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Coronary CT angiography (CCTA) has been gradually adopted into clinical practice over the last two decades. CCTA has high diagnostic accuracy, prognostic value, and unique features such as assessment of plaque composition. CCTA-derived functional assessment techniques such as fractional flow reserve and CT perfusion are also available and can increase the diagnostic specificity of the modality. These properties propound CCTA as a competitor of functional testing in diagnosis of obstructive CAD, however, utilizing CCTA in a concomitant fashion to potentiate the performance of the latter can lead to better patient care and may provide more accurate prognostic information. Although multiple diagnostic challenges such as evaluation of calcified segments, stents, and small distal vessels still exist, the technologic developments in hardware as well as growing incorporation of artificial intelligence to daily practice are all set to augment the diagnostic and prognostic role of CCTA in cardiovascular disorders. [ABSTRACT FROM AUTHOR]

Background: Across medical specialties, including nuclear cardiology, competency based medical education (CBME) changes the emphasis of learning from a time or experiential emphasis to a proficiency focused approached. Plotted on a learning-curve graph the emphasis on learning has shifted from the duration/ volume-based x-axis to the performance-based y-axis. Current status: It has proven difficult to establish y-axis -based standards within nuclear cardiology to assess learning. As such there is a paucity of data to verify current experiential training targets and only recently is data emerging that seeks to find CBME targets by which proficiency (y-axis units) can be evaluated. Initial reports from such CBME-oriented studies indicate that in current nuclear cardiology practice, the number of studies required to achieve competency is dependent upon the chosen measure of competency that is assessed (summed stress score versus % LV ischemia), the case mix, and the modality being learnt (PET versus SPECT). Recent findings have also suggested that prior levels of experiential training may be an underestimation of the number of supervised studies learners need to interpret before they achieve competency. Summary: Nuclear cardiology training has adopted the concept of CBME and is progressing toward a more modern approach to trainee assessment. This brief review provides the background, current requirements and insights into new developments in nuclear cardiology training. [ABSTRACT FROM AUTHOR]

Coronary computed tomography angiography (CCTA) is an important non-invasive tool for the assessment of coronary artery disease and the delivery of information incremental to coronary anatomy. CCTA measured left ventricular (LV) mid-diastolic volume (LV MDV) and LV mass (LV Mass) have important prognostic information but the utility of prospectively ECG-triggered CCTA to predict reduced left ventricular ejection fraction (LVEF) is unknown. The objective of this study was to determine if indexed LV MDV (LV MDVi) and the LV MDV :LV Mass ratio on CCTA can identify patients with reduced LVEF. 8179 patients with prospectively ECG-triggered CCTA between November 2014 and December 2019 were reviewed. A subset derivation cohort of 4352 healthy patients was used to define normal LV MDVi and LV MDV :LV Mass. Sex-specific thresholds were tested in a validation cohort of 1783 patients, excluded from the derivation cohort, with cardiac disease and known LVEF. The operating characteristics for 1 SD above the mean were tested for the identification of abnormal LVEF, LVEF≤35 ​% and ≤30 ​%. The derivation cohort had a mean LV MDVi of 61.0 ​± ​13.7 ​mL/m2 and LV MDV :LV Mass of 1.11 ​± ​0.24 ​mL/g. LV MDVi and LV MDV :LV Mass were both higher in patients with reduced LVEF than those with normal LVEF (98.8 ​± ​40.8 ​mL/m2 vs. 63.3 ​± ​19.7 ​mL/m2, p ​< ​0.001, and 1.32 ​± ​0.44 ​mL/g vs. 1.05 ​± ​0.28 ​mL/g, p ​< ​0.001). Both mean LV MDVi and LV MDV :LV Mass increased with the severity of LVEF reduction. Sex-specific LV MDVi thresholds were 79 ​% and 80 ​% specific for identifying abnormal LVEF in females (LV MDVi ​≥ ​69.9 ​mL/m2) and males (LV MDVi ​≥ ​78.8 ​mL/m2), respectively. LV MDV :LV Mass thresholds had high specificity (87 ​%) in both females (LV MDVi :LV Mass ​≥ ​1.39 ​mL/g) and males (LV MDVi :LV Mass ​≥ ​1.30 ​mL/g). Our study provides reference thresholds for LV MDVi and LV MDV :LV Mass on prospectively ECG-triggered CCTA, which may identify patients who require further LV function assessment. [ABSTRACT FROM AUTHOR]

Coronary computed tomography angiography (CCTA) is vital for diagnosing coronary artery disease; however, prospective ECG-triggered acquisition, minimizing radiation exposure, limits left ventricular (LV) ejection fraction (EF) evaluation. We aimed to assess the feasibility and utility of LVEF 100msec , a new index for estimating LV function using volumetric changes during 100 msec within systole. This retrospective study analyzed patients who underwent prospective ECG-triggered CCTA with systolic acquisition between January 2015 and June 2022. The LVEF 100msec was calculated using the maximum and minimum LV volumes among the three phases (300, 350, and 400 msec post-QRS) and expressed as a percentage. Patients were classified into normal, mild-moderately reduced, or severely reduced LV function categories based on the reference test. The LVEF 100msec was compared among groups, and the optimal cutoff value of LVEF 100msec for predicting severe LV dysfunction was investigated. The study included 271 patients (median age ​= ​58 years, 52% male). LVEF was normal in 188 (69.4%), mild-moderately reduced in 57 (21.0%), and severely reduced in 26 (9.6%) patients. Median LVEF 100msec value was 9.0 (6.7–12.6) for normal LV function, 4.7 (3.1–8.8) for mild-moderately reduced, and 2.9 (1.5–3.8) for severely reduced LV function. LVEF 100msec values significantly differed among categories (p ​< ​0.001). The optimal LVEF 100msec cutoff for severe LV dysfunction was 4.3%, with an AUC of 0.924, sensitivity of 88%, and specificity of 89%. The LVEF 100msec may serve as a valuable indicator of severe LV dysfunction. [ABSTRACT FROM AUTHOR]

