Association Between Ambulatory Blood Pressure and Coronary Artery Calcification: The JHS

[Figure: see text].

Abstract 071: Ten-year Change In Tv Viewing Is Associated With Concurrent Change In Pericardial Adipose Tissue In Middle-aged Adults: The Coronary Artery Risk Development In Young Adults (CARDIA) Study

Introduction: Pericardial adipose tissue (PAT), an ectopic adipose depot surrounding the coronary arteries, is a pathogenic risk factor for cardiometabolic disease; however, the association of sedentary behavior with PAT is poorly understood. We examined the longitudinal association of 10-year change in TV viewing with concurrent change in PAT.

Hypothesis: Increased h/day of TV viewing over 10 years are associated with larger mean increases in PAT during the same 10-year period.

Methods: Middle-aged adults (N=1659, mean age=40.4, 912 females, 733 blacks) from the Coronary Artery Risk Development in Young Adults (CARDIA) Study at the exam years 15 (2000-2001) and 25 (2010-2011) were included. Both TV viewing (h/day) and the volume of PAT (mL) were measured at Years 15 and 25 using the CARDIA physical activity questionnaire and computed tomography, respectively. Covariates measured at year 15 included PAT, sociodemographic factors, cardiovascular disease risk factors, diet quality, TV viewing, moderate-to-vigorous intensity physical activity (MVPA), inflammatory cytokines, and waist circumference. Multivariable linear regression was used to estimate 10-year change in PAT across increasing tertiles (≤ -1, > -1 to < 1, ≥ 1 h/day) of 10-year changes in TV viewing.

Results: On average, TV viewing and PAT increased between the two exam years by 0.2 h/day (8.7% increase, mean: 2.3 → 2.5 h/day) and 11.8 mL (25.9% increase, mean: 45.6 → 57.4 mL), respectively (all p < 0.01). In the fully adjusted model including MVPA and other major confounders, the highest tertile of 10-year change in TV viewing was associated with greater change in PAT (β = 2.97 mL, p < 0.01) when compared with the lowest tertile (see Figure 1 ), while mean PAT change was intermediate in the middle tertile.

Conclusions: A greater 10-year increase in TV viewing is associated with a greater concurrent increase in PAT, independent of MVPA and other important confounders. Reducing TV viewing time may be associated with less PAT accumulation with age.

Non-alcoholic fatty liver disease and cognitive function in middle-aged adults: the CARDIA study

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is associated with cardiovascular disease (CVD) risk factors that have been linked to cognitive decline. Whether NAFLD is associated with cognitive performance in midlife remains uncertain.

METHODS

Coronary Artery Risk Development in Young Adults study participants with CT examination and cognitive assessment at Y25 (2010-2011; n = 2809) were included. Cognitive function was reassessed at Y30. NAFLD was defined according to liver attenuation and treated both continuously and categorically (using ≤ 40 and ≤ 51 Hounsfield units to define severity) after exclusion for other causes of liver fat. Cognitive tests including the Digit Symbol Substitution (processing speed), Rey Auditory Verbal Learning (verbal memory), and Stroop (executive function) were analyzed with standardized z-scores. Linear models were constructed to (a) examine the cross-sectional associations of NAFLD with cognitive scores and (b) evaluate its predictive role in 5-year change in cognitive performance.

RESULTS

Participants' mean age (Y25) was 50.1 (SD 3.6) years (57% female; 48% black), with 392 (14%) having mild NAFLD and 281 (10%) having severe NAFLD. NAFLD was positively associated with CVD risk factors and inversely associated with cognitive scores. However, after adjustment for CVD risk factors, no associations were shown between NAFLD and cognitive scores (all βs ≈ 0). Similarly, no associations were observed with 5-year cognitive decline. CVD history, hypertension, smoking, diabetes and hypertriglyceridemia showed stronger associations with baseline cognitive scores and were predictive of subsequent cognitive decline (all P ≤ .05).

CONCLUSION

Among middle-aged adults, inverse associations between NAFLD and cognitive scores were attenuated after adjustment for CVD risk factors, with the latter predictive of poorer cognitive performance both at baseline and follow-up.

