O Impacto da COVID-19 no Diagnóstico de Doenças Cardíacas na América Latina Uma Subanálise do INCAPS COVID / The Impact of COVID-19 on Diagnosis of Heart Disease in Latin America an INCAPS COVID Sub-analysis

Resumo Fundamento A pandemia de COVID-19 interferiu na prestação de atendimento a doenças cardiovasculares na América Latina. No entanto, o efeito da pandemia nos volumes de procedimentos cardíacos diagnósticos ainda não foi quantificado. Objetivo Avaliar (1) o impacto de COVID-19 nos volumes de diagnóstico cardíaco na América Latina e (2) determinar sua relação com a incidência de casos de COVID-19 e as medidas de distanciamento social. Métodos A International Atomic Energy Agency realizou uma pesquisa mundial avaliando mudanças nos volumes diagnósticos cardíacos decorrentes da COVID-19. Foram obtidos os volumes diagnósticos cardíacos dos locais participantes para março e abril de 2020 e comparados com março de 2019. Foram coletados dados de distanciamento social a partir dos Relatórios de mobilidade da comunidade de Google e a incidência de COVID-19 por país a partir de Our World in Data. Resultados Foram realizadas pesquisas em 194 centros que realizam procedimentos diagnósticos cardíacos, em 19 países da América Latina. Em comparação com o mês de março de 2019, os volumes dos procedimentos diagnósticos cardíacos diminuíram 36% em março de 2020 e 82% em abril de 2020.As maiores reduções ocorreram em relação aos testes de estresse ecocardiográfico (91%), testes ergométricos de esteira (88%) e escore de cálcio por tomografia computadorizada (87%), com pequenas variações entre as sub-regiões da América Latina. As mudanças em padrões de distanciamento social (p < 0,001) estavam mais fortemente associadas com a redução do volume do que a incidência de COVID-19 (p = 0,003). Conclusões A COVID-19 foi associada a uma redução significativa de procedimentos diagnósticos cardíacos na América Latina, a qual foi mais relacionada ao distanciamento social do que ao aumento da incidência da COVID-19. São necessários melhor equilíbrio e timing de medidas de distanciamento social e planejamento para manter o acesso ao atendimento médico durante um surto pandêmico, especialmente em regiões com alta mortalidade cardiovascular.

Abstract Background The COVID-19 pandemic has disrupted the delivery of care for cardiovascular diseases in Latin America. However, the effect of the pandemic on the cardiac diagnostic procedure volumes has not been quantified. Objective To assess (1) the impact of COVID-19 on cardiac diagnostic volumes in Latin America and (2) determine its relationship with COVID-19 case incidence and social distancing measures. Methods The International Atomic Energy Agency conducted a worldwide survey assessing changes in cardiac diagnostic volumes resulting from COVID-19. Cardiac diagnostic volumes were obtained from participating sites for March and April 2020 and compared to March 2019. Social distancing data were collected from Google COVID-19 community mobility reports and COVID-19 incidence per country from the Our World in Data. Results Surveys were conducted in 194 centers performing cardiac diagnostic procedures, in 19 countries in Latin America. Procedure volumes decreased 36% from March 2019 to March 2020, and 82% from March 2019 to April 2020. The greatest decreases occurred in echocardiogram stress tests (91%), exercise treadmill tests (88%), and computed tomography calcium scores (87%), with slight variations between sub-regions of Latin America. Changes in social distancing patterns (p < 0.001) were more strongly associated with volume reduction than COVID-19 incidence (p = 0.003). Conclusions COVID-19 was associated with a significant reduction in cardiac diagnostic procedures in Latin America, which was more related to social distancing than to the COVID-19 incidence. Better balance and timing of social distancing measures and planning to maintain access to medical care is warranted during a pandemic surge, especially in regions with high cardiovascular mortality.

The Impact of COVID-19 on Diagnosis of Heart Disease in Latin America an INCAPS COVID Sub-analysis. / O Impacto da COVID-19 no Diagnóstico de Doenças Cardíacas na América Latina Uma Subanálise do INCAPS COVID.

