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PURPOSE OF REVIEW: To provide an update and to outline the status of coronary computer tomography angiography (CCTA) in evaluation of coronary plaques and discuss the relevance of serial CCTA in guiding cardiovascular risk stratification and anti- atherosclerotic medical therapy. RECENT FINDINGS: Coronary CTA is now the imaging modality of choice in monitoring changes in coronary plaque. It has been used in innumerable clinical trials which have demonstrated the benefits of several therapeutic agents and has excellent correlation with previously used invasive imaging modalities. It is safe, fast, less cumbersome, and a cost-effective testing method compared to other invasive imaging modalities for coronary plaque analysis. SUMMARY: The emergence of a noninvasive imaging modality such as CCTA, now permits quantification not only of plaque burden but also allows for further distinction of plaque components and identification of vulnerable plaques. Application of these findings continues to extend the prospect of coronary CTA in evaluation and management of atherosclerotic coronary artery disease (CAD) in clinical practice. In the future artificial intelligence and machine learning will play a significant role in plaque analysis allowing for high accuracy and reproducibility which will lead to a substantial increase in the utilization of coronary CTA.

Background Coronary artery calcium (CAC) density is inversely associated with coronary heart disease (CHD) and cardiovascular disease (CVD) risk. We examined this relation in those with diabetes mellitus (DM) or metabolic syndrome (MetS). Methods We studied 3,818 participants with non-zero CAC scores from the Multiethnic Study of Atherosclerosis and classified them as DM, MetS (without DM) or neither DM/MetS. Risk factor-adjusted CAC density was calculated and examined in relation to incident CHD and CVD events over a median follow-up of 15 years among these three disease groups. Results Adjusted CAC density was 2.54, 2.61 and 2.69 among those with DM, MetS or neither DM/MetS. Hazard ratios (HRs) for CHD per 1 SD increase of CAC density was 0.91 (95% CI: 0.72–1.16), 0.70 (95% CI: 0.56–0.87) and 0.79 (95% CI: 0.66–0.95) for those with DM, MetS or neither DM/MetS groups and were 0.77 (95% CI: 0.64–0.94), 0.83 (95% CI: 0.70–0.99) and 0.82 (95% CI: 0.71–0.95) for CVD, respectively. Adjustment for CAC density increased the HRs of CAC volume for CHD/CVD events. Compared to prediction models with or without single CAC measures, c-statistics of models with CAC volume and density were the highest ranging 0.67–0.72. Conclusion CAC density is lower among patients with DM or MetS than those with neither DM/MetS and is inversely associated with future CHD/CVD risk among them. Including CAC density in risk assessment among those with MetS may improve prediction of CHD and CVD.

Introduction VERTIS CV is the cardiovascular outcome trial for the sodium–glucose cotransporter 2 (SGLT2) inhibitor ertugliflozin. A sub-study was conducted to assess the efficacy and safety of ertugliflozin in patients with type 2 diabetes mellitus (T2DM) inadequately glycemic-controlled on metformin and a sulfonylurea (SU). Methods Patients with T2DM, established atherosclerotic cardiovascular disease (ASCVD), and an HbA1c of 7.0–10.5% on stable metformin (≥ 1500 mg/day) and moderate to high SU doses were randomly assigned to once-daily ertugliflozin (5 or 15 mg) or placebo. The primary sub-study objectives were to assess the effect of ertugliflozin on HbA1c compared with placebo and to evaluate safety following 18 weeks of treatment. Key secondary endpoints included changes in fasting plasma glucose (FPG), body weight (BW), blood pressure (BP), and the proportion of patients achieving HbA1c

Coronary artery calcium (CAC) scoring is used in asymptomatic patients to improve their clinically predicted risk for future cardiovascular events. Current CT protocols seek to reduce radiation exposure without diminishing image quality. Reported radiation exposure remains widely variable (0.8–5 mSv) depending on the type of protocol. In this study, we report the radiation exposure of CAC scoring from the Society for Heart Attack Prevention and Eradication (SHAPE) early detection program cohort sites, which spanned multiple centers using 64-MDCT (multi-detector computed tomography) scanners. We reviewed radiation exposure in milliSieverts (mSv) for 82,214 participants from the SHAPE early detection program cohort who underwent CAC scoring. This occurred over a 2.5-year period (2012–2014) divided among 33 sites in 7 countries with four different types 64-MDCT scanners. The effective radiation dose was reported as mSv. Mean radiation dosing amongst all 82,214 participants was 1.03 mSv, a median dose of 0.94 mSv. The mean radiation dose ranged from 0.76 to 1.31 mSv across the 33 sites involved with the SHAPE program cohort. Subgroup analysis by age, gender or body mass index (BMI) less than 30 kg/m2 showed no variability. Radiation dose in patients with BMI > 30 kg/m2 were significantly greater than other subgroups (µ = 1.96 mSv, p