Measure Partial Liver Volumetric Variations from Paired Inspiratory-expiratory Chest CT Scans

Liver stiffness is an essential clinical biomarker for diagnosing liver fibrosis and cirrhosis. In current clinical practice, elastography techniques are standard non-invasive diagnosis tools to assess stiffness of liver, using either Ultrasound (US) or magnetic resonance imaging (MRI). However, the US elastography yields ≈ 10 % failure rate and degraded performance on obese patients, while the MR elastography is costlier and less available. Compared with US and MRI, the computerized tomography (CT) imaging has not been widely used in measuring liver stiffness. In this paper, we performed a pilot study to assess if volumetric variations of liver can be captured from paired inspiratory-expiratory chest (PIEC) CT scans. To enable the assessment, we propose a Hierarchical Intra-Patient Organ-specific (HIPO) registration pipeline to quantify the partial liver volumetric variations with lung pressure from a respiratory cycle. The PIEC protocol is employed since it naturally provides two paired CT scans with liver deformation from regulated respiratory motions. For the subjects whose registration results passed both an automatic quantitative quality assurance (QA) and another visual qualitative QA, 6.0% average volumetric variations of liver were measured, from inspiratory phase to expiratory phase. Future clinical validations will be required to validate the findings in this pilot study.

A Noncoding Variant Near PPP1R3B Promotes Liver Glycogen Storage and MetS, but Protects Against Myocardial Infarction

CONTEXT

Glycogen storage diseases are rare. Increased glycogen in the liver results in increased attenuation.

OBJECTIVE

Investigate the association and function of a noncoding region associated with liver attenuation but not histologic nonalcoholic fatty liver disease.

DESIGN

Genetics of Obesity-associated Liver Disease Consortium.

SETTING

Population-based.

MAIN OUTCOME

Computed tomography measured liver attenuation.

RESULTS

Carriers of rs4841132-A (frequency 2%-19%) do not show increased hepatic steatosis; they have increased liver attenuation indicative of increased glycogen deposition. rs4841132 falls in a noncoding RNA LOC157273 ~190 kb upstream of PPP1R3B. We demonstrate that rs4841132-A increases PPP1R3B through a cis genetic effect. Using CRISPR/Cas9 we engineered a 105-bp deletion including rs4841132-A in human hepatocarcinoma cells that increases PPP1R3B, decreases LOC157273, and increases glycogen perfectly mirroring the human disease. Overexpression of PPP1R3B or knockdown of LOC157273 increased glycogen but did not result in decreased LOC157273 or increased PPP1R3B, respectively, suggesting that the effects may not all occur via affecting RNA levels. Based on electronic health record (EHR) data, rs4841132-A associates with all components of the metabolic syndrome (MetS). However, rs4841132-A associated with decreased low-density lipoprotein (LDL) cholesterol and risk for myocardial infarction (MI). A metabolic signature for rs4841132-A includes increased glycine, lactate, triglycerides, and decreased acetoacetate and beta-hydroxybutyrate.

CONCLUSIONS

These results show that rs4841132-A promotes a hepatic glycogen storage disease by increasing PPP1R3B and decreasing LOC157273. rs4841132-A promotes glycogen accumulation and development of MetS but lowers LDL cholesterol and risk for MI. These results suggest that elevated hepatic glycogen is one cause of MetS that does not invariably promote MI.

Prediction of Type II Diabetes Onset with Computed Tomography and Electronic Medical Records

Type II diabetes mellitus (T2DM) is a significant public health concern with multiple known risk factors (e.g., body mass index (BMI), body fat distribution, glucose levels). Improved prediction or prognosis would enable earlier intervention before possibly irreversible damage has occurred. Meanwhile, abdominal computed tomography (CT) is a relatively common imaging technique. Herein, we explore secondary use of the CT imaging data to refine the risk profile of future diagnosis of T2DM. In this work, we delineate quantitative information and imaging slices of patient history to predict onset T2DM retrieved from ICD-9 codes at least one year in the future. Furthermore, we investigate the role of five different types of electronic medical records (EMR), specifically 1) demographics; 2) pancreas volume; 3) visceral/subcutaneous fat volumes in L2 region of interest; 4) abdominal body fat distribution and 5) glucose lab tests in prediction. Next, we build a deep neural network to predict onset T2DM with pancreas imaging slices. Finally, motivated by multi-modal machine learning, we construct a merged framework to combine CT imaging slices with EMR information to refine the prediction. We empirically demonstrate our proposed joint analysis involving images and EMR leads to 4.25% and 6.93% AUC increase in predicting T2DM compared with only using images or EMR. In this study, we used case-control dataset of 997 subjects with CT scans and contextual EMR scores. To the best of our knowledge, this is the first work to show the ability to prognose T2DM using the patients' contextual and imaging history. We believe this study has promising potential for heterogeneous data analysis and multi-modal medical applications.

Cost-effectiveness of Contemporary Statin Use Guidelines With or Without Coronary Artery Calcium Assessment in African American Individuals

Importance

Clinical and economic consequences of statin treatment guidelines supplemented by targeted coronary artery calcium (CAC) assessment have not been evaluated in African American individuals, who are at increased risk for atherosclerotic cardiovascular disease and less likely than non-African American individuals to receive statin therapy.