BACKGROUND: The COVID-19 pandemic has disrupted the delivery of care for cardiovascular diseases in Latin America. However, the effect of the pandemic on the cardiac diagnostic procedure volumes has not been quantified. OBJECTIVE: To assess (1) the impact of COVID-19 on cardiac diagnostic volumes in Latin America and (2) determine its relationship with COVID-19 case incidence and social distancing measures. METHODS: The International Atomic Energy Agency conducted a worldwide survey assessing changes in cardiac diagnostic volumes resulting from COVID-19. Cardiac diagnostic volumes were obtained from participating sites for March and April 2020 and compared to March 2019. Social distancing data were collected from Google COVID-19 community mobility reports and COVID-19 incidence per country from the Our World in Data. RESULTS: Surveys were conducted in 194 centers performing cardiac diagnostic procedures, in 19 countries in Latin America. Procedure volumes decreased 36% from March 2019 to March 2020, and 82% from March 2019 to April 2020. The greatest decreases occurred in echocardiogram stress tests (91%), exercise treadmill tests (88%), and computed tomography calcium scores (87%), with slight variations between sub-regions of Latin America. Changes in social distancing patterns (p < 0.001) were more strongly associated with volume reduction than COVID-19 incidence (p = 0.003). CONCLUSIONS: COVID-19 was associated with a significant reduction in cardiac diagnostic procedures in Latin America, which was more related to social distancing than to the COVID-19 incidence. Better balance and timing of social distancing measures and planning to maintain access to medical care is warranted during a pandemic surge, especially in regions with high cardiovascular mortality.

FUNDAMENTO: A pandemia de COVID-19 interferiu na prestação de atendimento a doenças cardiovasculares na América Latina. No entanto, o efeito da pandemia nos volumes de procedimentos cardíacos diagnósticos ainda não foi quantificado. OBJETIVO: Avaliar (1) o impacto de COVID-19 nos volumes de diagnóstico cardíaco na América Latina e (2) determinar sua relação com a incidência de casos de COVID-19 e as medidas de distanciamento social. MÉTODOS: A International Atomic Energy Agency realizou uma pesquisa mundial avaliando mudanças nos volumes diagnósticos cardíacos decorrentes da COVID-19. Foram obtidos os volumes diagnósticos cardíacos dos locais participantes para março e abril de 2020 e comparados com março de 2019. Foram coletados dados de distanciamento social a partir dos Relatórios de mobilidade da comunidade de Google e a incidência de COVID-19 por país a partir de Our World in Data. RESULTADOS: Foram realizadas pesquisas em 194 centros que realizam procedimentos diagnósticos cardíacos, em 19 países da América Latina. Em comparação com o mês de março de 2019, os volumes dos procedimentos diagnósticos cardíacos diminuíram 36% em março de 2020 e 82% em abril de 2020.As maiores reduções ocorreram em relação aos testes de estresse ecocardiográfico (91%), testes ergométricos de esteira (88%) e escore de cálcio por tomografia computadorizada (87%), com pequenas variações entre as sub-regiões da América Latina. As mudanças em padrões de distanciamento social (p < 0,001) estavam mais fortemente associadas com a redução do volume do que a incidência de COVID-19 (p = 0,003). CONCLUSÕES: A COVID-19 foi associada a uma redução significativa de procedimentos diagnósticos cardíacos na América Latina, a qual foi mais relacionada ao distanciamento social do que ao aumento da incidência da COVID-19. São necessários melhor equilíbrio e timing de medidas de distanciamento social e planejamento para manter o acesso ao atendimento médico durante um surto pandêmico, especialmente em regiões com alta mortalidade cardiovascular.

Anatomic or functional testing in stable patients with suspected CAD: contemporary role of cardiac CT in the ISCHEMIA trial era.

One of the foundations of the management of patients with suspected coronary artery disease (CAD) is to avoid unnecessary invasive coronary angiography (ICA) referrals. However, the diagnostic yield of ICA following abnormal conventional stress testing is low. The ability of ischemia testing to predict subsequent myocardial infarction and death is currently being challenged, and more than half of cardiac events among stable patients with suspected CAD occur in those with normal functional tests. The optimal management of patients with stable CAD remains controversial and ischemia-driven interventions, though improving anginal symptoms, have failed to reduce the risk of hard cardiovascular events. In this context, there is an ongoing debate whether the initial diagnostic test among patients with stable suspected CAD should be a functional test or coronary computed tomography angiography. Aside from considering the specific characteristics of individual patients and local availability and conditions, the choice of the initial test relates to whether the objective concerns its role as gatekeeper for ICA, prognosis, or treatment decision-making. Therefore, the aim of this review is to provide a contemporary overview of these issues and discuss the emerging role of CCTA as the upfront imaging tool for most patients with suspected CAD.

Impact of pectus excavatum on cardiac morphology and function according to the site of maximum compression: effect of physical exertion and respiratory cycle.

