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

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.

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.

Predictors of Appropriate Therapies and Death in Patients with Implantable Cardioverter-Defibrillator and Chronic Chagas Heart Disease. / Preditores de Terapias Apropriadas e Óbito em Pacientes com Cardiodesfibrilador Implantável e Cardiopatia Chagásica Crônica.

BACKGROUND: There are few retrospective and prospective studies on implantable cardioverter-defibrillators (ICD) in primary and secondary prevention of sudden death in chronic Chagas heart disease (CCHD). OBJECTIVES: To describe the long-term evolution of patients with CCHD and ICD and to identify and analyze predictors of mortality and appropriate device therapy in this population. METHODS: This was a historical prospective study with 117 patients with ICD and CCHD. Devices were implanted from January 2003 to December 2021. Predictors of appropriate therapies and long-term mortality were identified and analyzed. The level of statistical significance was p < 0.05. RESULTS: Patients (n = 117) had a median follow-up of 61 months (25 to 121 months); they were predominantly male (74%), with a median age of 55 years (48 to 64 years). There were 43.6% appropriate shocks, 26.5% antitachycardia pacing (ATP), and 51% appropriate therapies. During follow-up, 46 patients (39.7%) died. Mortality was 6.2% person-years (95% confidence interval [CI]: 4.6 to 8.3), with 2 sudden deaths during follow-up. Secondary prevention (hazard ratio [HR] 2.1; 95% CI: 1.1 to 4.3; p = 0.029) and ejection fraction less than 30% (HR 1.8; 95% CI: 1.1 to 3.1; p < 0.05) were predictors of appropriate therapies. Intermediate Rassi score showed a strong association with the occurrence of ATP alone (p = 0.015). Functional class IV (p = 0.007), left ventricular ejection fraction < 30 (p = 0.010), and age above 75 years (p = 0.042) were predictors of total mortality. CONCLUSION: ICDs in CCHD showed a high incidence of appropriate activation, especially in patients with secondary prevention, low left ventricular ejection fraction, and intermediate Rassi score. Patients with congestive heart failure, elevated functional class, and age over 75 years showed elevated mortality. Survival function of patients with implantable cardioverter-defibrillators and chronic Chagas heart disease. A - According to New York Heart Association functional class; B - According to left ventricular ejection fraction; C - According to Rassi score. D - According to age. CCHD: chronic Chagas heart disease; HR: hazard ratio; ICD: implantable cardioverter-defibrillator.

Effect of an exercise-based cardiac rehabilitation program on quality of life of patients with chronic Chagas cardiomyopathy: results from the PEACH randomized clinical trial.

To investigate the effect of an exercise-based cardiac rehabilitation program on the quality of life (QoL) of patients with chronic Chagas cardiomyopathy (CCC). PEACH study was a single-center, superiority randomized clinical trial of exercise training versus no exercise (control). The sample comprised Chagas disease patients with CCC, left ventricular ejection fraction < 45%, without or with HF symptoms (CCC stages B2 or C, respectively). QoL was assessed at baseline, after three months, and at the end of six months of follow-up using the SF-36 questionnaire. Patients randomized for the exercise group (n = 15) performed exercise training (aerobic, strength and stretching exercises) for 60 min, three times a week, during six months. Patients in the control group (n = 15) were not provided with a formal exercise prescription. Both groups received identical nutritional and pharmaceutical counseling during the study. Longitudinal analysis of the effects of exercise training on QoL, considering the interaction term (group × time) to estimate the rate of changes between groups in the outcomes (represented as beta coefficient), was performed using linear mixed models. Models were fitted adjusting for each respective baseline QoL value. There were significant improvements in physical functioning (ß = + 10.7; p = 0.02), role limitations due to physical problems (ß = + 25.0; p = 0.01), and social functioning (ß = + 19.2; p < 0.01) scales during the first three months in the exercise compared to the control group. No significant differences were observed between groups after six months. Exercise-based cardiac rehabilitation provided short-term improvements in the physical and mental aspects of QoL of patients with CCC.Trial registration: ClinicalTrials.gov Identifier: NCT02517632; August 7, 2015.

Stroke in Chagas disease: from pathophysiology to clinical practice.