Objective

To evaluate the cost-effectiveness of the 2013 American College of Cardiology/American Heart Association (ACC/AHA) guideline without a recommendation for CAC assessment vs the 2018 ACC/AHA guideline recommendation for use of a non-0 CAC score measured on one occasion to target generic-formulation, moderate-intensity statin treatment in African American individuals at risk for atherosclerotic cardiovascular disease.

Design, Setting, and Participants

A microsimulation model was designed to estimate life expectancy, quality of life, costs, and health outcomes over a lifetime horizon. African American-specific data from 472 participants in the Jackson Heart Study (JHS) at intermediate risk for atherosclerotic cardiovascular disease and other US population-specific data on individuals from published sources were used. Data analysis was conducted from November 11, 2018, to November 1, 2019.

Main Outcomes and Measures

Lifetime costs and quality-adjusted life-years (QALYs), discounted at 3% annually.

Results

In a model-based economic evaluation informed in part by follow-up data, the analysis was focused on 472 individuals in the JHS at intermediate risk for atherosclerotic cardiovascular disease; mean (SD) age was 63 (6.7) years. The sample included 243 women (51.5%) and 229 men (48.5%). Of these, 178 of 304 participants (58.6%) who underwent CAC assessment had a non-0 CAC score. In the base-case scenario, implementation of 2013 ACC/AHA guidelines without CAC assessment provided a greater quality-adjusted life expectancy (0.0027 QALY) at a higher cost ($428.97) compared with the 2018 ACC/AHA guideline strategy with CAC assessment, yielding an incremental cost-effectiveness ratio of $158 325/QALY, which is considered to represent low-value care by the ACC/AHA definition. The 2018 ACC/AHA guideline strategy with CAC assessment provided greater quality-adjusted life expectancy at a lower cost compared with the 2013 ACC/AHA guidelines without CAC assessment when there was a strong patient preference to avoid use of daily medication therapy. In probability sensitivity analyses, the 2018 ACC/AHA guideline strategy with CAC assessment was cost-effective compared with the 2013 ACC/AHA guidelines without CAC assessment in 76% of simulations at a willingness-to-pay value of $100 000/QALY when there was a preference to lose 2 weeks of perfect health to avoid 1 decade of daily therapy.

Conclusions and Relevance

A CAC assessment-guided strategy for statin therapy appears to be cost-effective compared with initiating statin therapy in all African American individuals at intermediate risk for atherosclerotic cardiovascular disease and may provide greater quality-adjusted life expectancy at a lower cost than a non-CAC assessment-guided strategy when there is a strong patient preference to avoid the need for daily medication. Coronary artery calcium testing may play a role in shared decision-making regarding statin use.

Added sugar intake is associated with pericardial adipose tissue volume

AIM

The purpose of this study was to determine the relationships of pericardial adipose tissue and visceral adipose tissue volume with added sugar and sugar-sweetened beverage intakes. We hypothesized that both added sugar and sugar-sweetened beverages were positively associated with pericardial adipose tissue and visceral adipose tissue volumes in black and white men and women enrolled in the prospective Coronary Artery Risk Development in Young Adults study.

METHODS AND RESULTS

Dietary intake was assessed by diet history at baseline, year 7 and year 20 examinations in 3070 participants aged 18-30 and generally healthy at baseline. After 25 years follow-up, participants underwent a computed tomography scan of chest and abdomen; the computed tomography scans were read, and pericardial adipose tissue, visceral adipose tissue, and subcutaneous adipose tissue volumes were calculated. Quintiles were created for the average of baseline, year 7 and year 20 added sugar and for the average of sugar-sweetened beverages. General linear regression analysis evaluated the associations of pericardial adipose tissue and visceral adipose tissue volumes across quintiles of added sugar and across quintiles of sugar-sweetened beverage intakes adjusted for potential confounding factors. In a multivariable model, pericardial adipose tissue volume was higher across increasing quintiles of added sugar and sugar-sweetened beverage intakes (p_trend = 0.001 and p_trend < 0.001, respectively). A similar relation was observed for visceral adipose tissue (p_trend < 0.001 for both added sugar and sugar-sweetened beverages).

CONCLUSIONS

Long-term intakes of added sugar and sugar-sweetened beverages were associated with higher pericardial adipose tissue, visceral adipose tissue, and subcutaneous adipose tissue volumes. Because these ectopic fat depots are associated with greater risk of disease incidence, these findings support limiting intakes of added sugar and sugar-sweetened beverages.

