Cardiac Magnetic Resonance in the Assessment of Chagas Disease and its Complications

Abstract The well-known occurrence of Chagas disease in endemic areas has become a worldwide problem, and cardiac magnetic resonance allows the early detection of cardiac involvement and complications of this disease. Cardiac magnetic resonance is a useful tool in all phases of Chagas disease, and new promising techniques using T1 mapping and extracellular volume measurements are able to detect cardiac involvement even earlier than conventional techniques.

Hypotheses, rationale, design, and methods for prognostic evaluation of a randomized comparison between patients with coronary artery disease associated with ischemic cardiomyopathy who undergo medical or surgical treatment: MASS-VI (HF).

BACKGROUND: Ischemic cardiomyopathy and severe left ventricular dysfunction are well established to represent the main determinants of poor survival and premature death compared with preserved ventricular function. However, the role of myocardial revascularization as a therapeutic alternative is not known to improve the long-term prognosis in this group of patients. This study will investigate whether myocardial revascularization contributes to a better prognosis for patients compared with those treated with drugs alone and followed over the long term. METHODS: The study will include 600 patients with coronary artery disease associated with ischemic cardiomyopathy. The surgical or drug therapy option will be randomized, and the events considered for analysis will be all-cause mortality, nonfatal infarction, unstable angina requiring additional revascularization, and stroke. The events will be analyzed according to the intent-to-treat principle. Patients with multivessel coronary disease and left ventricular ejection fraction measurements of less than 35% will be included. In addition, myocardial ischemia will be documented by myocardial scintigraphy. Markers of myocardial necrosis will be checked at admission and after the procedure. DISCUSSION: The role of myocardial revascularization (CABG) in the treatment of patients with coronary artery disease and heart failure is not clearly established. The surgical option of revascularizing the myocardium is a procedure designed to reduce the load of myocardial hibernation in patients with heart failure caused by coronary artery disease. On the other hand, the assessment of myocardial viability is frequently used to identify patients with left ventricular ischemic dysfunction in which CABG may add survival benefit. However, the effectiveness of this option is uncertain. The great difficulty in establishing the efficacy of surgical intervention is based on the understanding of viability without ischemia. Thus, this study will include only patients with viable and truly ischemic myocardium to correct this anomaly. TRIAL REGISTRATION: Evaluation of a randomized comparison between patients with coronary artery disease associated with ischemic cardiomyopathy submitted to medical or surgical treatment: MASS-VI (HF), ISRCTN77449548, Oct 10th, 2019 (retrospectively registered).

Longitudinal Shortening of the Left Ventricle by Cine-CMR for Assessment of Diastolic Function in Patients with Aortic Valve Disease / Encurtamento Longitudinal do Ventrículo Esquerdo por Cine-RMC para Avaliação da Função Diastólica em Pacientes com Doença Valvar Aórtica

Abstract Background: Diastolic dysfunction, commonly evaluated by echocardiography, is an important early finding in many cardiomyopathies. Cardiac magnetic resonance (CMR) often requires specialized sequences that extends the test time. Recently, feature-tracking imaging has been made available, but still requires expensive software and lacks clinical validation. Objective: To assess diastolic function in patients with aortic valve disease (AVD) and compare it with normal controls by evaluating left ventricular (LV) longitudinal displacement by CMR. Methods: We compared 26 AVD patients with 19 normal controls. Diastolic function was evaluated as LV longitudinal displacement in 4-chamber view cine-CMR images using steady state free precession (SSFP) sequence during the entire cardiac cycle with temporal resolution < 50 ms. The resulting plot of atrioventricular junction (AVJ) position versus time generated variables of AVJ motion. Significance level of p < 0.05 was used. Results: Maximum longitudinal displacement (0.12 vs. 0.17 cm), maximum velocity during early diastole (MVED, 0.6 vs. 1.4s-1), slope of the best-fit line of displacement in diastasis (VDS, 0.22 vs. 0.03s-1), and VDS/MVED ratio (0.35 vs. 0.02) were significantly reduced in AVD patients compared with controls, respectively. Aortic regurgitation showed significantly worse longitudinal LV shortening compared with aortic stenosis. Higher LV mass indicated worse diastolic dysfunction. Conclusions: A simple linear measurement detected significant differences on LV diastolic function between AVD patients and controls. LV mass was the only independent predictor of diastolic dysfunction in these patients. This method can help in the evaluation of diastolic dysfunction, improving cardiomyopathy detection by CMR, without prolonging exam time or depending on expensive software.