Although single photon emission computed tomography-myocardial perfusion image (SPECT-MPI) and fractional flow reserve (FFR) derived from coronary computed tomographic angiography (CCTA) (FFRCT) have permitted functional assessment of coronary artery disease (CAD), the concordance between these modalities has not been well described. The aim of this study is to compare SPECT-MPI and anatomical stenosis by CCTA and invasive coronary angiography to FFRCT for assessing functional significance of CAD. We identified 62 patients with suspected CAD who underwent ≥64 slice coronary CTA and SPECT-MPI within 3 months. FFRCT was analyzed from CCTA data using the computational fluid dynamic techniques. The association between SPECT-MPI ischemia and FFRCT (≤0.80) was evaluated. Out of 62 patients, 186 vessels were evaluated. On a per-vessel analysis, accuracy, sensitivity and specificity of SPECT-MPI to predict FFRCT ≤ 0.80 was 74.2, 45.0 and 77.7%, respectively. The area under the curve (AUC) by receiver-operating characteristic curve analysis for SPECT-MPI demonstrated a modest performance for predicting FFRCT ≤ 0.80 (AUC 0.56). Among patients with suspected CAD who were assessed by non-invasive functional modalities, SPECT-MPI showed modest concordance with FFRCT.

Background Persons with human immunodeficiency virus (HIV) have higher risks for myocardial infarction (MI) than the general population. This is driven in part by higher type 2 MI (T2MI, due to coronary supply-demand mismatch) rates among persons with HIV (PWH). In the general population, T2MI has higher mortality than type 1 MI (T1MI, spontaneous and generally due to plaque rupture and thrombosis). PWH have a greater burden of comorbidities and may therefore have an even greater excess risk for complication and death in the setting of T2MI. However, mortality patterns after T1MI and T2MI in HIV are unknown. Methods We analyzed mortality after MI among PWH enrolled in the multicenter, US-based Centers for AIDS Research Network of Integrated Clinical Systems (CNICS) cohort (N = 28,186). Incident MIs occurring between January 1, 1996, and December 31, 2014, were centrally adjudicated and classified as T1MI or T2MI. We first compared mortality following T1MI vs. T2MI among PWH. Cox survival analyses and Bayesian model averaging were then used to evaluate pre-MI covariates associated with mortality following T1MI and T2MI. Results Among the 596 out of 28,186 PWH who experienced MI (2.1%; 293 T1MI and 303 T2MI), mortality rates were significantly greater after T2MI (22.2/100 person-years; 1-, 3-, and 5-year mortality 39%, 52%, and 62%) than T1MI (8.2/100 person-years; 1-, 3-, and 5-year mortality 15%, 22%, and 30%). Significant mortality predictors after T1MI were higher HIV viral load, renal dysfunction, and older age. Significant predictors of mortality after T2MI were low body-mass index (BMI) and detectable HIV viral load. Conclusions Mortality is high following MI for PWH and substantially greater after T2MI than T1MI. Predictors of death after MI differed by type of MI, reinforcing the different clinical scenarios associated with each MI type and the importance of considering MI types separately. Electronic supplementary material The online version of this article (10.1186/s12916-019-1385-7) contains supplementary material, which is available to authorized users.

© 2015 Springer Science+Business Media Dordrecht With the increasing use of coronary artery calcium (CAC) scoring to risk stratify asymptomatic patients for future cardiovascular events, there have been concerns raised regarding the theoretical risk of radiation exposure to this potentially large patient population. Newer CT protocols have sought to reduce radiation exposure without compromising image quality, but the reported radiation exposures in the literature remains widely variable (0.7–10.5 mSv). In this study, we report the radiation exposure of calcium scoring from our MESA cohort across several modern CT scanners with the aim of clarifying the radiation exposure of this imaging modality. To evaluate the mean effective doses of radiation, using dose length product, utilized for coronary artery calcium scoring in the MESA cohort, in an effort to understand estimated population quantity effective dose using individual measurements of scanner radiation output using current CT scanners. We reviewed effective dose in milliSieverts (mSv) for 3442 participants from the MESA cohort undergoing coronary artery calcium scoring, divided over six sites with four different modern CT scanners (Siemens64, Siemens Somatom Definition, GE64, and Toshiba 320). For effective dose calculation (milliSieverts, mSv), we multiplied the dose length product by conversion factor k (0.014). The mean effective dose amongst all participants was 1.05 mSv, a median dose of 0.95 mSV. The mean effective dose ranged from 0.74 to 1.26 across the six centers involved with the MESA cohort. The Siemens Somatom Definition scanner had effective dose of 0.53 (n = 123), Siemens 64 with 0.97 (n = 1684), GE 64 with 1.16 (n = 1219), and Toshiba 320 with 1.26 mSv (n = 416). Subgroup analysis by BMI, age, and gender showed no variability between scanners, gender, ages 45–74 years old, or BMI less than 30 kg/m2. Subjects over age 75 yo had a mean effective dose of 1.29 ± 0.31 mSv, while the 40 kg/m2 was significantly greater than other subgroups, with mean dose of 1.47 ± 0.51 mSv (p < 0.01). Using contemporary CT scanners and protocols, the effective dose for coronary artery calcium is approximately 1 mSv, an estimate which is consistently lower than previously reported for CAC scanning, regardless of age, gender, and body mass index.