Hepatic and Skeletal Muscle Adiposity Are Associated with Diabetes Independent of Visceral Adiposity in Nonobese African-Caribbean Men

Background: Adipose tissue (AT) around and within non-AT organs (i.e., ectopic adiposity) is emerging as a strong risk factor for type 2 diabetes (T2D). Not known is whether major ectopic adiposity depots, such as hepatic, skeletal muscle, and pericardial adiposity (PAT), are associated with T2D independent of visceral adiposity (VAT). More data are particularly needed among high-risk nonobese minority populations, as the race/ethnic gap in T2D risk is greatest among nonobese. Methods: Thus, we measured several ectopic adiposity depots by computed tomography in 718 (mean age = 64 years) African-Caribbean men on the Island of Tobago overall, and stratified by obesity (obese N = 187 and nonobese N = 532). Results: In age, lifestyle risk factors, health status, lipid-lowering medication intake, body mass index and all other adiposity-adjusted regression analyses, and hepatic and skeletal muscle adiposity were associated with T2D among nonobese men only (all P < 0.05), despite no association between VAT and PAT and T2D. Conclusions: Our results support the "ectopic fat syndrome" theory in the pathogenesis of T2D among nonobese African-Caribbean men. Longitudinal studies are needed to clarify the independent role of ectopic adiposity in T2D, and to identify possible biological mechanisms underlying this relationship, particularly in high-risk African ancestry and other nonwhite populations.

Deep Learning for Automatic Calcium Scoring in CT: Validation Using Multiple Cardiac CT and Chest CT Protocols

Background Although several deep learning (DL) calcium scoring methods have achieved excellent performance for specific CT protocols, their performance in a range of CT examination types is unknown. Purpose To evaluate the performance of a DL method for automatic calcium scoring across a wide range of CT examination types and to investigate whether the method can adapt to different types of CT examinations when representative images are added to the existing training data set. Materials and Methods The study included 7240 participants who underwent various types of nonenhanced CT examinations that included the heart: coronary artery calcium (CAC) scoring CT, diagnostic CT of the chest, PET attenuation correction CT, radiation therapy treatment planning CT, CAC screening CT, and low-dose CT of the chest. CAC and thoracic aorta calcification (TAC) were quantified using a convolutional neural network trained with (a) 1181 low-dose chest CT examinations (baseline), (b) a small set of examinations of the respective type supplemented to the baseline (data specific), and (c) a combination of examinations of all available types (combined). Supplemental training sets contained 199-568 CT images depending on the calcium burden of each population. The DL algorithm performance was evaluated with intraclass correlation coefficients (ICCs) between DL and manual (Agatston) CAC and (volume) TAC scoring and with linearly weighted κ values for cardiovascular risk categories (Agatston score; cardiovascular disease risk categories: 0, 1-10, 11-100, 101-400, >400). Results At baseline, the DL algorithm yielded ICCs of 0.79-0.97 for CAC and 0.66-0.98 for TAC across the range of different types of CT examinations. ICCs improved to 0.84-0.99 (CAC) and 0.92-0.99 (TAC) for CT protocol-specific training and to 0.85-0.99 (CAC) and 0.96-0.99 (TAC) for combined training. For assignment of cardiovascular disease risk category, the κ value for all test CT scans was 0.90 (95% confidence interval [CI]: 0.89, 0.91) for the baseline training. It increased to 0.92 (95% CI: 0.91, 0.93) for both data-specific and combined training. Conclusion A deep learning calcium scoring algorithm for quantification of coronary and thoracic calcium was robust, despite substantial differences in CT protocol and variations in subject population. Augmenting the algorithm training with CT protocol-specific images further improved algorithm performance. © RSNA, 2020 See also the editorial by Vannier in this issue.

Associations of Unhealthy Food Environment With the Development of Coronary Artery Calcification: The CARDIA Study

Background

While prior studies have linked the neighborhood environment and development of subclinical atherosclerosis, it is unknown whether living in neighborhoods with greater availability of “unhealthy” food outlets (fast‐food chain restaurants and convenience stores) is associated with risk of developing coronary artery calcification (CAC).

Methods and Results

We included 2706 CARDIA study (Coronary Artery Risk Development in Young Adults) participants who underwent CAC measurement during follow‐up years 15 (2000–2001), 20 (2005–2006), and 25 (2010–2011). Neighborhood features examined included percentage of all food outlets that were convenience stores and fast‐food chain restaurants within a 3‐km Euclidean buffer distance from each participant's residence. Econometric fixed effects models, which by design control for all time‐invariant covariates, were used to model the longitudinal association between simultaneous within‐person change in percentage food outlet and change in CAC. At baseline (year 15), 9.7% of participants had prevalent CAC. During 10 years of follow‐up, 21.1% of participants developed CAC. Each 1‐SD increase in percentage of convenience stores was associated with a 1.34 higher odds of developing CAC (95% CI: 1.04, 1.72) after adjusting for individual‐ and neighborhood‐level covariates; however, there was no significant association between increased percentage of fast‐food chain restaurants and developing CAC (odds ratio=1.15; 95% CI: 0.96, 1.38). There were no significant associations between increases in either food outlet percentage and progression of CAC.

