression models to compare advanced CAC measures between SA and other ethnicities.

RESULTS

Our analyses included 7,625 individuals (810 SA, 2,622 whites, 1,893 African Americans, 1,496 Hispanics, 803 Chinese Americans) with mean (SD) age 62 (10) years and 48% men. In adjusted analyses, compared to NHW, SA had lower overall CAC volume [beta coefficient (95% CI)] [-0.46 (-0.62,-0.29)] but higher overall CAC density [0.14 (0.11,0.18)]. These trends were similar when SA were compared to non-whites (Hispanics, Chinese Americans, and African Americans). SA had higher overall [0.07 (0.03,0.12)] and right coronary artery [0.09 (0.03,0.16)] CAC density compared to non-whites, while CAC volume was not significantly different between these two groups.

CONCLUSIONS

SA have lower CAC volume compared to NHW but similar compared to non-whites. Overall CAC density is higher among SA compared to NHW and non-whites. Future longitudinal studies of ASCVD events are required to confirm the prognostic significance of these findings among SA.

Lipoprotein (a) and aortic valve calcium in South Asians compared to other race/ethnic groups

BACKGROUND AND AIMS

South Asians are at increased risk for cardiovascular disease (CVD). Aortic valve calcium (AVC) is associated with CVD risk and aortic stenosis. Elevated Lp(a) is a heritable risk factor for CVD and AVC. AVC prevalence and its association with Lp(a) have not been studied in South Asians.

METHODS

Among participants in the Mediators of Atherosclerosis in South Asians Living in America (MASALA) study (n = 695), AVC prevalence and extent were compared to four race/ethnic groups in the Multi-Ethnic Study of Atherosclerosis (MESA) (n = 4671). Multivariable regression was performed to evaluate associations between Lp(a) and AVC stratified by race/ethnic groups, adjusting for cardiovascular risk factors.

RESULTS

After age and sex adjustment, South Asians had higher median Lp(a) (17.0 mg/dL) compared to Whites (12.9 mg/dL), Hispanics (13.1 mg/dL) and Chinese Americans (12.9 mg/dL), and Blacks had highest Lp(a) levels (35.1 mg/dL). There were no differences in the odds of AVC in South Asians compared with Whites or Hispanics, after age and sex adjustment (p = 0.64 and 0.63, respectively). Odds of AVC was lower in Chinese (OR 0.35; 95%CI 0.23-0.54) and somewhat lower in Blacks compared with South Asians (OR 0.76; 0.56-1.04). There were no associations between Lp(a) and AVC presence or extent in South Asians. Lp(a) was associated with AVC only among Blacks and Whites.

CONCLUSIONS

Although present in Whites and Blacks, there were no associations between Lp(a) and AVC in South Asians. These differences may be due to statistic power or race specific modifying factors that influences the effect of Lp(a) particles on AVC pathogenesis.

Endothelial dysfunction and the risk of heart failure in a community-based study: the Multi-Ethnic Study of Atherosclerosis

Aims

We aimed to investigate the association between endothelial dysfunction, assessed by brachial flow‐mediated dilation (FMD), and the incidence of heart failure (HF) in the community‐based Multi‐Ethnic Study of Atherosclerosis.

Methods and results

Brachial artery FMD was measured in a nested case‐cohort sample including 3496 of 6814 Multi‐Ethnic Study of Atherosclerosis participants without prevalent cardiovascular disease (mean age 61 years, 50% women). Multivariable probability‐weighted Cox proportional hazards analysis was used to examine the association between FMD and incident HF. We also investigated the association between FMD and HF with reduced vs. preserved ejection fraction [HFrEF (left ventricular ejection fraction <45%) vs. HFpEF (left ventricular ejection fraction ≥45%)]. During follow‐up (median 12 years), 149 participants developed incident HF (incidence rate 3.7 events per 1000 person years). There were 56 HFrEF and 69 HFpEF events (incidence rates 1.4 and 1.7 events per 1000 person years, respectively). In multivariable models adjusted for established HF risk factors (age, sex, race/ethnicity, body mass index, systolic blood pressure, antihypertensive treatment, heart rate, diabetes mellitus, history of myocardial infarction, current smoker, and former smoker status), individuals in the highest quartile of FMD (reflecting better endothelial function) had a lower HF risk compared with individuals in the lowest quartile [hazard ratio 0.53, 95% confidence interval (CI) 0.31–0.95]. Lower risk according to higher FMD was particularly evident for HFrEF, but not for HFpEF (hazard ratio per standard deviation increase 0.79, 95% CI 0.64–0.97 vs. 0.99, 95% CI 0.78–1.26, respectively). Results remained similar after adjustment for baseline natriuretic peptide levels. The addition of FMD to established HF risk factors generally rendered no or only modest improvement in C‐statistics [C‐statistics for model with established HF risk factors: 0.774, and with the addition of FMD: 0.776 (delta C 0.002, 95% confidence interval −0.002 to 0.006)].

