El dilema clínico frente a los pacientes con ergometría positiva y prueba de perfusión miocárdica con SPECT normal / The clinical dilemma facing patients with positive stress test and normal SPECT myocardial perfusion imaging

La evaluación de la perfusión miocárdica con SPECT combina una prueba de esfuerzo (ergometría o estrés farmacológico) junto a imágenes de perfusión con radioisótopos. Este estudio es útil para establecer el diagnóstico de enfermedad arterial coronaria, estratificar el riesgo de infarto y tomar decisiones terapéuticas. Un resultado normal aporta un alto valor predictivo negativo, es decir, una muy baja probabilidad de que el paciente presente eventos cardiovasculares. El hallazgo de signos de isquemia en la ergometría podría poner en jaque el valor predictivo negativo de una perfusión normal. En presencia de este resultado, el paso siguiente es evaluar los predictores de riesgo en la ergometría, el riesgo propio del paciente en función de los antecedentes clínicos y el puntaje cálcico coronario, cuando este se encuentra disponible. Ante la presencia concomitante de otros marcadores de riesgo se sugiere completar la evaluación con un estudio anatómico.El uso de nuevas tecnologías podría mejorar la precisión en la predicción de eventos. (AU)

Assessment of myocardial perfusion with SPECT combines a stress test (ergometry or pharmacological stress) with radioisotope perfusion imaging. This test is helpful to diagnose coronary artery disease, stratify the risk of heart attack, and make therapeutic decisions. A normal result provides a high negative predictive value; therefore, the probability of cardiovascular events is very low. Signs of ischemia on an ergometry could jeopardize the negative predictive value of normal perfusion. In this clinical setting, the next step is to evaluate the risk predictors in the stress test, the individual risk based on the clinical history, and the coronary calcium score when available. Given the simultaneous presence of other risk markers,completing the evaluation with an anatomical study is suggested. The use of new technologies could improve the accuracy of event prediction. (AU)

Incremental value of epicardial fat volume on predicting obstructive coronary artery disease with myocardial ischemia / 中华心血管病杂志

Objective: This study aimed to investigate the association between epicardial fat volume (EFV) and obstructive coronary artery disease (CAD) with myocardial ischemia, and evaluate the incremental value of EFV on top of traditional risk factors and coronary artery calcium (CAC) in predicting obstructive CAD with myocardial ischemia. Methods: This study was a retrospective cross-sectional study. Patients with suspected CAD who underwent coronary angiography (CAG) and single photon emission computerized tomography-myocardial perfusion imaging (SPECT-MPI) at the Third Affiliated Hospital of Soochow University from March 2018 to November 2019 were consecutively enrolled. EFV and CAC were measured by non-contrast chest computed tomography (CT) scan. Obstructive CAD was defined as coronary artery stenosis≥50% in at least one of the major epicardial coronary arteries, and myocardial ischemia was defined as reversible perfusion defects in stress and rest MPI. Obstructive CAD with myocardial ischemia was defined in patients with coronary stenosis severity≥50% and reversible perfusion defects in the corresponding areas of SPECT-MPI. Patients with myocardial ischemia bot without obstructive CAD were defined as none-obstructive CAD with myocardial ischemia group. We collected and compared the general clinical data, CAC and EFV between the two groups. Multivariable logistic regression analysis was performed to identify the relationship between EFV and obstructive CAD with myocardial ischemia. ROC curves were performed to determine whether addition of EFV improved predictive value beyond traditional risk factors and CAC for obstructive CAD with myocardial ischemia. Results: Among the 164 patients with suspected CAD, 111 patients were males, and average age was (61.4±9.9) years old. 62 (37.8%) patients were included into the obstructive CAD with myocardial ischemia group. 102 (62.2%) patients were included into the none-obstructive CAD with myocardial ischemia group. EFV was significantly higher in obstructive CAD with myocardial ischemia group than in none-obstructive CAD with myocardial ischemia group ((135.63±33.29)cm3 and (105.18±31.16)cm3, P<0.01). Univariate regression analysis showed the risk of obstructive CAD with myocardial ischemia increased by 1.96 times for each SD increase in EFV(OR 2.96; 95%CI, 1.89-4.62; P<0.01). After adjustment for traditional risk factors and CAC, EFV remained as an independent predictor for obstructive CAD with myocardial ischemia (OR, 4.48, 95%CI, 2.17-9.23; P<0.01). Addition of EFV to CAC and traditional risk factors was related to larger AUC for predicting obstructive CAD with myocardial ischemia (0.90 vs. 0.85, P=0.04, 95%CI: 0.85-0.95) and the global chi-square increased by 21.81 (P<0.05). Conclusions: EFV is an independent predictor for obstructive CAD with myocardial ischemia. Addition of EFV to traditional risk factors and CAC has incremental value for predicting obstructive CAD with myocardial ischemia in this patient cohort.