Conclusions

Our findings suggest that increases in the relative availability of convenience stores in participants' neighborhoods is related to the development of CAC over time.

Associations of Thigh and Abdominal Adipose Tissue Radiodensity with Glucose and Insulin in Nondiabetic African-Ancestry Men

OBJECTIVE

Decreased radiodensity of adipose tissue (AT) located in the visceral AT (VAT), subcutaneous AT (SAT), and intermuscular AT (IMAT) abdominal depots is associated with hyperglycemia, hyperinsulinemia, and insulin resistance independent of AT volumes. These associations were sought in African-ancestry men, who have higher risk for type 2 diabetes and have been underrepresented in previous studies.

METHODS

This cross-sectional analysis included 505 nondiabetic men of African-Caribbean ancestry (median age: 61 years; median BMI: 26.8 kg/m² ) from the Tobago Health Study. AT volumes and radiodensities were assessed using computed tomography, including abdominal (VAT and SAT) and thigh (IMAT) depots. Associations between AT radiodensities were assessed with fasting serum glucose and insulin and with insulin resistance (updated homeostatic model assessment of insulin resistance, HOMA2-IR).

RESULTS

Higher radiodensity in any AT depot was associated with lower log-insulin and log-HOMA2-IR (β range: -0.16 to -0.18 for each; all P < 0.0001). No AT radiodensity was associated with glucose. Thigh IMAT radiodensity associations were independent of, and similar in magnitude to, VAT radiodensities. Model fit statistics suggested that AT radiodensities were a better predictor for insulin and insulin resistance compared with AT volumes in individuals with overweight and obesity.

CONCLUSIONS

AT radiodensities at multiple depots are significantly associated with insulin and insulin resistance in African-ancestry men.

Stochastic tissue window normalization of deep learning on computed tomography

Tissue window filtering has been widely used in deep learning for computed tomography (CT) image analyses to improve training performance (e.g., soft tissue windows for abdominal CT). However, the effectiveness of tissue window normalization is questionable since the generalizability of the trained model might be further harmed, especially when such models are applied to new cohorts with different CT reconstruction kernels, contrast mechanisms, dynamic variations in the acquisition, and physiological changes. We evaluate the effectiveness of both with and without using soft tissue window normalization on multisite CT cohorts. Moreover, we propose a stochastic tissue window normalization (SWN) method to improve the generalizability of tissue window normalization. Different from the random sampling, the SWN method centers the randomization around the soft tissue window to maintain the specificity for abdominal organs. To evaluate the performance of different strategies, 80 training and 453 validation and testing scans from six datasets are employed to perform multiorgan segmentation using standard 2D U-Net. The six datasets cover the scenarios, where the training and testing scans are from (1) same scanner and same population, (2) same CT contrast but different pathology, and (3) different CT contrast and pathology. The traditional soft tissue window and nonwindowed approaches achieved better performance on (1). The proposed SWN achieved general superior performance on (2) and (3) with statistical analyses, which offers better generalizability for a trained model.

Higher Aortic Stiffness Is Related to Lower Cerebral Blood Flow and Preserved Cerebrovascular Reactivity in Older Adults

BACKGROUND

Mechanisms underlying the association between age-related arterial stiffening and poor brain health remain elusive. Cerebral blood flow (CBF) homeostasis may be implicated. This study evaluates how aortic stiffening relates to resting CBF and cerebrovascular reactivity (CVR) in older adults.

METHODS

Vanderbilt Memory & Aging Project participants free of clinical dementia, stroke, and heart failure were studied, including older adults with normal cognition (n=155; age, 72±7 years; 59% male) or mild cognitive impairment (n=115; age, 73±7 years; 57% male). Aortic pulse wave velocity (PWV; meters per second) was quantified from cardiac magnetic resonance. Resting CBF (milliliters per 100 g per minute) and CVR (CBF response to hypercapnic normoxia stimulus) were quantified from pseudocontinuous arterial spin labeling magnetic resonance imaging. Linear regression models related aortic PWV to regional CBF, adjusting for age, race/ethnicity, education, Framingham Stroke Risk Profile (diabetes mellitus, smoking, left ventricular hypertrophy, prevalent cardiovascular disease, atrial fibrillation), hypertension, body mass index, apolipoprotein E4 ( APOE ε4) status, and regional tissue volume. Models were repeated testing PWV× APOE ε4 interactions. Sensitivity analyses excluded participants with prevalent cardiovascular disease and atrial fibrillation.