Despite substantial progress toward its control, Chagas disease continues to be a major public health problem in Latin America and has become a global health concern. The disease affects approximately 6 million people, of whom 20-40% will develop cardiomyopathy over the years after the initial Trypanosoma cruzi infection. Chagas cardiomyopathy is the most serious and frequent manifestation of Chagas disease. Clinical manifestations vary widely according to the severity of myocardial dysfunction, ranging from asymptomatic to severe forms, including dilated cardiomyopathy with heart failure, arrhythmias, thromboembolism events, and sudden death. Chagas disease is a risk factor for stroke regardless of the severity of cardiomyopathy, which is a leading cause of chronic disability. Classically, stroke etiology in patients with Chagas disease is thought to be cardioembolic and related to apical aneurysm, mural thrombus, and atrial arrhythmias. Although most strokes are thromboembolic, other etiologies have been observed. Small vessel disease, atherosclerosis, and cryptogenic diseases have been reported in patients with Chagas disease and stroke. The potential mechanisms involved in non-embolic strokes include the presence of associated risk factors, pro-inflammatory and prothrombotic disease states, and endothelial dysfunction. However, the contribution of each mechanism to stroke in Chagas disease remains unclear. The review aims to provide an overview of stroke in Chagas disease, highlighting the main pathophysiological mechanisms, clinical presentation, approaches for prevention, and unanswered questions regarding treatment strategies.

Does left ventricular reverse remodeling influence long-term outcomes in patients with Chagas cardiomyopathy?

BACKGROUND: The impact of left ventricular reverse remodeling (LVRR) on the prognosis of Chagas cardiomyopathy is unknown. The aim of this study was to determine whether the presence of LVRR can predict mortality in these patients. METHODS: From January 2000 to December 2010, the medical charts of 159 patients were reviewed. LVRR was defined as an increase of left ventricular ejection fraction (LVEF) and a decrease of left ventricular end-diastolic diameter (LVDD) by two-dimensional echocardiography. No patient underwent cardiac resynchronization therapy or required mechanical ventricular assistance. RESULTS: At baseline, median (25th-75th) LVDD was 64 mm (59-70), and median LVEF was 33.2% (26.4-40.1). LVRR was detected in 24.5% of patients in a 40-month (26-64) median follow-up. In the LVRR group, LVDD decreased from 64 mm (59-68) to 60 mm (56-65; p < 0.001), and LVEF increased from 31.3% (24.1-39.0) to 42.5% (32.2-47.7; p < 0.001). However, LVRR was not associated with heart failure hospitalization, cardiogenic shock, heart transplantation, or mortality (p > 0.05 for all comparisons). The Cox proportional hazard model analysis identified only cardiogenic shock (hazard ratio [HR]: 2.41; 95% confidence interval [CI]: 1.51-3.85; p < 0.001) and serum sodium level (HR: 0.91; 95% CI: 0.86-0.96; p < 0.001) as independent predictors of all-cause mortality. CONCLUSIONS: Left ventricular reverse remodeling occurs in one quarter of patients with Chagas cardiomyopathy and have no impact on the outcomes of patients with this condition.

Acute and subacute hemodynamic responses and perception of effort in subjects with chronic Chagas cardiomyopathy submitted to different protocols of inspiratory muscle training: a cross-over trial.

PURPOSE: This study aimed to evaluate acute and subacute hemodynamic responses and perception of effort in individuals with CCC submitted to different IMT protocols. MATERIALS AND METHODS: This was a randomized cross-over trial conducted on CCC subjects with systolic left ventricular dysfunction (<45% left ventricular ejection fraction) without or with heart failure (stages B2 and C, respectively). Twenty-one participants performed two IMT protocols, one targeting 60% maximal inspiratory pressure with 3 × 10 repetitions (MIP60) and the other targeting 30% maximal inspiratory pressure (MIP30) with 3 × 20 repetitions with a 2 min recovery between sets for both. MIP60 and MIP30 were performed on the same day with a 2 h washout period. Measurements were taken at baseline, during and 60 min after IMT. RESULTS: No differences in hemodynamic variables were observed across protocols. The perception of effort increased in both protocols, with higher scores for the MIP30 protocol (ß = +1.6, p = 0.01; ß = +1.1, p = 0.02; ß = +0.9, p = 0.08 for the 1st, 2nd and 3rd sets, respectively). CONCLUSIONS: There were no differences in hemodynamic responses comparing MIP60 and MIP30 protocols in subjects with CCC. Despite the higher perception of effort during endurance protocol, both protocols can be considered a safe therapeutic strategy.IMPLICATIONS FOR REHABILITATIONDespite inspiratory muscle training may result in functional capacity improvements, no previous study evaluated the hemodynamic acute and subacute responses to inspiratory muscle training in chronic Chagas cardiomyopathy.The two inspiratory muscle training protocols (30% and 60% of maximal inspiratory pressure) did not cause significant hemodynamic repercussions in subjects with chronic Chagas cardiomyopathy.Inspiratory muscle training seems to be an effective strategy to improve functional capacity and can be implemented in the rehabilitation programs for patients with Chagas cardiomyopathy.Since no significant adverse responses were observed in any of the hemodynamic parameters during the inspiratory muscle training sessions, these two protocols of inspiratory muscle training (30% and 60% of maximal inspiratory pressure) seems to be safe in subjects with Chagas cardiomyopathy.