Ischemia with nonobstructive coronary arteries (INOCA) is common clinically, particularly among women, but its prevalence among patients with at least moderate ischemia and the relationship between ischemia severity and non-obstructive atherosclerosis severity are unknown. The authors investigated predictors of INOCA in enrolled, nonrandomized participants in ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches), sex differences, and the relationship between ischemia and atherosclerosis in patients with INOCA. Core laboratories independently reviewed screening noninvasive stress test results (nuclear imaging, echocardiography, magnetic resonance imaging or nonimaging exercise tolerance testing), and coronary computed tomography angiography (CCTA), blinded to results of the screening test. INOCA was defined as all stenoses <50% on CCTA in a patient with moderate or severe ischemia on stress testing. INOCA patients, who were excluded from randomization, were compared with randomized participants with ≥50% stenosis in ≥1 vessel and moderate or severe ischemia. Among 3,612 participants with core laboratory-confirmed moderate or severe ischemia and interpretable CCTA, 476 (13%) had INOCA. Patients with INOCA were younger, were predominantly female, and had fewer atherosclerosis risk factors. For each stress testing modality, the extent of ischemia tended to be less among patients with INOCA, particularly with nuclear imaging. There was no significant relationship between severity of ischemia and extent or severity of nonobstructive atherosclerosis on CCTA. On multivariable analysis, female sex was independently associated with INOCA (odds ratio: 4.2 [95% CI: 3.4-5.2]). Among participants enrolled in ISCHEMIA with core laboratory-confirmed moderate or severe ischemia, the prevalence of INOCA was 13%. Severity of ischemia was not associated with severity of nonobstructive atherosclerosis. (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches [ISCHEMIA]; NCT01471522) [Display omitted] [ABSTRACT FROM AUTHOR]

We examined age differences in whole-heart volumes of non-calcified and calcified atherosclerosis by coronary computed tomography angiography (CCTA) of patients with future ACS. A total of 234 patients with core-lab adjudicated ACS after baseline CCTA were enrolled. Atherosclerotic plaque was quantified and characterized from the main epicardial vessels and side branches on a 0.5 ​mm cross-sectional basis. Calcified plaque and non-calcified plaque were defined by above or below 350 Hounsfield units. Patients were categorized according to their age by deciles. Also, coronary artery calcium scores (CACS) were evaluated when available. Patients were on average 62.2 ​± ​11.5 years old. On the pre-ACS CCTA, patients showed diffuse, multi-site, predominantly non-obstructive atherosclerosis across all age categories, with plaque being detected in 93.5% of all ACS cases. The proportion calcified plaque from the total plaque burden increased significantly with older presentation (10% calcification in those <50 years, and 50% calcification in those >80 years old). Patients with ACS <50 years had remarkably lower atherosclerotic burden compared with older patients, but a high proportion of high risk markers such as low-attenuation plaque. CACS was >0 in 85% of the patients older than 50 years, and in 57% of patients younger than 50 years. The proportion of calcified plaque varied depending on patient age at the time of ACS. Only a small proportion of plaque was calcified when ACS occurred at <50 years old, while this increased gradually with older age. Purely non-calcified atherosclerotic plaque was not uncommon in patients <50 years. [ABSTRACT FROM AUTHOR]

This study sought to assess training volumes and its relationship to learning and identify potential new thresholds for determining expertise. Competency-based medical education (CBME) is being rapidly adopted and therefore training programs will need to adapt and identify new and novel methods of defining, measuring, and assessing clinical skills. Consecutive cardiac computed tomography (CT) studies were interpreted independently by trainees and expert readers, and their interpretations (Agatston score, coronary artery disease severity, and Coronary Artery Disease Reporting and Data System) were collected. Kappa agreements were measured between trainees and experts for every 50 consecutive cases. Agreements between trainees and experts were tracked and compared with the agreement between expert readers. A total of 36 trainees interpreted 14,432 cardiac CT studies. Agreement between trainees and experts increased with CT case volumes, but trainees learned at different rates. Using a threshold for expertise, skill of measuring coronary calcification was achieved within 50 cases, but expertise for coronary CT angiography appeared to require a mean case volume of 750, comprising 400 abnormal cases. Current volume-based training guidelines may be insufficient and higher case volumes may be required. We demonstrate that tracking cardiac CT learners is feasible and that CBME could be incorporated into CT training programs. [Display omitted] [ABSTRACT FROM AUTHOR]

We sought to determine the prognostic value of coronary computed tomography angiography (CCTA) in patients with a history of percutaneous coronary intervention (PCI). Although the prognostic value of CCTA has been well studied, its incremental value in patients with previous PCI has not been robustly investigated. Consecutive patients with previous PCI were prospectively enrolled and CCTA images were evaluated for coronary artery disease (CAD) severity. Patients were followed for major adverse cardiovascular events (MACE) which was a composite of cardiac death and non-fatal myocardial infarction. All-cause death was assessed as a secondary endpoint. A total of 501 patients were analyzed with a mean follow-up time of 59.5 ± 32.0 months and 52 patients (10.4%) experienced MACE. Multivariable Cox regression analysis showed that CAD severity was a predictor of MACE with 0, 1, 2, and 3 vessel disease having annual rates of 1.3%, 2.2%, 2.2%, and 5.3%, respectively. All-cause death was similar in all categories of CAD. In patients with previous PCI, CAD severity as measured with CCTA has independent and incremental prognostic value. 501 PCI patients who underwent CCTA were followed for a mean of 59.5 months. 52 patients (10.4%) experienced MACE. CAD severity was a predictor of MACE with 0, 1, 2, and 3 vessel disease having annual rates of 1.3%, 2.2%, 2.2%, and 5.3%, respectively. In PCI patients, CAD severity as measured with CCTA has independent and incremental prognostic value. [ABSTRACT FROM AUTHOR]

Coronary CT angiography (CCTA) is increasing seen as a first line investigation in patients with suspected coronary artery disease. Heart-rate control improves the image quality and diagnostic accuracy of CCTA. Typically, beta-blockers are administered to induce sinus bradycardia. Sinus bradycardia may also be induced by ivabradine. We hypothesized that in a real-world population ivabradine would be an effective alternative to metoprolol at heart rate lowering for CCTA. This was a retrospective analysis of consecutive patients who were exposed to an ivabradine-based (IB) versus a metoprolol-only (MO) protocol to achieve a target heart rate 65 and received heart-rate lowering medication: 1958 patients had MO, and 718 received IB protocol. Target heart rate of

This study sought to identify culprit lesion (CL) precursors among acute coronary syndrome (ACS) patients based on qualitative and quantitative computed tomography–based plaque characteristics. Coronary computed tomography angiography (CTA) has been validated for patient-level prediction of ACS. However, the applicability of coronary CTA to CL assessment is not known. Utilizing the ICONIC (Incident COroNary Syndromes Identified by Computed Tomography) study, a nested case-control study of 468 patients with baseline coronary CTA, the study included ACS patients with invasive coronary angiography–adjudicated CLs that could be aligned to CL precursors on baseline coronary CTA. Separate blinded core laboratories adjudicated CLs and performed atherosclerotic plaque evaluation. Thereafter, the study used a boosted ensemble algorithm (XGBoost) to develop a predictive model of CLs. Data were randomly split into a training set (80%) and a test set (20%). The area under the receiver-operating characteristic curve of this model was compared with that of diameter stenosis (model 1), high-risk plaque features (model 2), and lesion-level features of CL precursors from the ICONIC study (model 3). Thereafter, the machine learning (ML) model was applied to 234 non-ACS patients with 864 lesions to determine model performance for CL exclusion. CL precursors were identified by both coronary angiography and baseline coronary CTA in 124 of 234 (53.0%) patients, with a total of 582 lesions (containing 124 CLs) included in the analysis. The ML model demonstrated significantly higher area under the receiver-operating characteristic curve for discriminating CL precursors (0.774; 95% confidence interval [CI]: 0.758 to 0.790) compared with model 1 (0.599; 95% CI: 0.599 to 0.599; p < 0.01), model 2 (0.532; 95% CI: 0.501 to 0.563; p < 0.01), and model 3 (0.672; 95% CI: 0.662 to 0.682; p < 0.01). When applied to the non-ACS cohort, the ML model had a specificity of 89.3% for excluding CLs. In a high-risk cohort, a boosted ensemble algorithm can be used to predict CL from non-CL precursors on coronary CTA. [ABSTRACT FROM AUTHOR]

