Treinamento Físico Reduz a Inflamação e a Fibrose e Preserva a Função e a Perfusão Miocárdica em um Modelo de Cardiomiopatia Chagásica Crônica / Exercise Training Reduces Inflammation and Fibrosis and Preserves Myocardial Function and Perfusion in a Model of Chronic Chagas Cardiomyopathy

Resumo Fundamento: A Cardiomiopatia Chagásica Crônica (CCC) é causada por um processo inflamatório induzido pelo Trypanosoma cruzi, que leva à miocardite com fibrose reativa e reparativa. A CCC progride com alterações de perfusão miocárdica e eventos histopatológicos que afetam a Aptidão Cardiorrespiratória (ACR). Objetivos: Avaliamos os efeitos do Treinamento Físico Aeróbico (TFA) na perfusão miocárdica e nos comprometimentos morfológicos e funcionais relacionados à inflamação e fibrose em hamsters sírios com CCC. Como objetivo secundário, analisamos as áreas de secção transversa do músculo esquelético. Métodos: Hamsters com CCC e seus respectivos controles foram divididos em quatro grupos: CCC sedentário, CCC-TFA, controle sedentário e controle TFA. Sete meses após a infecção, os animais foram submetidos à ecocardiografia, à cintilografia de perfusão miocárdica e ao teste de esforço cardiopulmonar. TFA de intensidade moderada foi realizado durante cinquenta minutos, cinco vezes por semana, por oito semanas. Posteriormente, os animais foram reavaliados. A análise histopatológica foi realizada após os procedimentos acima mencionados. O nível de significância foi estabelecido em 5% em todas as análises (p<0,05). Resultados: Animais com CCC sedentários apresentaram piores Defeitos de Perfusão Miocárdica (DPM) ao longo do tempo, Fração de Ejeção do Ventrículo Esquerdo (FEVE) reduzida, e apresentaram mais inflamação e fibrose quando comparados aos demais grupos (análise ANOVA mista). Por outro lado, o TFA foi capaz de mitigar a progressão do DPM, atenuar a inflamação e a fibrose e melhorar a eficiência da ACR em animais CCC-TFA. Conclusão: Nosso estudo demonstrou que o TFA melhorou a disfunção cardíaca, DPM e reduziu a inflamação e a fibrose em modelos de hamster com CCC. Além disso, os animais CCC-SED apresentaram atrofia do músculo esquelético, enquanto os animais CCC-TFA apresentaram a AST do músculo esquelético preservada. Compreender os efeitos da TFA nas dimensões fisiopatológicas da CCC é crucial para futuras pesquisas e intervenções terapêuticas.

Abstract Background: Chronic Chagas cardiomyopathy (CCC) is caused by an inflammatory process induced by Trypanosoma cruzi, which leads to myocarditis with reactive and reparative fibrosis. CCC progresses with myocardial perfusion abnormalities and histopathological events that affect cardiorespiratory fitness (CRF). Objectives: We evaluated the effects of aerobic physical training (APT) on myocardial perfusion and on morphological and functional impairments related with inflammation and fibrosis in Syrian hamsters with CCC. As a secondary objective, we analyzed the cross-sectional areas of the skeletal muscle. Methods: Hamsters with CCC and their respective controls were divided into four groups: CCC sedentary, CCC-APT, sedentary control and APT control. Seven months after infection, the animals underwent echocardiography, myocardial perfusion scintigraphy and cardiopulmonary exercise testing. Moderate-intensity APT was performed for fifty minutes, five times a week, for eight weeks. Subsequently, the animals were reassessed. Histopathological analysis was conducted after the above-mentioned procedures. The level of significance was set at 5% in all analyses (p<0.05). Results: CCC sedentary animals presented worse myocardial perfusion defects (MPD) over time, reduced left ventricle ejection fraction (LVEF) and showed more inflammation and fibrosis when compared to other groups (mixed ANOVA analysis). Conversely, APT was able to mitigate the progression of MPD, ameliorate inflammation and fibrosis and improve CRF efficiency in CCC-APT animals. Conclusions: Our study demonstrated that APT ameliorated cardiac dysfunction, MPD, and reduced inflammation and fibrosis in CCC hamster models. Additionally, CCC-SED animals presented skeletal muscle atrophy while CCC-APT animals showed preserved skeletal muscle CSA. Understanding APT's effects on CCC's pathophysiological dimensions is crucial for future research and therapeutic interventions.