AIMS: Previous studies have demonstrated diverse cardiac manifestations in patients with pectus excavatum (PEX), although mostly addressing morphological or physiological impact as separate findings. Using multimodality imaging, we evaluated the impact of PEX on cardiac morphology and function according to the site of maximum compression, and the effect of exertion and breathing. METHODS AND RESULTS: All patients underwent chest computed tomography, cardiac magnetic resonance (CMR), and stress echocardiography (echo) in order to establish surgical candidacy. We evaluated diastolic function and trans-tricuspid gradient during stress (echo); and systolic function and respiratory-related septal wall motion abnormalities (CMR). Patients were classified according to the site of cardiac compression as type 0 (without cardiac compression); type 1 (right ventricle); and type 2 [right ventricle and atrioventricular (AV) groove]. Fifty-nine patients underwent multimodality imaging, with a mean age of 19.5 ± 5.9 years. Compared with a sex and age matched control group, peak exercise capacity was lower in patients with PEX (8.4 ± 2.0 METs vs. 15.1 ± 4.6 METs, P < 0.0001). At stress, significant differences were found between groups regarding left ventricular E/A (P = 0.004) and e/a ratio (P = 0.005), right ventricular E/A ratio (P = 0.03), and trans-tricuspid gradient (P = 0.001). At CMR, only 9 (15%) patients with PEX had normal septal motion, whereas 17 (29%) had septal flattening during inspiration. Septal motion abnormalities were significantly related to the cardiac compression classification (P < 0.0001). CONCLUSIONS: The present study demonstrated that patients with PEX, particularly those with compression affecting the right ventricle and AV groove, manifest diverse cardiac abnormalities that are mostly related to exertion, inspiration, and diastolic function.

Relationship between left atrial dimensions and global and regional fat depots.

Background and Objectives: The relationship between body fat depots and the left atrial (LA) dimensions has not been fully explored. Our objective is to determine if there is a relationship not only with total body fat depots, but specifically with regional fatty depots. Materials and Methods: It was an observational, retrospective study that included consecutive patients referred to our institution with an order to perform computed tomography angiography triggered by electrocardiogram for different clinical indications. Measurements of the LA were made in the systolic phase, using four and two cameras views. Results: A total of 87 patients were included. The mean age was 66.4 ± 12.5 years; 67% were men. The LA volume indexed by the body surface area was 48.0 ± 16.6 cm3/m2. We identified significant correlations between the LA dimensions and the age (p < 0.05). However, no significant correlations were found between the LA dimensions and the body fat depots, either total or regional. Conclusions: In this study, we did not identify significant relationships between LA dimensions and global or regional body fat depots.

Antecedentes y objetivos: La relación entre los depósitos de grasa corporal y las dimensiones de la aurícula izquierda (AI) no ha sido del todo explorada. Nuestro objetivo es determinar si existe relación no solo con los depósitos de grasa corporal totales, sino específicamente con los depósitos grasos regionales. Materiales y métodos: Estudio observacional, retrospectivo, que incluyó pacientes consecutivos remitidos a nuestra institución con orden de realización de angiotomografía computarizada toracoabdominal gatillada con electrocardiograma por distintas indicaciones clínicas. Las mediciones de la AI se realizaron en la fase sistólica, utilizando vistas de cuatro y dos cámaras. Resultados: Se incluyeron un total de 87 pacientes. La edad media fue de 66.4 ± 12.5 años; un 67% de los sujetos fueron hombres. El volumen de la AI indexado por la superficie corporal fue de 48.0 ± 16.6 cm3/m2. Identificamos correlaciones significativas entre las dimensiones de la AI y la edad (p < 0.05). Sin embargo, no se evidenciaron correlaciones significativas entre las dimensiones de la AI y los distintos depósitos de grasa corporal, ya sea totales o regionales. Conclusiones: En este estudio, no identificamos relaciones significativas entre las dimensiones de la AI y los depósitos de grasa corporal globales o regionales.

Invasive coronary angiography findings across the CAD-RADS classification spectrum.