This study sought to develop a clinical model that identifies a lower-risk population for coronary artery disease that could benefit from stress-first myocardial perfusion imaging (MPI) protocols and that can be used at point of care to risk stratify patients. There is an increasing interest in stress-first and stress-only imaging to reduce patient radiation exposure and improve patient workflow and experience. A secondary analysis was conducted on a single-center cohort of patients undergoing single-photon emission computed tomography (SPECT) and positron emission tomography (PET) studies. Normal MPI was defined by the absence of perfusion abnormalities and other ischemic markers and the presence of normal left ventricular wall motion and left ventricular ejection fraction. A model was derived using a cohort of 18,389 consecutive patients who underwent SPECT and was validated in a separate cohort of patients who underwent SPECT (n = 5,819), 1 internal cohort of patients who underwent PET (n=4,631), and 1 external PET cohort (n = 7,028). Final models were made for men and women and consisted of 9 variables including age, smoking, hypertension, diabetes, dyslipidemia, typical angina, prior percutaneous coronary intervention, prior coronary artery bypass graft, and prior myocardial infarction. Patients with a score ≤1 were stratified as low risk. The model was robust with areas under the curve of 0.684 (95% confidence interval [CI]: 0.674 to 0.694) and 0.681 (95% CI: 0.666 to 0.696) in the derivation cohort, 0.745 (95% CI: 0.728 to 0.762) and 0.701 (95% CI: 0.673 to 0.728) in the SPECT validation cohort, 0.672 (95% CI: 0.649 to 0.696) and 0.686 (95% CI: 0.663 to 0.710) in the internal PET validation cohort, and 0.756 (95% CI: 0.740 to 0.772) and 0.737 (95% CI: 0.716 to 0.757) in the external PET validation cohort in men and women, respectively. Men and women who scored ≤1 had negative likelihood ratios of 0.48 and 0.52, respectively. A novel model, based on easily obtained clinical variables, is proposed to identify patients with low probability of having abnormal MPI results. This point-of-care tool may be used to identify a population that might qualify for stress-first MPI protocols. [ABSTRACT FROM AUTHOR]

While an assessment of the right ventricular (RV) size remains challenging, the entire RV is can be imaged on coronary computed tomography angiography (CCTA) studies. With prospective ECG-triggering, the RV end diastolic volume (RVEDV) cannot be measured; however, the RV mid-diastolic volume (RVMDV) can still be measured accurately from routine CCTA data sets. The objective of this study is to establish normal reference values for RVMDV. Right ventricular mid-diastolic volumes were measured in 4855 consecutive patients undergoing prospectively ECG-triggered coronary CTA. All patients with known cardiac or pulmonary disease (coronary artery disease, myocardial infarction, revascularization, heart failure, pulmonary hypertension, congenital heart disease, valvular heart disease, atrial fibrillation, implantable cardiac defibrillator implantation, cardiac transplant, or cardiac surgery) or smoking history (3313 patients) were excluded. 1542 patients were analyzed (mean age 56.4 ± 11.1 years, mean BSA 1.96 ± 0.26 and 47% male). The mean RVMDV for men and women was 168.6 ± 37.6 mL and 117.6 ± 26.4 mL, respectively. Mean BSA-indexed RVMDV was 80.0 ± 15.3 mL/m2 and 64.1 ± 12.2 mL/m2 for men and women, respectively. The presence of hypertension and diabetes did not have an impact on these values. RVMDV and BSA-indexed RVMDV were lower in women and in older individuals. Normal reference ranges for RVMDV were established using prospectively ECG-triggered coronary CTA studies. This data can be used to identify patients with abnormal RV volumes and potentially RV dysfunction, adding incremental diagnostic value to routine CCTA studies. [ABSTRACT FROM AUTHOR]

We aimed to compare semiquantitative coronary computed tomography angiography (CCTA) risk scores – which score presence, extent, composition, stenosis and/or location of coronary artery disease (CAD) – and their prognostic value between patients with and without diabetes mellitus (DM). Risk scores derived from general chest-pain populations are often challenging to apply in DM patients, because of numerous confounders. Out of a combined cohort from the Leiden University Medical Center and the CONFIRM registry with 5-year follow-up data, we performed a secondary analysis in diabetic patients with suspected CAD who were clinically referred for CCTA. A total of 732 DM patients was 1:1 propensity-matched with 732 non-DM patients by age, sex and cardiovascular risk factors. A subset of 7 semiquantitative CCTA risk scores was compared between groups: 1) any stenosis ≥50%, 2) any stenosis ≥70%, 3) stenosis-severity component of the coronary artery disease-reporting and data system (CAD-RADS), 4) segment involvement score (SIS), 5) segment stenosis score (SSS), 6) CT-adapted Leaman score (CT-LeSc), and 7) Leiden CCTA risk score. Cox-regression analysis was performed to assess the association between the scores and the primary endpoint of all-cause death and non-fatal myocardial infarction. Also, area under the receiver-operating characteristics curves were compared to evaluate discriminatory ability. A total of 1,464 DM and non-DM patients (mean age 58 ± 12 years, 40% women) underwent CCTA and 155 (11%) events were documented after median follow-up of 5.1 years. In DM patients, the 7 semiquantitative CCTA risk scores were significantly more prevalent or higher as compared to non-DM patients (p ≤ 0.022). All scores were independently associated with the primary endpoint in both patients with and without DM (p ≤ 0.020), with non-significant interaction between the scores and diabetes (interaction p ≥ 0.109). Discriminatory ability of the Leiden CCTA risk score in DM patients was significantly better than any stenosis ≥50% and ≥70% (p = 0.003 and p = 0.007, respectively), but comparable to the CAD-RADS, SIS, SSS and CT-LeSc that also focus on the extent of CAD (p ≥ 0.265). Coronary atherosclerosis scoring with semiquantitative CCTA risk scores incorporating the total extent of CAD discriminate major adverse cardiac events well, and might be useful for risk stratification of patients with DM beyond the binary evaluation of obstructive stenosis alone. [ABSTRACT FROM AUTHOR]

