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Background: The Coronary Artery Disease Reporting and Data System (CAD-RADS) provides a lexicon and standardized reporting system for coronary CT angiography. Objectives: To evaluate inter-observer agreement of the CAD-RADS among an panel of early career and expert readers. Methods: Four early career and four expert cardiac imaging readers prospectively and independently evaluated 50 coronary CT angiography cases using the CAD-RADS lexicon. All readers assessed image quality using a five-point Likert scale, with mean Likert score ≥4 designating high image quality, and

Coronary computed tomography angiography (CCTA) has gained a prominent role in the evaluation of coronary artery disease. However, its anatomical nature does not allow the evaluation of the functional repercussion of coronary obstructions. It has been made possible to evaluate Myocardial computed tomography perfusion (Myocardial CTP) recently, based on myocardial contrast changes related to coronary stenoses. Several studies have validated this technique against the anatomical reference method (cardiac catheterization) and other functional methods, including myocardial perfusion scintigraphy and fractional flow reserve. The Myocardial CTP is performed in conjunction with the CCTA, a combined analysis of anatomy and function. The stress phase (with assessment of myocardial perfusion) can be performed before or after the resting phase (assessment of resting perfusion and coronary arteries), and different acquisition parameters are proposed according to the protocol and type of equipment used. Stressors used are based on coronary vasodilation (e.g. dipyridamole, adenosine). Image interpretation, similar to other perfusion assessment methods, is based on the identification and quantification of myocardial perfusion defects. The integration of both perfusion and anatomical findings is fundamental for the examination interpretation algorithm, allowing to define if the stenoses identified are hemodynamically significant and may be related to myocardial ischemia. Resumo A angiografia coronariana por tomografia computadorizada (ACTC) assumiu um papel de destaque na avaliação da doença arterial coronariana. Entretanto, sua natureza anatômica não permitia a avaliação da repercussão funcional das obstruções coronarianas. Recentemente, tornou-se possível a avaliação da perfusão miocárdica por tomografia computadorizada (PMTC), baseando-se nas alterações de contrastação miocárdicas relacionadas às estenoses coronarianas. Diversos estudos permitiram validar esta técnica perante o método anatômico de referência (cateterismo cardíaco) e outros métodos funcionais, incluindo cintilografia de perfusão miocárdica e a reserva de fluxo fracionada. A PMTC é realizada conjuntamente com a ACTC, em uma análise combinada de anatomia e função. A fase de estresse (com avaliação da perfusão miocárdica) pode ser realizada antes ou depois da fase de repouso (avaliação da perfusão de repouso e artérias coronárias), e diferentes parâmetros de aquisição são propostos conforme o protocolo e o tipo de equipamento utilizados. Os agentes estressores utilizados baseiam-se na vasodilatação coronariana (ex: dipiridamol, adenosina). A interpretação das imagens, semelhante a outros métodos de avaliação perfusional, baseia-se na identificação e quantificação de defeitos de perfusão miocárdicos. A integração dos achados perfusionais e anatômicos é parte fundamental do algoritmo de interpretação do exame, permitindo definir se as estenoses identificadas são hemodinamicamente significativas, podendo se relacionar com isquemia miocárdica.

Objective The aim of this study was to compare image quality and radiation dose of coronary computed tomography (CT) angiography performed with dual-source CT scanner using 2 different protocols in patients with atrial fibrillation. Methods Forty-seven patients with AF underwent 2 different acquisition protocols: double high-pitch (DHP) spiral acquisition and retrospective spiral acquisition. The image quality was ranked according to a qualitative score by 2 experts: 1, no evident motion; 2, minimal motion not influencing coronary artery luminal evaluation; and 3, motion with impaired luminal evaluation. A third expert solved any disagreement. Results A total of 732 segments were evaluated. The DHP group (24 patients, 374 segments) showed more segments classified as score 1 than the retrospective spiral acquisition group (71.3% vs 37.4%). Image quality evaluation agreement was high between observers (κ = 0.8). There was significantly lower radiation exposure for the DHP group (3.65 [1.29] vs 23.57 [10.32] mSv). Conclusions In this original direct comparison, a DHP spiral protocol for coronary CT angiography acquisition in patients with atrial fibrillation resulted in lower radiation exposure and superior image quality compared with conventional spiral retrospective acquisition.

The coronary computed tomography angiography has recently emerged as an accurate diagnostic tool in the evaluation of coronary artery disease, providing diagnostic and prognostic data that correlate directly with the data provided by invasive coronary angiography. The association of recent technological developments has allowed improved temporal resolution and better spatial coverage of the cardiac volume with significant reduction in radiation dose, and with the crucial need for more effective protocols of risk stratification of patients with chest pain in the emergency room, recent evaluation of the computed tomography coronary angiography has been performed in the setting of acute chest pain, as about two thirds of invasive coronary angiographies show no significantly obstructive coronary artery disease. In daily practice, without the use of more efficient technologies, such as coronary angiography by computed tomography, safe and efficient stratification of patients with acute chest pain remains a challenge to the medical team in the emergency room. Recently, several studies, including three randomized trials, showed favorable results with the use of this technology in the emergency department for patients with low to intermediate likelihood of coronary artery disease. In this review, we show data resulting from coronary angiography by computed tomography in risk stratification of patients with chest pain in the emergency room, its diagnostic value, prognosis and cost-effectiveness and a critical analysis of recently published multicenter studies.