Prognóstico de Pacientes Chagásicos e não Chagásicos Submetidos a Implante de Marca-passo e Ressincronizador Cardíaco em Centro Terciário / Prognostic Evaluation of Chagasic and Non-Chagasic Patients Undergoing Pacemaker Implantation and Cardiac Resynchronization in a Tertiary Center

Resumo Fundamento: A cardiomiopatia chagásica (CCh) é responsável pelo implante de marca-passo (MP) em muitos pacientes, tendo sido associada a prognóstico adverso. Objetivos: Comparar o prognóstico da população chagásica e não chagásica submetida ao implante de MP e ressincronizador cardíaco. Métodos: Estudo observacional, retrospectivo, que analisou coorte de pacientes submetidos a implante desses dispositivos, em centro terciário, de outubro 2007 a dezembro de 2017, comparando o grupo de pacientes chagásicos com os não-chagásicos. O método não paramétrico de Kaplan-Meier foi utilizado para calcular a sobrevida dos pacientes. O nível de significância adotado na análise estatística foi de 5%. O desfecho primário foi a mortalidade por qualquer causa, enquanto os desfechos secundários foram a ocorrência de internação e o desfecho combinado internação e morte. Resultados: Um total de 911 pacientes foram incluídos, sendo que 23,4% apresentavam CCh. Em análise de Cox ajustada por sexo e idade, a doença de Chagas (dCh) não esteve associada ao risco aumentado de morte (HR: 1,14, IC:95%, 0,86-1,51, p=0,365), internação (HR: 0,79, IC:95%, 0,61-1,04, p=0,09) ou desfecho combinado morte e internação (HR: 0,90, IC:95%, 0,72-1,12, p=0,49). Conclusões: A dCh não se associou ao aumento do risco de morte, internação, ou desfecho combinado morte e internação, mesmo após ajuste para sexo e idade. Tais resultados se contrapõem aos de estudos prévios e sugerem modificação da qualidade do cuidado ao paciente cardiopata.

Abstract Background: Chagas cardiomyopathy (ChCC) is one of the causes of the implantation of pacemakers (PM) in many patients and has been associated with an adverse prognosis. Objectives: To compare the prognosis of the chagasic and non-chagasic populations undergoing PM and cardiac resynchronizer implantation. Methods: Observational, retrospective study, which analyzed a cohort of patients who underwent implantation of these devices, in a tertiary center, from October 2007 to December 2017, comparing the chagasic group with non-chagasic patients. The non-parametric Kaplan-Meier method was used to calculate patient survival. The significance level adopted in the statistical analysis was 5%. The primary outcome was mortality from any cause, while the secondary outcomes were the occurrence of hospitalization and the combination of hospitalization and death. Results: A total of 911 patients were included, of which 23.4% had ChCC. In a Cox analysis adjusted for sex and age, Chagas disease (ChD) was not associated with an increased risk of death (HR: 1.14, CI:95%, 0.86-1.51, p=0.365), hospitalization (HR: 0.79, CI:95%, 0.61-1.04, p=0.09) or combined outcome of death and hospitalization (HR: 0.90, CI:95%, 0.72-1 .12, p=0.49). Conclusions: ChD was not associated with an increased risk of death, hospitalization, or combined outcome of death and hospitalization, even after adjustment for sex and age. These results contrast with those of previous studies and suggest changes in the quality of care of patients with cardiomyopathy.

Comparative analysis of health-related fitness in patients with acute versus chronic Chagas disease / Análisis comparativo del estado físico relacionado con la salud en pacientes con enfermedad aguda versus crónica de Chagas

Abstract Introduction. Although Chagas disease causes high levels of morbidity, the muscle function and tolerance to physical activity in Chagas disease patients are still not completely understood. Objective. To compare health-related fitness of patient groups with acute Chagas disease versus chronic Chagas disease. Materials and methods. We conducted a cross-sectional study involving 18 patients. The data were obtained from patient's records, and functional capacity was measured with the six-minute walk test, the peripheral muscle strength with handgrip strength, and respiratory muscle strength using the maximum inspiratory pressure and the maximum expiratory pressure. Results. The 18 patients were divided in two groups: acute Chagas disease (n=9) and chronic Chagas disease (n=9). The distance walked in the six-minute walk test was lower than the predicted distance walked in both groups (p < 0.0001). The maximum expiratory pressure was lower than the predicted one (p = 0.005), and statistically significant for chronic Chagas disease patients (p = 0.02). Heart rate increased faster in the chronic Chagas disease group within the first two minutes of the six-minute walk test (p = 0.04). The sixminute walk test in the acute Chagas disease group presented a strong correlation with peripheral muscle strength (p = 0.012) and maximum inspiratory pressure (p = 0.0142), while in the chronic Chagas disease group, only peripheral muscle strength and maximum inspiratory pressure were correlated (p = 0.0259). Conclusion. The results suggest lowered functional capacity and reduced respiratory and peripheral muscle strength in patients with Chagas disease, although no differences were observed between groups. The early increase in heart rate during exercise in the chronic Chagas disease group implies a greater myocardial overload.

