Methods and Reproducibility of Liver Fat Measurement Using 3-Dimensional Liver Segmentation From Noncontrast Computed Tomography in EVAPORATE Cohort.

OBJECTIVE: Nonalcoholic fatty liver disease not only shares multiple risk factors with cardiovascular disease but also independently predicts its increased risk and related outcomes. Here, we evaluate reproducibility of 3-dimensional (3D) liver volume segmentation method to identify fatty liver on noncontrast cardiac computed tomography (CT) and compare measures with previously validated 2-dimensional (2D) segmentation CT criteria for the measurement of liver fat. METHODS: The study included 68 participants enrolled in the EVAPORATE trial and underwent serial noncontrast cardiac CT. Liver attenuation < 40 Hounsfield units (HU) was used for diagnosing fatty liver, as done in the MESA study. Two-dimensional and 3D segmentation of the liver were performed by Philips software. Bland-Altman plot analysis was used to assess reproducibility. RESULTS: Interreader reproducibility of 3D liver mean HU measurements was 96% in a sample of 111 scans. Reproducibility of 2D and 3D liver mean HU measurements was 93% in a sample of 111 scans. Reproducibility of change in 2D and 3D liver mean HU was 94% in 68 scans. Kappa, a measure of agreement in which the 2D and 3D measures both identified fatty liver, was excellent at 96.4% in 111 scans. CONCLUSIONS: Fatty liver can be reliably diagnosed and measured serially in a stable and reproducible way by 3D liver segmentation of noncontrast cardiac CT scans. Future studies need to explore the sensitivity and stability of measures for low liver fat content by 3D segmentation, over the current 2D methodology. This measure can serve as an imaging biomarker to understand mechanistic correlations between atherosclerosis, fatty liver, and cardiovascular disease risk.

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.

The Role of Cardiac Computed Tomography in Heart Failure.

PURPOSE OF REVIEW: Cardiac computed tomography (CT) is becoming a more widely applied tool in the diagnosis and management of a variety of cardiovascular conditions, including heart failure. The aim of this narrative review is to examine the role of cardiac CT in patients with heart failure. RECENT FINDINGS: Coronary computed tomographic angiography has robust diagnostic accuracy for ruling out coronary artery disease. These data are reflected in updated guidelines from major cardiology organizations. New roles for cardiac CT in myocardial imaging, perfusion scanning, and periprocedural planning, execution, and monitoring are being implemented. Cardiac CT is useful in ruling out coronary artery disease its diagnostic accuracy, accessibility, and safety. It is also intricately linked to invasive cardiac procedures that patients with heart failure routinely undergo.

COVID-19 IgG/IgM antibody testing in Los Angeles County, California.

Evidence suggests that asymptomatic and mild SARS-CoV-2 infections comprise > 95% of all cases. Developing a test that indicates past infection and possible immunity against the virus is important. We administered 244 antibody tests to three groups of high-risk population. The test consisted of an IgG component and an IgM component. The overall IgM/IgG positivity for patients with none, mild, moderate, and severe symptoms were 21.1%, 21.8%, 14.2%, and 26.9%, respectively. Those with moderate or severe symptoms were no more or less likely to have positive antibody tests than those with no or mild symptoms.

Effect of icosapent ethyl on progression of coronary atherosclerosis in patients with elevated triglycerides on statin therapy: final results of the EVAPORATE trial.

AIMS: Despite the effects of statins in reducing cardiovascular events and slowing progression of coronary atherosclerosis, significant cardiovascular (CV) risk remains. Icosapent ethyl (IPE), a highly purified eicosapentaenoic acid ethyl ester, added to a statin was shown to reduce initial CV events by 25% and total CV events by 32% in the REDUCE-IT trial, with the mechanisms of benefit not yet fully explained. The EVAPORATE trial sought to determine whether IPE 4 g/day, as an adjunct to diet and statin therapy, would result in a greater change from baseline in plaque volume, measured by serial multidetector computed tomography (MDCT), than placebo in statin-treated patients. METHODS AND RESULTS: A total of 80 patients were enrolled in this randomized, double-blind, placebo-controlled trial. Patients had to have coronary atherosclerosis as documented by MDCT (one or more angiographic stenoses with ≥20% narrowing), be on statin therapy, and have persistently elevated triglyceride (TG) levels. Patients underwent an interim scan at 9 months and a final scan at 18 months with coronary computed tomographic angiography. The pre-specified primary endpoint was change in low-attenuation plaque (LAP) volume at 18 months between IPE and placebo groups. Baseline demographics, vitals, and laboratory results were not significantly different between the IPE and placebo groups; the median TG level was 259.1 ± 78.1 mg/dL. There was a significant reduction in the primary endpoint as IPE reduced LAP plaque volume by 17%, while in the placebo group LAP plaque volume more than doubled (+109%) (P = 0.0061). There were significant differences in rates of progression between IPE and placebo at study end involving other plaque volumes including fibrous, and fibrofatty (FF) plaque volumes which regressed in the IPE group and progressed in the placebo group (P < 0.01 for all). When further adjusted for age, sex, diabetes status, hypertension, and baseline TG, plaque volume changes between groups remained significantly different, P < 0.01. Only dense calcium did not show a significant difference between groups in multivariable modelling (P = 0.053). CONCLUSIONS: Icosapent ethyl demonstrated significant regression of LAP volume on MDCT compared with placebo over 18 months. EVAPORATE provides important mechanistic data on plaque characteristics that may have relevance to the REDUCE-IT results and clinical use of IPE.