RESULTS

Among participants with normal cognition, higher aortic PWV related to lower frontal lobe CBF (β=-0.43; P=0.04) and higher CVR in the whole brain (β=0.11; P=0.02), frontal lobes (β=0.12; P<0.05), temporal lobes (β=0.11; P=0.02), and occipital lobes (β=0.14; P=0.01). Among APOE ε4 carriers with normal cognition, findings were more pronounced with higher PWV relating to lower whole-brain CBF (β=-1.16; P=0.047), lower temporal lobe CBF (β=-1.81; P=0.004), and higher temporal lobe CVR (β=0.26; P=0.08), although the last result did not meet the a priori significance threshold. Results were similar in sensitivity models. Among participants with mild cognitive impairment, higher aortic PWV related to lower CBF in the occipital lobe (β=-0.70; P=0.02), but this finding was attenuated when participants with prevalent cardiovascular disease and atrial fibrillation were excluded. Among APOE ε4 carriers with mild cognitive impairment, findings were more pronounced with higher PWV relating to lower temporal lobe CBF (β=-1.20; P=0.02).

CONCLUSIONS

Greater aortic stiffening relates to lower regional CBF and higher CVR in cognitively normal older adults, especially among individuals with increased genetic predisposition for Alzheimer's disease. Central arterial stiffening may contribute to reductions in regional CBF despite preserved cerebrovascular reserve capacity.

Impact of Abdominal Obesity on Proximal and Distal Aorta Wall Thickness in African Americans: The Jackson Heart Study

OBJECTIVE

Abdominal obesity and wall thickness of the central arteries have been associated with higher risk of cardiovascular disease. Despite the higher burden of overweight and cardiovascular disease among African Americans, limited data are available on the association of abdominal obesity with aortic wall thickness in African Americans. We assessed the cross-sectional and the longitudinal associations of abdominal obesity with aortic intima-media thickness (aIMT) in a cohort of African Americans from the Jackson Heart Study.

METHODS

Data on aIMT and repeated measures of waist circumference (WC) and waist to height ratio from 1,572 participants, as well as on abdominal subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), and aIMT from 1,223 participants, were analyzed. aIMT was measured at proximal ascending aorta (PA-aIMT), proximal descending aorta (PD-aIMT), and distal aorta (bifurcation) using cardiac magnetic resonance. SAT and VAT were measured using computerized tomography.

RESULTS

WC and WHtR were longitudinally associated with PA-aIMT and PD-aIMT; SAT and VAT were associated with PA-aIMT only. Only WC was associated with distal aIMT.

CONCLUSIONS

Abdominal obesity measures are associated with increased proximal aIMT in adult African Americans. Only WC is associated with wall thickness in all three segments of the aorta.

Association Between Regional Adipose Tissue Distribution and Risk of Heart Failure Among Blacks

BACKGROUND

Obesity is highly prevalent among blacks and is associated with a greater risk of heart failure (HF). However, the contribution of regional adiposity depots such as visceral adipose tissue (VAT) and abdominal subcutaneous adipose tissue toward risk of HF in blacks is unknown.

METHODS AND RESULTS

We included 2602 participants (mean age: 59 years, 35% men) from the Jackson Heart Study without prevalent HF who underwent computed tomography quantification of VAT and subcutaneous adipose tissue during the second visit (2005-2009). The associations between different adiposity measures and HF were evaluated using adjusted Cox models. There were 122 incident HF events over a median follow-up of 7.1 years. Higher amounts of VAT were associated with greater risk of HF in age- and sex-adjusted analyses (hazard ratio [95% CI] per 1-SD higher VAT: 1.29 [1.09-1.52]). This association was attenuated and not significant after additional adjustment for traditional HF risk factors and body mass index. Overall obesity, represented by body mass index, was associated with higher risk of HF independent of risk factors and VAT (hazard ratio [95% CI] per 1-kg/m² higher body mass index: 1.06 [1.02-1.11]). Subcutaneous adipose tissue was not associated with risk of HF in adjusted analyses.

CONCLUSIONS

In a community-dwelling black population, higher amounts of overall and visceral adiposity are associated with higher risk of HF. The association between VAT and HF risk in blacks may reflect differences in traditional HF risk factor burden. Future studies are needed to confirm this observation and clarify the independent role of different measures of adiposity on HF outcomes.