Myocardial stress CT perfusion (CTP) can detect myocardial ischemia.We evaluated the transmural perfusion ratio (TPR) of dipyridamole stress CTP to detect significant coronary stenosis (70%) defined by quantitative invasive coronary angiography (ICA).Twenty-six patients (61.6 ± 8.0 years old; 14 males), without prior myocardial infarction, with positive single-photon emission computed tomography (SPECT;2 months) and clinical indication for ICA, underwent a customized multidetector-row CT (MDCT) protocol with rest/stress myocardial perfusion evaluation and coronary CT angiography. TPR was defined as mean subendocardial divided by mean subepicardial attenuation and quantified on rest and stress MDCT images. Abnormal TPR was defined as 2 SDs below the mean rest TPR.All 26 patients completed the CT protocol with no adverse events. Rest TPR was measured in all patients with a mean of 1.06 ± 0.11, and abnormal TPR was considered0.85. For 6 patients with normal coronary arteries by ICA, the mean TPR of territories with a previous positive perfusion defect in SPECT was 1.02 ± 0.18 (95% CI, 0.86-1.18; n = 6), and mean TPR of territories without perfusion defect in SPECT was 1.03 ± 0.09 (95% CI, -0.95 to 1.11; n = 12; P = 0.83). Mean stress TPR in territories with positive SPECT and significant coronary artery disease by quantitative ICA was 0.71 ± 0.13 (95% CI, -0.64 to 0.77) and in the remote myocardial was 1.01 ± 0.09 (95% CI, -0.96 to 1.06; P0001). In these territories, a significant Pearson's correlation was observed (r = -0.74, P0.001).TPR has a good correlation with SPECT and ICA to detect significant coronary stenosis.

Background Coronary computed tomography angiography (CTA) is a well-established diagnostic tool for coronary artery disease (CAD). However, coronary segments with prior stent implantation visualized with CTA may have limited evaluation and reduced accuracy. Objective We assessed the incremental value of stress myocardial CT perfusion (CTP) over anatomical assessment by coronary CTA alone in patients with stents, using quantitative invasive coronary angiography (≥50%) as reference. Methods Forty-six patients (56.9 ± 7.2 years; 28 men) referred to invasive coronary angiography were evaluated, combining coronary CTA and dipyridamole stress myocardial CTP with 64 detector-row CT. Coronary CTA was evaluated for ≥50% coronary stenosis, and myocardial CTP was used to potentially reclassify coronary territories, including those with stents and poorly evaluated stents because of artifacts. Results We evaluated 138 coronary territories, 62 with ≥1 stent. From these, 21 (34%) territories had adequately evaluated stents, 28 (45%) had limitedly evaluated stents still allowing diagnosis, and 13 (21%) had inadequately evaluated stents (no luminal assessment possible). Sensitivity, specificity, positive predictive value, negative predictive value and accuracy for coronary CTA in stent territories were, respectively, 85%, 77%, 87%, 74%, and 81%, and the combined use of coronary CTA and myocardial CTP were 88%, 95%, 97%, 81%, and 91% ( P = 0.0292). In territories with impaired stent evaluation (limited or inadequate), the diagnostic performance of coronary CTA alone was 83%, 72%, 79%, 76% and 77%, and combined with myocardial CTP were 87%, 94%, 95%, 85%, and 91% ( P = 0.036). Conclusion The combined evaluation of coronary CTA and stress myocardial CTP improved the diagnostic accuracy for the detection of significant obstructive CAD in patients with stents.

A angiotomografia de múltiplos detectores (TC) é um exame útil no diagnóstico de doença arterial coronariana (DAC). Recentemente, a TC foi associada à perfusão miocárdica com estresse (PTC) para detectar DAC. O objetivo é comparar a perfusão miocárdica da TC, após estresse com dipiridamol, com a cintilografia miocárdica (SPECT) na detecção de estenose coronariana significativa (>70%), usando o cateterismo (CATE) como método de referência. Trinta e seis pacientes (62±8,0 anos, 20 homens) com suspeita de DAC e com SPECT positivo em menos de 2 meses foram submetidos a um protocolo de TC para avaliação da PTC e angiografia pela tomografia computadorizada (ATC). TC foi realizada em um equipamento de 64 detectores (Aquillion 64, Toshiba), com uma primeira aquisição com os seguintes parâmetros:100mA,120Kv, 32x1mm colimação e 60ml de contraste a 3ml/s, após estresse com dipiridamol (0,56mg/Kg/4min), seguida de uma aquisição de repouso/ATC após aminofilina e metoprolol (270-400mA, 120Kv,64x0,5mm e 80 ml de contraste a 5ml/s). Observadores cegos e independentes, sem conhecimento prévio dos dados clínicos ou dos exames, realizaram análise visual e quantitativa da perfusão e angiotomografia, além de análise angiográfica quantitativa (QCA) para avaliação do CATE. Todos os pacientes completaram o protocolo sem efeitos adversos com dose de radiação média de 14,7 ± 3,0 mSv e exames interpretáveis. PTC foi positiva em 27 de 36 pacientes (75%). Dos nove casos (25%) com discordâncias (PTC negativa e SPECT positivo), 6 pacientes tinham ATC ou CATE normal e 2 tinham estenose coronariana menor que 50%. Um apresentava stent pérvio e o outro um ramo diagonal com redução luminal de 50%.O terceiro paciente apresentava uma oclusão do ramo