Resumen Introducción. Aunque la enfermedad de Chagas causa gran morbilidad, la función muscular y la tolerancia a la actividad física de estos pacientes aún no se comprenden por completo. Objetivos. Comparar el estado físico relacionado con la salud de pacientes con enfermedad de Chagas aguda versus crónica de Chagas. Materiales y métodos. Se hizo un estudio transversal que incluyó 18 pacientes. La información se obtuvo de los registros de los pacientes. La capacidad funcional se evaluó con la prueba de la caminata de seis minutos, se determinó la fuerza de prensión manual para evaluar los músculos periféricos y se estableció la fuerza de los músculos respiratorios mediante presión inspiratoria máxima y la presión espiratoria máxima. Resultados. Se evaluaron 18 pacientes, nueve con enfermedad de Chagas aguda y nueve con enfermedad de Chagas crónica. La distancia recorrida en la prueba de caminata de seis minutos fue menor que la distancia recorrida predicha en ambos grupos (p < 0,0001). La presión espiratoria máxima fue más baja de lo previsto (forma aguda: p = 0,005; forma crónica: p = 0,02). La frecuencia cardíaca aumentó más rápido en el grupo con enfermedad de Chagas crónica dentro de los primeros dos minutos de la caminata (p = 0,04). La distancia recorrida en el grupo con la forma aguda se correlacionó con la fuerza de prensión manual (p = 0,01) y la presión inspiratoria máxima (p = 0,01). En el grupo con la enfermedad crónica, solo hubo correlación entre la fuerza de presión manual y la presión inspiratoria máxima (p = 0,02). Conclusiones. Los resultados sugirieren disminución de la capacidad funcional y de la fuerza muscular respiratoria y periférica, aunque sin diferencias entre ambos grupos. El aumento de la frecuencia cardiaca en el grupo con enfermedad de Chagas crónica sugiere una mayor sobrecarga miocárdica.

Survival Analysis in Adult Heart Transplantation: Experience from a Brazilian Single Center

ABSTRACT Introduction: Heart transplantation is the gold standard for advanced heart failure treatment. This study examines the survival rates and risk factors for early mortality in adult heart transplant recipients at a Brazilian center. Methods: This retrospective cohort study involved 255 adult heart transplant patients from a single center in Brazil. Data were collected from medical records and databases including three defined periods (2012-2015, 2016-2019, and 2020-2022). Statistical analysis employed Kaplan-Meier survival curves, Cox proportional hazards analysis for 30-day mortality risk factors, and Log-rank tests. Results: The recipients were mostly male (74.9%), and the mean age was 46.6 years. Main causes of heart failure were idiopathic dilated cardiomyopathy (33.9%), Chagas cardiomyopathy (18%), and ischemic cardiomyopathy (14.3%). The study revealed an overall survival of 68.1% at one year, 58% at five years, and 40.8% at 10 years after heart transplantation. Survivalimproved significantly over time, combining the most recent periods (2016 to 2022) it was 73.2% in the first year and 63% in five years. The main risk factors for 30-day mortality were longer time on cardiopulmonary bypass, the initial period of transplants (2012 to 2015), older age of the donor, and nutritional status of the donor (overweight or obese). The main causes of death within 30 days post-transplant were infection and primary graft dysfunction. Conclusion: The survival analysis by period demonstrated that the increased surgical volume, coupled with the team's experience and modifications to the immunosuppression protocol, contributed to the improved early and mid-term outcomes.

Prognóstico de pacientes chagásicos e não chagásicos submetidos a implante de marcapasso e ressincronizador cardíaco em centro terciário / Prognosis of chagasic and non-chagasic patients undergoing pacemaker and cardiac resynchronizer implantation in a tertiary center

Fundamento: A cardiomiopatia chagásica (CCh) é responsável pelo implante de marcapasso (MP) em muitos pacientes, tendo sido associada a prognóstico adverso. Objetivos: Comparar o prognóstico da população chagásica e não chagásica submetida ao implante de MP e ressincronizador cardíaco. Métodos: Estudo observacional, retrospectivo, que analisou coorte de pacientes submetidos a implante desses dispositivos, em centro terciário, de Outubro 2007 a Dezembro de 2017, comparando o grupo de pacientes chagásicos com os não-chagásicos. O desfecho primário foi a mortalidade por qualquer causa, enquanto os desfechos secundários foram a ocorrência de internação e o desfecho combinado internação e morte. Resultados: Um total de 911 pacientes foram incluídos, sendo que 23,4% apresentavam CCh. Em análise de Cox ajustada por sexo e idade, a doença de Chagas (dCh) não esteve associada ao risco aumentado de morte (HR: 1,14, IC:95%, 0,86-1,51, p=0,365), internação (HR: 0,79, IC:95%, 0,61-1,04, p=0,09) ou desfecho combinado morte e internação (HR: 0,90, IC:95%, 0,72-1,12, p=0,49). Conclusões: A dCh não se associou ao aumento do risco de morte, internação, ou desfecho combinado morte e internação, mesmo após ajuste para sexo e idade. Trabalhos semelhantes ainda não foram publicados na literatura vigente considerando-se especificamente a população chagásica portadora de dispositivos cardíacos, e novos estudos são necessários para se confirmar esses achados