Randomized trials have shown favorable clinical outcomes for coronary CT angiography (CTA) in patients with suspected acute coronary syndrome (ACS). Our goal was to estimate the cost-effectiveness of coronary CTA as compared to alternative management strategies for ACP patients over lifetime. Markov microsimulation model was developed to compare cost-effectiveness of competitive strategies for ACP patients: 1) coronary CTA, 2) standard of care (SOC), 3) AHA/ACC Guidelines, and 4) expedited emergency department (ED) discharge protocol with outpatient testing. ROMICAT-II trial was used to populate the model with low to intermediate risk of ACS patient data, whereas diagnostic test-, treatment effect-, morbidity/mortality-, quality of life- and cost data were obtained from the literature. We predicted test utilization, costs, 1-, 3-, 10-year and over lifetime cardiovascular morbidity/mortality for each strategy. We determined quality adjusted life years (QALY) and incremental cost-effectiveness ratio. Observed outcomes in ROMICAT-II were used to validate the short-term model. Estimated short-term outcomes accurately reflected observed outcomes in ROMICAT-II as coronary CTA was associated with higher costs ($4,490 vs. $2,513-$4,144) and revascularization rates (5.2% vs. 2.6%-3.7%) compared to alternative strategies. Over lifetime, coronary CTA dominated SOC and ACC/AHA Guidelines and was cost-effective compared to expedited ED protocol ($49,428/QALY). This was driven by lower cardiovascular mortality (coronary CTA vs. expedited discharge: 3-year: 1.04% vs. 1.10–1.17; 10-year: 5.06% vs. 5.21–5.36%; respectively). Coronary CTA in patients with suspected ACS renders affordable long-term health benefits as compared to alternative strategies. [ABSTRACT FROM AUTHOR]

This study sought to: 1) determine if the current training volume guidelines are reasonable for attaining competence for interpreting myocardial perfusion imaging (MPI); and if not, 2) identify potential thresholds for training volumes and competence. There is a growing desire to adopt competency-based medical education (CBME). As such, the implementation of CBME will require new and novel methods of defining, measuring, and assessing clinical competence. The potential use of CBME in cardiac imaging has not been well studied. Consecutive MPI studies were interpreted independently by trainees, and expert readers reviewed the same studies. Studies were quantified using summed scores and % left ventricular (LV) ischemia and the kappa agreement between trainee and expert were measured every 50 cases. Agreement for all MPI and abnormal MPI cases was calculated. A total of 24 trainees interpreted 9,668 MPI studies over 37 months. Agreement between trainees and expert readers increased with MPI case volumes but at different rates. The threshold for competence was set at 2 SDs below expert interobserver agreement. The average trainee surpassed this threshold for both summed stress score and %LV ischemia after 800 studies and after 400 abnormal MPI studies. Trainees learned at different rates and surpassed the competence threshold after different case volumes. The use of CBME within nuclear cardiology appears to be feasible. Our results suggest that current guidelines may be insufficient to ensure competence and would support the need to increase the MPI case volumes. The use of CBME principles would suggest that trainees may achieve competence at different rates and our results suggest a shift in focus from volume-based learning toward target agreement thresholds. [ABSTRACT FROM AUTHOR]

Obesity is an in independent risk factor for cardiovascular disease. To describe the early LV remodelling pattern in patients with overweight and obesity and structurally normal hearts. Consecutive patients (n = 2374), with structurally normal hearts and BMI ≥ 18.5 kg/m2, undergoing prospective mid-diastolic ECG gated CTCA were selected. Left ventricular mass (LVM) and Left ventricular mid-diastolic volume (LVMDV) were measured. The concentricity index (LVM/LVMDV) were calculated. According to the definitions of the World Health Organization (WHO), the patients were divided into weight categories. The mean LVM ± Std. deviation in the subgroups according to WHO classification was 101.68 ± 28.99 g (normal weight), 115.79 ± 29.14 g (overweight), 123.8 ± 33.44 g (class I obesity), 125.85 ± 32.89 g (class II obesity) and 132.45 ± 37.85 g (class III obesity). (p < 0.001) The mean LVMDV progressed with increasing WHO weight category from 112.37 ± 36.46 in patients with normal BMI to 140.26 ± 43.78 in patients with class III obesity. (p < 0.001) The concentricity index was 0.935 ± 0.216 g/ml in patients with normal BMI, 0.979 ± 0.253 g/ml, 1.058 ± 0.635 g/ml, 0.996 ± 0.284 g/ml and 0.9768 ± 0.244 g/ml in patients with BMI categories 25–29.99, 30–34.99, 35–39.99 and ≥40 kg/m2, respectively. Our study demonstrates a non-linear (inverse U-shape) relationship between increasing BMI class and concentricity index, reaching its maximum at a BMI of 30–34.99 kg/m2. Further increase in BMI results in LV dilation. [ABSTRACT FROM AUTHOR]

Coronary computed tomography angiography (CCTA) left ventricle (LV) volumes have prognostic value. LV measurements however can differ depending on post-processing software. Two common methods are the contour (CON) or attenuation (ATT) based methods. This study aims to determine differences in LV volume measurements using the 2 methods. LV mid-diastolic volumes (LVMDV) were measured using both ATT and CON from 2 vendors in 750 consecutive patients undergoing CCTA. 500 were measured in a derivation cohort to establish a linear regression equation that would correct for any detected differences between the two methods. The equation was then assessed in 250 cases in the validation cohort. Comparisons were made between intra-vendor LVMDV CON and LVMDV ATT as well as inter-vendor LVMDV ATT. In the derivation cohort, the correlation between the two methods and vendors were very good (0.98 and 0.97 respectively). LVMDV CON was 20.4 ± 7.4% greater than LVMDV ATT. LVMDV ATT was 9.2 ± 6.6% greater with one vendor compared to the other. Validation cohort corrected LVMDV ATT was not statistically different to measured LVMDV ATT (p = 0.45). A systematic difference was found between ATT and CON measuring methods. Using a derived linear regression equation, we were able to correct for differences in measurement techniques. The method of LVMDV measurement requires careful consideration when establishing reference values and extrapolating published study results. [ABSTRACT FROM AUTHOR]