ventricular posterior da artéria coronária direita com circulação colateral detectado pela ATC e confirmado pelo CATE. A comparação entre a PTC e o SPECT em uma análise por paciente mostrou boa concordância (Kappa =0,53;p70%) as reference method. Thirty-six patients (62.0±8.0 years old, 20 males) with suspected CAD and < 2 months prior positive SPECT underwent a customized multidetector-row computed tomography (MDCT) protocol with rest/stress myocardial perfusion evaluation and CTA. MDCT was performed in a 64 scanner (Aquillion 64, Toshiba) with stress perfusion after 0.56mg/kg/4min of dipyridamole (100mA, 120 kV, collimation-32 x 1 mm and 60 ml of iodinated contrast) followed by aminophyline and metoprolol infusion prior to a second rest perfusion/CTA acquisition (270-400mA, 120 kV, collimation-64 x 0,5 mm and 80 ml of iodinated contrast). Independent blinded observers with no knowledge of clinical data or other exams performed visual and quantitative analysis of CTP, CTA, SPECT and quantitative coronary angiography (QCA) analysis, that was performed on CCA. All 36 patients completed the CT protocol with no adverse events, mean radiation dose of 14.7 ± 3.0 mSv and with interpretable scans. CTP was positive in 27 of 36 patients (75%). From the 9 (25%) disagreements with normal CTP and positive SPECT, 6 patients had normal CCA or CTA and 2 had no coronary stenosis > 70 %. One had patent stents and the other had a diagonal branch with mild luminal reduction at CCA. The remaining patient had an occluded right posterior lateral branch with collateral flow detect by CTA and confirmed by CCA. Good agreement was demonstrated between CTP and SPECT on a per-patient analysis (kappa 0.53). In 26 patients using CCA as reference, sensitivity, specificity, positive predictive value, negative predictive values and accuracy for CTP were 88.0, 79.3, 66.7, 93.3%, 82,1% and for SPECT 68.8, 76.1, 66.7, 77.8% and 73,1% respectively. Rest and dipyridamole-stress computed tomography myocardial perfusion is feasible and results are similar to SPECT scintigraphy. The combined anatomical information provided by computed tomography coronary angiography may allow identification of false-positives on perfusion scans.

For years, cardiovascular diseases have been the leading cause of death worldwide, bringing on important social and economic consequences. Given this scenario, the search for a method capable of diagnosing coronary artery diseases in an early and accurate way is increasingly higher. The coronary computed tomography angiogram is already widely established for the stratification of coronary artery diseases, and, more recently, the computed tomography myocardial perfusion imaging has been providing relevant information by correlating ischemias and the coronary anatomy. The objective of this review is to describe the evaluation of myocardial ischemia by multiple detector computed tomography. This study will resort to controlled clinical trials that show the possibility of a single method to identify the atherosclerotic load, presence of coronary artery luminal narrowing and possible myocardial ischemia, by means of a fast, practical and reliable method validated by a multicenter study.

Recently, stress myocardial computed tomographic perfusion (CTP) was shown to detect myocardial ischemia. Our main objective was to evaluate the feasibility of dipyridamole stress CTP and compare it to single-photon emission computed tomography (SPECT) to detect significant coronary stenosis using invasive conventional coronary angiography (CCA; stenosis70%) as the reference method. Thirty-six patients (62 +/- 8 years old, 20 men) with previous positive results with SPECT (2 months) as the primary inclusion criterion and suspected coronary artery disease underwent a customized multidetector-row CT protocol with myocardial perfusion evaluation at rest and during stress and coronary CT angiography (CTA). Multidetector-row computed tomography was performed in a 64-slice scanner with dipyridamole stress perfusion acquisition before a second perfusion/CT angiographic acquisition at rest. Independent blinded observers performed analysis of images from CTP, CTA, and CCA. All 36 patients completed the CT protocol with no adverse events (mean radiation dose 14.7 +/- 3.0 mSv) and with interpretable scans. CTP results were positive in 27 of 36 patients (75%). From the 9 (25%) disagreements, 6 patients had normal coronary arteries and 2 had no significant stenosis (8 false-positive results with SPECT, 22%). The remaining patient had an occluded artery with collateral flow confirmed by conventional coronary angiogram. Good agreement was demonstrated between CTP and SPECT on a per-patient analysis (kappa 0.53). In 26 patients using CCA as reference, sensitivity, specificity, and positive and negative predictive values were 88.0%, 79.3%, 66.7%, and 93.3% for CTP and 68.8, 76.1%, 66.7%, and 77.8%, for SPECT, respectively (p = NS). In conclusion, dipyridamole CT myocardial perfusion at rest and during stress is feasible and results are similar to single-photon emission CT scintigraphy. The anatomical-perfusion information provided by this combined CT protocol may allow identification of false-positive results by SPECT.