Background: Chagas cardiomyopathy (ChCC) is responsible for the implantation of pacemaker (PM) in many patients and has been associated with an adverse prognosis. Objectives: To compare the prognosis of the chagasic and non-chagasic population undergoing PM and cardiac resynchronizer implantation. Methods: Observational, retrospective study, which analyzed a cohort of patients who underwent implantation of these devices, in a tertiary center, from October 2007 to December 2017, comparing the group of chagasic with non-chagasic patients. The primary outcome was mortality from any cause, while the secondary outcomes were the occurrence of hospitalization and the combined outcome of hospitalization and death. Results: A total of 911 patients were included, of which 23.4% had ChCC. In a Cox analysis adjusted for sex and age, Chagas disease (ChD) was not associated with an increased risk of death (HR: 1.14, CI:95%, 0.86-1.51, p=0.365), hospitalization (HR: 0.79, CI:95%, 0.61-1.04, p=0.09) or combined outcome of death and hospitalization (HR: 0.90, CI:95%, 0.72-1 .12, p=0.49). Conclusions: ChD was not associated with an increased risk of death, hospitalization, or combined outcome of death and hospitalization, even after adjustment for sex and age. Similar studies have not yet been published in the current literature specifically considering the chagasic population with cardiac devices, and new studies are needed to confirm these findings.

Infección por dengue sin signos de alarma en un niño con cardiopatía chagásica crónica / Dengue infection in a child with chronic heart disease for Chagas

Se presenta el caso de un preescolar en que se diagnosticó una cardiomiopatía chagásica crónica posterior a una infección aguda por virus dengue. El niño, residente de un área endémica para enfermedad de Chagas, debutó con insuficiencia cardíaca que mejoró con el tratamiento de soporte y tras la resolución completa de la arbovirosis, persistieron los cambios de cardiomiopatía crónica. Esta evidencia de alteración estructural miocárdica se atribuyó a la cardiomiopatía chagásica de base previamente subclínica. La coexistencia de enfermedades infecciosas en el trópico representa un reto diagnóstico, situación a la que se agregan problemas socioeconómicos como la pobreza y falta de acceso a servicios sanitarios básicos.

A case is reported of a chronic chagasic cardiomyopathy in a two-years old child who was diagnosed after an acute dengue virus infection. The patient residing in an endemic area for Chagas disease, debuted with heart failure that improved with support treatment and after the complete resolution of the arbovirus, the changes of chronic cardiomyopathy persisted. The myocardial structural alteration was attributed to subclinical chagasic cardiomyopathy. The coexistence of infectious diseases in the tropics represents a diagnostic challenge, a situation to which are added problems such as poverty and lack of access to basic health services.

Exploring the Historical Background and Clinical Implications of Electrocardiogram in the Context of Chagas Disease Research

ABSTRACT Chagas disease (CD) remains one of the most significant endemic diseases in Latin America. Approximately 30% of individuals with CD develop the cardiac form, the main determinant of morbidity and mortality, which is characterized by typical electrocardiogram (ECG) changes caused by chronic chagasic cardiopathy (CCC). This review accentuates to how crucial it is for research teams and reference centers that treat patients with CD to standardize ECG in CCC. This was a non-systematic review of the literature. ECG is the most widely used examination in the diagnosis and evaluation of CCC, and it is also employed in epidemiological surveys, risk stratification for cardiovascular events and death, and monitoring the clinical progression of the disease. Carlos Chagas and Eurico Villela published the first work addressing CCC in 1922. Other works followed, including the study by Evandro Chagas' which was the first to perform ECG in CD, culminating in Francisco Laranja's seminal work in 1956. Since the 1980s, standardizations and ECG reading codes for CD have been established. This standardization aimed to code complex arrhythmias and characteristic ventricular conduction disorders and standardize ECG readings for clinical and epidemiological studies in CD. Nearly all existing electrocardiographic abnormalities can be found in CD, with a predominance of abnormalities in the formation and conduction of cardiac stimuli. The complex and heterogeneous substrate of CD with varied electrocardiographic manifestations poses a significant challenge when comparing studies involving patients with CCC, emphasizing the need for ECG standardization in CD.

Inspiratory Muscle Strength in Chagas Cardiomyopathy: A Systematic Scoping Review

ABSTRACT The increase in inflammatory markers associated with persistent chronic fibrosing myocarditis, a characteristic of chronic Chagas disease, can result in a reduction in inspiratory muscle strength (IMS) in Chagas cardiomyopathy (CC). However, literature in this field is still scarce. This review aimed to map and summarize the evidence regarding IMS in patients with CC. The inclusion criteria included reports with adult participants with a CC diagnosis, with or without heart failure (HF). The core concept examined was the maximum inspiratory pressure evaluated in the untrained and trained groups in the pre-training period. The context was open, including but not limited to hospitals and health centers. Two authors independently identified eligible studies and extracted the data. Descriptive synthesis was used as the primary strategy for analyzing the results. Nine studies (five clinical trials, three cross-sectional, and one cohort) were included. The CC classification differed among the studies, with no mention of HF in five and no CC staging specification in six. IMS was assessed using a manovacuometer, and only six studies analyzed and interpreted the data concerning the predicted values. The CC population with HF appeared to have impaired IMS. All studies involved only Brazilian volunteers. In conclusion, randomized clinical trials evaluating IMS and the effects of inspiratory muscle training need to be conducted to better understand the prevalence and risk of inspiratory muscle weakness in the CC population, as well as the effects of training. Such studies should be conducted at different stages of CC in different populations and countries.