Comparison of electrocardiogram quality and clinical interpretations using prepositioned ECG electrodes and conventional individual electrodes.

BACKGROUND: Efforts have been made to simplify and reduce technical errors, such as limb leads reversal and inaccurate chest leads placement, for the 12-lead ECG tests. We compared standard ECG using individual electrodes with a novel pre-positioned electrode system to determine equivalency. METHODS: Subjects were recruited from the Emergency Department and cardiac lab of an acute care hospital in Los Angeles. First, subjects underwent a conventional 12-lead ECG using Philips PageWriter (clinical ECG). A second ECG was then performed using a novel system containing pre-positioned electrodes and a compact recorder (study ECG). All ECGs were reviewed by 3 blinded, board-certified adult cardiologists using 14 pre-specified ECG diagnostic categories to determine if the interpretations of clinical ECG and study ECG of the same patient were "equivalent". Majority rule was applied when there were discrepant interpretations among the 3 cardiologists. RESULTS: One hundred subjects, ages 18 to 74 completed the study. With pre-positioned electrodes, the rate of "electrode fit" as judged by the research associates at the time of lead placement was 96.2%. We found that the study ECG system was equivalent (in clinical interpretation) to the clinical ECG system, with equivalency rate of 96% (95% confidence interval 92% to 100%) in "overall interpretation". The equivalence rate for the 14 ECG diagnostic categories ranged from 96% to 100%, with mean 99.2 ± 1.1%. CONCLUSIONS: 12-lead ECGs performed using single-piece, pre-positioned electrodes are clinically equivalent to those performed using 10 individually placed conventional electrodes. With 4 sizes for adults, the single-piece electrodes can fit 96% of the study patients.

A Leaky False Pouch: Left Ventricle Pseudoaneurysm with Active Hemopericardium Detected on Cardiac Computed Tomography Angiography.

Pseudoaneurysm is a rare but fatal complication of myocardial infarction (MI). With the advances in cardiovascular disease detection and treatments, fatal structural complications post-MI are now rare. When they occur, advanced diagnostic modalities can be used for early diagnosis, aiding surgical planning, and improving prognosis. In our case, post-MI left ventricle pseudoaneurysm complicated by hemopericardium was diagnosed using cardiac computed tomography angiography (CCTA). Use of attenuation measurement on CCTA helped diagnose active extravasation into the hemopericardium. This case highlights the high index of suspicion needed for rare but fatal complications post-MI and the utility of CCTA in their management.

AI-enabled cardiac chambers volumetry in coronary artery calcium scans (AI-CACTM) predicts heart failure and outperforms NT-proBNP: The multi-ethnic study of Atherosclerosis.