With advances in multidetector computed tomography (MDCT) technology, the new generation of 64-slice MDCT scanners with submillimeter collimation and a faster gantry rotation allows imaging of the entire heart in a single breath-hold with excellent temporal and spatial resolution. This potentially permits a comprehensive assessment of coronary anatomy, left ventricular function, and myocardial perfusion. As will be seen in this review of the current literature regarding 16- and 64-slice MDCT, there is great promise for a comprehensive cardiac computed tomography (CT) study. The available data support the notion that CT coronary angiography may be an alternative to invasive coronary angiography in symptomatic patients with a low to intermediate likelihood of having coronary artery disease. By use of the same data acquired for CT coronary angiography, evaluation of global and regional left ventricular function and myocardial perfusion can be added to the MDCT evaluation without additional exposure to contrast medium or radiation and may provide a more conclusive cardiac workup in these patients. The potential applications and limitations of coronary stenosis detection, global and regional left ventricular function, and myocardial perfusion assessment by MDCT will be reviewed. The full potential of cardiac MDCT is just beginning to be realized.

Introdução: O teste ergométrico com alterações eletrocardiográficas compatíveis com isquemia miocárdica pode levar a outros exames complementares, frequentemente, à cintilografia de perfusão do miocárdio (CPM). Objetivos: Avaliar o desempenho diagnóstico da tomografia computadorizada de perfusão miocárdica (PMTC) e da reserva fracionada de fluxo derivada de tomografia computadorizada por machine learning (cFFR) em comparação à CPM em uma população de pacientes com isquemia induzida em testes ergométricos (TE), tendo a tomografia computadorizada de artérias coronárias (ACTC) como o método de referência. Métodos: Neste estudo de coorte prospectivo, 60 pacientes (58.4 ± 9.2 anos) foram submetidos à avaliação clínica e a dois protocolos de imagem: CPM e ACTC com PMTC durante o estresse com dipiridamol. Resultados: A PMTC apresentou acurácia diagnóstica significativamente superior à CPM, na análise por paciente e por território (AUC= 0,76 vs. 0,60 e 0,72 vs. 0,62, respectivamente, com p=0,04 para ambos). O menor valor encontrado de cFFR e a estenose quantitativa baseada na área luminal mínima (ALM) que apresentaram maior acurácia diagnóstica que métodos perfusionais (AUC= 0,86 e 0,90). Na análise por paciente, o escore de cálcio (EC) teve acurácia de 0,87 para detecção de doença arterial coronária (DAC) obstrutiva. A PMTC, cFFR, ALM, EC e ACTC foram mais fortes preditores de revascularização que a CPM (AUC = 0,79, 0,81, 0,85, 0,87 e 0,94, vs. 0,60, respectivamente). Conclusões: PMTC isoladamente teve maior acurácia que a CPM em pacientes com TE positivo e probabilidade baixa ou intermediária de DAC obstrutiva. A cFFR e a EC derivadas da tomografia computadorizada também apresentaram alta a acurácia diagnóstica. Estes resultados sugerem que o uso de PMTC, cFFR ou EC na prática clínica podem ser considerados, como alternativa adequada à CPM nesta população com teste ergométrico positivo e probabilidade intermediária para a doença arterial coronariana Background: Patients with low to intermediate probability of CAD presenting exercise treadmill test (ETT) consistent with myocardial ischemia is a common scenario and may lead to other complementary tests, frequently myocardial scintigraphy (SPECT).Objectives: We sought to evaluate the diagnostic performance of myocardial perfusion (CTP), and Fractional Flow Reserve Derived from Computed Tomography (cFFR) compared to SPECT in a population of patients with inducible ischemia on exercise treadmill tests (ETT), using coronary computed tomography angiography (CTA) as the reference method. Methods: Sixty patients (58.4 ± 9.2 years old) underwent clinical evaluation and two non-invasive imaging exams: SPECT and CTA with CTP during stress with dipyridamole. Results: CTP showed significantly higher diagnostic accuracy than SPECT, in a per-patient and per-territory analysis (AUC= 0.76 vs. 0.60 and 0.72 vs. 0.62, respectively, with p=0.04 for both). The cFFR and quantitative stenosis based on minimal luminal area (MLA) showed higher diagnostic accuracy than perfusion methods (AUC= 0.86, and 0.90). In a per-patient analysis, coronary calcium score (CAC) showed AUC of 0.87 for the detection of obstructive CAD. CTP, cFFR, MLA, CAC and CTA were stronger predictors of revascularization than SPECT (AUC = 0.79, 0.81, 0.85, 0.87 and 0.94, vs. 0.60, respectively. Conclusions: CTP alone presented higher accuracy than SPECT in patients with positive ETT with low or intermediate probability of CAD. cFFR and CAC derived from computed tomography also showed high diagnostic accuracy. These results suggest that the use of CTP, cFFR or CAC in clinical practice might be adequate alternatives to SPECT in this group of patients with positive ETT and intermediate probability of coronary artery disease