Echocardiographic prognostication of new onset heart failure in a cohort of ischemic heart disease patients / Pronóstico Ecocardiográfico de un nuevo evento de insuficiencia cardíaca en una cohorte de pacientes con Cardiopatía Isquémica

Background: Echocardiographic predictors for new onset heart failure in patients with ischemic heart disease with reduced left ventricular ejection fraction (HFrEF) or with preserved left ventricular ejection fraction (HFpEF) in Ethiopian and Sub-Saharan African is not well-known.Methods: Two hundred twenty-eight patients with ischemic heart disease were retrospectively recruited and followed. Analysis on baseline clinical and echocardiographic characteristics of patients, and risk factors for new onset HFpEF and new onset HFrEF were done. The exclusion criteria were known heart failure at baseline and those who did not have echocardiography data.Results: During the follow up period, heart failure developed in 62.2% (61/98) of ischemic heart disease patients with preserved left ventricular ejection fraction and in 70.1% (92/130) of ischemic heart disease patients with reduced left ventricular ejection fraction. We did not find significant difference between HFrEF and HFpEF in time to new onset heart failure. Systolic blood pressure, diastolic blood pressure, diabetes, left atrium and diastolic left ventricular dimension had significant association with new onset HFrEF on univariate regression analysis. Whereas new onset HFpEF was significantly associated with age, sex, presence of hypertension, Systolic blood pressure and diastolic left ventricular dimension. On cox regression analysis diastolic left ventricular dimension was associated with both new onset HFpEF and HFrEF. Age, diabetes, and dimension of left atrium were also associated with HFrEF.Conclusion: This cohort study in ischemic heart disease patients suggests a key role for the diastolic left ventricular dimension, left atrium size, diabetes, sex and age as predictors of new onset HFrEF and HFpEF. Strategies directed to prevention and early treatment of diabetes, dilatation of left ventricle and left atrium may prevent a considerable proportion of HFrEF or HFpEF.

Antecedentes: Los predictores ecocardiográficos de nuevos eventos de insuficiencia cardiaca en pacientes con cardiopatía isquémica con fracción de eyección ventricular preservada (HFpEF) o con fracción de eyección ventricular reducida (HFrEF) no son bien conocidos en la Africa etíope y subsahariana.Métodos: Doscientos veintiocho pacientes con cardiopatía isquémica fueron reclutados y seguidos retrospectivamente. Se realizaron análisis sobre las características clínicas y ecocardiográficas basales de los pacientes, así como los factores de riesgo para un nuevo evento de HFpEF y un nuevo evento de HFrEF. Los criterios de exclusión fueron insuficiencia cardíaca conocida al inicio del estudio y aquellos que no tenían datos de ecocardiografía.Resultados: Durante el período de seguimiento, la insuficiencia cardíaca se desarrolló en el 62,2% (61/98) de pacientes con cardiopatía isquémica con fracción de eyección ventricular izquierda preservada y en el 70,1% (92/130) de pacientes con cardiopatía isquémica con fracción de eyección ventricular izquierda reducida. No encontramos diferencias significativas entre HFrEF y HFpEF en el tiempo hasta la nueva aparición de insuficiencia cardíaca. La presión arterial sistólica, la presión arterial diastólica, la diabetes y las dimensiones de la aurícula iquierda y del ventrículo izquierdo en diástole tuvieron una asociación significativa con nuevos eventos de HFrEF en el análisis de regresión univariada. Mientras que un nuevo evento de HFpEF se asoció significativamente con la edad, el sexo, la presencia de hipertensión, la presión arterial sistólica y la dimensión ventricular izquierda diastólica. En el análisis de regresión de cox, la dimensión ventricular izquierda diastólica se asoció con HFpEF de nuevo inicio y HFrEF. La edad, la diabetes y la dimensión de la aurícula izquierda también se asociaron con HFrEF. Conclusión: Este estudio de cohorte en pacientes con cardiopatía isquémica sugiere un papel clave para la dimensión ventricular izquierda diastólica, el tamaño de la aurícula izquierda, la diabetes, el sexo y la edad como predictores de un nuevo evento de HFrEF y HFpEF. Las estrategias dirigidas a la prevención y el tratamiento temprano de la diabetes, la dilatación del ventrículo izquierdo y la aurícula izquierda pueden prevenir una proporción considerable de HFrEF o HFpEF.