Nonalcoholic fatty liver disease (NAFLD) is the number one cause of liver disease in the United States. The prevalence rates in African Americans (AA), while significantly lower than other ethnic groups with similar known risk factors, have been quoted as high as 24 %. We aim to determine if the presence of NAFLD in African Americans is associated with lower triglyceride and/or higher HDL-c levels and if NAFLD risk factors in African Americans differ from other ethnic groups.A total of 3,056 participants of the Multi Ethnic Study of Atherosclerosis were included in this study. We utilized the baseline serum, anthropometric and radiographic measurements obtained between 2000 and 2002. NAFLD was defined as liver spleen ratio1 from CT measurements.The prevalence of NAFLD was and 11 % in AA. We found that age, education, triglyceride levels, HDL-c levels, waist circumference and HOMA-IR were independent correlates of NAFLD in this population. Among those with NAFLD, AA had significantly lower triglyceride levels than Hispanics [125 mg/dl (95 % CI 107-143) versus 192 mg/dl (95 % CI 169-215), p0.001] and Caucasians [185 mg/dl (95 % CI 161-209), p = 0.001]. Serum HDL-c was significantly higher in AA with NAFLD (47 mg/dl; 95 % CI 45-50) when compared to Hispanics (44 mg/dl; 95 % CI 43-66, p = 0.02) and Caucasians (44 mg/dl; 95 % CI 42-46, p = 0.02) with NAFLD.This study demonstrated that the clinical correlates of NAFLD in African Americans are similar to the correlates of NAFLD in other ethnic groups. Our data also suggests that when evaluating African Americans for NAFLD risk, lower cutoff values should be used to define abnormal triglyceride levels.

Cardiovascular disease (CVD) remains the leading cause of death among adults with diabetes, and CVD prevention remains a major challenge. Coronary artery calcium (CAC) score measured by electron beam tomography (EBT) or multi-slice detector computed tomography correlates closely with plaque burden and coronary angiography, and predicts coronary events independently of other risk factors. Further, progression of CAC over several years has been shown to predict increased mortality. Coronary calcification is an active process strongly associated with atherosclerotic plaque evolution and is an accepted surrogate endpoint in studies of patients with diabetes older than 30. In this review, recent findings regarding the mechanisms and implications of vascular calcification in diabetes will be discussed.

Regional ejection fraction (REF) provides important functional information of the left ventricular regional myocardium. We aimed to test the diagnostic accuracy of computerized REF analysis for detecting the ischemia and significant stenosis with multidetector CT angiography (MDCT). This is a retrospective study including 155 patients who underwent MDCT scans for evaluation of coronary artery disease. Among them, 83 patients also underwent SPECT imaging and invasive coronary angiography (ICA). Two groups of patients were defined: Control group with 0 coronary artery calcium and normal global and regional ventricular function, and comparison group. REF measurement was performed on all patients using computerized software. Control group REF measurements will be used as reference standard (mean-2SD REF/mean global ejection fraction) to define abnormal REF. The sensitivity, specificity, positive and negative predictive value of REF in detecting perfusion defects (fixed and reversible) was 73, 80, 75 and 79 % respectively, in a patient based analysis of comparison group. The diagnostic accuracy of REF in predicting significant stenosis (>50 %) on ICA compared with SPECT was 72 versus 61 % and 85 versus 79 % in patient and vessel based analysis of comparison group, respectively. ROC curve analysis showed REF to be a better predictor of perfusion defects on SPECT compared with significant stenosis (>50 %) alone or stenosis combined with REF (P < 0.05). The computerized assessment of REF analysis is comparable to SPECT in predicting ischemia and a better predictor of significant stenosis than SPECT. This study also provides reference standard to define abnormal values.

Coronary computed tomographic angiography (CCTA) employing CT scanners of 64-detector rows or greater represents a novel non-invasive method for detection of coronary artery disease (CAD), providing excellent diagnostic information when compared to invasive angiography. In addition to its high diagnostic performance, prior studies have shown that CCTA can provide important prognostic information, although these prior studies have been generally limited to small cohorts at single centers. The Coronary CT Angiography Evaluation for Clinical Outcomes: An International Multicenter registry, or CONFIRM, is a large, prospective, multinational, dynamic observational cohort study of patients undergoing CCTA. This registry currently represents more than 32,000 consecutive adults suspected of having CAD who underwent a parts per thousand yen64-detector row CCTA at 12 centers in 6 countries between 2005 and 2009. Based on its large sample size and adequate statistical power, the data derived from CONFIRM registry have and will continue to provide key answers to many important topics regarding CCTA. Based on its multisite international national design, the results derived from CONFIRM should be considered as more generalizable than prior smaller single-center studies. This article summarizes the current status of several studies from CONFIRM registry.

Cardiovascular disease is the leading cause of mortality in women. Results from observational studies consistently demonstrated lower heart disease rates among women who used hormone replacement therapy (HRT) compared to non-users. Data from two large randomized controlled trials showed mixed results. Subsequent post-hoc analysis found cardiovascular disease among HRT users to be lower than non-users in women 50 to 59 years of age or less than 10 years post-menopause. This has sparked much debate on the role of postmenopausal hormone therapy, especially in peri-menopausal women. Two hypotheses have been suggested to explain this divergent data: 1) HRT may be cardioprotective when introduced prior to atherosclerosis development but may be harmful in women with established CVD; or 2) HRT may be useful when started closer to menopause initiation and harmful when started later in life.