INTRODUCTION: Coronary artery calcium (CAC) scans contain useful information beyond the Agatston CAC score that is not currently reported. We recently reported that artificial intelligence (AI)-enabled cardiac chambers volumetry in CAC scans (AI-CAC™) predicted incident atrial fibrillation in the Multi-Ethnic Study of Atherosclerosis (MESA). In this study, we investigated the performance of AI-CAC cardiac chambers for prediction of incident heart failure (HF). METHODS: We applied AI-CAC to 5750 CAC scans of asymptomatic individuals (52% female, White 40%, Black 26%, Hispanic 22% Chinese 12%) free of known cardiovascular disease at the MESA baseline examination (2000-2002). We used the 15-year outcomes data and compared the time-dependent area under the curve (AUC) of AI-CAC volumetry versus NT-proBNP, Agatston score, and 9 known clinical risk factors (age, gender, diabetes, current smoking, hypertension medication, systolic and diastolic blood pressure, LDL, HDL for predicting incident HF over 15 years. RESULTS: Over 15 years of follow-up, 256 HF events accrued. The time-dependent AUC [95% CI] at 15 years for predicting HF with AI-CAC all chambers volumetry (0.86 [0.82,0.91]) was significantly higher than NT-proBNP (0.74 [0.69, 0.77]) and Agatston score (0.71 [0.68, 0.78]) (p â€‹< â€‹0.0001), and comparable to clinical risk factors (0.85, p â€‹= â€‹0.4141). Category-free Net Reclassification Index (NRI) [95% CI] adding AI-CAC LV significantly improved on clinical risk factors (0.32 [0.16,0.41]), NT-proBNP (0.46 [0.33,0.58]), and Agatston score (0.71 [0.57,0.81]) for HF prediction at 15 years (p â€‹< â€‹0.0001). CONCLUSION: AI-CAC volumetry significantly outperformed NT-proBNP and the Agatston CAC score, and significantly improved the AUC and category-free NRI of clinical risk factors for incident HF prediction.

Thoracic versus coronary calcification for atherosclerotic cardiovascular disease events prediction.

This study compared the prognostic value of quantified thoracic artery calcium (TAC) including aortic arch on chest CT and coronary artery calcium (CAC) score on ECG-gated cardiac CT. METHODS: A total of 2412 participants who underwent both chest CT and ECG-gated cardiac CT at the same period were included in the Multi-Ethnic Study of Atherosclerosis Exam 5. All participants were monitored for incident atherosclerotic cardiovascular disease (ASCVD) events. TAC is defined as calcification in the ascending aorta, aortic arch and descending aorta on chest CT. The quantification of TAC was measured using the Agatston method. Time-dependent receiver-operating characteristic (ROC) curves were used to compare the prognostic value of TAC and CAC scores. RESULTS: Participants were 69±9 years of age and 47% were male. The Spearman correlation between TAC and CAC scores was 0.46 (p<0.001). During the median follow-up period of 8.8 years, 234 participants (9.7%) experienced ASCVD events. In multivariable Cox regression analysis, TAC score was independently associated with increased risk of ASCVD events (HR 1.31, 95% CI 1.09 to 1.58) as well as CAC score (HR 1.82, 95% CI 1.53 to 2.17). However, the area under the time-dependent ROC curve for CAC score was greater than that for TAC score in all participants (0.698 and 0.641, p=0.031). This was particularly pronounced in participants with borderline/intermediate and high 10-year ASCVD risk scores. CONCLUSION: Our study demonstrated a significant association between TAC and CAC scores but a superior prognostic value of CAC score for ASCVD events. These findings suggest TAC on chest CT provides supplementary data to estimate ASCVD risk but does not replace CAC on ECG-gated cardiac CT.

AI-enabled left atrial volumetry in coronary artery calcium scans (AI-CACTM) predicts atrial fibrillation as early as one year, improves CHARGE-AF, and outperforms NT-proBNP: The multi-ethnic study of atherosclerosis.

BACKGROUND: Coronary artery calcium (CAC) scans contain actionable information beyond CAC scores that is not currently reported. METHODS: We have applied artificial intelligence-enabled automated cardiac chambers volumetry to CAC scans (AI-CACTM) to 5535 asymptomatic individuals (52.2% women, ages 45-84) that were previously obtained for CAC scoring in the baseline examination (2000-2002) of the Multi-Ethnic Study of Atherosclerosis (MESA). AI-CAC took on average 21 â€‹s per CAC scan. We used the 5-year outcomes data for incident atrial fibrillation (AF) and assessed discrimination using the time-dependent area under the curve (AUC) of AI-CAC LA volume with known predictors of AF, the CHARGE-AF Risk Score and NT-proBNP. The mean follow-up time to an AF event was 2.9 â€‹± â€‹1.4 years. RESULTS: At 1,2,3,4, and 5 years follow-up 36, 77, 123, 182, and 236 cases of AF were identified, respectively. The AUC for AI-CAC LA volume was significantly higher than CHARGE-AF for Years 1, 2, and 3 (0.83 vs. 0.74, 0.84 vs. 0.80, and 0.81 vs. 0.78, respectively, all p â€‹< â€‹0.05), but similar for Years 4 and 5, and significantly higher than NT-proBNP at Years 1-5 (all p â€‹< â€‹0.01), but not for combined CHARGE-AF and NT-proBNP at any year. AI-CAC LA significantly improved the continuous Net Reclassification Index for prediction of AF over years 1-5 when added to CHARGE-AF Risk Score (0.60, 0.28, 0.32, 0.19, 0.24), and NT-proBNP (0.68, 0.44, 0.42, 0.30, 0.37) (all p â€‹< â€‹0.01). CONCLUSION: AI-CAC LA volume enabled prediction of AF as early as one year and significantly improved on risk classification of CHARGE-AF Risk Score and NT-proBNP.