Teste de Limiar de Desfibrilação e Seguimento a Longo Prazo de Pacientes com Cardiopatia Crônica da Doença de Chagas / Defibrillation Threshold Testing and Long-term Follow-up in Chagas Disease

Resumo Fundamento A morte súbita cardíaca (MSC) é a causa mais comum de óbito na cardiomiopatia crônica da doença de Chagas (CCDC). Visto que muitos pacientes com CCDC que são candidatos a receber um cardioversor desfibrilador implantável (CDI) atendem a critérios que sugerem alto risco de apresentarem limiares de desfibrilação elevados, sugere-se realizar um teste de limite de desfibrilação (LDF). Objetivos Investigamos o uso do teste de LDF em pacientes com CCDC, com enfoque nos óbitos relacionados ao implante do CDI e na ocorrência de eventos arrítmicos e o tratamento oferecido durante o seguimento de longo prazo. Métodos Avaliações retrospectivas de 133 pacientes com CCDC que receberam CDI, principalmente para prevenção secundária. Foram coletados dados demográficos, clínicos e laboratoriais, escore de Rassi e dados do teste de LDF. Adotou-se p<0,05 como estatisticamente significativo. Resultados A média de idade foi 61±13 anos, e 72% da amostra era do sexo masculino. A fração de ejeção basal do ventrículo esquerdo foi 40±15%, e o escore de Rassi médio foi 10±4 pontos. Não ocorreram óbitos durante o teste de LDF, e não foram documentadas falhas do CDI. Foi identificada relação entre escore de Rassi basal mais elevado e LDFs mais elevados (ANOVA =0,007). O tempo médio até o primeiro choque foi de 474±628 dias, mas a aplicação de choque foi necessária em apenas 28 (35%) pacientes com TV, visto que a maioria dos casos se resolveu espontaneamente ou através da programação de ATP. Após seguimento clínico de 1728±1189 dias, em média, ocorreram 43 óbitos, relacionados principalmente a insuficiência cardíaca progressiva e sepse. Conclusões Um teste de LDF de rotina pode não ser necessário para pacientes com CCDCs que receberam CDI para prevenção secundária. LDFs elevados parecem ser incomuns e podem estar relacionados a escore de Rassi elevado.

Abstract Background Sudden cardiac death is the most common cause of death in chronic Chagas cardiomyopathy (CCC). Because most CCC patients who are candidates for implantable cardioverter-defibrillators (ICD) meet criteria for high defibrillation threshold values, a defibrillator threshold test (DTT) is suggested. Objectives We investigated the use of DTT in CCC patients, focusing on deaths related to ICD and arrhythmic events, as well as treatment during long-term follow-up. Methods We retrospectively evaluated 133 CCC patients who received an ICD mainly for secondary prevention. Demographic, clinical, laboratory data, Rassi score, and DTT data were collected, with p < 0.05 considered significant. Results The mean patient age was 61 (SD, 13) years and 72% were men. The baseline left ventricular ejection fraction was 40 (SD, 15%) and the mean Rassi score was 10 (SD, 4). No deaths occurred during DTT and no ICD failures were documented. There was a relationship between higher baseline Rassi scores and higher DTT scores (ANOVA = 0.007). The mean time to first shock was 474 (SD, 628) days, although shock was only necessary for 28 (35%) patients with ventricular tachycardia, since most cases resolved spontaneously or through antitachycardia pacing. After a mean clinical follow-up of 1728 (SD, 1189) days, 43 deaths occurred, mainly related to progressive heart failure and sepsis. Conclusions A routine DTT may not be necessary for CCC patients who receive an ICD for secondary prevention. High DTT values seem to be unusual and may be related to high Rassi scores.

Dysautonomia Evaluation by Holter in Chagas Heart Disease

Abstract Background Sudden cardiac death is the main lethal mechanism associated with Chagas cardiomyopathy. Studies suggest that dysautonomia may represent a relevant, intense, independent, and early phenomenon in the natural history of the disease, even when ventricular systolic function is preserved, and may also be the mechanism that triggers malignant ventricular arrhythmias. Objective To evaluate the degree of dysautonomia and its possible association with ventricular arrhythmias in patients with Chagas cardiomyopathy, according to different categories of mortality risk, as defined by the score proposed by Rassi, used as a surrogate outcome for death. Methods A cross-sectional study involving 43 patients with Chagas cardiomyopathy stratified into risk categories based on the Rassi score, with 23 being classified as low risk and 20 as intermediate-to-high risk. Heart rate variability (HRV) was assessed using Holter monitoring for long-term recordings of 24 hours (time domain) and for short-term recordings of 5 minutes (frequency domain) at rest and after autonomic tests: deep breathing and Valsalva maneuver. The HRV variables were compared between the groups using the Student's t-test and α=0.05. Results Comparison of the results between the risk stratification groups showed no differences in HRV indexes, either in the time or frequency domain. However, results showed a significant increase in the number of arrhythmias as a function of increased risk (p=0.02). Conclusion There was no association between the degree of dysautonomia, evaluated by Holter monitoring, and the categories of mortality risk, despite a direct association between the rate of arrhythmias and the higher risk group.