ObjectiveTo investigate whether leptin and adiponectin are associated with body fat composition in a South Asian population independent of metabolic variables.DesignCross-sectional study.Subjects150 South Asian men and women, between the ages of 45-79 years, in the San Francisco Bay Area without pre-existing clinical cardiovascular disease.MeasurementsBlood samples were obtained to measure glucose metabolism variables, lipid profiles and adipokines. Total body fat was determined using dual-energy X-ray absorptiometry. Abdominal computed tomography was used to measure subcutaneous, visceral and hepatic fat.ResultsAverage body mass index (BMI) was overweight at 26.1±4.6 kg m(-2) and did not differ by sex. However, women had significantly more total body fat (P

To determine via meta-analysis the diagnostic accuracy of 64-slice computed tomography coronary angiography (CTA) for assessment of significant obstructive coronary artery stenosis at different coronary artery calcium score (CACS) levels. Data of 12,053 versus 5,890 segments, 906 versus 758 arteries and 1,120 versus 514 patients in low versus high CACS subgroups from 19 eligible studies were compared. The per-patient prevalence of coronary artery disease was 48% versus 68%, respectively. Subgroups were stratified by different CACS thresholds ranging from 100 to 400. Meta-analyses of per-patient data comparing overall low versus high CACS subgroups resulted in a sensitivity of 97.5 (95.5–99)% versus 97 (94.5–98.5)%, specificity of 85 (82–88)% versus 66.5 (58–74.5)%, diagnostic odds ratio of 153 (81–290) versus 40 (20–83), positive predictive value of 85 (82–87)% versus 86 (84–88)%, negative predictive value of 97.5 (95–99)% versus 91 (88–94)% and overall accuracy of 91% versus 89% with 95% confidence interval, respectively. The drop in specificity was significant (P = 0.035), while the sensitivity and overall accuracy were insignificantly changed (P > 0.05). Meta-analyses of independent subgroups at CACS levels ≤10 and ≤100 demonstrated high specificities of 90 (94–100)% and 88.5 (81–91.5)%, whereas at CACS levels ≥400 the specificity declined significantly to 42 (28–56)% but with consistently retained high sensitivity of 97.5 (94–99)%. The specificity of CTA decreases with increasing CACS, while the sensitivity remains high independent of that. The suggested CACS thresholds are arbitrary and do not necessarily warrant cancelling angiography. Diagnostic studies are needed to explore whether a specific CACS threshold may serve as a pre-angiographic gatekeeper to prevent likely equivocal angiographies.

Noninvasive imaging of atherosclerosis by cardiac CT continues to rapidly evolve. A large collection of data has emerged on detection and quantification of coronary plaque in vivo with cardiac CT with comparison to the gold standard of clinical plaque assessment, intravascular ultrasound. Given inherent spatial limitations, although the correlation is significant, the variability and limits of agreement of these measurements are wide. More recently, focus has shifted to detecting plaque stability, or rather high-risk features of plaque, and identifying those “vulnerable” to rupture. This is a concept originated in histopathology and translated clinically into invasive plaque characterization through virtual histology, or IVUS-VH. We will review the literature regarding methods of plaque assessment, as well as plaque progression and outcomes data, in cardiac CT with regard to its correlation with IVUS and IVUS-VH. The potential in cardiac CT lies within the noninvasive detection of coronary artery disease, its ability to help distinguish those plaques and thus, those patients most vulnerable, which ultimately may be utilized for risk stratification, direction of aggressive therapy, and even as a way to evaluate effects of medical therapies.

BackgroundThis study evaluates whether non-contrast cardiac computed tomography (CCT) can detect chronic myocardial infarction (MI) in patients with irreversible perfusion defects on nuclear myocardial perfusion imaging (MPI).MethodsOne hundred twenty-two symptomatic patients with irreversible perfusion defect (N = 62) or normal MPI (N = 60) underwent coronary artery calcium (CAC) scanning. MI on these non-contrast CCTs was visually detected based on the hypo-attenuation areas (dark) in the myocardium and corresponding Hounsfield units (HU) were measured.ResultsNon-contrast CCT accurately detected MI in 57 patients with irreversible perfusion defect on MPI, yielding a sensitivity of 92%, specificity of 72%, negative predictive value (NPV) of 90%, and a positive predictive value (PPV) of 77%. On a per myocardial region analysis, non-contrast CT showed a sensitivity of 70%, specificity of 85%, NPV of 91%, and a PPV of 57%. The ROC curve showed that the optimal cutoff value of LV myocardium HU to predict MI on non-contrast CCT was 21.7 with a sensitivity of 97.4% and specificity of 99.7%.ConclusionNon-contrast CCT has an excellent agreement with MPI in detecting chronic MI. This study highlights a novel clinical utility of non-contrast CCT in addition to assessment of overall burden of atherosclerosis measured by CAC.