A insuficiência cardíaca congestiva (ICC) é uma condição em que o coração não consegue bombear o sangue de acordo com as necessidades metabólicas dos tecidos. Quando a ICC entra em seu estágio final, já refratária ao tratamento medicamentoso, ou outras opções terapêuticas, o transplante cardíaco constitui-se em medida salvadora destes pacientes. Após o primeiro ano de evolução do procedimento, a doença vascular do enxerto (DVE) é a complicação mais temida nestes pacientes. Esta doença caracteriza-se por aterosclerose acelerada, com acometimento concêntrico do vaso, predominando nos terços médios e distais. Sintomas isquêmicos geralmente não estão presentes devido ao coração denervado destes pacientes. Daí a importância em se ter um método com boa acurácia e que possibilite o diagnóstico da DVE em seus estágios iniciais, que, muitas vezes, não é demonstrado pela cineangiocoronariografia (CINE). O nosso trabalho teve como objetivo avaliar se o diagnóstico da DVE pela tomografia computadorizada por múltiplos detectores (TCMD) foi preditor de eventos maiores, definimos como: morte súbita, infarto, angioplastia, queda da fração de ejeção e retransplante. Em nossa amostra, selecionamos 59 pacientes transplantados que tinham sido submetidos à TCMD por indicação clínica. Encontramos idade média de 49 anos ± 11,36 anos e tempo médio de transplante na realização da TCMD de 82,67 ± 36,38 meses. A prevalência de hipertensão (HAS) foi de 59,32%, dislipidemia (DLP) 57,63% e diabetes mellitus (DM) 33,90%. Em relação à etilogia da ICC dos receptores, em primeiro lugar, tivemos doença isquêmica com 38,98%, seguida por doença chagásica com 33,90% e por miocardiopatia dilatada idiopática com 13,56% da amostra. Desta população, um subgrupo de 41 pacientes, além de ter feito a TCMD, fez também a CINE. A comparação dos dois métodos mostrou sensibilidade de 100%, especificidade de 77,27%, valor preditivo positivo (VPP) de 46,34% e valor preditivo negativo (VPN) de 100%. Os resultados mostraram que a presença de DVE pela tomografia foi preditora de eventos maiores no seguimento destes pacientes com significância estatística p 0,001. Outras variáveis analisadas que também tiveram impacto significativo foram escore de cálcio positivo (p< 0,05), piora da classe funcional na evolução para classe II e III, e os receptores que tinham o diagnóstico prévio de miocardiopatia dilatada. Concluímos que a TCMD é um exame que tem boa acurácia diagnóstica na DVE, podendo a CINE ficar restrita aos casos duvidosos. Além disso, alterações deste exame são preditoras de eventos adversos. O escore de cálcio e a piora da classe funcional também foram preditores de eventos. Congestive heart failure (CHD) is a condition characterized by the heart inot meeting the body oxygen demands. For end-stage CHD, refractory to medical treatment, heart transplant is a lifesaver treatment, but its late results may suffer a negative impact if there is allograft vasculopathy, the main reason of late adverse outcome in this population. This condition is is characterized by accelarated atherosclerosis with concentric disease predominant at the mid and distal segments of the coronary arteries. Ischemic symptoms seldom happen for the heart is denervated, and thus, it would be highly desirable to possess a test that could accuratelly foretell the presence of such abnormality. Furthermore, a possible gold standard, invasive coronary angiography (ICA) has been show to lack sensivity. The aim of this study was to evaluate if multidetector computed tomography( MDCT) could identify and thus to predict patients at higher risk of presenting late adverse events. Major events were considered as: sudden cardiac death (SCD), Hear attack, angioplasty, left ventricle impairment and retransplant. Consulting medical records we selected 59 heart transplant patients that underwent MDCT at least 7 years by clinical discretion. Mean age at the time of the exam was 49 ± 11.36 years. Mean post heart transplantantion time was 82.67 ± 36.38 months. Hypertension (HAS) prevalence was 59,32%, hyperlipidemia 57,63% and diabetes was 33,90%. Main pre-transplant CHD cause was ischemic heart disease in 38,98%, followed by Chaga\'s disease, 33.90% and idiopathic dilated cardiomyoapthy. We had 41 patients that also underwent ICA. Comparing both methods we found that MDCT had a sensibility of 100%, a specificity of 77,27%, a positive preditive value of 46,34% and a negative preditive value of 100%. The diagnosis of CAV done by MDCT was a predictor of major events at the follow-up (p=0,001). Other predictors that achieved statistical significance were positive calcium score (p

A angiografia coronariana por tomografia computadorizada (ACTC) é um exame bem estabelecido no diagnóstico da doença arterial coronariana. Entretanto, segmentos coronarianos submetidos a implante de stent podem apresentar limitação na avaliação luminal. O objetivo deste estudo é avaliar o valor adicional da perfusão miocárdica por tomografia computadorizada (PMTC) à avaliação anatômica isolada pela ACTC em portadores de stent, tendo o cateterismo (CATE) como referência. Quarenta e seis pacientes (56,9±7,2 anos, 28 homens) com indicação clínica de CATE em até 60 dias foram submetidos à avaliação combinada de ACTC e PMTC, por meio de tomógrafo de 64 detectores (Aquillion 64, Toshiba). A aquisição foi iniciada com a fase de estresse (PMTC) usando-se dipiridamol a 0,56mg/kg/4min e 60ml de contraste a 3ml/s, seguido de reversão com aminofilina 240mg e metoprolol (até 20mg). Em seguida, realizou-se a ACTC com 80-90ml de constraste a 5ml/s. Os dados da PMTC, da ACTC, e do CATE foram analisados por dois observadores independentes, sem