Conclusions

Endothelial dysfunction was independently associated with HF in this community cohort, suggesting a pathophysiological contribution of endothelial function to the development of HF, in particular HFrEF. However, the value of FMD measurements for HF risk prediction seems limited.

Machine Learning-based Algorithm Enables the Exclusion of Obstructive Coronary Artery Disease in the Patients Who Underwent Coronary Artery Calcium Scoring

RATIONALE AND OBJECTIVES

An application of artificial intelligence to screen for obstructive coronary artery disease (CAD) after coronary artery calcium scoring (CACS) test.

MATERIALS AND METHODS

As an initial step we analyzed a group of 435 patients (23% male, mean age 61 ± 10) with low to moderate probability of CAD, who underwent clinically indicated CACS and coronary computed tomography angiography. Based on those data we elaborated a gradient boosting machine (GBM) model for prediction of obstructive CAD. Later the model was evaluated on a control group of 126 consecutive patients (31% male, mean age 59 ± 10).

RESULTS

Stratified 10-fold cross-validation performed on the group of 435 patients demonstrated the GBM model's sensitivity at 100 ± 0% and specificity at 69.8 ± 3.6%, while the outcomes (confusion matrix) of a clinical application on the group of 126 patients were: 73 true negative, 0 false negative, 20 true positive, and 33 false positive.

CONCLUSION

The GBM algorithm showcased a considerably high discriminatory power for excluding the presence of obstructive CAD, with negative predictive value and positive predictive value of 100% and 38%, respectively.

The relationship between coronary artery calcium density and optical coherence tomography-derived plaque characteristics

BACKGROUND AND AIMS

Although coronary artery calcium (CAC) density has been associated with plaque stability, pathological evidence is lacking. We investigated the relationship between coronary computed tomography (CCT)-derived CAC density and multiple calcified and high-risk plaque (HRP) characteristics using optical coherence tomography (OCT).

METHODS

We analyzed 83 plaques from 33 stable angina patients who underwent both CCT and OCT. CAC density was measured at calcium plaques with ≥90 Hounsfield units (HU) and ≥130 HU using custom CT software. The correlation between median CAC density and OCT-derived calcium size (thickness and area) was assessed. To investigate whether median CAC densities measured at the 90 HU threshold were associated with plaque vulnerability, OCT-derived plaque characteristics and HRP characteristics were compared between the low (90-129 HU), intermediate (130-199 HU) and high (≥200 HU) CAC HU groups.

RESULTS

Median CAC densities at 130 HU were moderately associated with calcium thickness (R = 0.573, p < 0.001) and area (R = 0.560, p < 0.001). Similar results were observed at 90 HU (thickness, R = 0.615, p < 0.001; area, R = 0.612, p < 0.001). Among groups with low, intermediate and high HU levels, calcium thickness (0.42 ± 0.14 mm, 0.60 ± 0.17 mm and 0.77 ± 0.19 mm, respectively; p < 0.001) and area (0.55 ± 0.29 mm², 1.20 ± 0.58 mm² and 1.78 ± 0.87 mm², respectively; p < 0.001) were significantly greater in the high HU group. HRP characteristics, however, did not differ among the three groups.

CONCLUSIONS

OCT-derived calcium size, but not HRP characteristics, were associated with CAC density, suggesting that CAC density is driven mainly by calcified plaque size but not local plaque vulnerability.

Best practice for the nuclear medicine technologist in CT-based attenuation correction and calcium score for nuclear cardiology

The use of hybrid systems is increasingly growing in Europe and this is progressively important for the final result of diagnostic tests. As an integral part of the hybrid imaging system, computed tomography (CT) plays a crucial role in myocardial perfusion imaging diagnostics. Throughout Europe, a variety of equipment is available and also different university curricula of the nuclear medicine technologist are observed. Hence, the Technologist Committee of the European Association of Nuclear Medicine proposes to identify, through a bibliographic review, the recommendations for best practice in computed tomography applied to attenuation correction and calcium score in myocardial perfusion imaging, which courses in the set of knowledge, skills, and competencies for nuclear medicine technologists. This document aims at providing recommendations for CT acquisition protocols and CT image optimization in nuclear cardiology.