Immunomodulation for the Treatment of Chronic Chagas Disease Cardiomyopathy: A New Approach to an Old Enemy.

Chagas disease is a parasitic infection caused by the intracellular protozoan Trypanosoma cruzi. Chronic Chagas cardiomyopathy (CCC) is the most severe manifestation of the disease, developed by approximately 20-40% of patients and characterized by occurrence of arrhythmias, heart failure and death. Despite having more than 100 years of discovery, Chagas disease remains without an effective treatment, especially for patients with CCC. Since the pathogenesis of CCC depends on a parasite-driven systemic inflammatory profile that leads to cardiac tissue damage, the use of immunomodulators has become a rational alternative for the treatment of CCC. In this context, different classes of drugs, cell therapies with dendritic cells or stem cells and gene therapy have shown potential to modulate systemic inflammation and myocarditis in CCC models. Based on that, the present review provides an overview of current reports regarding the use of immunomodulatory agents in treatment of CCC, bringing the challenges and future directions in this field.

Therapeutic miR-21 Silencing Reduces Cardiac Fibrosis and Modulates Inflammatory Response in Chronic Chagas Disease.

Chagas disease, caused by the parasite Trypanosoma cruzi (T. cruzi), remains a serious public health problem for which there is no effective treatment in the chronic stage. Intense cardiac fibrosis and inflammation are hallmarks of chronic Chagas disease cardiomyopathy (CCC). Previously, we identified upregulation of circulating and cardiac miR-21, a pro-fibrotic microRNA (miRNA), in subjects with CCC. Here, we explored the potential role of miR-21 as a therapeutic target in a model of chronic Chagas disease. PCR array-based 88 microRNA screening was performed in heart samples obtained from C57Bl/6 mice chronically infected with T. cruzi and serum samples collected from CCC patients. MiR-21 was found upregulated in both human and mouse samples, which was corroborated by an in silico analysis of miRNA-mRNA target prediction. In vitro miR-21 functional assays (gain-and loss-of-function) were performed in cardiac fibroblasts, showing upregulation of miR-21 and collagen expression upon transforming growth factor beta 1 (TGFß1) and T. cruzi stimulation, while miR-21 blockage reduced collagen expression. Finally, treatment of T. cruzi-infected mice with locked nucleic acid (LNA)-anti-miR-21 inhibitor promoted a significant reduction in cardiac fibrosis. Our data suggest that miR-21 is a mediator involved in the pathogenesis of cardiac fibrosis and indicates the pharmacological silencing of miR-21 as a potential therapeutic approach for CCC.

Effect of exercise training on cardiovascular autonomic and muscular function in subclinical Chagas cardiomyopathy: a randomized controlled trial.