Previous studies showed strong correlations between low fingertip temperature rebound measured by digital thermal monitoring (DTM) during a 5 min arm-cuff induced reactive hyperemia and both the Framingham Risk Score (FRS), and coronary artery calcification (CAC) in asymptomatic populations. This study evaluates the correlation between DTM and coronary artery disease (CAD) measured by CT angiography (CTA) in symptomatic patients. It also investigates the correlation between CTA and a new index of neurovascular reactivity measured by DTM. 129 patients, age 63 ± 9 years, 68% male, underwent DTM, CAC and CTA. Adjusted DTM indices in the occluded arm were calculated: temperature rebound: aTR and area under the temperature curve aTMP-AUC. DTM neurovascular reactivity (NVR) index was measured based on increased fingertip temperature in the non-occluded arm. Obstructive CAD was defined as ≥50% luminal stenosis, and normal as no stenosis and CAC = 0. Baseline fingertip temperature was not different across the groups. However, all DTM indices of vascular and neurovascular reactivity significantly decreased from normal to non-obstructive to obstructive CAD [(aTR 1.77 ± 1.18 to 1.24 ± 1.14 to 0.94 ± 0.92) (P = 0.009), (aTMP-AUC: 355.6 ± 242.4 to 277.4 ± 182.4 to 184.4 ± 171.2) (P = 0.001), (NVR: 161.5 ± 147.4 to 77.6 ± 88.2 to 48.8 ± 63.8) (P = 0.015)]. After adjusting for risk factors, the odds ratio for obstructive CAD compared to normal in the lowest versus two upper tertiles of FRS, aTR, aTMP-AUC, and NVR were 2.41 (1.02–5.93), P = 0.05, 8.67 (2.6–9.4), P = 0.001, 11.62 (5.1–28.7), P = 0.001, and 3.58 (1.09–11.69), P = 0.01, respectively. DTM indices and FRS combined resulted in a ROC curve area of 0.88 for the prediction of obstructive CAD. In patients suspected of CAD, low fingertip temperature rebound measured by DTM significantly predicted CTA-diagnosed obstructive disease.

Although the quantification of coronary arterial calcification (CAC) correlates well with disease burden, calcified plaques only represent a portion of the total plaque burden. Contrast-enhanced multidetector CT angiography has emerged as a promising noninvasive tool to directly examine the coronary artery wall and accurately determine atherosclerotic plaque burden and composition. Published literature on plaque subtypes (noncalcified, mixed, and calcified) suggests that mixed plaque burden is more likely to be associated with high-risk groups, such as those with diabetes mellitus, inflammatory biomarkers, increasing stenotic coronary artery disease, myocardial perfusion defects, higher CAC scores and, more importantly, features of plaque instability such as thin-cap fibroatheroma. One small study suggested that mixed plaque burden can predict cardiovascular outcomes. Based on emerging data, determination of mixed plaque burden appears more promising, but the value of exclusively calcified and noncalcified plaque is less convincing.

Current 64-multidetector Computed Tomographic scanners (MDCT) utilize retrospective overlapping helical acquisition (RS-OHA) which imparts a higher than desired radiation dose. Although the radiation burden of computed tomographic angio- graphy (CTA) can be efficiently reduced by dose modulation and limiting field of view, a further decrease in radiation without compromising diagnos- tic image quality would be indeed very desirable. An alternative imaging mode is the axial prospective ECG-triggering acquisition (prospective gating). This study was done to compare the effective radiation dose and the image quality with two techniques to reduce radiation doses with CTA studies utilizing 64- MDCT scanners. The study included 149 consecutive patients (48 females and 101 males) 64-MDCT (mean age = 67 ± 11 years, 72.2% male). Patients under- went CT coronary angiography using one of three algorithms: retrospective triggering with dose modulation; prospective triggering with padding (step and shoot acquisition with additional adjacent phases); and prospective triggering without padding (single phase acquisition only). Based on body habitus, two different voltages were utilized: 100 kVp (\85 kg) or 120 kVp ((85 kg). Radiation doses and image quality (signal to noise ratio) was measured for each patient, and compared between different acquisition protocols. The signal to-noise ratio of the ascending aorta (SNR-AA) was calculated from the mean pixel values of the contrast-filled left ventricular chamber divided by the standard deviation of these pixel values. Use of 100 kVp reduced radiation dose 41.5% using prospective triggering and 39.6% using retrospective imaging as compared to 120 kVp (P \ 0.001). Use of prospective imaging reduced radiation exposure by 82.6% as compared to retrospective imaging (P \ 0.001). Using both pro- spective imaging and 100 kVp without padding (single phase data, no other phases obtained), radia- tion dose was reduced by 90% (P \ 0.001). In terms of image quality, the coefficient of variation of ascending aortic contrast enhancement between kVp of 120 and kVp of 100 was 6% (1.05, 95 CI 0.93- 1.17), and 7.8% (0.9, 95% CI 0.7-1.2) at the pulmonary artery. The prospective ECG-Triggered acquisition and 100 kVp images were of diagnostic quality, allowing adequate assessment in all patients. CTA using PA and 100 kVp reduced the radiation dose by up to 90% without compromising the image quality.

Cardiac CT (CCT) has evolved rapidly over the past 20 years. Initially designed as a test for myocardial perfusion, CCT has developed into a potent screening test for atherosclerosis and a surrogate for invasive angiography (CT angiography). CT angiography, with high correlation to invasive angiography, is now being increasingly used in clinical practice as an alternative to cardiac catheterization or stress imaging. This technology’s high spatial temporal resolution allows for evaluation of major branches of coronary tree, compared to echocardiography, and nuclear or magnetic resonance imaging. The technology of CCT has undergone rapid transformation in recent years such that new scanners have sub-second image acquisition and multi-row capability (multi-detector CT). This article reviews the current scientific evidence and clinical uses for CCT.