informações clínicas dos pacientes. Primariamente analisou-se a ACTC, seguida da avaliação da PMTC. Concluída esta fase, os observadores tinham a possibilidade de reclassificar os segmentos coronarianos submetidos a stent cuja avaliação estivesse limitada ou inadequada por artefatos. A dose total média de radiação foi 15,83±4,93 mSv e todos os exames foram adequados. Um total de 129 segmentos coronarianos foi avaliado na ACTC, bem como os respectivos territórios miocárdicos pela PMTC. Destes, 54 territórios (42%) eram relacionados à presença de stents, sendo 19 com stents de avaliação adequada e 23 com avaliação luminal limitada, porém possível, e 12 segmentos de avaliação inadequada (sem possibilidade de avaliação luminal). Os valores de sensibilidade, especificidade, valor preditivo positivo, valor preditivo negativo e acurácia para a ACTC isolada nos territórios com stents foram de, respectivamente: 85%, 76%, 85%, 76% e 81%, e com o uso combinado da ACTC + PMTC foram de, respectivamente 88%, 95%, 97%, 83% e 92% (p=0,0314). Nos territórios com stent e avaliação luminal prejudicada (limitada ou inadequada) os valores para análise da ACTC isolada foram de, respectivamente: 83%, 71%, 75%, 80% e 77% e após a análise da ACTC + PMTC foram de, respectivamente: 89%, 94%, 94%, 89% e 92% (p = 0,0441). A avaliação combinada da ACTC + PMTC permitiu melhorar a acurácia diagnóstica da avaliação de obstrução coronariana significativa em pacientes portadores de stents, comparativamente à avaliação isolada da ACTC Coronary computed tomography angiography (coronary CTA) is a well established examination in the diagnosis of coronary artery disease (CAD). However, the segments with prior coronary stent implantation may have limited luminal evaluation. The aim of this study is to assess the incremental value of myocardial computed tomography perfusion (myocardial CTP) to the anatomical assessment by coronary CTA alone in patients with stents, using catheterization (CAT) as a reference method. Forty-six patients (56.9 ± 7.2 years, 28 men) referred to CAT by clinical indication within 60 days, were evaluated with combined evaluation of coronary CTA and myocardial CTP through 64-detector CT scanner (Aquillion 64, Toshiba). The acquisition protocol began with the stress phase (myocardial CTP), using dipyridamole to 0.56 mg/kg/4min and 60ml of contrast (3ml/s), followed by a bolus of aminophylline 240 mg and metoprolol (up to 20mg). After, it was performed the coronary CTA wih 80-90ml of contrast (5 ml/s). Data from the myocardial CTP, coronary CTA and CAT were analyzed by two independent observers, with no knowledge to clinical information. The observers reviewed the coronary CTA findings, and in a second time performed the evaluation of myocardial CTP. So, they had the possibility to reclassify segments with coronary stent that were considered with limited or inadequate assessment due to artifacts. Mean total dose of radiation was 15.83 ± 4.93 mSv, and all examinations were interpretable. A total of 129 coronary segments were evaluated by coronary CTA, and also were their correspondent myocardial territories by myocardial CTP. Of these, 54 territories (42%) were related to the presence of stents, 19 stents with adequate evaluation, 23 with limited evaluation, but possible, and 12 with inadequate evaluation (no luminal assessment possible). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy for the coronary CTA in territories with stents were respectively: 85%, 76%, 85%, 76% and 81%, and the combined use of coronary CTA + Myocardial CTP were respectively 88%, 95%, 97%, 83% and 92% (p=0.0314). In territories with impaired luminal stent evaluation (limited or inadequate), the values for analysis of coronary CTA alone were: 83%, 71%, 75%, 80% and 77%, and after analysis of myocardial CTP were, respectively: 89%, 94%, 94%, 89% and 92% (p = 0.0441). The combined evaluation of the coronary CTA and myocardial CTP has improved the diagnostic accuracy of the evaluation of significant coronary obstruction in patients with stents, compared to the assessment of coronary CTA alone

INTRODUÇÃO: A angiotomografia computadorizada com múltiplos detectores (ATCMD) apresenta alta acurácia para a detecção de estenose luminal significativa das artérias coronárias ( 50%) quando comparada à angiografia coronária invasiva (ACI). Recentemente, esse método vem sendo investigado na avaliação de pacientes com dor torácica aguda de baixo risco. No entanto, poucos estudos investigaram a capacidade da ATCMD na avaliação de pacientes com maior risco para síndrome coronária aguda (SCA). OBJETIVOS: Investigar a acurácia diagnóstica da ATCMD com 64 colunas de detectores para a detecção de estenose luminal coronária 50% definida pela ACI em indivíduos com suspeita de SCA sem supradesnível do segmento ST e comparar estes resultados com a acurácia encontrada em pacientes com suspeita de doença coronária crônica; avaliar a capacidade da ATCMD em predizer revascularização miocárdica nos 30 primeiros dias de seguimento. Adicionalmente objetivamos verificar a prevalência e a acurácia da presença de calcificação coronária para detecção de estenose luminal coronária significativa. MÉTODOS: Pacientes que participaram do estudo multicêntrico internacional CorE64 foram classificados nos grupos SCA e não-SCA de acordo com critérios clínicos, incluindo a presença de angina ao repouso, alterações