PURPOSE: Patients with chronic chagasic cardiomyopathy with preserved ventricular function present with autonomic imbalance. This study evaluated the effects of exercise training (ET) in restoring peripheral and cardiac autonomic control and skeletal muscle phenotype in patients with subclinical chronic chagasic cardiomyopathy. METHODS: This controlled trial (NCT02295215) included 24 chronic chagasic cardiomyopathy patients who were randomized www.random.org/lists/ into two groups: those who underwent exercise training (n = 12) and those who continued their usual activities (n = 12). Eight patients completed the exercise training protocol, and 10 patients were clinically followed up for 4 months. Muscular sympathetic nerve activity was measured by microneurography and muscle blood flow (MBF) using venous occlusion plethysmography. The low-frequency component of heart rate variability in normalized units (LFnuHR) reflects sympathetic activity in the heart, and the low-frequency component of systolic blood pressure variability in normalized units reflects sympathetic activity in the vessels. The infusion of vasoactive drugs (phenylephrine and sodium nitroprusside) was used to evaluate cardiac baroreflex sensitivity, and a vastus lateralis muscle biopsy was performed to evaluate atrogin-1 and MuRF-1 gene expression. RESULTS: The baroreflex sensitivity for increases (p = 0.002) and decreases (p = 0.02) in systolic blood pressure increased in the ET group. Muscle blood flow also increased only in the ET group (p = 0.004). Only the ET group had reduced resting muscular sympathetic nerve activity levels (p = 0.008) and sympathetic activity in the heart (LFnu; p = 0.004) and vessels (p = 0.04) after 4 months. Regarding skeletal muscle, after 4 months, participants in the exercise training group presented with lower atrogin-1 gene expression than participants who continued their activities as usual (p = 0.001). The reduction in muscular sympathetic nerve activity was positively associated with reduced atrogin-1 (r = 0.86; p = 0.02) and MuRF-1 gene expression (r = 0.64; p = 0.06); it was negatively associated with improved baroreflex sensitivity both for increases (r = -0.72; p = 0.020) and decreases (r = -0.82; p = 0.001) in blood pressure. CONCLUSIONS: ET improved cardiac and peripheral autonomic function in patients with subclinical chagasic cardiomyopathy. ET reduced MSNA and sympathetic activity in the heart and vessels and increased cardiac parasympathetic tone and baroreflex sensitivity. Regarding peripheral muscle, after 4 months, patients who underwent exercise training had an increased cross-sectional area of type I fibers and oxidative metabolism of muscle fibers, and decreased atrogin-1 gene expression, compared to participants who continued their activities as usual. In addition, the reduction in MSNA was associated with improved cardiac baroreflex sensitivity, reduced sympathetic cardiovascular tone, and reduced atrogin-1 and MuRF-1 gene expression. TRIAL REGISTRATION: ID: NCT02295215. Registered in June 2013.

Tolerogenic Dendritic Cells Reduce Cardiac Inflammation and Fibrosis in Chronic Chagas Disease.

Chronic Chagas disease cardiomyopathy (CCC) is the most frequent and severe form of this parasitic disease. CCC is caused by a progressive inflammation in the heart, resulting in alterations that can culminate in heart failure and death. The use of dendritic cells (DCs) appears as an option for the development of treatments due to their important role in regulating immune responses. Here, we investigated whether tolerogenic cells (tDCs) could interfere with the progression of CCC in an experimental model of Chagas disease. The tDCs were generated and characterized as CD11b+ CD11c+ cells, low expression of MHC-II, CD86, CD80, and CD40, and increased expression of PD-L. These cells produced low levels of IL-6 and IL-12p70 and higher levels of IL-10, compared to mature DCs (mDCs). Interestingly, tDCs inhibited lymphoproliferation and markedly increased the population of FoxP3+ Treg cells in vitro, compared to mature DCs. In a mouse model of CCC, treatment with tDCs reduced heart inflammation and fibrosis. Furthermore, tDCs treatment reduced the gene expression of pro-inflammatory cytokines (Ifng and Il12) and of genes related to cardiac remodeling (Col1a2 and Lgals3), while increasing the gene expression of IL-10. Finally, administration of tDCs, increased the percentage of Treg cells in the hearts and spleens of chagasic mice. Ours results show that tolerogenic dendritic cells have therapeutic potential on CCC, inhibiting disease progression.

Risk Score for Predicting 2-Year Mortality in Patients With Chagas Cardiomyopathy From Endemic Areas: SaMi-Trop Cohort Study.

Background Risk stratification of Chagas disease patients in the limited-resource setting would be helpful in crafting management strategies. We developed a score to predict 2-year mortality in patients with Chagas cardiomyopathy from remote endemic areas. Methods and Results This study enrolled 1551 patients with Chagas cardiomyopathy from Minas Gerais State, Brazil, from the SaMi-Trop cohort (The São Paulo-Minas Gerais Tropical Medicine Research Center). Clinical evaluation, ECG, and NT-proBNP (N-terminal pro-B-type natriuretic peptide) were performed. A Cox proportional hazards model was used to develop a prediction model based on the key predictors. The end point was all-cause mortality. The patients were classified into 3 risk categories at baseline (low, <2%; intermediate, ≥2% to 10%; high, ≥10%). External validation was performed by applying the score to an independent population with Chagas disease. After 2 years of follow-up, 110 patients died, with an overall mortality rate of 3.505 deaths per 100 person-years. Based on the nomogram, the independent predictors of mortality were assigned points: age (10 points per decade), New York Heart Association functional class higher than I (15 points), heart rate ≥80 beats/min (20 points), QRS duration ≥150 ms (15 points), and abnormal NT-proBNP adjusted by age (55 points). The observed mortality rates in the low-, intermediate-, and high-risk groups were 0%, 3.6%, and 32.7%, respectively, in the derivation cohort and 3.2%, 8.7%, and 19.1%, respectively, in the validation cohort. The discrimination of the score was good in the development cohort (C statistic: 0.82), and validation cohort (C statistic: 0.71). Conclusions In a large population of patients with Chagas cardiomyopathy, a combination of risk factors accurately predicted early mortality. This helpful simple score could be used in remote areas with limited technological resources.