The recently introduced coronary artery disease reporting and data system (CAD-RADS) evaluated by computed tomography and based on stenosis severity, might not adequately reflect the complexity of CAD. We explored the relationship between CAD-RADS and the spatial distribution, burden, and complexity of lesions by invasive coronary angiography (ICA). Stable patients who underwent coronary computed tomography angiography (CCTA) and ICA comprised the study population. Patients were classified according to the CAD-RADS: 0, No plaque; 1, 1-24% stenosis; 2, 25-49%; 3, 50-69%; 4A, 70-99%; 4B, left main stenosis or 3-vessel obstructive disease; and 5, total occlusion. Based on ICA findings, we calculated the SYNTAX score and the CAD extension index. Ninety-one patients were included, with a mean age of 61.4 ± 10.5 years (74% male). We found significant relationships between CAD-RADS and both the SYNTAX score (p < 0.0001) and the CAD extension index (p < 0.0001), although the complexity of coronary anatomy differed among patients with CAD-RADS ≥ 4A. Among patients with CAD-RADS < 4, the mean segment involvement score (SIS) was 8.4 ± 4.0, 52% of them with a SIS > 5. Of the 30 patients with CAD-RADS 5, 9 (30%) affected distal segments or secondary branches, and 9 (30%) had concomitant severe non-extensive disease at ICA. Regarding the spatial distribution of the non-occluded most severe lesions, 27 (44%) comprised distal segments or secondary branches. In the present study including a high-risk population, we identified diverse coronary anatomy complexity scenarios and relevant differences in spatial distribution sharing the same CAD-RADS classification.

Relationship between left atrial dimensions and global and regional fat depots.

Background and Objectives: The relationship between body fat depots and the left atrial (LA) dimensions has not been fully explored. Our objective is to determine if there is a relationship not only with total body fat depots, but specifically with regional fatty depots. Materials and Methods: It was an observational, retrospective study that included consecutive patients referred to our institution with an order to perform computed tomography angiography triggered by electrocardiogram for different clinical indications. Measurements of the LA were made in the systolic phase, using four and two cameras views. Results: A total of 87 patients were included. The mean age was 66.4 ± 12.5 years; 67% were men. The LA volume indexed by the body surface area was 48.0 ± 16.6 cm3/m2. We identified significant correlations between the LA dimensions and the age (p < 0.05). However, no significant correlations were found between the LA dimensions and the body fat depots, either total or regional. Conclusions: In this study, we did not identify significant relationships between LA dimensions and global or regional body fat depots.

Antecedentes y objetivos: La relación entre los depósitos de grasa corporal y las dimensiones de la aurícula izquierda (AI) no ha sido del todo explorada. Nuestro objetivo es determinar si existe relación no solo con los depósitos de grasa corporal totales, sino específicamente con los depósitos grasos regionales. Materiales y métodos: Estudio observacional, retrospectivo, que incluyó pacientes consecutivos remitidos a nuestra institución con orden de realización de angiotomografía computarizada toracoabdominal gatillada con electrocardiograma por distintas indicaciones clínicas. Las mediciones de la AI se realizaron en la fase sistólica, utilizando vistas de cuatro y dos cámaras. Resultados: Se incluyeron un total de 87 pacientes. La edad media fue de 66.4 ± 12.5 años; un 67% de los sujetos fueron hombres. El volumen de la AI indexado por la superficie corporal fue de 48.0 ± 16.6 cm3/m2. Identificamos correlaciones significativas entre las dimensiones de la AI y la edad (p < 0.05). Sin embargo, no se evidenciaron correlaciones significativas entre las dimensiones de la AI y los distintos depósitos de grasa corporal, ya sea totales o regionales. Conclusiones: En este estudio, no identificamos relaciones significativas entre las dimensiones de la AI y los depósitos de grasa corporal globales o regionales.

Relación entre las dimensiones de la aurícula izquierda y los depósitos globales y regionales de grasa corporal / Relationship between left atrial dimensions and global and regional fat depots

Resumen Antecedentes y objetivos: La relación entre los depósitos de grasa corporal y las dimensiones de la aurícula izquierda (AI) no ha sido del todo explorada. Nuestro objetivo es determinar si existe relación no solo con los depósitos de grasa corporal totales, sino específicamente con los depósitos grasos regionales. Materiales y métodos: Estudio observacional, retrospectivo, que incluyó pacientes consecutivos remitidos a nuestra institución con orden de realización de angiotomografía computarizada toracoabdominal gatillada con electrocardiograma por distintas indicaciones clínicas. Las mediciones de la AI se realizaron en la fase sistólica, utilizando vistas de cuatro y dos cámaras. Resultados: Se incluyeron un total de 87 pacientes. La edad media fue de 66.4 ± 12.5 años; un 67% de los sujetos fueron hombres. El volumen de la AI indexado por la superficie corporal fue de 48.0 ± 16.6 cm3/m2. Identificamos correlaciones significativas entre las dimensiones de la AI y la edad (p < 0.05). Sin embargo, no se evidenciaron correlaciones significativas entre las dimensiones de la AI y los distintos depósitos de grasa corporal, ya sea totales o regionales. Conclusiones: En este estudio, no identificamos relaciones significativas entre las dimensiones de la AI y los depósitos de grasa corporal globales o regionales.