High-pitch dual-source CT for coronary artery calcium scoring: A head-to-head comparison of non-triggered chest versus triggered cardiac acquisition

BACKGROUND

To determine the effect of low-dose, high-pitch non-electrocardiographic (ECG)-triggered chest CT on coronary artery calcium (CAC) detection, quantification and risk stratification, compared to ECG-triggered cardiac CT.

METHODS

We selected 1,000 participants from the ImaLife study, 50% with coronary calcification on cardiac CT. All participants underwent non-contrast cardiac CT followed by chest CT using third-generation dual-source technology. Reconstruction settings were equal for both acquisitions. CAC scores were determined by Agatston's method, and divided dichotomously (0, >0), and into risk categories (0, 1-99, 100-399, ≥400). We investigated the influence of heart rate and body mass index (BMI) on risk reclassification.

RESULTS

Positive CAC scores on cardiac CT ranged from 1 to 6926 (median 39). Compared to cardiac CT, chest CT had sensitivity of 0.96 (95%CI 0.94-0.98) and specificity of 0.99 (95%CI 0.97-0.99) for CAC detection (κ = 0.95). In participants with coronary calcification on cardiac CT, CAC score on chest CT was lower than on cardiac CT (median 30 versus 40, p˂0.001). Agreement in CAC-based risk strata was excellent (weighted κ = 0.95). Sixty-five cases (6.5%) were reclassified by one risk category in chest CT, with fifty-five (84.6%) shifting downward. Higher BMI resulted in higher reclassification rate (13% for BMI ≥30 versus 5.2% for BMI <30, p = 0.001), but there was no effect of heart rate.

CONCLUSION

Low-dose, high-pitch chest CT, using third-generation dual-source technology shows almost perfect agreement with cardiac CT in CAC detection and risk stratification. However, low-dose chest CT mainly underestimates the CAC score as compared to cardiac CT, and results in inaccurate risk categorization in BMI ≥30.

Genetic risk scores for coronary artery disease and its traditional risk factors: Their role in the progression of coronary artery calcification-Results of the Heinz Nixdorf Recall study

Background

Atherosclerosis is the primary cause of coronary artery disease (CAD). Several observational studies have examined the association of traditional CAD risk factors with the progression of coronary artery calcification (CAC). In our study we investigated the effect of 11 different genetic risk scores associated with CAD and CAD risk factors on the progression of CAC.

Methods and results

We included 3097 participants from the Heinz Nixdorf Recall study who had available CAC measurements at baseline (CAC_b) and at the 5-year follow-up (CAC_5y). A weighted genetic risk score for CAD and each of the CAD-associated risk factors was constructed. Multiple regression analyses were applied to i) the difference between the observed log(CAC_5y+1) (log(obs)) and expected log(CAC_5y+1) (log(exp)) at the 5-year follow-up following the individual’s log(CAC_b+1) percentile for the time between scans (log(obs)–log(exp)) and ii) the 5-year CAC progression, defined as 5*(log(CAC_5y+1)–log(CAC_b+1))/time between the scans, adjusted for age, sex, and log(CAC_b+1) as well as for risk factors. The median percent deviation from the expected (CAC_5y+1) and the 5-year progression of (CAC+1) in our study were 0 (first quartile: Q1; third quartile: Q3: -0.32; 0.48) and 45.4% (0%; 171.0%) respectively. In the age-, sex- and log(CAC_b+1)-adjusted model, the per-standard deviation (SD) increase in CAD genetic risk score was associated with the percent deviation from the expected (CAC_5y+1) (9.7% (95% confidence interval: 5.2%; 14.5%), p = 1.6x10^-5) and the 5-year progression of CAC (7.1% (3.0%; 11.4%), p = 0.0005). The CAD genetic risk score explains an additional 0.6% of the observed phenotypic variance for “log(obs)–log(exp)” and 0.4% for 5-year progression of CAC. Additionally, the per-SD increase in the CAC genetic risk score was associated with the percent deviation from the expected (CAC_5y+1) (6.2% (1.9%; 10.8%, p = 0.005)) explaining an additional 0.2% of the observed phenotypic variance. However, the per-SD increase in the CAC genetic risk score was not associated with the 5-year progression of CAC (4.4% (0.4%; 8.5%), p = 0.03) after multiple testing. Adjusting for risk factors did not change the results. None of the other genetic risk scores showed an association with the percent deviation from the expected (CAC_5y+1) or with the 5-year progression of CAC.