Resumo Fundamentos: A disfunção diastólica, comumente avaliada por ecocardiografia, é um importante achado precoce na maioria das cardiomiopatias. A ressonância magnética cardíaca (RMC) frequentemente requer sequências específicas que prolongam o tempo de exame. Recentemente, métodos de imagens com monitoramento de dados (feature-tracking) foram desenvolvidos, mas ainda requerem softwares caros e carecem de validação clínica. Objetivos: Avaliar a função diastólica em pacientes com doença valvar aórtica (DVA) e compará-la a controles normais pela medida do deslocamento longitudinal do ventrículo esquerdo (VE) por RMC. Métodos: Nós comparamos 26 pacientes com DVA com 19 controles normais. A função diastólica foi avaliada como uma medida do deslocamento longitudinal do VE nas imagens de cine-RMC no plano quatro câmaras usando a sequência steady state free precession (SSFP) durante todo o ciclo cardíaco com resolução temporal < 50 ms. O gráfico resultante da posição da junção atrioventricular versus tempo gerou variáveis de movimento da junção atrioventricular. Utilizamos nível de significância de p < 0,005. Resultados: Deslocamento longitudinal máximo (0,12 vs. 0,17 cm), velocidade máxima em início de diástole (0,6 vs. 1,4s-1), velocidade máxima na diástase (0,22 vs. 0,03s-1) e a razão entre a velocidade máxima na diástase e a velocidade máxima em diástole inicial (0,35 vs. 0,02) foram significativamente menores nos pacientes com DVA em comparação aos controles normais, respectivamente. Pacientes com insuficiência aórtica apresentaram medidas de encurtamento longitudinal do VE significativamente piores em comparação aqueles com estenose aórtica. O aumento da massa ventricular esquerda indicou pior disfunção diastólica. Conclusões: Esta simples medida linear detectou diferenças significativas na função diastólica do VE entre pacientes com DVA e controles normais. A massa ventricular esquerda foi o único preditor independente de disfunção diastólica nesses pacientes. Este método pode auxiliar na avaliação da disfunção diastólica, melhorando a detecção de cardiomiopatias por RMC sem prolongar o tempo de exame ou depender de caros softwares.

Longitudinal Shortening of the Left Ventricle by Cine-CMR for Assessment of Diastolic Function in Patients with Aortic Valve Disease.

BACKGROUND: Diastolic dysfunction, commonly evaluated by echocardiography, is an important early finding in many cardiomyopathies. Cardiac magnetic resonance (CMR) often requires specialized sequences that extends the test time. Recently, feature-tracking imaging has been made available, but still requires expensive software and lacks clinical validation. OBJECTIVE: To assess diastolic function in patients with aortic valve disease (AVD) and compare it with normal controls by evaluating left ventricular (LV) longitudinal displacement by CMR. METHODS: We compared 26 AVD patients with 19 normal controls. Diastolic function was evaluated as LV longitudinal displacement in 4-chamber view cine-CMR images using steady state free precession (SSFP) sequence during the entire cardiac cycle with temporal resolution < 50 ms. The resulting plot of atrioventricular junction (AVJ) position versus time generated variables of AVJ motion. Significance level of p < 0.05 was used. RESULTS: Maximum longitudinal displacement (0.12 vs. 0.17 cm), maximum velocity during early diastole (MVED, 0.6 vs. 1.4s-1), slope of the best-fit line of displacement in diastasis (VDS, 0.22 vs. 0.03s-1), and VDS/MVED ratio (0.35 vs. 0.02) were significantly reduced in AVD patients compared with controls, respectively. Aortic regurgitation showed significantly worse longitudinal LV shortening compared with aortic stenosis. Higher LV mass indicated worse diastolic dysfunction. CONCLUSIONS: A simple linear measurement detected significant differences on LV diastolic function between AVD patients and controls. LV mass was the only independent predictor of diastolic dysfunction in these patients. This method can help in the evaluation of diastolic dysfunction, improving cardiomyopathy detection by CMR, without prolonging exam time or depending on expensive software.

Comprehensive Assessment of Cardiac Involvement in Muscular Dystrophies by Cardiac MR Imaging.

Muscular dystrophy is a group of genetically inherited diseases with irreversible and progressive muscle loss and is associated with cardiac involvement. Particularly in Duchenne and Becker dystrophies, cardiac disorders are the leading causes of mortality. Cardiovascular magnetic resonance imaging (CMR) can detect even incipient myocardial fibrosis (late gadolinium enhancement), which has prognostic significance in patients with preserved left ventricular function by echocardiogram and before the onset of symptoms. Early detection of cardiac abnormalities by CMR enables early cardioprotective treatment, leading to a better prognosis.

Ex-vivo Assessment of Coronary Artery Atherosclerosis by Magnetic Resonance Imaging: Correlation with Histopathology.