Primer choque apropiado del desfibrilador automático implantable en pacientes con cardiopatía chagásica / First appropriate implantable defibrillator shocks in patients with Chagasic heart disease

Resumen Objetivos: Determinar si los pacientes con cardiopatía chagásica (CCh) presentaron choques apropiados del desfibrilador automático implantable (DAI) de manera más precoz que los pacientes con cardiopatía isquémica (CI). Métodos: Estudio de cohorte retrospectivo que incluyó los pacientes con CCh y CI en quienes se implantó un DAI entre los años 2009 y 2018 en un hospital de alta complejidad. El seguimiento se realizó hasta los 36 meses, evaluándose el momento del primer choque apropiado del dispositivo. Resultados: Se incluyeron 64 pacientes, 20 con CCh y 44 con CI. Se observó que una mayor proporción de pacientes con CCh presentaron choques apropiados durante el primer año (hazard ratio [HR]: 8.4; intervalo de confianza del 95% [IC95%]: 2.09-34.02; p = 0.0027) y a 3 años (HR: 4.61; IC95%: 1.51-14.07; p = 0.0072). El 100% de la población con CCh e implante del DAI como prevención secundaria de muerte súbita presentaron choques apropiados durante los primeros 26 meses de seguimiento. Conclusiones: Los pacientes con CCh presentaron choques apropiados del DAI de manera más precoz que los pacientes con CI. Todos los pacientes con CCh y DAI como prevención secundaria presentaron choques apropiados, representando una población de mayor riesgo. Esta información apoya la indicación del DAI en estos pacientes a pesar de la escasa evidencia en ensayos aleatorizados.

Abstract Objetives: To assess if patients with Chagasic heart disease (CHD) received effective automatic implantable defibrillator (AID) shocks earlier than patients with ischemic heart disease (IHD). Methods: Retrospective cohort of patients with CHD and IHD who received an implantable cardioverter defibrillator (ICD) between 2009 and 2018, in a tertiary hospital. We evaluated the time between the implant of ICD and the first effective shock in patients with CHD and compared it with the IHD control population. Results: We included a total of 64 patients, 20 with CHD and 44 with IHD. CHD patients presented earlier an effective shock than patients with IHD during the first year (hazard ratio [HR]: 8.4; 95% confidence interval [95% CI]: 2.09-34.02; p = 0.0027), and at three years (HR: 4.61; 95% CI: 1.51-14.07; p = 0.0072). 100% of CHD patients who received the ICD as secondary prevention of sudden cardiac death presented an effective shock during the first 26 months of follow-up. Conclusions: Patients with CHD received effective ICD shocks earlier than the IHD patients. All patients with CHD and ICD as secondary prevention had an appropriate ICD shock at short term, representing the highest risk population, and supporting the indication of the device in a setting where randomized clinical trials are lacking.

Aneurismas ventriculares en una población de pacientes con cardiomiopatía chagásica / Ventricular aneurysms in a chronic Chagasic cardiomyopathy population

Resumen Antecedentes: Los pacientes con enfermedad de Chagas pueden desarrollar cardiomiopatía crónica (CChC); los aneurismas ventriculares son característicos de esta condición. Objetivo: Analizar una población de pacientes con CChC con aneurismas ventriculares, buscando asociaciones entre las variables sexo, edad, síntomas, fracción de eyección del ventrículo izquierdo (FEVI), tamaño de los aneurismas y presencia de arritmias ventriculares. Método: Los pacientes fueron valorados con historia clínica, electrocardiografía (ECG), radiología, ecocardiografía y Holter. Resultados: De 627 pacientes con CChC, 60 (9.6%) presentaron aneurismas (60%). Había una relación significativa entre edad mayor de 50 años y FEVI normal. El valor predictivo negativo de clase funcional I y ECG sin anomalías del QRS para detectar FEVI < 50% o taquicardia ventricular fue del 47.4%. No hubo relación significativa entre anomalías del QRS con FEVI < 50% ni taquicardia ventricular. Los aneurismas grandes estaban asociados a FEVI < 50%, pero no fueron predictores de taquicardia ventricular. No hubo asociación significativa entre volúmenes de fin de diástole del ventrículo izquierdo y FEVI o taquicardia ventricular; los pacientes en fase B1-2 no presentaron mayor riesgo de taquicardia ventricular que los de fase C-D. Conclusiones: En los pacientes con CChC se recomienda un estudio integral con ecocardiografía y Holter; el valor predictivo negativo de la clínica y del electrocardiograma es muy reducido.