Comportamento dos critérios de uso apropriado da cintilografia de perfusão miocárdica na avaliação de assintomáticos de alto risco cardiovascular ou com doença coronária conhecida / Appropriate use of myocardial perfusion scintigraphy criteria for assessing asymptomatic patients with high cardiovascular risk or known coronary disease

Fundamentos: O papel da cintilografia de perfusão miocárdica em pacientes assintomáticos permanece restrito a situações clínicas muito específicas, muitas delas abordadas nos Critérios de Uso Apropriado (AUC) de Cintilografia de Perfusão Miocárdica. Objetivo: Realizar uma análise crítica da aplicação desses critérios nas indicações de exames realizados em pacientes assintomáticos do Instituto Dante Pazzanese de Cardiologia, cuja população é notadamente de alto risco cardiovascular. Métodos: Foram selecionados pacientes assintomáticos que realizaram cintilografia de perfusão miocárdica para pesquisa de isquemia. As indicações dos exames foram classificadas em apropriadas, inapropriadas ou incertas. Hipocaptação fixa, hipocaptação transitória ou dilatação isquêmica transitória foram consideradas exames alterados. Na análise estatística, buscou-se avaliar a correlação entre o grau de recomendação das indicações e a presença de exames alterados. Resultados: A partir de uma seleção inicial de 2.999 prontuários, 490 foram considerados assintomáticos e incluídos conforme critérios de inclusão estabelecidos previamente. Apenas 9,8% das indicações foram inapropriadas, enquanto que 61,4% foram apropriadas, e 28,8% foram incertas. A hipocaptação fixa do radiofármaco ocorreu em 43,5% dos casos e a hipocaptação transitória, em 16,1%. Solicitar o exame de maneira apropriada ou incerta foi fator preditor de exame com resultado alterado nesta população. Conclusão: O uso dos critérios de uso apropriado da cintilografia de perfusão miocárdica mostrou-se eficaz em predizer exames alterados em uma população assintomática de alto risco cardiovascular, especialmente no grupo de pacientes com indicação incerta, o que pode significar que algumas das indicações consideradas incertas talvez sejam apropriadas para uma população de alto risco cardiovascular. (AU)

Segmentation method of myocardial perfusion bull-eye for the degree of loss of cardiac ischemia / 生物医学工程学杂志

As one of the non-invasive imaging techniques, myocardial perfusion imaging provides a basis for the diagnosis of myocardial ischemia in coronary heart disease. Aiming at the bull-eye image in myocardial perfusion imaging, this paper proposed a branching structure, which included multi-layer transposed convolution up-sampling concatenate module and four-channel weighted channels attention module, and the output results of the branch structure were fused with the output results of trunk U-Net, to achieve accurate segmentation of the cardiac ischemia missing degree in myocardial perfusion bull-eye image. The experimental results show that the multi-layer transposed convolution up-sampling concatenate module realizes the fusion of different depth feature maps, and effectively reduces the interference of the severe sparse degree which is similar to the missing degree on the segmentation. Four-channel weighted attention module can further improve the ability to distinguish between the two similar degrees and the ability to learn edge details of the targets, and retain more abundant edge details features. The experimental data came from Tianjin Medical University General Hospital, Tianjin TEDA Hospital, Tianjin First Central Hospital and Third Central Hospital. The Jaccard scores in the self-built dataset was 5.00% higher than that of U-Net. The model presented in this paper is superior to other optimized models based on U-Net, and the subjective evaluation meets the accuracy requirements for clinical diagnosis.