INTRODUCTION: In recent years, high-resolution magnetic resonance imaging (MRI) has emerged as a very promising technique for studying atherosclerotic disease in humans. AIM: In the present study we sought to determine whether MRI allowed for the morphological characterization of the coronary vessel wall and atherosclerotic plaques using histopathological assessment as the reference standard. METHODS: The study population consisted of 13 patients who died of acute myocardial infarction and underwent autopsy. The proximal portions of the coronary arteries were excised and were evaluated both by MRI and by histopathology. For each arterial segment, the following parameters were calculated through manual planimetry: 1. total vessel area (TVA); 2. luminal area (LA) and 3. plaque area (PA). RESULTS: A total of 207 coronary artery cross-sections were found to be suitable for analysis by both MRI and histopathology and were included in the final analyses. Both methods demonstrated moderate to good agreement for the quantification of TVA (mean difference = 2.4±2.4 mm(2), 95‰ limits of agreement from -2.4 to +7.2 mm(2); CCC = 0.69, 95‰ CI from 0.63 to 0.75), LA (mean difference = 0.0±1.7 mm(2), 95‰ limits of agreement from -3.3 to + 3.3 mm(2); CCC = 0.84, 95‰ CI from 0.80 to 0.88) and PA (mean difference = 2.4±2.4 mm(2), 95‰ limits of agreement from -2.3 to + 7.1 mm(2); CCC = 0.64, 95‰ CI from 0.58 to 0.71). CONCLUSION: In this ex vivo experimental model we demonstrated good agreement between coronary artery morphometrical measurements obtained by high-resolution MRI and by histopathology.

Angiotomografia de coronárias na avaliação da dor torácica aguda na sala de emergência / Coronary computed tomography angiography in the assessment of acute chest pain in the emergency room

A angiotomografia de coronárias emergiu recentemente como uma ferramenta diagnóstica acurada na avaliação da doença arterial coronariana, fornecendo dados diagnósticos e prognósticos que se correlacionam diretamente com os dados fornecidos pela cineangiocoronariografia. Com a evolução tecnológica, permitindo melhora na resolução temporal, espacial, melhor cobertura do volume cardíaco com redução significativa da dose de radiação, somada à necessidade de protocolos de estratificação de risco mais efetivos para pacientes com dor torácica no pronto-socorro, sua aplicação passou a ser testada no cenário da dor torácica aguda, já que cerca de dois terços das angiografias coronarianas invasivas não demonstram doença coronariana obstrutiva significativa. Na prática diária, sem o uso de tecnologias mais eficientes, como a angiotomografia de coronárias, permanece um desafio ao médico do setor de emergência a estratificação segura e eficiente do paciente com dor torácica aguda. Recentemente, vários estudos, incluindo três randomizados, mostraram resultados favoráveis ao uso dessa tecnologia no pronto-socorro para pacientes com baixa a intermediária probabilidade de doença arterial coronariana. Nesta revisão, apresentamos os dados do uso da angiotomografia de coronárias na estratificação de risco de pacientes com dor torácica na sala de emergência, o seu valor diagnóstico, prognóstico e custo-efetividade e uma análise crítica dos recentes estudos multicêntricos publicados.

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.

Coronary computed tomography angiography in the assessment of acute chest pain in the emergency room.

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.

Single-Breathhold Four-Dimensional Assessment of Left Ventricular Morphological and Functional Parameters by Magnetic Resonance Imaging Using the VAST Technique.

INTRODUCTION: The accurate and reproducible assessment of cardiac volumes, function, and mass is of paramount importance in cardiology. In the present study we sought to determine whether the 3D cine-magnetic resonance (MR) technique, using the variable asymmetric sampling in time (VAST) approach, provided an accurate assessment of LV functional parameters when compared with the conventional 2D cine-MR technique. METHODS: A total of 43 consecutive patients referred for a CMR examination for clinical reasons and 14 healthy volunteers were included in the study. Cine images were acquired using a steady-state free precession pulse sequence. Two different multiphase acquisitions were performed: conventional 2D cine-MR and 3D cine-MR. The short-axis cine images acquired by both cine-MR techniques were used for the quantitative assessment of LV end-diastolic, end-systolic and stroke volumes, LV mass and ejection fraction. RESULTS: All CMR examinations were completed successfully, with both cine-MR imaging techniques yielding interpretable diagnostic results in all patients. Regarding the quantitative assessment, Bland-Altman analyses demonstrated a good agreement between the measurements of both cine-MR techniques for all LV parameters. In addition, the agreement between 2D and 3D cine-MR techniques for the qualitative assessment of LV global function was perfect (kappa = 1.0, P<0.001) for the two observers in consensus. The assessment performed by the third independent observer also demonstrated very good agreement (kappa = 0.88, P<0.001). CONCLUSION: The single breathhold 3D cine-MR technique provides an accurate and reproducible quantitative assessment of LV volumes, mass and function when compared with the conventional 2D cine-MR method.