Abstract Background: Chagas disease patients can develop chronic cardiomyopathy; ventricular aneurysms are characteristic of this condition. Objective: A population of patients with Chagas cardiomyopathy with ventricular aneurysms was analyzed, looking for associations between variables sex, age, symptoms, left ventricular ejection fraction, size of aneurysms and presence of ventricular arrhythmias. Method: The patients were evaluated with a clinical history, electrocardiography, radiology, echocardiography and Holter. Results: Of 627 patients with CChC, 60 (9.6%) had aneurysms, 60%. There was a significant relationship between age older than 50 years and normal LVEF. The negative predictive value of Functional Class I and ECG without QRS abnormalities to detect LVEF < 50% or ventricular tachycardia was 47.4%. There was no significant relationship between QRS abnormalities with LVEF < 50% or ventricular tachycardia. Large aneurysms were associated with LVEF < 50% but were not predictive of ventricular tachycardia. There was no significant association between left ventricular end-diastole volumes and LVEF or ventricular tachycardia; patients in phase B1-2 did not present a greater risk of ventricular tachycardia than those in phase C-D. Conclusions: In patients with CHCC, a comprehensive study with ECO and Holter is recommended, the negative predictive value of the symptoms and the electrocardiogram is very low.

A Curva Volume-Tempo Obtida pela Ecocardiografia Tridimensional na Cardiomiopatia Chagásica: Análise do Mecanismo das Adaptações Hemodinâmicas / The Volume-Time Curve by Three-Dimensional Echocardiography in Chagas Cardiomyopathy: Insights into the Mechanism of Hemodynamic Adaptations

Resumo Fundamento A ecocardiografia tridimensional (ECO 3D) permite a geração de uma curva volume-tempo representativa das alterações no volume ventricular esquerdo (VE) ao longo de todo o ciclo cardíaco. Objetivo O presente estudo tem como objetivo demonstrar as adaptações hemodinâmicas presentes na cardiomiopatia chagásica (CC) por meio das medidas de volume e fluxo obtidas pela curva volume-tempo por ECO 3D. Métodos Vinte pacientes com CC e 15 indivíduos saudáveis foram incluídos prospectivamente em um estudo de desenho transversal. Realizou-se ECO 3D em todos os indivíduos e as curvas volume-tempo do VE foram geradas. O fluxo foi obtido pela primeira derivada da curva volume-tempo por meio do software MATLAB. A significância estatística foi definida com p<0,05. Resultados Embora os pacientes com CC tivessem menor fração de ejeção do VE em comparação com o grupo controle (29,8±7,5 vs. 57,7±6,1, p<0,001), o volume (61,5±25,2 vs. 53,8±21,0, p=0,364) e o fluxo de ejeção máximo durante a sístole (-360,3±147,5 vs. -305,6±126,0, p = 0,231) mostraram-se semelhantes entre os grupos. Da mesma forma, o fluxo máximo na fase de enchimento inicial e durante a contração atrial mostrou-se semelhante entre os grupos. Um aumento na pré-carga expressa pelo volume diastólico final do VE (204,8±79,4 vs. 93,0±32,6), p<0,001) pode manter o fluxo e o volume ejetado semelhantes aos dos controles. Conclusão Com uma ferramenta não invasiva, demonstramos que o aumento no volume diastólico final do VE pode ser o principal mecanismo de adaptação que mantém o fluxo e o volume ejetado no cenário de disfunção sistólica ventricular esquerda severa.

Abstract Background Three-dimensional echocardiography (3D ECHO) allows the generation of a volume-time curve representative of changes in the left ventricular (LV) volume throughout the entire cardiac cycle. Objective This study aims to demonstrate the hemodynamic adaptations present in Chagas cardiomyopathy (CC) by means of the volume and flow measurements obtained by the volume-time curve by 3D ECHO. Methods Twenty patients with CC and 15 healthy subjects were prospectively enrolled in a cross-sectional design study. 3D ECHO was performed in all subjects and the volume over time curves of the LV was generated. The flow was obtained by the first derivative of the volume-time curve using the software MATLAB. Statistical significance was set at p<0.05. Results Although CC patients had lower LV ejection fraction compared to the control group (29.8±7.5 vs. 57.7±6.1, p<0.001), stroke volume (61.5±25.2 vs. 53.8±21.0, p=0.364) and maximum ejection flow during systole (-360.3±147.5 vs. -305.6±126.0, p=0.231) were similar between the groups. Likewise, the maximum flow in the early diastolic filling phase and during atrial contraction was similar between groups. An increase in preload expressed by LV end diastolic volume (204.8±79.4 vs. 93.0±32.6), p<0.001) may maintain the flow and stroke volumes similar to the controls. Conclusion Using a non-invasive tool, we demonstrated that an increase in LV end-diastolic volume may be the main adaptation mechanism that maintains the flow and stroke volumes in the setting of severe LV systolic dysfunction.