Individuals with spinal cord injury (SCI) have been reported to have an increased prevalence of premature cardiovascular disease. Whether the increased risk of disease is owing to clustering of traditional cardiac risk factor or is over and above that predicted by risk factors was addressed.Ninety-one persons with chronic SCI were studied for subclinical atherosclerosis. Cardiac risk factors and coronary artery calcium (CAC) was compared to matched non-SCI controls. The 273 controls were 3:1 matched for age, gender, ethnicity and risk factors and were drawn from a national database of over 30,000 asymptomatic persons undergoing coronary scanning.Seventy-six men and 15 women were studied. Average age was 49.7+/-12 years. Duration of injury was 19.7+/-10 years. The ethnicity of the study cohort included 36% Caucasian, 49% Latino, 10% African American, and 5% other. The mean calcium score of the SCI group was significantly greater than the control group (75+/-218 versus 28+/-104, P0.001). The prevalence of any CAC score was greater in the SCI population than the control population (51 versus 39%, P0.05), as was CAC score100 (16 versus 7%, P0.01). Women with SCI had a significantly lower CAC score than men (mean score: 12 versus 86, P0.01).Patients with SCI were shown to have greater atherosclerotic burden than able-bodied controls. Of note, and unexplained, this finding is beyond that explained by the clustering of traditional risk factors. On the basis of these findings, increased attention should be directed toward the prevention of coronary heart disease in those with SCI.

© 2015, Springer Science+Business Media New York. Coronary plaque progression is a multi-faceted process influenced by cardiovascular risk factors, as well as the presence, extent, stenosis, morphology, and vulnerability of plaque, which may ultimately result in myocardial infarction or death. Traditionally, intravascular ultrasound (IVUS) has been the primary modality to study atherosclerosis progression. However, it is invasive and impractical for screening or monitoring. While coronary artery calcium (CAC) scoring has been widely studied as a non-invasive method to measure plaque progression, it is limited to visualization of stenosis and non-calcified plaque. Coronary computed tomographic angiography (CCTA) allows for visualization of the severity of stenosis, plaque burden, plaque morphology, and ability to differentiate between plaque types. Furthermore, certain CCTA plaque features are useful in identifying vulnerable plaque including low attenuation plaque, positive remodeling, spotty calcification, and napkin-ring sign. This review covers multiple aspects of plaque progression—its pathophysiology, clinical implications, and use of novel non-invasive technology for the assessment of plaque progression over time.

To evaluate the effect of scanner collimation on the ability to detect small cardiac vessels using electron beam CT coronary angiography (EBA).EBA scans from 40 patients who underwent study on two separate occasions with 3 mm (initial scan) and 1.5 mm (follow-up scan) collimation protocols were analyzed. Vessels of2 mm in diameter were identified.The 1.5 mm collimation allowed 3-D visualization of 129 vessels2 mm in diameter, while 3 mm collimation only allowed visualization of 89 vessels (p0.001). The right coronary artery branches and distal LAD segments though were not displayed satisfactorily in almost half of the 3-D studies with either protocol.There was significant improvement in detection of small cardiac vessels with a 1.5 mm collimation EBA protocol compared to a 3 mm protocol. Both protocols though were insufficient for reliable visualization of the right coronary artery branches and distal LAD segments.

Purpose: To estimate the variation of left ventricular (LV) mass and volume measurement with cine and angiography by electron beam tomography (EBT). Method and materials: Sixty-three consecutive patients (41 men, 22 women; age range 46–91) referred for cardiac imaging for clinical indications underwent cine and coronary artery electron beam angiography (EBA) studies on the same day. The cine images consisted of 144 images (12 slices/level × 12 levels), taken 12 frames/s for a full cardiac cycle. The EBA images consisted of 50–70 slices triggered at end-systole, with an acquisition time of 100 ms/slice. Slice thickness was 8 mm for the cine images and 1.5 mm for the EBA images. A total volume of 120–180 ml of nonionic contrast was used for each subject. The LV mass (myocardial tissue volume), LV cavity volume and total LV volume (tissue + cavity) measurements were completed using the software from the EBT computer console (G.E., S. San Francisco, CA). Results: The LV mass, cavity volume and total LV volumes at end-systole were 124.11 g, 45.66 and 163.86 ml when derived from the cine images and 130.74 g, 41.31 and 165.82 ml when derived from the EBA images. There were no significant differences between the cine and EBA-derived measurements, however the EBA-derived measurements showed slightly larger LV mass (mean 6.63 g), smaller cavity volume (mean −4.35 ml) and larger total LV volume (mean 1.96 ml, all p > 0.05) than did the cine-derived measurements. Based on case-by-case observations, these differences appear to be related to the higher spatial resolution of the thinner EBA images which allows better discrimination between papillary and trabecular muscle and LV. This leads to slightly smaller cavity size estimations and greater LV mass measurements. There was significant correlation between cine and EBA-derived measurements. Formulas were developed for relating the measurements made from the two modalities as follows: For LV mass: EBA value = 0.91 × cine value + 17.09, R = 0.95, p < 0.001; For LV cavity volume: EBA value = 1.06 × cine value − 6.91, R = 0.96, p < 0.001; For total LV volume: EBA value = 0.98 × cine value + 5.09 in ml, p < 0.001. The mean differences in measurements using the two modalities were 8.1, 18.2 and 6.5% for LV mass, LV cavity volume and total LV volume, respectively. Conclusion: Both cine and EBA images were useful for measuring LV mass and volume with good inter-test agreement. Cardiac volume and mass measurements derived from cine EBT studies probably slightly underestimate LV mass and overestimate LV volume.