isquêmicas ao ECG e elevação de marcadores de necrose miocárdica. Todos os pacientes foram submetidos à ATCMD e posteriormente à ACI e para a análise primária foram considerados apenas aqueles com escore de cálcio (EC) 600. RESULTADOS: Dos 291 pacientes incluídos, 80 (27%) foram classificados no grupo SCA. A prevalência de estenose coronária 50% foi de 68% neste grupo e de 52% no grupo não-SCA (p=0,015). A acurácia diagnóstica da ATCMD, em análise por paciente, para detecção de estenose coronária significativa demonstrada pela análise da área sob a Curva de Características Operacionais (AUC) foi de 0,95 (IC 95%: 0,90-0,99) e 0,92 (IC 95%: 0,89-0,96) nos grupos SCA e não-SCA, respectivamente (p=0,44). Nos 30 dias de seguimento, 98 pacientes foram submetidos à revascularização miocárdica (48 do grupo SCA e 50 do grupo não-SCA). A AUC da ATCMD e da ACI para predição de revascularização foi de 0,91 (95% IC: 0,83-0,99) e 0,89 (95% IC: 0,80-0,98), respectivamente, no grupo SCA (p=0,61) e 0,80 (95% IC: 0,74-0,86) e 0,79 (95% IC: 0,73-0,85) no grupo não-SCA, p=0,75. Comparando os dois grupos estudados, a ATCMD foi melhor preditora de revascularização no grupo SCA (p=0,035). No grupo SCA, 6 pacientes (7,5%) tinham EC zero e estenose coronária significativa, comparado a 8 indivíduos (3,8%) do grupo não-SCA (p=0,22). Considerando pacientes com EC baixo (0 a 9), 12 (15%) do grupo SCA e 11 (5,2%) do não- SCA apresentaram estenose coronária 50% (p=0,012). A acurácia do EC para detecção de estenose coronária significativa nos grupos SCA e não- SCA foi de 0,73 (IC 95%: 0,63-0,82) e 0,70 (IC 95%: 0,64-0,76), respectivamente (p=0,75), sendo que o valor preditivo negativo no grupo SCA foi estatisticamente menor que no grupo não-SCA [0,63 (IC95%: 0,39- 0,86) e 0,86 (IC 95%: 0,77-0,95), respectivamente, p=0,038]. CONCLUSÕES: A ATCMD apresentou alta acurácia diagnóstica para detecção de estenose coronária significativa nos grupos SCA e não-SCA, não havendo diferença significativa entre ambos. A ATCMD obteve acurácia semelhante à ACI na predição de revascularização, sendo maior no grupo SCA que no não-SCA. A acurácia do EC para a detecção de estenose coronária 50% foi moderada em ambos os grupos, sendo que um EC zero ou baixo não excluiu a ocorrência de estenose significativa, especialmente no grupo SCA BACKGROUND: Multi-detector computed tomography angiography (MDCTA) has shown high accuracy to detect obstructive coronary luminal stenosis ( 50%) compared to invasive coronary angiography (ICA). Recently, this technology has been investigated in the evaluation of patients with low-risk acute chest pain. However, few studies investigated its diagnostic performance in higher-risk patients with suspected acute coronary syndrome (ACS). OBJECTIVES: To estimate the diagnostic accuracy of 64- row computed tomography angiography to detect significant coronary stenosis defined by ICA in a per-patient analysis and its ability to predict coronary revascularization in patients with suspected acute coronary syndrome and in those with chronic, stable coronary artery disease; to identify the prevalence and the diagnostic accuracy of coronary calcification to detect significant luminal stenosis in both groups. METHODS: Patients included in the international multicenter trial CorE64 were categorized as suspected ACS or non-ACS based on clinical data. A 64-row coronary MDCTA was performed before ICA and both exams were evaluated by blinded, independent core laboratories. RESULTS: From 291 patients with coronary calcium score (CCS) 600 included in the primary analysis, 80 were categorized as suspected ACS. The prevalence of obstructive coronary disease was 68% in suspected ACS and 52% in non-ACS group (p=0.015). Patient-based analysis showed an area under the receiver-operatingcharacteristic curve (AUC) for detecting coronary stenosis 50% of 0.95 (95% CI: 0.90-0.99) in ACS and 0.92 (95% CI: 0.89-0.96) in non-ACS group (p=0.44). After 30 days of follow-up, 98 patients were submitted to coronary revascularization (48 from the ACS and 50 from the non-ACS group). MDCTA was similar to ICA to predict coronary revascularization in both groups with AUC of 0.91 (95% CI: 0.83-0.99) for MDCTA versus 0.89 (95% CI: 0.80-0.98) for ICA in the ACS group (p=0.61) and 0.80 (95% CI: 0.74- 0.86) for MDCTA versus 0.79 (95% CI: 0.73-0.85) for ICA in non-ACS group (p=0.75). MDCTA was better to predict revascularization in ACS than in non- ACS group (p=0.035). In the suspected ACS group, 6 patients (7.5%) had no coronary calcification and coronary stenosis 50%, compared with 8 patients (3.8%) in the non-ACS group (p=0.22). Considering patients with zero or low (0 to 9) CCS, 12 (15%) in the ACS and 11 (5.2%) in the non-ACS group had significant coronary stenosis (p=0.012). The accuracy of CCS to detect obstructive coronary stenosis in the ACS and non-ACS groups were 0.73 (95% CI: 0.63-0.82) e 0.70 (95% CI: 0.64-0.76), p=0.75, and its negative predictive value in the suspected ACS group was lower than in non-ACS patients [0.63 (95% CI: 0.39-0.86) and 0.86 (95% CI: 0.77-0.95), respectively, p=0.038]. CONCLUSIONS: Coronary MDCTA diagnostic accuracy was high and comparable for both ACS and non-ACS patients. MDCTA predicted revascularization similarly to ICA and its prediction ability was significantly better in the ACS than in non-ACS group. The diagnostic accuracy of a positive CCS to detect luminal stenosis 50% was moderate in both groups and a zero or low CCS could not exclude reliably significant coronary stenosis, particularly in suspected ACS patients