Revisiting the History of Chagas Disease: "Live to tell"

Abstract In 1907, Carlos Chagas was designated to fight paludism in the Rio das Velhas region along the Central do Brasil railroad. During his field research, Chagas discovered a hematophagous insect ( Panstrongylus megitus ) carrying a new trypanosomatide, which he named Trypanosoma cruzi . On April 14th, 1909, he found the same parasite in the blood of a febrile child, submitting the announcement of his discoveries to the Brasil Médico scientific journal. Here, we discuss the early stages in the establishment of a new human morbid entity during the first decades after its discovery with a definite influence from its discoverer, Carlos Chagas, as well the first collaborators. Moreover, we cover the importance of the Center for the Study and Prophylaxis of Chagas Disease in Bambuí (MG), unraveling the most advanced developments in research within the disease's habitat and the widening perspectives for modern research that have emerged after the 1960s and continue to improve to this day. In this revisitation to the history of Chagas disease, we begin at Manguinhos (RJ ), making our way to Lassance (MG), where the discovery took place. Then, we travel back to Rio de Janeiro in the beginning of the twentieth century and Brazilian republic until the current day, revealing milestone publications that settled Chagas disease both as a source of pride for Brazilian medicine and as a challenge with important aspects that remain to be clarified. Any similarities to our country's politics and economy in the twentieth century are not mere coincidences.

Trasplante cardíaco en miocardiopatía chagásica: 23 años de experiencia en un centro de referencia / Heart Transplantation in Chagas Cardiomyopathy: 23-Year Follow-Up in a Referral Center

RESUMEN Introducción: La enfermedad de Chagas afecta aproximadamente a 6 millones de personas en América Latina. El 25 a 35% evoluciona hacia la Miocardiopatía Chagásica (MCh). Una opción terapéutica en sus estadios avanzados es el trasplante cardíaco (TxC). Objetivos: Comparar la supervivencia de pacientes con TxC por MCh frente a otras etiologías. Analizar la incidencia de la reactivación (Ra) de enfermedad de Chagas y su impacto en la supervivencia en este subgrupo de pacientes. Material y métodos: Se evaluaron retrospectivamente pacientes con TxC entre agosto 1998 y marzo 2021. Se analizó la supervivencia mediante curvas de Kaplan-Meier y log rank test. El diagnóstico de Ra se realizó mediante métodos moleculares, prueba de Strout en sangre periférica, tejido miocárdico y/o cutáneo. Resultados: De 606 pacientes con TxC, 39 (6,4%) presentaban MCh. Seguimiento medio 4,4 años (Rango Intercuartilo 1,2-8,6). Edad subgrupo MCh 51 años (RIC 45-60). Hombres 28 (72%). Se documentó Ra en el 38,5% de los pacientes. Supervivencia a 1, 5 y 10 años en TxC por MCh con Ra versus no Ra: 85%, 76% y 61% versus 72%, 55% y 44% (p = 0,3). Supervivencia a 1, 5 y 10 años en TxC por MCh versus TxC por otras causas: 79%, 65% y 50% versus 79%, 62% y 47% (p = 0,5). Conclusión: En nuestra serie no se encontró diferencia estadísticamente significativa en la supervivencia de los pacientes trasplantados cardíacos por MCh en comparación con aquellos trasplantados por otras causas; así como tampoco entre los pacientes que reactivaron la enfermedad de Chagas y los que no lo hicieron.

ABSTRACT Background: Chagas disease affects about 6 million people in Latin America, and 25 to 35% progress to Chagas cardiomyopathy (ChCM). Heart transplantation (HTx) is a therapeutic option in advanced stages. Objectives: The aim of this study is to compare survival of patients with HTx due to ChCM versus those transplanted for other etiologies and to analyze the incidence of Chagas disease reactivation (Ra) and its impact on survival in this group of patients. Methods: Patients undergoing HTx between August 1998 and March 2021 were retrospectively evaluated. Survival was analyzed using Kaplan-Meier curves and the log-rank test. The diagnosis of Ra was performed by molecular methods, Strout's test in peripheral blood, myocardial tissue or skin tissue. Results: Of 606 patients with Htx, 39(6,4%) presented ChCM. Median follow up was 4.4 years (interquartile range 1.2-8.6). Median age of the subgroup with ChCM was 51 years (IQR 45-60) and 28 were men (72%). Reactivation was documented in 38.5% of the patients. Survival at 1, 5 and 10 years in HTx recipients due to ChCM and Ra versus no Ra was 85%, 76% and 61% versus 72%, 55% and 44%, respectively (p = 0.3). Survival at 1, 5 and 10 years in HTx recipients due to ChCM versus HTx for other causes was 79%, 65% and 50% versus 79%, 62% and 47%, respectively (p = 0.5). Conclusion: In our series we did not find statistically significant differences in survival of heart transplant recipients due to ChCM versus those transplanted due to other reasons. Survival in patients with Chagas disease reactivation and those without reactivation was also similar.