Abstract Background and Objectives: The relationship between body fat depots and the left atrial (LA) dimensions has not been fully explored. Our objective is to determine if there is a relationship not only with total body fat depots, but specifically with regional fatty depots. Materials and Methods: It was an observational, retrospective study that included consecutive patients referred to our institution with an order to perform computed tomography angiography triggered by electrocardiogram for different clinical indications. Measurements of the LA were made in the systolic phase, using four and two cameras views. Results: A total of 87 patients were included. The mean age was 66.4 ± 12.5 years; 67% were men. The LA volume indexed by the body surface area was 48.0 ± 16.6 cm3/m2. We identified significant correlations between the LA dimensions and the age (p < 0.05). However, no significant correlations were found between the LA dimensions and the body fat depots, either total or regional. Conclusions: In this study, we did not identify significant relationships between LA dimensions and global or regional body fat depots.

Evaluation of pectus excavatum indexes during standard cardiac magnetic resonance: Potential for single preoperative tool.

PURPOSE: Preoperative assessment of patients with pectus excavatum (PE) demands evaluation of malformation indexes, generally with chest computed tomography (CT). In addition, assessment of the cardiac impact of sternal depression has become a rule in high referral centers, thus requiring two independent imaging modalities and use ionizing radiation in a very young population. The objective of this study was to explore the agreement between chest CT and standard cardiac MR (CMR) for the evaluation of chest wall malformation indexes. METHODS: We included consecutive patients with PE referred to undergo chest CT and CMR to establish surgical candidacy and/or to define treatment strategies. Both CT and CMR were performed at full-expiration. In both modalities, the Haller index (HI) and the Correction index (CI) were calculated by two independent observers. In CMR, only scout images were used. Agreement was evaluated using intra-class correlation coefficients (ICC). RESULTS: Fifty patients comprised the study population (median age 19.0 years) and underwent chest CT and CMR within the same month. CMR assessment of chest malformation indexes was reproducible, with a very good inter-observer agreement for HI [ICC 0.93 (0.88-0.96), p < 0.0001] and CI [ICC 0.91 (0.83-0.95), p < 0.0001]. CMR also had a very good agreement with chest CT for HI [ICC 0.90 (0.82-0.94), p < 0.0001] and CI measurements [ICC 0.93 (95% CI 0.88-0.96), p < 0.0001]. CONCLUSIONS: We demonstrated an excellent agreement between chest CT and standard CMR for the assessment of chest wall malformations, thus potentially enabling preoperative assessment of PE severity and cardiac involvement with a single diagnostic tool.

Prognostic Value of Vascular Calcifications and Regional Fat Depots Derived From Conventional Chest Computed Tomography.

PURPOSE: The prognostic value of vascular calcifications as well as of regional fat depots has been reported separately, in population-based studies, and using gated-computed tomography (CT) examinations. We, therefore, explored the interplay and prognostic value of vascular calcifications and adipose tissue depots assessed during conventional nongated chest CT. MATERIALS AND METHODS: We enrolled a consecutive series of 1250 patients aged between 35 and 74 years who underwent clinically indicated chest CT scans. We measured the extent of coronary artery calcification (CAC) using the segment-involvement score (CACSIS), and aortic and valve calcification. Pericardial fat volume (PFV), hepatic fat, and abdominal subcutaneous adipose tissue were also calculated. Patients were followed-up for all-cause mortality. RESULTS: A total of 577 (46%) patients had presence of CAC in the coronary tree. Over a mean follow-up of 3.7 years, 51 (4%) deaths occurred, 23 (4.1%) in male patients and 28 (4.1%) in female patients. Patients with higher PFV were older (P<0.0001), more frequently male (P<0.0001), had higher abdominal subcutaneous adipose tissue (P<0.0001), hepatic fat (P<0.0001), as well as a larger extent of CAC (P<0.0001), aortic calcium (P<0.0001), and valve calcium (P<0.0001). From a multivariable Cox regression model, age (hazard ratio [HR], 1.07; 95% confidence interval [CI], 1.03-1.11), P=0.001, PFV upper tertile (HR, 4.07; 95% CI, 2.09-7.92), P<0.0001, and CACSIS>5 (HR, 2.19; 95% CI, 1.14-4.23; P<0.0001) were independent predictors of all-cause death. CONCLUSIONS: In this relatively large patient cohort undergoing clinically indicated conventional chest CT scans, PFV and coronary calcification were high-risk markers associated with worsening survival.

Regional differences of fat depot attenuation using non-contrast, contrast-enhanced, and delayed-enhanced cardiac CT.