Estudio de la deformación miocárdica longitudinal en pacientes con cardiopatía isquémica / Study of longitudinal myocardial deformation in patients with ischemic cardiopathy

Resumen Introducción: Las enfermedades cardiovasculares constituyen la primera causa de muerte en Cuba y la mayoría de los países desarrollados. La ecocardiografía con speckle tracking bidimensional (ST 2D) es una técnica reciente en la evaluación de la función cardíaca. Objetivos: Determinar la relación entre la deformación miocárdica medida por ST 2D y el estado de la circulación coronaria en pacientes con cardiopatía isquémica, en el CIMEQ, durante un año. Material y método: Se realizó un estudio analítico y transversal con 55 pacientes con indicación de coronariografía sometidos a ecocardiograma bidimensional y estudio de ST 2D con medición de la deformación longitudinal (DLG). Se crearon dos grupos: enfermedad coronaria significativa (ECS = 32) y no significativa (ECNS = 23). Se utilizó SSPS para análisis de los resultados. Resultados: La edad promedio fue mayor en la ECS (55.6 ± 9.3 vs. 61.8 ± 8.8; p = 0.014). Predominaron los hombres con ECS (47.3%), los hipertensos (ECS = 90.6% y ENCS = 65.2%; p = 0.02) y los fumadores (ECS = 59.4% y ENCS = 17.4%; p = 0.002). El diagnóstico más frecuente fue la angina crónica estable (87%). En la ECS predominó la enfermedad de tres vasos (75%). La DLG fue menor en la ECS [(-20.0 ± 3.2 vs. -22.1 ± 3.6; p = 0.035); AUC = 0.458]. No hubo diferencias en la DLG según el número de vasos significativamente afectados. Conclusiones: Los resultados encontrados no justifican el empleo del ST 2D para diferenciar la ECS.

Abstract Introduction: Cardiovascular diseases are the leading cause of death in Cuba and most of the developed countries. Two-dimensional speckle tracking echocardiography (2D ST) is a recent technique in the evaluation of cardiac function. Objectives: To determine the relationship between myocardial deformation measured by 2D ST and coronary circulation in patients with ischemic heart disease, in the CIMEQ, for 1 year. Material and method: An analytical, cross-sectional study was carried out with 55 patients with an indication for coronary angiography who underwent 2D echocardiography and 2D ST study with longitudinal strain measurement (LSM). Two groups significant coronary disease (SCD = 32) and not significant (NSCD = 23) were created. SSPS was used to analyze the results. Results: The average age was higher in SCD (55.6 ± 9.3 vs. 61.8 ± 8.8, p = 0.014). Men with SCD (47.3%), hypertensive (SCD = 90.6% and NSCD = 65.2%, p = 0.02) and smokers (SCD = 59.4% and NSCD = 17.4%, p = 0.002) predominated. The most frequent diagnosis was chronic stable angina (87%). Three-vessel disease (75%) prevailed in SCD. The LMS was lower in SCD ([−20.0 ± 3.2 vs. −22.1 ± 3.6, p = 0.035]; AUC = 0.458). There were no differences in LSM according to the number of significantly diseased vessels. Conclusions: The results found do not justify the use of 2D ST to discriminate SCD.

Injuria miocárdica luego de cirugía no cardíaca / Myocardial injury after non-cardiac surgery

Resumen Las complicaciones cardiovasculares mayores en el postoperatorio son frecuentes y el principal factor contribuyente es la injuria miocárdica o infarto (MINS, Myocardial Injury after Noncardiac Surgery) asociado a cirugía no cardíaca. El riesgo de mortalidad a 30 días de los pacientes con injuria miocárdica es 4-5 veces mayor que los pacientes que no lo presentan. Se estima que 85% de los pacientes con MINS no presentan síntomas, por lo que la única manera de detectarlos es mediante screening sistemático de troponinas. Si bien no existen intervenciones de aplicación sistemática que permitan prevenir esta complicación, existen alternativas de tratamiento y manejo, por lo que la pesquisa activa es costo-efectiva y relevante desde el punto de visto clínico.