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.

Exploring the relationship between epicardial fat and coronary plaque burden and characteristics: insights from cardiac ct imaging.

Epicardial adipose tissue (EAT) may enhance the risk of coronary artery disease (CAD). We investigated the relationship between EAT density (a maker of local inflammation) and coronary plaque characteristics in stable CAD patients. This study included 123 individuals who underwent coronary artery calcium scan and coronary CT angiography to evaluate CAD. Plaque characteristics were analyzed by semi-automated software (QAngio, Leiden, Netherlands). Non-contrast CT scans were used to measure EAT density (HU) and volume (cc) (Philips, Cleveland, OH). Multivariate regression models were used to evaluate the association of EAT density and volume with different plaque types. The mean (SD) age was 59.4±10.1 years, 53% were male, the mean (SD) EAT density was -77.2±4.6 HU and the volume was 118.5±41.2 cc. After adjustment for cardiovascular risk factors, EAT density was associated with fibrous fatty (FF) plaque (p<0.03). A 1 unit increase in HU was associated with a 7% higher FF plaque, and lower EAT density is independently associated to FF plaque. The association between EAT density and fibrous (p=0.08), and total noncalcified (p=0.09) plaque trended toward but did not reach significance. There was no association between EAT volume and any plaque type. These results suggest that inflammatory EAT may promote coronary atherosclerosis. Therefore, non-contrast cardiac CT evaluation of EAT quality can help better assess cardiovascular risk.

Anti-inflammatory Therapeutics and Coronary Artery Disease.

It has been demonstrated that atherosclerotic disease progression is contingent upon chronic inflammation. The sequence of events leading up to plaque formation, instability, and eventual plaque rupture hinges upon the interaction of proinflammatory cytokines and fat deposition within the coronary vasculature. Over the past decade, a large body of evidence has demonstrated the efficacy of specific anti-inflammatory therapeutics in halting the progression of coronary artery disease. Despite this, these therapeutics have yet to be included in guideline-directed medical therapy regimens. This review will focus on several anti-inflammatories, which have been studied in the context of cardiovascular disease-colchicine, canakinumab, VIA-2291, and methotrexate, and will highlight the potential benefits majority hold in hindering atherosclerosis and cardiovascular disease progression. This holds especially true for individuals already on optimal medical therapy who continue to be at high risk for adverse cardiovascular events.

Case Report: Culture-negative Prosthetic Valve Endocarditis.

BACKGROUND: Prosthetic valve endocarditis can be difficult to diagnose and cause significant morbidity and mortality, especially when no culture data are available to guide therapy. Transthoracic and transesophageal echocardiograms, the studies of choice for initial endocarditis evaluation, can be less reliable due to artifact and post-surgical changes. Some less common forms of endocarditis may be difficult to culture and, due to their fastidious nature, may delay the identification of causative organisms. Given the lack of directed antimicrobial treatment, culturenegative prosthetic valve endocarditis is specifically difficult. A wide differential diagnosis is critical to make a timely diagnosis and initiate treatment. CASE PRESENTATION: We present a case of a patient presenting with dyspnea which was found to have culture-negative endocarditis requiring mitral and aortic valve replacement that ultimately was complicated with culture-negative prosthetic valve endocarditis. Identifying a culprit organism made appropriate and timely antimicrobial treatment difficult, ultimately resulting in the patient dying from endocarditis complications. CONCLUSION: A high index of suspicion is needed when managing infective endocarditis, especially when prosthetic valves are involved. Diagnostic accuracy of cultures and echocardiography may be reduced when dealing with prosthetic valve endocarditis; thus, alternative methods of diagnosis may be required to make a timely diagnosis of causative organisms.

Coronary artery calcium progression and all-cause mortality.