BACKGROUND: Regional fat density assessed by computed tomography (CT) has been suggested as a marker of perivascular adipose tissue inflammation. Dual energy CT (DECT) allows improved tissue characterization compared to conventional CT. PURPOSE: To explore whether DECT might aid regional fat density discrimination. MATERIAL AND METHODS: We included patients who had completed a non-enhanced cardiac CT scan, CT coronary angiography (CTCA), and a delayed enhancement CT. Attenuation levels (Hounsfield units [HU]) were assessed at the epicardial, paracardial, visceral, and subcutaneous fat. The number of coronary segments with disease (SIS) was calculated. RESULTS: A total of 36 patients were included in the analysis. Twenty-six (72%) patients had evidence of obstructive disease at CCTA and 25 (69%) patients had evidence of previous myocardial infarction. At non-contrast CT, we did not identify significant attenuation differences between epicardial, paracardial, subcutaneous, and visceral fat depots (-110.8 ± 9 HU, vs. -113.7 ± 9 HU, vs. -114.7 ± 8 HU, vs. -113.8 ± 11 HU, P = 0.36). Significant attenuation differences were detected between fat depots at mid and low energy levels, both at CTCA and delayed-enhancement scans ( P < 0.05 for all). Epicardial fat showed the least negative attenuation, irrespective of the acquisition mode; epicardial fat evaluated at 40 keV was related to the SIS (r = 0.37, P = 0.03). CONCLUSIONS: In this study, regional fat depots amenable to examination during thoracic CT scans have distinctive regional attenuation values. Furthermore, such differences were better displayed using contrast-enhanced monochromatic imaging at low energy levels.

Atherosclerotic plaque burden evaluated from neck to groin: effect of gender and cardiovascular risk factors.

We explored the impact of gender and cardiovascular risk factors (RF) in the distribution and burden of coronary and extra-coronary atherosclerotic plaques among patients undergoing ECG-gated thoracoabdominal computed tomography angiography (CTA) from the supra-aortic trunks to the femoral arteries. We included a consecutive cohort of patients who underwent ECG-gated thoracoabdominal aortic CTA from the supra-aortic trunks to the pubic symphysis. We evaluated the number of coronary segments with plaques [segment-involvement score (SIS)]; and the extra-coronary atherosclerotic plaque burden, comprising the aorta and supra-aortic trunks, iliofemoral arteries, and visceral arteries (extra-coronary SS). A total of 3400 vascular segments were evaluated in 100 patients (mean age 67.0 ± 12.6 years, 66% male). Seventy-two (72%) patients had evidence of atherosclerosis in the coronary tree (coronary SIS ≥ 1), of which 32% was extensive (coronary SIS > 5). Males had a significantly higher prevalence of coronary SIS ≥ 1 [53 (80%), vs. 19 (56%), p = 0.018], and coronary SIS > 5 [24 (36%) vs. 8 (24%), p = 0.035] than females. Extra-coronary SS was similar between genders (males 10.2 ± 5.8 vs. females 9.7 ± 5.4, p = 0.70), irrespective of the location along the different vascular beds. The number of coronary RF was significantly related to the coronary SIS (p = 0.038), and hypertension and diabetes were consistently related to coronary and extra-coronary plaque burden. In the present study involving analysis of multiple vascular beds from the supra-aortic trunks to the femoral arteries, we identified significant sex-related differences in coronary plaque burden, whereas extra-coronary plaque burden was similar between genders irrespective of the vascular bed assessed.

Detection of Myocardial Infarction Using Delayed Enhancement Dual-Energy CT in Stable Patients.

OBJECTIVE: The objective of our study was to explore whether delayed enhancement dual-energy CT (DECT) allows the detection of myocardial infarcts in stable patients. SUBJECTS AND METHODS: Patients with known or suspected coronary artery disease clinically referred for myocardial perfusion imaging using SPECT were prospectively included. All patients (n = 34) also underwent stress, rest, and delayed enhancement DECT on a DECT scanner. At SPECT, segments with myocardial infarction (MI) were defined as those with a summed rest score of ≥ 2 in two or more consecutive segments, and a diagnosis of MI was supported by wall motion abnormalities, clinical history, and ECG findings. RESULTS: Segments with MI were identified in 13 (38%), 15 (44%), and 14 (41%) patients using SPECT, perfusion CT, and delayed enhancement DECT, respectively. When combined SPECT and perfusion CT results were used as the reference standard, delayed enhancement DECT had a sensitivity, specificity, positive predictive value, and negative predictive value for the detection of MI of 91.7% (95% CI, 62-98%), 86.4% (95% CI, 65-97%), 78.6% (95% CI, 49-95%), and 95.0% (95% CI, 75-100%). At delayed enhancement DECT (40 keV), a signal attenuation higher than 161 HU had a sensitivity of 72% and a specificity of 79% for the detection of MI on a per-segment basis. The median signal attenuation of myocardial infarcts at 40 keV was 3.0 SDs (interquartile range, 1.3-4.0 SDs) above that of normal myocardium. CONCLUSION: In this study, delayed enhancement DECT allowed the detection of myocardial infarcts in stable patients.