Major cardiovascular complications in the postoperative period are frequent and the main contributing factor is myocardial injury or infarction (MINS, Myocardial Injury after Noncardiac Surgery) associated with non-cardiac surgery. The 30-day mortality risk in patients with myocardial injury is 4-5 times higher than in patients without this complication. It is estimated that 85% of patients with MINS/infarction are asymptomatic, hence the only way to detect them is through systematic screening of troponins. Although there are no systematic interventions to prevent this complication, there are treatment and management alternatives, so the active early diagnosis is cost effective and relevant from a clinical point of view.

Isquemia miocárdica sin lesiones coronarias obstructivas: MINOCA-INOCA: Revisión para la toma de decisiones GREECO (Grupo de Estudio de Enfermedades Coronarias) / Myocardial ischemia without coronary obstructions: MINOCA-INOCA. Review for decision making

Una de cada 4 coronariografías realizadas por isquemia miocárdica presenta lesiones menores al 50% Este dato desencadenó un creciente interés en la comunidad médica. La Sociedad Americana de Cardiología publicó recientemente un artículo que describe la posición consensuada de un grupo de expertos sobre la fisiopatología, el diagnóstico y el tratamiento de esta entidad. Nuestro trabajo refleja una revisión narrativa y la posición de un grupo de expertos pertenecientes a diferentes instituciones con servicios de Cardiología jerarquizados. Aborda aspectos fisiopatológicos y diagnósticos para comprender el enfoque actual del tratamiento, tanto en pacientes que ingresan con diagnóstico de MINOCA (infa rto de miocardio con lesiones angiográficas no graves) o de INOCA (angina e isquemia demostradas, pero sin lesiones coronarias que justifiquen este síndrome).

One in every four coronarographies performed to study myocardial ischemia shows coronary angiographic stenosis less than 50%. This data triggered an increasing interest in the medical community. The American Society of Cardiology recently published a position paper about the pathophysiology, diagnosis and treatment of this entity. Our group performed a narrative review reflecting the opinion of cardiology experts from different centers in Argentina. It aims physiopatologic and diagnostic aspect to understand the current approach in patients with MINOCA (myocardial infarction with non-obstructive coronary arteries) e INOCA (demonstrated angina and ischemia but without coronary lesions that justify this syndrome).

Human pilot study of bare-metal stent: INC-01

ABSTRACT Background: The cost of performing a percutaneous coronary intervention is considerably high for the patient as well as for health systems, which have promoted the development of local technology to help meet the need for these devices. Methods: The INC-01 bare-metal stent was developed at the National Institute of Cardiology in Mexico City and was first implanted on porcine models with technical success in 100% of the evaluated parameters. Presentation of Cases: We present the first three cases of patients with ischemic heart disease, to whom the INC-01 bare-metal stent was implanted. Intracoronary ultrasonography was performed post-stent implantation, showing all the characteristics of implant success during evaluation and clinical follow-up. Conclusions: Angiography and intracoronary ultrasound were carried out demonstrating that the INC-01 bare-metal stent has physical, biological, and histological characteristics similar to those found in commercial metallic stents.

Impact of One-Catheter Strategy with TIG I Catheter on Coronary Catheterization Performance and Economic Costs / Impacto da Estratégia de um Cateter com Cateter TIG I no Desempenho da Coronariografia por Cateterismo e Custos Econômicos