Introdução: A perfusão miocárdica de estresse pela tomografia (PMT) é um método emergente e não-invasivo para detecção de isquemia miocárdica. O objetivo deste estudo foi avaliar a acurácia diagnóstica da PMT em pacientes com bloqueio de ramo esquerdo (BRE) que estavam em pesquisa diagnóstica de doença arterial coronariana (DAC) e o valor adicional da PMT sobre a tomografia computadorizada com múltiplos detectores (ATC) usando tomógrafo com 320 detectores, e compará-los com a cintilografia de perfusão miocárdica (SPECT) para detecção de isquemia miocárdica com estenose coronariana significativa (estenose >- 70%), utilizando a angiografia coronariana quantitativa (QCA) e a angiografia coronariana pela tomografia computadorizada com múltiplos detectores como referências. Material e Métodos: Quarenta e dois pacientes com BRE e SPECT ( < 2 meses) em avaliação diagnóstica de DAC foram encaminhados para realizar o protocolo de tomografia que incluiu o escore de cálcio, PMT, ATC e realce tardio do miocárdio. Trinta pacientes foram encaminhados para angiografia coronária invasiva. As imagens foram interpretadas por observadores independentes e alheios aos resultados dos exames e aos dados clínicos. Foram realizadas análises por paciente e por território. O estudo obteve a aprovação da comissão de ética e todos os pacientes assinaram consentimento informado. Resultados: A idade média dos pacientes foi 63 +- 10 anos e, destes, 67% mulheres (28 pacientes). A dose média de radiação total foi de 9,3 +- 4,6 mSv. Na análise por paciente, sensibilidade, especificidade, valores preditivos positivo e negativo foram de 86%, 89%, 80 e 93% para a PMT (p=0,001) (kappa 0,74) e 63%, 91%, 65% e 90% (p < 0,001) na análise por território (kappa 0,55), respectivamente. Em ambas as análises, o ATC mostrou excelente precisão, com área sob a curva ROC=0,9. Considerável concordância foi demonstrada entre SPECT e o QCA (kappa 0,32 e 0,26) nas análises por paciente e por território, respectivamente. A avaliação combinada da ATC com a PMT permitiu melhorar a acurácia diagnóstica para detecção de estenose coronariana com redução luminal hemodinamicamente significativa ( >= 70%) comparando-se com a ATC, PMT ou SPECT isolados, demonstrado por valores de sensibilidade, especificidade, e valores preditivos positivos e negativos de 93%, 87%, 87%, 93% (p < 0,0001) na avaliação combinada por paciente, e 85%, 90%, 79%, 93% (p < 0,0001) na avaliação combinada por território. Conclusão: O uso do protocolo tomográfico de estresse é viável e possui boa acurácia para diagnóstico de DAC em pacientes com BRE com resultados superiores ao SPECT. A combinação da PMT e ATC permitiu melhorar a acurácia diagnóstica da avaliação de obstrução coronariana significativa em pacientes com BRE Introduction: Stress computed tomography myocardial perfusion (CTP) is an emerging and non-invasive method to detect myocardial ischemia. The objective of this study was to evaluate diagnostic accuracy of CTP in patients with left bundle branch block (LBBB) who were being evaluated for coronary artery disease (CAD) and the additional value of CTP on computed tomography angiography (CTA) using 320-row detector CT scanner and compare them with single-photon emission computed tomography (SPECT) for detection of myocardial ischemia with significant coronary stenosis >= 70% using quantitative invasive coronary angiography (QCA) and coronary CT angiography as references. Material and Methods: Forty two LBBB patients with SPECT ( < 2 months) in diagnostic evaluation for CAD were referred to stress CT protocol which included calcium score, CTP, CTA and myocardial delayed enhancement. Thirty patients were referred to invasive coronary angiography. Independent blinded observers performed analyses of the images. Per-patient and perterritory analyses were conducted. Ethical committee aproval was obtained and all patients gave informed consent. Results: The mean age was 63 +- 10 years. 67% were women (28 patients). The total mean radiation dose was 9,3 +- 4,6 mSv. In per-patient sensitivity, specificity, positive and negative values were 86%, 89%, 80 and 93%, for CTP (p=0,001) (kappa 0.74) and 63%, 91% 65% and 90% (p < 0,001) in per-territory analysis (kappa 0.55), respectively. In both analyses, CTA showed excellent accuracy with area under receiver operating curve (AUC) = 0.9. Fair agreement was demonstrated between SPECT and QCA (kappa 0,32 e 0,26) in per-patient and per-territory analyses, respectively. The combined analysis of CTA with CTP, improved diagnostic accuracy for detection of coronary stenosis with hemodynamically significant luminal reduction ( >= 70%) compared with CTA, CTP or SPECT alone, demonstrated by sensitivity, specificity, and positive and negative predictive values of 93%, 87%, 87%, 93% (p < 0,0001) in the combined evaluation by patient and 85%, 90%, 79%, 93% (p < 0,0001) in the combined evaluation by territory. Conclusion: The use of customized stress CT protocol is feasible and has good accuracy for the diagnosis of CAD in patients with LBBB with results better than SPECT. The combination of PMT and ATC has improved the diagnostic accuracy of the assessment of significant coronary obstruction in patients with LBBB