Background: There is great interest in measuring and tracking atherosclerosis using electron beam tomography (EBT). We sought to assess the reproducibility of two new software systems, InSight and AccuImage, and the console workstation of an EBT scanner for measuring coronary calcification. Methods: Two sets of non-contrast EBT scans were obtained in 85 subjects. The calcium volume (CV) score and the Agatston score (AS) were analyzed and the relative differences were compared on three workstations. Results: The intra- and inter-observer variabilities by InSight and AccuImage were both significantly better than variabilities on the console workstation. Both intra- and inter-observer differences for the AS were significantly smaller than those for the CV on each workstation. However, inter-scan variability was lower for the volume method (13.3%) as compared to the AS (17%). Scores were divided into tertiles (T), and the relative inter-scan differences for the AS in T-I (scores 98%). There is minimal inter-scan variability for subjects with higher scores (>65) for both scoring methods.

Coronary artery calcification (CAC) imaging is widely used for the assessment of patients at moderate risk of cardiovascular disease. It is more logical and practical to detect preclinical coronary artery disease (CAD) rather than to make predictions based solely on risk factor assessment. Furthermore, CAC imaging leads to the reclassification of a significant proportion of moderate-risk patients into lower or higher risk categories. In higher-risk patients, including for example those with diabetes, a higher prevalence of CAC has been shown to be associated with a high short-term risk of cardiovascular events, while those with a zero calcium score have excellent event-free survival, similar to survival in nondiabetic patients. Having a zero calcium score is currently used in UK practice guidelines as a criterion for further investigations in patients presenting to emergency departments with chest pain. Unanswered questions include the concept of CAC progression that needs to be standardized with respect to technique, interpretation and subsequent management strategies. Recent studies have also demonstrated that risk assessment using CT is motivational to patients leading to better adherence to their preventive practices as well as medication. However, statin has not proved to be consistently beneficial in slowing the CAC progression rate, but does significantly reduce cardiovascular events in patients with increased CAC. Screening asymptomatic subjects to target measures for the prevention of cardiovascular events remains a major challenge. The established primary prevention risk-scoring methods use equations derived from large prospective cohort studies, but further fine-tuning of cardiovascular risk assessment remains important as 25 % of individuals with a low estimated risk may experience cardiac events. In this modern scientific world, the addition of CT is the best tool to add to the diagnostic work-up of CAD, as validated by multiple population-based studies and large-scale clinical trials.

Over 50% of myocardial infarctions lead to sudden death without any prior warning signs or previously known coronary disease (1). Thus, persons with preclinical atherosclerosis must be identified prior to the onset of angina, MI, stroke or death. It has been estimated that primary prevention can avert more than 100,000 premature deaths each year in the United States alone and 10 times that worldwide (2). new modalities are being investigated to look for atherosclerotic plaque burden, plaque morphology, and endothelial function. Multiple trials on cholesterol reduction have reproducibly demonstrated a positive mortality benefit in primary (3, 4) and secondary (5-6) prevention combining diet with statins. Newer therapies, including antibiotics, anti-oxidants, and angiogenesis medications are being introduced for the possible prevention or treatment of coronary artery disease. The ability to track the progression or regression of atherosclerosis non-invasively would allow better evaluation of these therapies.

Background: Quantitative determination of ejection fraction is predicated on precise measurement of end-diastolic and end-systolic volumes of the left ventricle. Contrast enhanced electron beam tomography (EBT), with excellent temporal and spatial resolution, has the potential for highly accurate measures of ejection fraction. Methods: EBT protocol used a short axis scan of the left ventricle (8–12 levels, apex to base) during infusion of iodinated contrast. To assess the accuracy of the measured left ventricular ejection fraction (LVEF), we compared EBT with first-pass radionuclide angiography (RNA) and cine angiography (CINE). Results: A total of 41 patients (26 men and 15 women) underwent all three tests within 1 week. Resting ejection fraction using each modality was assessed in a linear regression model to assess inter-test correlation with the other two modalities. Correlation between CINE and EBT was high (r = 0.90, intercept 4.67, p 40%. For LVEF ≤ 40%, we demonstrated some disparate results between cine angiography and RNA and between EBT and RNA, indicating that CINE or EBT may provide more accurate assessment.