Abstract Background: Coronary angiography with two catheters is the traditional strategy for diagnostic coronary procedures. TIG I catheter permits to cannulate both coronary arteries, avoiding exchanging catheters during coronary angiography by transradial access. Objective: The aim of this study is to evaluate the impact of one-catheter strategy, by avoiding catheter exchange, on coronary catheterization performance and economic costs. Methods: Transradial coronary diagnostic procedures conducted from January 2013 to June 2017 were collected. One-catheter strategy (TIG I catheter) and two-catheter strategy (left and right Judkins catheters) were compared. The volume of iodinated contrast administered was the primary endpoint. Secondary endpoints included radial spasm, procedural duration (fluoroscopy time) and exposure to ionizing radiation (dose-area product and air kerma). Direct economic costs were also evaluated. For statistical analyses, two-tailed p-values < 0.05 were considered statistically significant. Results: From a total of 1,953 procedures in 1,829 patients, 252 procedures were assigned to one-catheter strategy and 1,701 procedures to two-catheter strategy. There were no differences in baseline characteristics between the groups. One-catheter strategy required less iodinated contrast [primary endpoint; (60-105)-mL vs. 92 (64-120)-mL; p < 0.001] than the two-catheter strategy. Also, the one-catheter group presented less radial spasm (5.2% vs. 9.3%, p = 0.022) and shorter fluoroscopy time [3.9 (2.2-8.0)-min vs. 4.8 (2.9-8.3)-min, p = 0.001] and saved costs [149 (140-160)-€/procedure vs. 171 (160-183)-€/procedure; p < 0.001]. No differences in dose-area product and air kerma were detected between the groups. Conclusions: One-catheter strategy, with TIG I catheter, improves coronary catheterization performance and reduces economic costs compared to traditional two-catheter strategy in patients referred for coronary angiography.

Resumo Fundamento: A cineangiocoronariografia com dois cateteres é a estratégia tradicional para procedimentos coronarianos de diagnóstico. O cateter TIG I permite canular ambas as artérias coronárias, evitando a troca de cateteres durante a cineangiocoronariografia por acesso transradial. Objetivo: O objetivo deste estudo é avaliar o impacto da estratégia de um cateter, evitando a troca de cateter, no desempenho da coronariografia por cateterismo e nos seus custos econômicos. Métodos: Foram coletados os procedimentos diagnósticos coronarianos transradiais realizados entre janeiro de 2013 e junho de 2017. A estratégia de um cateter (cateter TIG I) e a estratégia de dois cateteres (cateteres coronários direito e esquerdo de Judkins) foram comparadas. O volume de contraste iodado administrado foi o endpoint primário. Os endpoints secundários eram espasmo radial, duração do procedimento (tempo de fluoroscopia) e exposição a radiações ionizantes (produto dose-área e kerma no ar). Os custos econômicos diretos também foram avaliados. Para as análises estatísticas, valores de p < 0,05 bicaudais foram considerados estatisticamente significativos. Resultados: De um total de 1.953 procedimentos em 1.829 pacientes, 252 procedimentos foram atribuídos à estratégia de um cateter e 1.701 procedimentos à estratégia de dois cateteres. Não houve diferenças nas características basais entre os grupos. A estratégia de um cateter exigiu menos contraste iodado [endpoint primário; (60-105) -mL vs. 92 (64-120) -mL; p < 0,001] em comparação com a estratégia de dois cateteres. Além disso, o grupo da estratégia de um cateter apresentou menos espasmo radial (5,2% vs. 9,3%, p = 0,022) e menor tempo de fluoroscopia [3,9 (2,2-8,0) -min vs. 4,8 (2,9-8,3) -min, p = 0,001] e economia de custos [149 (140-160)-€/procedimento vs. 171 (160-183) -€/procedimento; p < 0,001]. Não foram detectadas diferenças no produto dose-área e kerma no ar entre os grupos. Conclusões: A estratégia de um cateter, com cateter TIG I, melhora o desempenho da coronariografia por cateterismo e reduz os custos econômicos em comparação com a estratégia tradicional de dois cateteres em pacientes encaminhados para cineangiocoronariografia.

Evaluation of Myocardial Perfusion by Computed Tomography - Principles, Technical Background and Recommendations / Avaliação da Perfusão Miocárdica por Tomografia Computadorizada - Princípios, Fundamentação Técnica e Recomendações

Abstract 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.

Patency of individual and sequential coronary artery bypass in patients with ischemic heart disease: a meta-analysis