Fully automatic liver attenuation estimation combing CNN segmentation and morphological operations

PURPOSE

Manually tracing regions of interest (ROIs) within the liver is the de facto standard method for measuring liver attenuation on computed tomography (CT) in diagnosing nonalcoholic fatty liver disease (NAFLD). However, manual tracing is resource intensive. To address these limitations and to expand the availability of a quantitative CT measure of hepatic steatosis, we propose the automatic liver attenuation ROI-based measurement (ALARM) method for automated liver attenuation estimation.

METHODS

The ALARM method consists of two major stages: (a) deep convolutional neural network (DCNN)-based liver segmentation and (b) automated ROI extraction. First, liver segmentation was achieved using our previously developed SS-Net. Then, a single central ROI (center-ROI) and three circles ROI (periphery-ROI) were computed based on liver segmentation and morphological operations. The ALARM method is available as an open source Docker container (https://github.com/MASILab/ALARM).

RESULTS

Two hundred and forty-six subjects with 738 abdomen CT scans from the African American-Diabetes Heart Study (AA-DHS) were used for external validation (testing), independent from the training and validation cohort (100 clinically acquired CT abdominal scans). From the correlation analyses, the proposed ALARM method achieved Pearson correlations = 0.94 with manual estimation on liver attenuation estimations. When evaluating the ALARM method for detection of nonalcoholic fatty liver disease (NAFLD) using the traditional cut point of < 40 HU, the center-ROI achieved substantial agreements (Kappa = 0.79) with manual estimation, while the periphery-ROI method achieved "excellent" agreement (Kappa = 0.88) with manual estimation. The automated ALARM method had reduced variability compared to manual measurements as indicated by a smaller standard deviation.

CONCLUSIONS

We propose a fully automated liver attenuation estimation method termed ALARM by combining DCNN and morphological operations, which achieved "excellent" agreement with manual estimation for fatty liver detection. The entire pipeline is implemented as a Docker container which enables users to achieve liver attenuation estimation in five minutes per CT exam.

Subclinical Atherosclerosis, Statin Eligibility, and Outcomes in African American Individuals: The Jackson Heart Study

Importance

Modern prevention guidelines substantially increase the number of individuals who are eligible for treatment with statins. Efforts to refine statin eligibility via coronary calcification have been studied in white populations but not, to our knowledge, in large African American populations.

Objective

To compare the relative accuracy of US Preventive Services Task Force (USPSTF) and American College of Cardiology/American Heart Association (ACC/AHA) recommendations in identifying African American individuals with subclinical and clinical atherosclerotic cardiovascular disease (ASCVD).

Design, Setting, and Participants

In this prospective, community-based study, 2812 African American individuals aged 40 to 75 years without prevalent ASCVD underwent assessment of ASCVD risk. Of these, 1743 participants completed computed tomography.

Main Outcomes and Measures

Nonzero coronary artery calcium (CAC) score, abdominal aortic calcium score, and incident ASCVD (ie, myocardial infarction, ischemic stroke, or fatal coronary heart disease).

Results

Of the 2812 included participants, the mean (SD) age at baseline was 55.4 (9.4) years, and 1837 (65.3%) were female. The USPSTF guidelines captured 404 of 732 African American individuals (55.2%) with a CAC score greater than 0; the ACC/AHA guidelines identified 507 individuals (69.3%) (risk difference, 14.1%; 95% CI, 11.2-17.0; P < .001). Statin recommendation under both guidelines was associated with a CAC score greater than 0 (odds ratio, 5.1; 95% CI, 4.1-6.3; P < .001). While individuals indicated for statins under both guidelines experienced 9.6 cardiovascular events per 1000 patient-years, those indicated under only ACC/AHA guidelines were at low to intermediate risk (4.1 events per 1000 patient-years). Among individuals who were statin eligible by ACC/AHA guidelines, the 10-year ASCVD incidence per 1000 person-years was 8.1 (95% CI, 5.9-11.1) in the presence of CAC and 3.1 (95% CI, 1.6-5.9) without CAC (P = .02). While statin-eligible individuals by USPSTF guidelines did not have a significantly higher 10-year ASCVD event rate in the presence of CAC, African American individuals not eligible for statins by USPSTF guidelines had a higher ASCVD event rate in the presence of CAC (2.8 per 1000 person-years; 95% CI, 1.5-5.4) relative to without CAC (0.8 per 1000 person-years; 95%, CI 0.3-1.7) (P = .03).

Conclusions and Relevance

The USPSTF guidelines focus treatment recommendations on 38% of high-risk African American individuals at the expense of not recommending treatment in nearly 25% of African American individuals eligible for statins by ACC/AHA guidelines with vascular calcification and at low to intermediate ASCVD risk.