BACKGROUND: Coronary artery calcium (CAC) has been demonstrated as a noninvasive, low-cost means of assessing atherosclerotic burden and risk of major cardiovascular events. While it has been previously shown that CAC progression predicts all-cause mortality, we sought to quantify this association by examining a large cohort over a follow-up period of 1-22 years. METHODS: We studied 3260 persons aged 30-89 years referred by their primary physician for CAC measurement, with a follow-up scan at least 12 months from the initial scan. Receiver operator characteristic (ROC) curves assessed a level of annualized CAC progression that predicted all-cause mortality. Multivariate analyses using Cox proportional hazards models were used to compute hazard ratios and 95% confidence intervals (CIs) for the association between annualized CAC progression and death after adjusting for relevant cardiovascular risk factors. RESULTS: The average time between scans was 4.7 ±â€…3.2 years with an additional average of 9.1 ±â€…4.0 years of follow-up time. The average age of the cohort was 58.1 ±â€…10.5 years, 70% being male, and 164 deaths occurred. Annualized CAC progression of 20 units optimized sensitivity (58%) and specificity (82%) in ROC curve analysis. Annualized CAC progression of 20 units was significantly associated with mortality while adjusting for age, sex, race, diabetes, hypertension, hyperlipidemia, smoking, baseline CAC level, family history, and time between scans, hazard ratio 1.84 (95% CI, 1.28-2.64) P = 0.001. CONCLUSION: Annualized CAC progression of greater than 20 units per year significantly predicts all-cause mortality. This may add clinical value in encouraging close surveillance and aggressive treatment of individuals within this range.

Efficacy and Safety of Iodixanol in Computed Coronary Tomographic Angiography and Cardiac Catheterization.

Iodixanol is an iso-osmolar non-ionic dimeric hydrophilic contrast agent with a higher viscosity than the monomeric agents. It is the only Food and Drug Administration (FDA)-approved iso-osmolar agent in the United States, and it is the only contrast agent with an FDA-approved indication for use in cardiac computed tomographic angiography (CCTA), to assist in the diagnostic evaluation of patients with suspected coronary artery disease. In clinical studies, it has been noted to have fewer side effects and similar image quality when compared to low-osmolar contrast media. This can be attributed to the pharmacological properties of iodixanol. These contrast agents are used for coronary computed tomography angiography and cardiac catheterization. In this article, the use, tolerability, and efficacy of iodixanol are reviewed, specifically evaluating the use of CCTA and coronary angiography, including outcome studies, randomized trials, and comparisons to other contrast agents.

Ruptured Sinus of Valsalva Aneurysm Diagnosed on Coronary Computed Tomography Angiography in a Patient With Trisomy 13 Syndrome.

Trisomy 13 is a rare chromosomal disorder in which all or a percentage (mosaicism) of cells contain an extra 13th chromosome. Sinus of Valsalva aneurysms are rare, with an incidence of 0.1% to 3.5% of all congenital heart defects. This article reports the case of a patient with trisomy 13 with a new systolic murmur found to have a ruptured sinus of Valsalva aneurysm diagnosed on coronary computed tomography angiography. This is the first case to report sinus of Valsalva aneurysm rupture secondary to Streptococcus viridans endocarditis in a patient with trisomy 13 syndrome and highlights the importance of coronary computed tomography angiography in noninvasive imaging and surgical planning.

Evaluation of Image Quality for High Heart Rates for Coronary Computed Tomographic Angiography with Advancement in CT Technology: The CONVERGE Registry.

OBJECTIVE: This study aims to evaluate image quality in patients with heart rates above or equal to 70 beats per minute (bpm), performed on a 16 cm scanner (256-slice General Electric Revolution) in comparison to a CT scanner with only 4 cm of coverage (64 slice Volume CT). BACKGROUND: Recent advancements in image acquisition, such as whole-heart coverage in a single rotation and post-processing methods in coronary computed tomographic angiography (CCTA), include motion-correction algorithms, such as SnapShot Freeze (SSF), which improve temporal resolution and allow for the assessment of coronary artery disease (CAD) with lower motion scores and better image qualities. Studies from the comprehensive evaluation of high temporal- and spatial-resolution cardiac CT using a wide coverage system (CONVERGE) registry (a multicenter registry at four centers) have shown the 16 cm CT scanner having a better image quality in comparison to the 4 cm scanner. However, these studies failed to include patients with undesirable or high heart rates due to well-documented poor image acquisition on prior generations of CCTA scanners. METHODS: A prospective, observational, multicenter cohort study comparing image quality, quantitively and qualitatively, on scans performed on a 16 cm CCTA in comparison to a cohort of images captured on a 4 cm CCTA at four centers. Participants were recruited based on broad inclusion criteria, and each patient in the 16 cm CCTA arm of the study received a CCTA scan using a 256-slice, whole-heart, single-beat scanner. These patients were then matched by age, gender, and heart rate to patients who underwent CCTA scans on a 4 cm CT scanner. Image quality was graded based on the signal-to-noise ratio, contrast-to-noise ratio, and on a Likert scale of 0-4: 0, very poor-4, excellent. RESULTS: 104 patients were evaluated for this study. The mean heart rate was 75 ± 7 in the 4 cm scanner and 75 ± 7 in the 16 cm one (p = 0.426). The signal-to-noise and contrast-to-noise ratios were higher in the 16 cm scanner (p = 0.0001). In addition, more scans were evaluated as having an excellent quality on the 16 cm scanner than on the 4 cm scanner (p < 0.0001) based on a 4-point Likert scale. CONCLUSIONS: The 16 cm scanner has a superior image quality for fast heart rates compared to the 4 cm scanner. This study shows that there is a significantly higher frequency of excellent and good studies showing better contrast-to-noise and signal-to-noise ratios with the 16 cm scanner compared to the 4 cm scanner.