Chagas disease is associated with a poor outcome at 1-year follow-up after cardiac resynchronization therapy.

BACKGROUND: Cardiac resynchronization therapy (CRT) is a therapeutic modality for patients with heart failure (HF). The effectiveness of this treatment for event reduction is based on clinical trials where the population of patients with Chagas' disease (DC) is underrepresented. OBJECTIVE: To evaluate the prognosis after CRT of a population in which CD is an endemic cause of HF. METHODS: A retrospective cohort conducted between January 2015 and December 2016 that included patients with HF and left ventricular ejection fraction (LVEF) of less than 35% and undergoing CRT. Clinical and demographic data were collected to search for predictors for the combined outcome of death or hospitalization for HF at one year after CRT implantation. RESULTS: Fifty-four patients were evaluated, and 13 (24.1%) presented CD as the etiology of HF. The mean LVEF was 26.2± 6.1%, and 36 (66.7%) patients presented functional class III or IV HF. After the mean follow-up of 15 (±6,9) months, 17 (32.1%) patients presented the combined outcome. In the univariate analysis, CD was associated with the combined event when compared to other etiologies of HF, 8 (47%) vs. 9 (13,5%), RR: 3,91 CI: 1,46-10,45, p=0,007, as well as lower values of LVEF. In the multivariate analysis, CD and LVEF remained independent risk factors for the combined outcome. CONCLUSION: In a population of HF patients undergoing CRT, CD was independently associated with mortality and hospitalization for HF.

Chagas disease is associated with a poor outcome at 1-year follow-up after cardiac resynchronization therapy

SUMMARY BACKGROUND: Cardiac resynchronization therapy (CRT) is a therapeutic modality for patients with heart failure (HF). The effectiveness of this treatment for event reduction is based on clinical trials where the population of patients with Chagas' disease (DC) is underrepresented. OBJECTIVE: To evaluate the prognosis after CRT of a population in which CD is an endemic cause of HF. METHODS: A retrospective cohort conducted between January 2015 and December 2016 that included patients with HF and left ventricular ejection fraction (LVEF) of less than 35% and undergoing CRT. Clinical and demographic data were collected to search for predictors for the combined outcome of death or hospitalization for HF at one year after CRT implantation. RESULTS: Fifty-four patients were evaluated, and 13 (24.1%) presented CD as the etiology of HF. The mean LVEF was 26.2± 6.1%, and 36 (66.7%) patients presented functional class III or IV HF. After the mean follow-up of 15 (±6,9) months, 17 (32.1%) patients presented the combined outcome. In the univariate analysis, CD was associated with the combined event when compared to other etiologies of HF, 8 (47%) vs. 9 (13,5%), RR: 3,91 CI: 1,46-10,45, p=0,007, as well as lower values of LVEF. In the multivariate analysis, CD and LVEF remained independent risk factors for the combined outcome. CONCLUSION: In a population of HF patients undergoing CRT, CD was independently associated with mortality and hospitalization for HF.

RESUMO INTRODUÇÃO: A terapia de ressincronização cardíaca (TRC) é uma modalidade terapêutica para pacientes com insuficiência cardíaca (IC). A eficácia desse tratamento para redução de eventos baseia-se em ensaios clínicos em que a população de pacientes com doença de Chagas (DC) é sub-representada. OBJETIVO: Avaliar o prognóstico após TRC em uma população em que a DC é uma causa frequente de IC. MÉTODOS: Coorte retrospectiva realizada entre janeiro de 2015 e dezembro de 2016, sendo incluídos pacientes portadores de IC com fração de ejeção do ventrículo esquerdo (Feve) menor que 35% e submetidos à TRC. Os dados clínicos e demográficos foram coletados para pesquisa de preditores para o desfecho combinado de morte ou internação por IC após implante da TRC. RESULTADOS: Foram avaliados 54 pacientes, dos quais 13 (24,1%) apresentavam a DC como etiologia da IC. A Feve média foi de 26,2% (±6,1) e 36 (66,7%) pacientes apresentavam classe funcional de IC III ou IV. Após o seguimento médio de 15 meses, 17 (32,1%) pacientes apresentaram o desfecho combinado. Na análise univariada, a DC esteve associada ao evento combinado quando comparada a outras etiologias de IC, 8 (47%) vs 9 (13,5%), RR: 3,91 IC: 1,46-10,45, p=0,007, assim como valores mais baixos da Feve. Na análise multivariada, a DC e a Feve permaneceram como fatores de risco independentes para o desfecho combinado. CONCLUSÃO: Em uma população de pacientes com IC submetidos à TRC, a doença de Chagas esteve independentemente associada à mortalidade e internação por insuficiência cardíaca no seguimento de 15 meses.