Myocardial CT perfusion imaging for ischemia detection.

Coronary computed tomography angiography (CCTA) plays an important role in many specific scenarios such as in symptomatic patients with intermediate pretest of coronary artery disease (CAD), as well as in the triage of patients with acute chest pain with TIMI risk ≤2. However, it cannot detect the presence of associated ischemia, which is critical for clinical decision making among patients with moderate to severe stenosis. Although functional information can be obtained with different non-invasive tools, cardiac CT is the unique modality that can perform a comprehensive evaluation of coronary anatomy plus the functional significance of lesions. Myocardial CT perfusion (CTP) can be performed with different approaches such as static and dynamic CTP. In addition, static CTP can be performed using single energy CT (SECT) or dual energy CT (DECT). In this review, we will discuss the technical parameters and the available clinical evidence of static CTP using both SECT and DECT.

Spectral Signal Density of Carotid Plaque Using Dual-Energy Computed Tomography.

BACKGROUND AND PURPOSE: Plaque characterization using virtual monochromatic imaging derived from dual-energy computed tomography (CT) angiography requires the determination of normal signal density values of each plaque component. We sought to explore the signal density values of carotid plaque components using dual-energy compared to conventional single-energy CT angiography (CTA), and to establish the energy level with the largest differences between plaque components. METHODS: The present prospective study involved consecutive patients referred for carotid artery evaluation by CTA. Two scans (single-energy and dual-energy CTA) were performed in all patients, and a single radiologist analyzed the data. Single-source dual-energy CTA allowed the generation of virtual monochromatic images from 40 to 140 keV. RESULTS: A total of 35 internal carotid artery lesions were examined in 20 symptomatic patients. The mean age was 72.3 ± 6.7 years, and 9 (45%) patients were male. Internal carotid artery geometrical variables including lumen area (P = .96), vessel area (P = .97), and percent area stenosis (P = .99) did not differ between groups (single-energy CTA, and dual-energy CTA at 40, 70, 100, and 140 keV). Differences between signal densities of different tissues were largest at 40 keV (calcium/lumen, P < .0001; fat/noncalcified, P < .0001). CONCLUSIONS: In the present pilot investigation, virtual monochromatic imaging at low-energy levels derived from dual-energy CTA allowed the largest differences in attenuation levels between tissues, without affecting vessel or plaque geometry.

Improved Discrimination of Myocardial Perfusion Defects at Low Energy Levels Using Virtual Monochromatic Imaging.

OBJECTIVES: The aim of this study was to explore the diagnostic performance of dual-energy computed tomography perfusion (DE-CTP) at different energy levels. METHODS: Patients with known or suspected coronary artery disease underwent stress and rest DE-CTP and single-photon emission computed tomography. Images were evaluated using monochromatic data, and perfusion defects were initially identified in a qualitative manner and subsequently confirmed using attenuation levels. RESULTS: Thirty-six patients were included. Sensitivity, specificity, positive predictive value, and negative predictive value of DE-CTP for the identification of perfusion defects were 84.1%, 94.2%, 77.3%, and 96.2%, respectively. Perfusion defects showed significantly lower attenuation than normal segments, with the largest differences among low energy levels (sensitivity of 96% and specificity of 98% using a cutoff value ≤ 153 Hounsfield units at 40 keV), progressively declining at the higher levels (P < 0.001). CONCLUSIONS: Dual-energy CTP at the lowest energy levels allowed improved discrimination of perfusion defects compared with higher energy levels.