Conclusions

The association of the CAC genetic risk score and the CAD genetic risk score provides evidence that genetic determinants for CAC and CAD influence the progression of CAC.

Spotty Calcium on Cervicocerebral Computed Tomography Angiography Associates With Increased Risk of Ischemic Stroke

Background and Purpose- Cervicocerebral vascular calcification on computed tomography angiography is a known sign of advanced atherosclerosis. However, the clinical significance of calcification pattern remains unclear. In this study, we aimed to investigate the potential association between spotty calcium and acute ischemic stroke. Methods- This study included patients with first-time nonlacunar ischemic stroke (N=50) confirmed by brain magnetic resonance imaging or nonenhanced head computed tomography, as well as control subjects with asymptomatic carotid atherosclerosis (N=50) confirmed by carotid ultrasonography. Subjects in both groups underwent contrast-enhanced cervicocerebral computed tomography angiography within a week after the initial imaging examination. Spotty calcification was evaluated at 11 arterial segments commonly affected by atherosclerosis along the carotid and vertebrobasilar circulation. Statistical analysis was performed comparing the frequency and spatial pattern of spotty calcification between the 2 groups. Results- Spotty calcification in the Stroke group was markedly more prevalent than that in the Control group (total SC count: 8.74±4.96 versus 1.84±1.82, P<0.001). The odds ratio (95% CI) for stroke was 2.49 (1.55-4.00) for spotty calcification at bilateral carotid bifurcation, 1.52 (1.13-2.04) at carotid siphon, and 1.98 (1.45-2.69) at all evaluated locations. A total number of 3 spotty calcifications were determined as the optimal cutoff threshold for increased risk of stroke. Spotty calcium showed significantly greater area under the receiver operating characteristics curve than total calcium volume irrespective of size (0.88 versus 0.77). Within the Stroke group, ipsilateral lateral side showed significantly more spotty calcium than the contralateral side (5.18±3.05 versus 3.56±2.67, P<0.001). Conclusions- Nonlacunar ischemia stroke was associated with markedly increased incidence of spotty calcification with a distinct spatial pattern on cervicocerebral computed tomography compared with subclinical atherosclerosis, suggesting the potential role of spotty calcification for improving the risk stratification for ischemic stroke.

Differential association between the progression of coronary artery calcium score and coronary plaque volume progression according to statins: the Progression of AtheRosclerotic PlAque DetermIned by Computed TomoGraphic Angiography Imaging (PARADIGM) study

AIMS

Coronary artery calcium score (CACS) is a strong predictor of major adverse cardiac events (MACE). Conversely, statins, which markedly reduce MACE risk, increase CACS. We explored whether CACS progression represents compositional plaque volume (PV) progression differently according to statin use.

METHODS AND RESULTS

From a prospective multinational registry of consecutive patients (n = 2252) who underwent serial coronary computed tomography angiography (CCTA) at a ≥ 2-year interval, 654 patients (61 ± 10 years, 56% men, inter-scan interval 3.9 ± 1.5 years) with information regarding the use of statins and having a serial CACS were included. Patients were divided into non-statin (n = 246) and statin-taking (n = 408) groups. Coronary PVs (total, calcified, and non-calcified; sum of fibrous, fibro-fatty, and lipid-rich) were quantitatively analysed, and CACS was measured from both CCTAs. Multivariate linear regression models were constructed for both statin-taking and non-statin group to assess the association between compositional PV change and change in CACS. In multivariate linear regression analysis, in the non-statin group, CACS increase was positively associated with both non-calcified (β = 0.369, P = 0.004) and calcified PV increase (β = 1.579, P < 0.001). However, in the statin-taking group, CACS increase was positively associated with calcified PV change (β = 0.756, P < 0.001) but was negatively associated with non-calcified PV change (β = -0.194, P = 0.026).

CONCLUSION

In the non-statin group, CACS progression indicates the progression of both non-calcified and calcified PV progression. However, under the effect of statins, CACS progression indicates only calcified PV progression, but not non-calcified PV progression. Thus, the result of serial CACS should be differently interpreted according to the use of statins.

Association of Coronary Artery Calcium in Adults Aged 32 to 46 Years With Incident Coronary Heart Disease and Death

Importance

Coronary artery calcium (CAC) is associated with coronary heart disease (CHD) and cardiovascular disease (CVD); however, prognostic data on CAC are limited in younger adults.