Background The segment involvement score (SIS) is a semiquantitative measure of the extent of atherosclerosis burden by coronary computed tomography angiography (CTA). We sought to evaluate by meta-analysis the prognostic value of SIS, and to compare it with other CTA measures of coronary artery disease (CAD). Methods Electronic databases from 1946 to January 2016 were searched. Studies reporting SIS, or an equivalent measure by coronary CTA, and clinical outcomes were included. Maximally adjusted hazard ratios (HR), predominantly for clinical variables, were extracted for SIS, obstructive CAD, Agatston coronary artery calcium score, and plaque composition. These were pooled using DerSimonian-Laird random effects models. Results Eleven nonrandomized studies with good methodological quality enrolling 9777 subjects (mean age 61 ± 11 years, 57% male, mean follow up 3.3 years) who had 472 (4.8%) MACE (cardiac or all cause death, non-fatal myocardial infarction or late revascularization), were included. SIS (per segment increase) had pooled HR of 1.25 (95% CI: 1.16,1.35; I 2 = 71.4%, p < 0.001) for MACE. HR for MACE was 1.37 (95% CI: 1.32,1.42; I 2 = 95.6%, p < 0.001) for number of segments with stenosis (per segment increase), 3.39 (95% CI: 1.65,6.99; I 2 = 87.8%, p = 0.001) for obstructive CAD (binary variable) and 1.00 (95% CI: 1.00,1.01; I 2 = 75.0%, p = 0.490) for Agatston score (per unit increase). HRs by plaque composition (calcified, non-calcified and mixed; per segment change) were 1.24 (95% CI: 1.10,1.39; I 2 = 81.6%, p = 0.001), 1.20 (95% CI: 0.97,1.48; I 2 = 92.9%, p = 0.093) and 1.27 (95% CI: 1.03,1.58; I 2 = 89.8%, p = 0.029), respectively. Conclusion Despite heterogeneity in endpoints, extent of CAD as quantified by SIS on coronary CTA is a strong, independent predictor of cardiovascular events. [ABSTRACT FROM AUTHOR]

Introduction Aortic valve calcification (AVC) has been associated with major adverse cardiovascular events and all-cause mortality. We sought to develop and validate a method to quantify AVC using coronary CT angiography (CTA). Methods Of 59 patients who underwent both non-contrast and contrast enhanced coronary CTA, 25 patients served as the derivation cohort and 34 patients served as the validation cohort. For non-contrast enhanced CT, quantification of AVC was performed using the Agatston method for coronary artery calcification (CAC). For contrast enhanced coronary CTA, a region of interest (ROI) was placed in the ascending aorta and the mean aortic attenuation value (HU Aorta ) and standard deviation (SD) were measured. Using a calcium threshold of mean HU Aorta + 2SD, the AVC CTA was calculated. All other Agatston score parameters (weighting factors and area calculations) remained unchanged. Results In the derivation cohort, the correlation between AVC CAC and AVC CTA was excellent (r = 0.982). Using the line of best fit, a correction factor was calculated enabling the conversion of AVC CTA results to a AVC CAC equivalent (AVC Corrected = 1.868 × AVC CTA ). Using this correction in the validation cohort, the correlation and agreement between AVC CAC and AVC Corrected were good (ICC = 0.939; 95% CI: 0.881–0.969; kappa = 0.700; 95% CI: 0.469–0.931). Conclusion The quantification of AVC Corrected using contrast enhanced CTA is feasible using a systematic approach with very good reliability and good agreement with AVC CAC . Larger-scale validation studies are needed to determine whether the use of AVC CAC can be eliminated in favour of AVC Corrected . [ABSTRACT FROM AUTHOR]

Background The adoption of prospectively ECG-triggered acquisition coronary computed tomography angiography (CTA) has resulted in the inability to measure left ventricle (LV) end-diastolic volume and LV ejection fraction. However other prognostic measures such as LV mass and LV mid-diastolic volume (LVMDV) can still be assessed. The objective of this study is to establish normal reference values for LVMDV and LV mass. Methods Left ventricular mid-diastolic volumes and LV mass were prospectively measured in 2647 consecutive ‘normal’ patients undergoing prospectively ECG-triggered coronary CTA. Patients with known coronary artery disease (prior myocardial infarction or prior revascularization), heart failure, congenital heart disease, heart transplant or prior cardiac surgery were excluded. Commercially available software was used to calculate the LVMDV and LV mass. Results Among the 2647 patient cohort (mean age = 58 years, 54% men), the mean LVMDV indexed for body surface area was 57.5 ± 15.3 mL/m 2 and 64.5 ± 20.2 mL/m 2 for women and men, respectively. The mean indexed LV mass was 52.2 ± 10.9 g/m 2 for women and 63.6 ± 13.7 g/m 2 for men. Indexed LVMDV decreased with increasing age. The presence of hypertension, diabetes and obstructive coronary artery disease did not have a clinically relevant impact on these values. Age and sex specific upper limits of normal were defined. Conclusion We establish normal reference ranges for LVMDV and LV mass using prospectively ECG-triggered coronary CTA. These benchmarks may identify patients at increased risk of adverse events, supporting the potential for clinical reporting of these metrics. [ABSTRACT FROM AUTHOR]

• Accurate rhythm diagnosis on electrocardiograms (ECG) is critical in patients presenting with wide QRS complex tachycardia (WCT) arrhythmia. • Real-time visual interpretation of ECG of complex arrhythmias is difficult and requires expertise. • We designed a convolutional neural model through a neural architecture search that could accurately classify WCT into those that are ventricular in origin (87.5%) or supraventricular tachycardia (91.7%). • Our model was also shown to be useful for arrhythmia diagnosis from ECG data generated by both 12 leads as well as single-lead devices. • Our model can potentially be implemented in real clinical settings to assist physicians in more accurate and timely diagnosis of WCTs. Cardiac arrhythmias are a significant cause of morbidity and mortality in patients with cardiovascular disease. Accurate rhythm diagnosis is critical in patients presenting with wide QRS complex tachycardia (WCT). Real-time visual interpretation of electrocardiograms (ECG) of complex arrhythmias is difficult and requires expertise. We designed a convolutional neural network (CNN) that could accurately classify WCT into those that are ventricular in origin (ventricular tachycardia (VT)) or supraventricular tachycardia with aberrancy (SVT). A total of 3065 patients with wide complex ECGs were screened (415 with VT and 2650 with SVT). A CNN model was designed through a Neural Architecture Search (NAS) method. This CNN consisted of a stem convolution layer and five cells, each cell containing separable-convolution and dilated-separable-convolution layers. Using 5-fold cross-validation and executing algorithm for five independent runs (with five different seeds), the proposed CNN model achieved a detection accuracy of 87.5 ± 0.0025 and 91.7 %±0.0004 for VT and SVT, respectively. The total sensitivity, specificity, positive predictive value, negative predictive value and F1-score of the CNN model were 88.50 %, 88.50 %, 88.54 %, 88.54 %, and 88.49 %, respectively. In a cohort of patients presenting with a WCT, our CNN model achieved an accuracy of 87.5% and 91.7% to correctly diagnose VT and SVT, respectively. This model has the potential of being used in real-time settings and to assist physicians with interpretation and decision making. [ABSTRACT FROM AUTHOR]

