Inspiratory muscle endurance is similarly reduced in the early and late stages of chronic Chagas heart disease.

OBJECTIVE: Inspiratory muscle strength (IMS) appears to be reduced in subjects with chronic Chagas heart disease (CHD), especially in the presence of heart failure (HF). However, only one study about IMS and inspiratory muscle endurance (IME) in those with CHD without heart failure is available. This study aimed to compare IMS and IME in subjects with CHD in the presence and absence of HF. METHODS: This is a cross-sectional study in which 30 CHD adult patients were divided into CHD-CC group (initial phase of CHD, without HF; n = 15) and CHD-HF group (advanced phase of CHD, with HF; n = 15). We assessed IMS by maximum inspiratory pressure (MIP) and IME by incremental (Pthmax) and constant load (TLim) tests. Reduced IMS and IME were considered by predicted MIP values <70% and Pthmax/MIP <75%, respectively. RESULTS: Inspiratory muscle weakness (IMW) was more frequent in CHD-HF than in CHD-CC (46.7% vs. 13.3%; p = 0.05), and both groups had high frequencies of reduced IME (93.3% CHD-CC vs. 100.0% CHD-HF; p = 0.95). Age-adjusted logistic regression analysis using HF as a dependent variable showed that HF was associated with an increased chance of IMW compared with the CHD-CC group (OR = 7.47; p = 0.03; 95% CI 1.20-46.19). CONCLUSION: This study suggests that, in patients with CHD, HF is associated with IMW, and that reduction of IME is already present in the initial phase, similar to the advanced phase with HF.

Guideline of the Brazilian Society of Cardiology on Diagnosis and Treatment of Patients with Chagas Disease Cardiomyopathy / Diretriz da Sociedade Brasileira de Cardiologia sobre Diagnóstico e Tratamento de Pacientes com Cardiomiopatia da Doença de Chagas

This guideline aimed to update the concepts and formulate the standards of conduct and scientific evidence that support them, regarding the diagnosis and treatment of the Cardiomyopathy of Chagas disease, with special emphasis on the rationality base that supported it.  Chagas disease in the 21st century maintains an epidemiological pattern of endemicity in 21 Latin American countries. Researchers and managers from endemic and non-endemic countries point to the need to adopt comprehensive public health policies to effectively control the interhuman transmission of T. cruzi infection, and to obtain an optimized level of care for already infected individuals, focusing on diagnostic and therapeutic opportunistic opportunities.   Pathogenic and pathophysiological mechanisms of the Cardiomyopathy of Chagas disease were revisited after in-depth updating and the notion that necrosis and fibrosis are stimulated by tissue parasitic persistence and adverse immune reaction, as fundamental mechanisms, assisted by autonomic and microvascular disorders, was well established. Some of them have recently formed potential targets of therapies.  The natural history of the acute and chronic phases was reviewed, with enhancement for oral transmission, indeterminate form and chronic syndromes. Recent meta-analyses of observational studies have estimated the risk of evolution from acute and indeterminate forms and mortality after chronic cardiomyopathy. Therapeutic approaches applicable to individuals with Indeterminate form of Chagas disease were specifically addressed. All methods to detect structural and/or functional alterations with various cardiac imaging techniques were also reviewed, with recommendations for use in various clinical scenarios. Mortality risk stratification based on the Rassi score, with recent studies of its application, was complemented by methods that detect myocardial fibrosis.  The current methodology for etiological diagnosis and the consequent implications of trypanonomic treatment deserved a comprehensive and in-depth approach. Also the treatment of patients at risk or with heart failure, arrhythmias and thromboembolic events, based on pharmacological and complementary resources, received special attention. Additional chapters supported the conducts applicable to several special contexts, including t. cruzi/HIV co-infection, risk during surgeries, in pregnant women, in the reactivation of infection after heart transplantation, and others.     Finally, two chapters of great social significance, addressing the structuring of specialized services to care for individuals with the Cardiomyopathy of Chagas disease, and reviewing the concepts of severe heart disease and its medical-labor implications completed this guideline.