Systematic Review and Meta-Analysis of Clinical Outcome After Implantable Cardioverter-Defibrillator Therapy in Patients With Chagas Heart Disease.

OBJECTIVES: The goal of this analysis was to pool data from published studies on outcomes after implantable cardioverter-defibrillator (ICD) therapy in patients with Chagas heart disease (CHD). BACKGROUND: CHD is characterized by a high burden of ventricular arrhythmias and an increased risk of sudden cardiac death. The indications for ICD are not well established. METHODS: An extensive literature search without language restrictions was performed to identify all studies on ICD therapy in patients with CHD. A random effects model was used to calculate percentages and 95% confidence intervals (CIs). RESULTS: Of 397 articles screened, 13 studies (all observational) were included. There were 1,041 patients (mean age at implantation 57 ± 11 years; 64% men), most of whom (92%) received an ICD for secondary prevention. Antiarrhythmic medication consisted of amiodarone (79%) and beta-blockers (44%). Overall, the annual all-cause mortality rate was 9.0% (95% CI: 6.9 to 11.7) in 2.8 ± 1.9 years of follow-up, and the annual sudden cardiac death rate was 2.0% (95% CI: 1.3 to 3.3) in 2.6 ± 1.9 years. In addition, 24.8% (95% CI: 15.7 to 37.0) of patients received 1 or more appropriate interventions (shocks or antitachycardia pacing), 4.7% (95% CI: 3.2 to 6.9) received inappropriate shocks, and 9.1% (95% CI: 5.5 to 14.7) had electric storms annually. CONCLUSIONS: In patients with an ICD, annual all-cause mortality rate was 9%. Appropriate ICD interventions and electric storms were frequent, occurring at a rate of 25% and 9% per year, respectively. Inappropriate ICD shocks were not infrequent (5% per year). The benefits and risks of ICD therapy in patients with CHD should be carefully weighed until data from better studies become available.

Chagas disease is associated with a worse prognosis at 1-year follow-up after implantable cardioverter-defibrillator for secondary prevention in heart failure patients.

INTRODUCTION: There are conflicting data regarding the efficacy of implantable cardioverter-defibrillator (ICD) in Chagas disease (CD) patients. This study aims to evaluate the short-term outcome after ICD for secondary prevention, in a population where CD is a prevalent cause of heart failure (HF). METHODS AND RESULTS: Consecutive patients with HF and reduced left ventricular ejection fraction (LVEF), who underwent ICD implantation for secondary prevention of SCD. Clinical and demographic data were collected to investigate mortality predictors at 1 year. During the study period, 117 patients underwent ICD implantation, of which 108 were included. The most frequent causes of HF was CD: 52 (48.1%) and ischemic cardiomyopathy: 20 (18.5%). Chagas and non-Chagas patients were well balanced-male: 32 (61.5%) vs 38 (67.9%), P = .548; age: 59.2 (±10.9) vs 56.8 (±13.4), P = .681; and LVEF: 34.1 (±0.2) vs 31.3 (±8.7), P = .064, respectively. At the mean follow-up of 15.7 months, overall mortality occurred in 14 (12.9%) patients, with a higher incidence in patients with CD cardiomyopathy, 11 (21.2%) vs 3 (5.4%), P = .021 (log-rank). In the multivariate analysis, CD remained as an independent predictor for death (hazard ratio: 4.62, confidence interval [95% CI]: 1.27-16.81, P = .021). CONCLUSION: CD was associated with a poor short-term outcome in patients with HF submitted to ICD implantation for secondary prevention when compared with other HF etiologies. In this specific HF population, ICD indication should be individualized, considering the worst prognosis of these patients.