Abstract Objective: To evaluate the patency of individual and sequential coronary artery bypass in patients with ischemic heart disease. Methods: We searched PubMed, Cochrane Library, Excerpta Medica Database, and ClinicalTrials.gov databases for controlled trials. Endpoints included graft patency, anastomosis patency, occluded rates in left anterior descending (LAD) system and right coronary artery (RCA) system, in-hospital mortality, and follow-up mortality. Pooled risk ratios (RRs) and standardized mean difference (SMD) were used to assess the relative data. Results: Nine cohorts, including 7100 patients and 1440 grafts under individual or sequential coronary artery bypass. There were no significant differences between individual and sequential coronary artery bypass in the graft patency (RR=0.96; 95% CI=0.91-1.02; P=0.16; I2=87%), anastomosis patency (RR=0.95; 95% CI=0.91-1.00; P=0.05; I2=70%), occluded rate in LAD system (RR=1.03; 95% CI=0.92-1.16; P=0.58; I2=37%), occluded rate in RCA system (RR=1.36; 95% CI=0.72-2.57; P=0.35; I2=95%), in-hospital mortality (RR=1.57; 95% CI=0.92-2.69; P=0.10; I2=0%), and follow-up mortality (RR=0.96; 95% CI=0.36-2.53; P=0.93; I2=0%). Conclusion: No significant differences on clinical data were observed regarding anastomosis patency, occluded rate in LAD system, occluded rate in RCA system, in-hospital mortality, and follow-up mortality, indicating that the patency of individual and the patency of sequential coronary artery bypass are similar to each other.

Current Practices in Myocardial Perfusion Scintigraphy in Brazil and Adherence to the IAEA Recommendations: Results of a Cross-Sectional Study / Práticas Atuais na Cintilografia de Perfusão Miocárdica no Brasil e Adesão às Recomendações da AIEA: Resultado de Estudo Transversal

Abstract Background: Data on the current situation of nuclear medicine practices in cardiology in Brazil are scarce. The International Atomic Energy Agency (IAEA) has recommended eight "good practices" to minimize patients' ionizing radiation exposure during myocardial perfusion scintigraphy (MPS). Objectives: To assess the adoption of the eight good practices in MPS in Brazil. Methods: Cross-sectional study with data obtained by use of a questionnaire. All hypothesis tests performed considered a significance level of 5%. Results: We observed that 100% of the nuclear medicine services (NMS) assessed do not use thallium-201 as the preferred protocol. Regarding the use of technetium-99m, 57% of the NMS administer activities above the threshold recommended by the IAEA (36 mCi) or achieve an effective dose greater than 15 millisievert (mSv). The abbreviated stress-only myocardial perfusion imaging is not employed by 94% of the NMS; thus, only 19% count on strategies to reduce the radioactive doses. Approximately 52% of the NMS reported always performing dose adjustment for patient's weight, while 35% administer poorly calculated doses in the one-day protocol. Conclusion: A considerable number of NMS in Brazil have not adopted at least six practices recommended by the IAEA. Despite the difficulties found in nuclear practice in some Brazilian regions, almost all obstacles observed can be overcome with no cost increase, emphasizing the importance of developing strategies for adopting "good practices" when performing MPS.

Resumo Fundamento: A situação atual das práticas da medicina nuclear em cardiologia no Brasil ainda é pouco conhecida. A Agência Internacional de Energia Atômica (AIEA) recomendou oito "boas práticas" para minimizar a exposição dos pacientes à radiação ionizante durante a Cintilografia de Perfusão Miocárdica (CPM). Objetivo: Analisar a adoção das oito boas práticas na CPM no Brasil. Métodos: Estudo transversal com dados obtidos através de questionário. Todos os testes de hipóteses desenvolvidos consideraram uma significância de 5%. Resultados: Observamos que 100% dos Serviços de Medicina Nuclear (SMN) não utilizam Tálio-201 como protocolo preferencial. Sobre a utilização do Tecnécio-99m, notamos que 57% administram atividades acima do limiar recomendado pela AIEA (36 mCi) ou resultam em uma dose efetiva maior que 15 milisievert (mSv). A fase única de estresse não é praticada por 94% dos SMN; portanto, somente 19% contam com estratégias de redução das doses radioativas. Cerca de 52% dos SMN afirmam que sempre realizam o ajuste da dose por peso e 35% administram doses mal calculadas no protocolo de um dia. Conclusão: Observamos que um número considerável de SMN no Brasil ainda não seguem seis ou mais das práticas recomendadas pela AIEA. Apesar das dificuldades enfrentadas na prática nuclear em algumas regiões do Brasil, quase todos os déficits observados podem ser resolvidos sem aumento de custos, ressaltando a importância do desenvolvimento de estratégias para aderência às "boas práticas" na realização da CPM.