Quantitative imaging biomarkers of coronary plaque morphology: insights from EVAPORATE.

Aims: Residual cardiovascular risk persists despite statin therapy. In REDUCE-IT, icosapent ethyl (IPE) reduced total events, but the mechanisms of benefit are not fully understood. EVAPORATE evaluated the effects of IPE on plaque characteristics by coronary computed tomography angiography (CCTA). Given the conclusion that the IPE-treated patients demonstrate that plaque burden decreases has already been published in the primary study analysis, we aimed to demonstrate whether the use of an analytic technique defined and validated in histological terms could extend the primary study in terms of whether such changes could be reliably seen in less time on drug, at the individual (rather than only at the cohort) level, or both, as neither of these were established by the primary study result. Methods and Results: EVAPORATE randomized the patients to IPE 4 g/day or placebo. Plaque morphology, including lipid-rich necrotic core (LRNC), fibrous cap thickness, and intraplaque hemorrhage (IPH), was assessed using the ElucidVivo® (Elucid Bioimaging Inc.) on CCTA. The changes in plaque morphology between the treatment groups were analyzed. A neural network to predict treatment assignment was used to infer patient representation that encodes significant morphological changes. Fifty-five patients completed the 18-month visit in EVAPORATE with interpretable images at each of the three time points. The decrease of LRNC between the patients on IPE vs. placebo at 9 months (reduction of 2 mm3 vs. an increase of 41 mm3, p = 0.008), widening at 18 months (6 mm3 vs. 58 mm3 increase, p = 0.015) were observed. While not statistically significant on a univariable basis, reductions in wall thickness and increases in cap thickness motivated multivariable modeling on an individual patient basis. The per-patient response assessment was possible using a multivariable model of lipid-rich phenotype at the 9-month follow-up, p < 0.01 (sustained at 18 months), generalizing well to a validation cohort. Conclusion: Plaques in the IPE-treated patients acquired more characteristics of stability. Reliable assessment using histologically validated analysis of individual response is possible at 9 months, with sustained stabilization at 18 months, providing a quantitative basis to elucidate drug mechanism and assess individual patient response.

Coronary Computed Tomography Angiography for Evaluation of Chest Pain in the Emergency Department.

Coronary computed tomography angiography has emerged as an important diagnostic modality for evaluation of acute chest pain in the emergency department for patients at low to intermediate risk for acute coronary syndromes. Several clinical trials have shown excellent negative predictive value of coronary computed tomography angiography to detect obstructive coronary artery disease. Cardiac biomarkers such as troponins and creatine kinase MB, along with history, electrocardiogram, age, risk factors, troponin score, and Thrombolysis in Myocardial Infarction score should be used in conjunction with coronary computed tomography angiography for safe and rapid discharge of patients from the emergency department. Coronary computed tomography angiography along with high-sensitivity troponin assays could be effective for rapid evaluation of acute chest pain in the emergency department, but high-sensitivity troponins are not always available. Emergency department physicians are not quite comfortable making clinical decisions, especially if the coronary stenosis is in the range of 50% to 70%. In these cases, further evaluation with functional testing, such as nuclear stress testing or stress echocardiogram, is a common approach in many centers; however, newer methods such as fractional flow reserve computed tomography could be safely incorporated in coronary computed tomography angiography to help with clinical decision-making in these scenarios.