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.

Sex Hormone-Binding Globulin Levels in Young Men Are Associated With Nonalcoholic Fatty Liver Disease in Midlife

INTRODUCTION

Cross-sectional data note lower levels of testosterone and sex hormone-binding globulin (SHBG) levels in men with nonalcoholic fatty liver disease (NAFLD). Whether sex hormone levels in young men are predictive of later risk of NAFLD is not known.

METHODS

Among men in the prospective population-based multicenter Coronary Artery Risk Development in Young Adults study (mean age 50; n = 837), we assessed whether testosterone and SHBG levels measured at study year 10 (median age 35 years) were associated with prevalent NAFLD at study year 25. NAFLD was defined using noncontrast abdominal computed tomography (CT) scan after excluding other causes of hepatic steatosis. The association of testosterone and SHBG with prevalent NAFLD was assessed by logistic regression.

RESULTS

Total testosterone levels in young men were inversely associated with subsequent prevalent NAFLD on unadjusted analysis (odds ratio [OR] 0.64, 95% confidence interval 0.53-0.7, P < 0.001), although no longer significant after adjustment for year 10 metabolic covariates as well as change in metabolic covariates from years 10 to 25 (OR 0.99, 95% confidence interval 0.76-1.27). In contrast, there was a significant inverse association of SHBG with prevalent NAFLD, independent of testosterone and metabolic covariates (OR 0.68, OR 0.51-0.92, P = 0.013). On formal mediation testing, visceral adiposity was found to explain ∼41.0% (95% confidence interval 27%-73%) of the association of lower SHBG with prevalent NAFLD.

CONCLUSIONS

Lower levels of SHBG in young men are associated with increase in prevalent NAFLD in middle age, independent of comprehensive metabolic risk factors. SHBG may provide a novel marker of NAFLD risk in young men.

Association of abdominal muscle composition with prediabetes and diabetes: The CARDIA study

AIM

To evaluate the relationship of abdominal muscle lean tissue and adipose tissue volumes with prediabetes and diabetes.

RESEARCH DESIGN AND METHODS

We measured abdominal muscle composition in 3170 participants in the Coronary Artery Risk Development in Young Adults (CARDIA) study who underwent computed tomography (CT) at Year 25 of follow-up (ages, 43-55 years). Multinomial regression analysis was used to evaluate the associations of CT-measured intermuscular adipose tissue (IMAT), lean muscle tissue (lean) and visceral adipose tissue (VAT) volumes with diabetes at any point during the CARDIA study, newly detected prediabetes, prior history of prediabetes, and normal glucose tolerance. Models were adjusted for potential confounding factors: age, sex, race, height, smoking status, hypertension, hyperlipidaemia, cardiorespiratory fitness and study centre.

RESULTS

Higher IMAT, lean and VAT volumes were all separately associated with a higher prevalence of prediabetes and diabetes. Inclusion of VAT volume in models with both IMAT volume and lean volume attenuated the association of IMAT with both prediabetes and diabetes, but higher lean volume retained its association with prediabetes and diabetes. Individuals in the highest IMAT quartile, coupled with VAT in its lower three quartiles, had a higher prevalence of diabetes, but not of prediabetes, than those with both IMAT and VAT in their respective lower three quartiles. Adjusting for cardiorespiratory fitness did not substantially change the findings.

CONCLUSION

Higher IMAT volume was associated with a higher prevalence of diabetes even after adjustment for VAT volume. However, further study is warranted to understand the complicated relationship between abdominal muscle and adipose tissues.

Coronary Calcium Detection using 3D Attention Identical Dual Deep Network Based on Weakly Supervised Learning

Coronary artery calcium (CAC) is biomarker of advanced subclinical coronary artery disease and predicts myocardial infarction and death prior to age 60 years. The slice-wise manual delineation has been regarded as the gold standard of coronary calcium detection. However, manual efforts are time and resource consuming and even impracticable to be applied on large-scale cohorts. In this paper, we propose the attention identical dual network (AID-Net) to perform CAC detection using scan-rescan longitudinal non-contrast CT scans with weakly supervised attention by only using per scan level labels. To leverage the performance, 3D attention mechanisms were integrated into the AID-Net to provide complementary information for classification tasks. Moreover, the 3D Gradient-weighted Class Activation Mapping (Grad-CAM) was also proposed at the testing stage to interpret the behaviors of the deep neural network. 5075 non-contrast chest CT scans were used as training, validation and testing datasets. Baseline performance was assessed on the same cohort. From the results, the proposed AID-Net achieved the superior performance on classification accuracy (0.9272) and AUC (0.9627).