Tomografía computarizada de doble energía: nueva tecnología para la reducción de artefactos de metal / Dual-energy computed tomography: new technology for metal artifacts reduction

Introducción: El objetivo fue explorar la utilidad de la tomografía computarizada de doble energía mediante tecnología de imágenes espectrales gemstone y de un programa destinado a la reducción de artefactos de metal (MARS), para evaluar tejidos periprotésicos, y la interpretabilidad diagnóstica de patologías relacionadas con implantes. Materiales y Métodos: Se comparó la densidad ósea, de partes blandas y de grasa en el tejido periprotésico y en tejido de control sin implante, utilizando un escáner de alta definición de tomografía computarizada de doble energía tanto en imágenes policromáticas convencionales, como en monocromáticas virtuales con MARS, en 80 pacientes con prótesis metálicas en diversas regiones musculoesqueléticas. Se valoró la calidad de imagen y la interpretabilidad diagnóstica mediante la escala de Likert. Resultados: Con imágenes policromáticas hubo diferencias significativas entre el área periprotésica en los tres tejidos respecto a los controles (p <0,0001); sin diferencias significativas utilizando imágenes espectrales monocromáticas virtuales-MARS (hueso p = 0,053, partes blandas p = 0,32 y grasa p = 0,13), con más similitud con el tejido normal. Los niveles de ruido fueron significativamente mayores con imágenes policromáticas (p <0,0001) que con imágenes espectrales monocromáticas virtuales-MARS. Se consideraron no interpretables todas las regiones periprotésicas en las imágenes policromáticas y 11 (9%) en las imágenes espectrales monocromáticas virtuales-MARS. No hubo diferencias significativas en la dosis de radiación comparada con la del grupo control (p = 0,21). Conclusiones: La tomografía computarizada de doble energía puede reducir los artefactos periprotésicos, logrando un significativo incremento en la capacidad de identificar tejidos y la interpretabilidad diagnóstica de posibles patologías relacionadas con implantes. Nivel de Evidencia: II

Introduction: To explore the usefulness of dual energy imaging using gemstone spectral imaging technology and a dedicated software for metal artifact reduction (MARS) for the evaluation of periprosthetic tissues, and to assess image interpretability of implant-related complications. Methods: Signal density measurements were performed in periprosthetic and remote (control) areas in bone, soft tissue, and fat among 80 patients using a high definition scanner. Polychromatic images and virtual monochromatic spectral images with MARS were obtained, and image quality and diagnostic interpretability were evaluated using a Likert scale. Results: Using polychromatic images, the periprosthetic area showed significant differences compared to the remote areas among the three tissue explored (p<0.0001 for all); with no significant differences using virtual monochromatic spectral images-MARS (bone p=0.053, soft tissue p=0.32, fat p=0.13), suggesting similar signal density compared to normal (remote) tissue. Furthermore, periprosthetic polychromatic image noise levels were significantly higher than with virtual monochromatic spectral images-MARS (p<0.0001). All periprosthetic areas were deemed non-interpretable using polychromatic images, compared to 11 (9%) using virtual monochromatic spectral images-MARS. There were no differences in radiation dose compared to control group (p=0.21). Conclusions: Virtual monochromatic spectral images-MARS technology has the ability to reduce periprosthetic artifacts, achieving a significant increase to identify tissues and diagnostic interpretability of complications related to the implants. Level of Evidence: II

Exaggerated Interventricular Dependence Among Patients With Pectus Excavatum: Combined Assessment With Cardiac MRI and Chest CT.

OBJECTIVE: We sought to explore whether patients with pectus excavatum have exaggerated interventricular dependence and to evaluate the impact of the malformation severity (assessed on CT) on both anatomic and functional cardiac parameters (assessed on cardiac MRI). SUBJECTS AND METHODS: The current study involved consecutive patients with a diagnosis of pectus excavatum who were referred to undergo cardiac MRI and chest CT to establish surgical candidacy or to define treatment strategies. RESULTS: Sixty-two patients with pectus excavatum underwent cardiac MRI and chest CT. Fifty (81%) patients were male, and the median age was 17.5 years (range, 14.0-23.0 years). Forty-seven (76%) patients had evidence of right ventricular compression. The left ventricle showed a significantly decreased end-diastolic volume (inspiration vs expiration: 70.4 ± 11.6 vs 76.1 ± 13.7 mL/m2, respectively; p = 0.01) and a significantly higher eccentricity index (1.52 ± 0.2 vs 1.20 ± 0.1, p < 0.0001) during inspiration than during expiration. The median respiratory-related septal excursion was 8.1% (interquartile range, 5.1-11.7%). Patients with pericardial effusion showed a significantly higher pectus excavatum severity index than patients without pericardial effusion (6.3 ± 3.4 vs 4.4 ± 1.3, respectively; p = 0.003). Patients with a relative septal excursion equal to or larger than 11.8% showed a significantly higher pectus excavatum severity index than patients with a relative septal excursion of less than 11.8% (6.3 ± 2.6 vs 4.7 ± 2.4, respectively; p = 0.05). CONCLUSION: In this study, patients with pectus excavatum showed significant alterations of cardiac morphology and function that were related to the deformation severity and that manifest as an exaggerated interventricular dependence.