Hepatic steatosis has been associated with increased risk of coronary artery disease. Individuals with familial hypercholesterolaemia have accelerated but variable progression of coronary artery disease. We investigated whether hepatic steatosis is associated with novel coronary atherosclerosis biomarkers in adults with heterozygous familial hypercholesterolaemia, using comprehensive coronary computed tomographic angiography. We conducted a cross-sectional study of 213 asymptomatic patients with familial hypercholesterolaemia (median age 54.0 years, 59 % female) who underwent coronary computed tomographic angiography for cardiovascular risk assessment in an outpatient clinic. High-risk plaque features, plaque volume and pericoronary adipose tissue attenuation were assessed. From concurrently captured upper abdominal images, severity of hepatic steatosis was computed, as liver minus spleen computed tomography attenuation and stratified into quartiles. Of 213 familial hypercholesterolaemia patients, 59 % had coronary artery calcium, 36 % obstructive coronary artery disease (≥50 % stenosis) and 77 % high-risk plaque features. Increasing hepatic steatosis was associated with higher calcium scores, more high-risk plaque features and presence of obstructive coronary artery disease. Hepatic steatosis was associated with the presence of high-risk plaque features (OR: 1.48; 95 % CI: 1.09–2.00; p = 0.01), particularly in the proximal coronary segments (OR: 1.52; 95 % CI: 1.18–1.96; p = 0.001). Associations persisted on multivariable logistic regression analysis adjusting for cardiometabolic factors, obstructive coronary artery disease and calcium score. Hepatic steatosis was associated with higher plaque volumes (Q4: 499 mm3 vs Q1: 414 mm3, p = 0.02), involving mainly low attenuation and noncalcified plaques (both p = 0.03). No differences in pericoronary adipose tissue attenuation were observed. Hepatic steatosis is associated with multiple indices of advanced coronary atherosclerosis in familial hypercholesterolaemia patients, particularly high-risk plaque features, independent of conventional cardiovascular risk factors and markers. This may involve specific mechanisms related to hepatic steatosis. Clinical trial number: N/A. [Display omitted] • Hepatic fat independently predicts high-risk coronary artery plaque features in FH. • Hepatic fat associates with higher low attenuation and non-calcified plaque volumes. • CT assessment of hepatic fat may add incremental value to CVD risk stratification. [ABSTRACT FROM AUTHOR]

Background Cardiac computed tomography angiography (coronary CTA) has emerged as a non-invasive method of diagnosing coronary artery disease. The extent of utilization and uptake of this technology since initiation of its funding by the government of Ontario is unknown. Objectives The aim of our study was to examine coronary CTA utilization and the rates of elective invasive coronary angiography and revascularization before and after funding initiation. Methods We studied all coronary CTAs performed on adults in Ontario after initiation of funding. We also used an interrupted time series analysis to compare the average monthly rates of invasive angiography and revascularization before and after initiation of funding. Results There was an initial steep increase in age-and sex-standardized rates of coronary CTA from 5.0 to 11.4/100,000 over the first two quarters after funding initiation. Afterwards, there was a gradual increase in utilization from 11.4 to 17.1/100,000 over two subsequent calendar years. There was a significant reduction in both the mean monthly outpatient invasive coronary angiography (from 20.7 to 19.9 per 100,000 (p = 0.0004)) and revascularization (from 4.9 to 4.4 per 100,000 (p < 0.0001)) rates in the three years following introduction of the coronary CTA billing code as compared to the three prior to its introduction. Conclusions Since the introduction of coronary CTA funding in Ontario, there has been a steady and controlled increase in its utilization. The increasing use of coronary CTA was associated with a reduction in both the rates of invasive angiography and revascularization. [ABSTRACT FROM AUTHOR]

Objectives: This study sought to determine and compare the prognostic and incremental value of positron emission tomography (PET) in normal, overweight, and obese patients. Background: Cardiac rubidium 82 (Rb-82) PET is increasingly being used for myocardial perfusion imaging (MPI). A strength of PET is its accurate attenuation correction, thereby potentially improving its diagnostic accuracy in obese patients. The prognostic value of PET in obese patients has not been well studied. Methods: A total of 7,061 patients who had undergone Rb-82 PET MPI were entered into a multicenter observational registry. All patients underwent pharmacologic Rb-82 PET and were followed for cardiac death and all-cause mortality. Based on body mass index (BMI), patients were categorized as normal (<25 kg/m2), overweight (25 to 29.9 kg/m2), or obese (≥30 kg/m2). Using a 17-segment model and 5-point scoring system, the percentage of abnormal myocardium was calculated for stress and rest patients categorized as normal (0%), mild (0.1% to 9.9%), moderate (10% to 19.9%), and severe (≥20%). Results: A total of 6,037 patients were followed for cardiac death (median: 2.2 years) and the mean BMI was 30.5 ± 7.4 kg/m2. A total of 169 cardiac deaths were observed. PET MPI demonstrated independent and incremental prognostic value over BMI. Normal PET MPI conferred an excellent prognosis with very low annual cardiac death rates in normal (0.38%), overweight (0.43%), and obese (0.15%) patients. As well, both moderately and severe obese patients with a normal PET MPI had excellent prognosis (0.20% and 0.10%, respectively). The net reclassification improvement of PET was 0.46 (95% confidence interval [CI]: 0.31 to 0.61), and appeared similar in the moderately and severe obese patients which were 0.44 (95% CI: 0.12 to 0.76) and 0.63 (95% CI: 0.27 to 0.98), respectively. Conclusions: Rb-82 PET has incremental prognostic value in all patients irrespective of BMI. In the obese population, where other modalities may have reduced diagnostic accuracy, cardiac PET appears to be a promising noninvasive modality with prognostic value. [Copyright &y& Elsevier]

Cardiac PET has evolved over the past 30 years to gain wider acceptance as a valuable modality for a variety of cardiac conditions. Wider availability of scanners as well as changes in reimbursement policies in more recent years has further increased its use. Moreover, with the emergence of novel radionuclides as well as further advances in scanner technology, the use of cardiac PET can be expected to increase further in both clinical practice and the research arena. PET has demonstrated superior diagnostic accuracy for the diagnosis of coronary artery disease in comparison with single-photon emission tomography while it provides robust prognostic value. The addition of absolute flow quantification increases sensitivity for 3-vessel disease as well as providing incremental functional and prognostic information. Metabolic imaging using 18F-fluorodeoxyglucose can be used to guide revascularization in the setting of heart failure and also to detect active inflammation in conditions such as cardiac sarcoidosis and within atherosclerotic plaque, improving our understanding of the processes that underlie these conditions. However, although the pace of new developments is rapid, there remains a gap in evidence for many of these advances and further studies are required. [Copyright &y& Elsevier]