Purpose:There is considerable literature published on noninvasive contrast-enhanced techniques to diagnose pulmonary vascular abnormalities, however little data exists on the safety of contrast injections in patients with elevated pulmonary arterial pressures. We studied the safety of contrast-enhanced electron beam computed tomography (EBCT) in 29 patients with severe pulmonary hypertension. The mean dose of intravenous contrast used was 124 ± 39 cc. Materials and methods:Subjects underwent EBCT using contrast injected at a rate of 2–4 ml/s. All patients were watched closely for at least 15 min post-procedure prior to being released. Patients had Doppler echocardiograms to estimate pulmonary artery pressure. Right heart catheterization data was collected for patients in which echocardiographic data was unavailable. Results:A total of 29 patients with pulmonary arterial hypertension were studied. There were 17 patients with primary pulmonary hypertension (PPH), and 12 patients with secondary forms of pulmonary hypertension. None of the patients developed complications from their study. Conclusion:There is a paucity of data on the safety of contrast injections in patients with severely elevated pulmonary arterial pressures. Contrast-enhanced EBCT was well-tolerated in our diverse series of patients with severely elevated pulmonary arterial pressures. Clinicians concerned about invasive pulmonary angiography should consider contrast-enhanced EBCT as a safe alternative to angiography.

Rationale and objective:We devised to test the feasibility of measuring the left and right ventricular sizes by non-contrast electron beam tomographic images. Methods:Ventricular sizes consist of the sum of the intracavitary cavity and myocardial mass for each ventricle. A total of 50 image studies from subjects undergoing contrast-enhanced studies were used to develop the measurement methodology. About 20 contrast studies were used to test the measure. The methodology was then prospectively tested on 75 patients with non-contrast studies to estimate the intra-observer, inter-observer and inter-study reproducibility. Results:Multiple linear regression analysis was completed and the correct regression formulas to calculate ventricular volumes were acquired by using the area and span from the contrast studies. There was excellent correlation between the estimate of LV (r > 0.97, p 0.93, p 0.89, p < 0.001). Conclusion:We conclude that the left and right ventricular sizes can be accurately estimated from a single mid-ventricular slice on non-contrast electron beam tomographic images.

Risk stratification strategies used in the diagnosis and management of coronary artery disease (CAD) aim to identify patients with intermediate to high likelihood of significant CAD that might benefit from coronary revascularizations and/or aggressive medical therapy. Myocardial perfusion imaging (MPI) has been an integral part of the traditional risk stratification algorithm for more than two decades. While the presence of significant ischemia on MPI usually necessitates further evaluation with coronary catheterization, patients with normal or low risk scans are mostly managed medically. Even though a normal MPI result generally indicates a benign prognosis, the ‘‘warranty period’’ of such result could be substantially shorter in patients with certain clinical risk factors such as adenosine stress (due to inability to exercise), increasing age, diabetes, female gender in diabetics, and history of known CAD indicating a lower negative predictive value for MPI in this

Carotid Ultrasound is a safe and available non invasive diagnostic tool that provides information about the carotid arteries’ characteristics and may be used for early detection of coronary artery disease as well as cardiovascular and stroke event risk stratifications. We performed a systematic search of the articles discussing carotid ultrasound in English literature, published in PubMed from the year2010 to September 2012. Generally, the studies showed that Internal carotid artery intima media thickness is a more powerful variable than common carotid artery intima media thickness. Moreover, the presence of carotid plaque and plaque volumes are more reliable and accurate estimators of coronary artery disease and risk of a stroke or cardiovascular event than intima media thickness.

Calcium artery calcium (CAC) scoring has become an integral part in the era of preventive cardiology, it has been extensively studied and been validated as a powerful tool for cardiovascular risk assessment in conjunction with other traditional well established scoring systems such as Framingham risk score. In addition, CAC testing has found its way into emergency department algorithms assessing low to intermediate risk patients presenting with chest pain, this strategy was recently adopted by the UK NICE guidelines, confidently ruling out cardiac origin of chest pain. Several studies have demonstrated that risk assessment using CAC was motivational to patients leading to better adherence to their preventive practices as well as to medications. Accordingly, this test has several recommendations for use by national and international guidelines.

The true prognostic implication of carotid intima–media thickness (CIMT) remains a major question for clinicians and the preventive cardiology community. The merits of using CIMT for assessing asymptomatic individuals at risk for developing cardiovascular disease are discussed, together with the potential issues arising from an analysis of CIMT measurement in the Framingham Offspring Study cohort.

IntroductionIn cross-sectional studies, patients with rheumatoid arthritis (RA) have higher coronary artery calcium (CAC) than controls. However, their rate of progression of CAC and the predictors of CAC progression have heretofore remained unknown.MethodsIncidence and progression of CAC were compared in 155 patients with RA and 835 control participants. The association of demographic characteristics, traditional cardiovascular risk factors, RA disease characteristics and selected inflammatory markers with incidence and progression of CAC were evaluated.ResultsThe incidence rate of newly detected CAC was 8.2/100 person-years in RA and 7.3/100 person-years in non-RA control subjects [IRR 1.1 (0.7-1.8)]. RA patients who developed newly detectable CAC were older (59 ± 7 vs. 55 ± 6 years old, p=0.03), had higher triglyceride levels (137 ± 86 vs. 97 ± 60 mg/dL, p=0.03), and higher systolic blood pressure (129 ± 17 vs. 117 ± 15 mm Hg, p=0.01) compared to those who did not develop incident CAC. Differences in blood pressure and triglyceride levels remained significant after adjustment for age (p