Objective

To determine if CAC in adults aged 32 to 46 years is associated with incident clinical CHD, CVD, and all-cause mortality during 12.5 years of follow-up.

Design, Setting, and Participants

The Coronary Artery Risk Development in Young Adults (CARDIA) Study is a prospective community-based study that recruited 5115 black and white participants aged 18 to 30 years from March 25, 1985, to June 7, 1986. The cohort has been under surveillance for 30 years, with CAC measured 15 (n = 3043), 20 (n = 3141), and 25 (n = 3189) years after recruitment. The mean follow-up period for incident events was 12.5 years, from the year 15 computed tomographic scan through August 31, 2014.

Main Outcomes and Measures

Incident CHD included fatal or nonfatal myocardial infarction, acute coronary syndrome without myocardial infarction, coronary revascularization, or CHD death. Incident CVD included CHD, stroke, heart failure, and peripheral arterial disease. Death included all causes. The probability of developing CAC by age 32 to 56 years was estimated using clinical risk factors measured 7 years apart between ages 18 and 38 years.

Results

At year 15 of the study among 3043 participants (mean [SD] age, 40.3 [3.6] years; 1383 men and 1660 women), 309 individuals (10.2%) had CAC, with a geometric mean Agatston score of 21.6 (interquartile range, 17.3-26.8). Participants were followed up for 12.5 years, with 57 incident CHD events and 108 incident CVD events observed. After adjusting for demographics, risk factors, and treatments, those with any CAC experienced a 5-fold increase in CHD events (hazard ratio [HR], 5.0; 95% CI, 2.8-8.7) and 3-fold increase in CVD events (HR, 3.0; 95% CI, 1.9-4.7). Within CAC score strata of 1-19, 20-99, and 100 or more, the HRs for CHD were 2.6 (95% CI, 1.0-5.7), 5.8 (95% CI, 2.6-12.1), and 9.8 (95% CI, 4.5-20.5), respectively. A CAC score of 100 or more had an incidence of 22.4 deaths per 100 participants (HR, 3.7; 95% CI, 1.5-10.0); of the 13 deaths in participants with a CAC score of 100 or more, 10 were adjudicated as CHD events. Risk factors for CVD in early adult life identified those above the median risk for developing CAC and, if applied, in a selective CAC screening strategy could reduce the number of people screened for CAC by 50% and the number imaged needed to find 1 person with CAC from 3.5 to 2.2.

Conclusions and Relevance

The presence of CAC among individuals aged between 32 and 46 years was associated with increased risk of fatal and nonfatal CHD during 12.5 years of follow-up. A CAC score of 100 or more was associated with early death. Adults younger than 50 years with any CAC, even with very low scores, identified on a computed tomographic scan are at elevated risk of clinical CHD, CVD, and death. Selective use of screening for CAC might be considered in individuals with risk factors in early adulthood to inform discussions about primary prevention.

Long-term evaluation of coronary artery calcifications in kidney transplanted patients: a follow up of 5 years

Coronary artery calcifications(CACs), are related to the increased cardiovascular mortality during kidney transplantation(KTx). Using coronary-CT performed at 1 month(T0) and 5 years(T5) after KTx we evaluated: (1) the prevalence of CACs; (2) the clinical and biochemical factors related to CACs; 3) the factors implicated with CACs progression. We evaluated 67-pts selected from the 103-pts transplanted in our unit between 2007 and 2008. Clinical and biochemical parameters were recorded at the time of pre-KTx evaluation and for five years after KTx. Coronary-CT for the Agatson score (AS) evaluation was performed at T0 and at T5, and CACs progression was determined. At baseline AS was 45 [0–233]. At T5 AS was 119 [1–413]. At T0, 69% of patients had CACs. Age and dialytic vintage were the main independent variables related to CACs. At T5, CACs were present in 76% of patients. Age was the only independent factor in determining CACs. A progression of CACs was observed in 74% of patients. They were older, had higher CACs-T0 and higher SBP throughout the 5-years. The presence of CACs at T0 and age were the only independent factors in determining the CACs-progression. CACs-T0 had the best discriminative power for CACs progression. CACs prevalence is quite high in KTx patients; Age is strictly related to CACs; Age and the presence of CACs at baseline were the two major factors associated with the progression of CACs during the five years of follow up. CACs-T0 had the best discriminative power for progression of CACs.