Abstract: Background: The association between lipoprotein levels and coronary plaque composition is not well understood. Objective: The aim of this prospective international multicenter study of statin-naive individuals was to evaluate the association of low-density lipoprotein (LDL), high-density lipoprotein (HDL), and total cholesterol (TC) to coronary plaque composition by coronary computed tomographic angiography (CTA). Methods: We studied 4575 individuals without known coronary artery disease not taking statin medications who underwent coronary CTA. Comparisons were made between those with high versus low LDL, HDL, TC, and non-HDL. We assessed the relationship of lipoproteins and plaques of specific composition (noncalcified [NCP], partially calcified [PCP], or calcified [CP] plaque). Results: Mean age was 57 ± 11 years (55% men). In univariable analyses, high LDL, low HDL, high TC, and high non-HDL were each associated with increased prevalence of NCPs, PCPs, and CPs (P < 0.05 for all). In multivariable analyses, high non-HDL was associated with the presence of NCP (odds ratio, 1.47; 95% CI, 1.22–1.78: P < 0.001). In the further subanalysis, a weak relationship between the highest group of non HDL (≥190 mg/dL) and the presence of CP was also noted (odds ratio, 1.33; 95% CI, 1.01–1.76; P = 0.04). Further, high non-HDL was associated with increasing numbers of segments with NCP (β coefficient, 0.043; 95% CI, 0.021–0.065; P < 0.001) but not segments with PCP or CP. Conclusion: NCP presence and extent are associated with high non-HDL. These results suggest a relationship between lipid profile and plaque composition. [Copyright &y& Elsevier]

Objectives: We sought the incremental prognostic value of coronary computed tomography angiography (CTA) in coronary artery bypass graft (CABG) patients. Background: Coronary CTA is a noninvasive and accurate tool for the detection of obstructive coronary artery disease, and coronary CTA appears to have prognostic value in patients without previous revascularization. However, the prognostic value of coronary CTA to predict major adverse cardiac events in CABG patients is unclear. Methods: Consecutive CABG patients were prospectively enrolled and cardiac risk was calculated using the National Cholesterol Evaluation Program/Adult Treatment Panel III. Using the severity of native coronary artery disease and graft disease, the number of unprotected coronary territories (UCTs) (0, 1, 2, or 3) was calculated. Patients were followed for cardiac death and nonfatal myocardial infarction. All events were confirmed with death certificates or medical records and reviewed by a clinical events committee. Results: Between February 2006 and March 2009, 250 consecutive patients were enrolled and followed for a mean of 20.8 ± 10.1 months. At follow-up, 23 patients (9.2%) had major adverse cardiac events (15 cardiac deaths and 8 nonfatal MI). The absence of UCTs conferred a good prognosis with an annual event rate of 2.4%. Conversely, patients with 1, 2, and 3 UCTs had annualized event rates of 5.8%, 11.1%, and 21.7%, respectively. Multivariable analysis showed that UCTs (hazard ratio: 2.08; 95% confidence interval: 1.40 to 3.10; p < 0.001) was a predictor of major adverse cardiac events when adjusted for clinical variables. Examining the receiver-operator characteristic curves, the area under the curve increased from 0.61 to 0.76 when UCTs was combined with clinical variables (p = 0.001). Conclusions: Assessing UCTs with coronary CTA appears to have prognostic value in CABG patients and is incremental to clinical variables. Coronary CTA appears to be a promising tool for risk stratification of CABG patients. Further multicenter studies using large CABG cohorts are needed to confirm our findings. [Copyright &y& Elsevier]

Objectives: A proof-of-concept study was undertaken to determine whether differences in corrected coronary opacification (CCO) within coronary lumen can identify arteries with abnormal resting coronary flow. Background: Although computed tomographic coronary angiography can be used for the detection of obstructive coronary artery disease, it cannot reliably differentiate between anatomical and functional stenoses. Methods: Computed tomographic coronary angiography patients (without history of revascularization, cardiac transplantation, and congenital heart disease) who underwent invasive coronary angiography were enrolled. Attenuation values of coronary lumen were measured before and after stenoses and normalized to the aorta. Changes in CCO were calculated, and CCO differences were compared with severity of coronary stenosis and Thrombolysis In Myocardial Infarction (TIMI) flow at the time of invasive coronary angiography. Results: One hundred four coronary arteries (n = 52, mean age = 60.0 ± 9.5 years; men = 71.2%) were assessed. Compared with normal arteries, the CCO differences were greater in arteries with computed tomographic coronary angiography diameter stenoses ≥50%. Similarly, CCO differences were greater in arteries with TIMI flow grade <3 (0.406 ± 0.226) compared with those with normal flow (TIMI flow grade 3) (0.078 ± 0.078, p < 0.001). With CCO differences, abnormal coronary flow (TIMI flow grade <3) was identified with a sensitivity and specificity, positive predictive value, and negative predictive value of 83.3% (95% confidence interval [CI]: 57.7 to 95.6%), 91.2% (95% CI: 75.2% to 97.7%), 83.3% (95% CI: 57.7% to 95.6%), and 91.2% (95% CI: 75.2% to 97.7%), respectively. Accuracy of this method was 88.5% with very good agreement (kappa = 0.75, 95% CI: 0.55 to 0.94). Conclusions: Changes in CCO across coronary stenoses seem to predict abnormal (TIMI flow grade <3) resting coronary blood flow. Further studies are needed to understand its incremental diagnostic value and its potential to measure stress coronary blood flow. [Copyright &y& Elsevier]

Background: Coronary computed tomographic angiography (CCTA) of 64-detector rows or greater represents a novel noninvasive anatomic method for evaluation of patients with suspected coronary artery disease (CAD). Early studies suggest a potential for prognostic risk assessment by CCTA findings but were limited by small patient cohorts or single centers. The CONFIRM (COronary CT Angiography EvaluatioN For Clinical Outcomes: An InteRnational Multicenter) registry is a large, prospective, multinational dynamic observational study of patients undergoing CCTA. The primary aim of CONFIRM is to determine the prognostic value of CCTA findings for the prediction of future adverse CAD events. Methods: The CONFIRM registry currently represents 27,125 consecutive patients at 12 cluster sites in 6 countries in North America, Europe, and Asia. CONFIRM sites were chosen on the basis of adequate CCTA volume, site CCTA proficiency, and local demographic characteristics and medical facilities to ensure a broad-based sample of patients. Patients comprising the present CONFIRM cohort include those with suspected but without known CAD, with known CAD, or asymptomatic persons undergoing CAD evaluation. A data dictionary comprising a wide array of demographic, clinical, and CCTA findings was developed by the CONFIRM investigators and is uniformly used for all patients. Patients are followed up after CCTA performance to identify adverse CAD events, including death, myocardial infarction, unstable angina, target vessel revascularization, and CAD-related hospitalization. Conclusions: From a number of countries worldwide, the information collected from the CONFIRM registry will add incremental and important insights into CCTA findings that confer prognostic value beyond demographic and clinical characteristics. The results of the CONFIRM registry will provide valuable information about the optimal methods for using CCTA findings. [ABSTRACT FROM AUTHOR]

The accuracy of 64-slice computed tomographic coronary angiography (CTA) and its ability to direct revascularization in patients with acute chest pain syndrome (ACPS) was investigated. A total of 107 patients with ACPS presenting to the emergency department and referred to cardiology were prospectively enrolled and underwent CTA. From the clinical features, the patients were categorized as having high-risk acute coronary syndrome features or no high-risk features. At the treating physician''s discretion, the patients underwent risk stratification with either invasive coronary angiography (ICA) or technetium-99m single photon emission computed tomography. All tests were interpreted by experts unaware of the clinical information. All 52 patients with high-risk acute coronary syndrome features underwent ICA. Of the 55 patients with no high-risk features, 36 underwent single photon emission computed tomography and 19 underwent ICA. The patients were followed up until a decision regarding revascularization was made. Compared with ICA, the operating characteristics of CTA (per-patient analysis) were excellent, with a sensitivity of 98% (95% confidence interval [CI] 87% to 100%), specificity of 100% (95% CI 85% to 100%), positive predictive value of 100% (95% CI 90% to 100%), and negative predictive value of 97% (95% CI 80% to 100%). The agreement between CTA and routine testing (single photon emission computed tomography or ICA) was very good (κ = 0.94). CTA correctly identified 40 patients (100%) who underwent revascularization and 61 (91.0%) who were treated medically (κ = 0.88, 95% CI 0.79 to 0.97). In conclusion, CTA might represent a single modality that could be used to triage a wide spectrum of patients with ACPS and could have the potential to rule out coronary disease and identify those who might require revascularization. [Copyright &y& Elsevier]

Transcatheter aortic valve implantation (TAVI) is a new modality that may change the therapeutic landscape in the management of aortic valve stenosis. Despite the excellent results of surgical aortic valve replacement, TAVI has the potential to revolutionize the treatment of elderly and high-risk patients with aortic stenosis. It therefore constitutes a new reality that cardiac surgeons have to acknowledge. As TAVI indications and techniques become better defined, the importance of a team approach to the implementation and performance of TAVI is becoming increasingly evident. The surgeon has a crucial role to play in the introduction, development, and sustainability of TAVI at any institution. In this article, we discuss the procedural technique involved in TAVI, as well as the cardiologist and heart surgeon individualities and team dynamics. We make a case for judicious team-based adoption of TAVI technologies, considering that evidence-based and health economics data are not yet available. We also illustrate how a team approach may lead to improved outcomes, better patient and institutional acceptance, and a better definition of the therapeutic niche of TAVI modalities, amid the excellent results of conventional aortic valve replacement surgery. [ABSTRACT FROM AUTHOR]

Objectives: We sought to determine the prognostic and incremental value of coronary artery disease (CAD) severity, coronary atherosclerosis, and left ventricular ejection fraction (LVEF) measured with cardiac computed tomography angiography (CTA). Background: CTA is an emerging tool used for the detection of obstructive CAD. However, there are limited data supporting the prognostic value of 64-slice CTA and its ability to predict all-cause mortality and major adverse cardiac events such as cardiac death and nonfatal myocardial infarction. Methods: Consecutive patients (without history of revascularization, heart transplantation, and congenital heart disease) were prospectively enrolled. Each CTA was evaluated for CAD severity, total plaque score, and LVEF. Patients were followed, and all events were confirmed with death certificates or hospital or physician records and reviewed by a clinical events committee. Results: Between February 2006 and February 2008, 2,076 consecutive patients were prospectively enrolled and followed for a mean of 16 ± 8 months. At follow-up, a total of 31 (1.5%) patients had cardiac death or nonfatal myocardial infarction and 47 (2.3%) had all-cause mortality or nonfatal myocardial infarction. Multivariate analysis showed that CAD severity (hazard ratio [HR]: 3.02; 95% confidence interval [CI]: 1.89 to 4.83) was a predictor of major adverse cardiac events and that LVEF (HR: 1.47; 95% CI: 1.17 to 1.86) had incremental value over CAD severity. Total plaque score had incremental value over CAD severity and LVEF for all-cause mortality and nonfatal myocardial infarction (HR: 1.17; 95% CI: 1.06 to 1.29). Conclusions: Using CTA, CAD severity, LVEF, and total plaque score seems to have prognostic and incremental value over routine clinical predictors. Cardiac CTA seems to be a promising noninvasive modality with prognostic value. [Copyright &y& Elsevier]

Abstract: Background: Important to the risk stratification and management of cardiac patients is the assessment of left ventricular function (LVEF), thus imaging modalities which can provide both anatomical and functional data is desirable. Electrocardiographic (ECG) gated multi-detector computed tomographic (MDCT) images may provide accurate assessment of LV ejection fraction, volume and dimensions but have shown systemic errors in the past due to slow gantry rotation speed. Methods: Between May 2004 and January 2005, 306 patients underwent ECG-gated cardiac CT studies at the Massachusetts General Hospital. Patients with available CT data sets and a recent (within 3 months) ECHO and/or SPECT perfusion imaging were included in the study. ECG-gated data sets were acquired either with a 16-slice or with a 64-slice MDCT. Functional MDCT data sets were reconstructed in 10 cardiac phases (5–95%) with 1.5mm slices. Images were processed and interpreted by two observers blinded to ECHO and SPECT results. Results: A total of 69 patients had MDCT and ECHO or SPECT within 3 months (33 had 16-slice and 36 had 64-slice MDCT). There was fair correlation between LVEF measured by 16-slice MDCT and ‘ECHO or SPECT’ (62±10% vs. 62±10%; r =0.56). There was poor correlation between LVEF measured by 16-slice MDCT and ECHO (64±10% vs. 59±11%; r =0.26) and there was good correlation between LVEF measured by 16-slice MDCT and SPECT (62±11% and 64±9%, respectively; r =0.76). There was very good correlation between LVEF measured by 64-slice MDCT and ‘ECHO or SPECT’ (57±15% vs. 58±13%; r =0.86). There was very good correlation between LVEF measured by MDCT and ECHO (56±14% vs. 54±15%; r =0.89) and between LVEF measured by 64-slice MDCT and SPECT (60±13% and 60±14%, respectively; r =0.90). Conclusion: The assessment of LVEF and LV dimensions with 64-slice MDCT provide values which are similar to those obtained by echocardiography and Tc-99m gated SPECT. The accuracy of the 64-slice MDCT with a gantry rotation speed of 330ms (when compared to ECHO and SPECT) may be superior to that of the 16-slice MDCT at 420ms gantry rotation. [Copyright &y& Elsevier]