Esta diretriz teve como objetivo principal atualizar os conceitos e formular as normas de conduta e evidências científicas que as suportam, quanto ao diagnóstico e tratamento da CDC, com especial ênfase na base de racionalidade que a embasou. A DC no século XXI mantém padrão epidemiológico de endemicidade em 21 países da América Latina. Investigadores e gestores de países endêmicos e não endêmicos indigitam a necessidade de se adotarem políticas abrangentes, de saúde pública, para controle eficaz da transmissão inter-humanos da infecção pelo T. cruzi, e obter-se nível otimizado de atendimento aos indivíduos já infectados, com foco em oportunização diagnóstica e terapêutica. Mecanismos patogênicos e fisiopatológicos da CDC foram revisitados após atualização aprofundada e ficou bem consolidada a noção de que necrose e fibrose sejam estimuladas pela persistência parasitária tissular e reação imune adversa, como mecanismos fundamentais, coadjuvados por distúrbios autonômicos e microvasculares. Alguns deles recentemente constituíram alvos potenciais de terapêuticas. A história natural das fases aguda e crônica foi revista, com realce para a transmissão oral, a forma indeterminada e as síndromes crônicas. Metanálises recentes de estudos observacionais estimaram o risco de evolução a partir das formas aguda e indeterminada e de mortalidade após instalação da cardiomiopatia crônica. Condutas terapêuticas aplicáveis aos indivíduos com a FIDC foram abordadas especificamente. Todos os métodos para detectar alterações estruturais e/ou funcionais com variadas técnicas de imageamento cardíaco também foram revisados, com recomendações de uso nos vários cenários clínicos. Estratificação de risco de mortalidade fundamentada no escore de Rassi, com estudos recentes de sua aplicação, foi complementada por métodos que detectam fibrose miocárdica. A metodologia atual para diagnóstico etiológico e as consequentes implicações do tratamento tripanossomicida mereceram enfoque abrangente e aprofundado. Também o tratamento de pacientes em risco ou com insuficiência cardíaca, arritmias e eventos tromboembólicos, baseado em recursos farmacológicos e complementares, recebeu especial atenção. Capítulos suplementares subsidiaram as condutas aplicáveis a diversos contextos especiais, entre eles o da co-infecção por T. cruzi/HIV, risco durante cirurgias, em grávidas, na reativação da infecção após transplante cardíacos, e outros.    Por fim, dois capítulos de grande significado social, abordando a estruturação de serviços especializados para atendimento aos indivíduos com a CDC, e revisando os conceitos de cardiopatia grave e suas implicações médico-trabalhistas completaram esta diretriz. 

Selenium Treatment and Chagasic Cardiopathy (STCC): study protocol for a double-blind randomized controlled trial.

BACKGROUND: Heart disease progression occurs in 30% of patients with chronic Trypanosoma cruzi infection. Supplementation with selenium (Se) in animal model of T. cruzi infection produced promising results. There is evidence that patients with Chagas heart disease have lower Se levels than healthy individuals and patients with T. cruzi infection without of cardiac disease. The aim of this investigation is to estimate the effect of Se treatment on prevention of heart disease progression in patients with chagasic cardiopathy. METHODS: The Selenium Treatment and Chagasic Cardiopathy trial is a superiority, double-blind, placebo-controlled, randomized clinical trial. The eligibility criteria are as follows: (1) a Chagas disease diagnosis confirmed by serology; (2) segmental, mild or moderate global left ventricular systolic dysfunction; and (3) age between 18 and 65 years. The exclusion criteria are as follows: (1) pregnancy, (2) diabetes mellitus, (3) tobacco use, (4) alcohol abuse, (5) evidence of nonchagasic heart disease, (6) depression, (7) dysphagia with evidence of food residues in the esophagus, (8) dysphagia with weight loss higher than 15% of usual weight in the last four months and/or (9) conditions that may result in low protocol adherence. The intervention will be 100 µg of sodium selenite once daily for 365 consecutive days compared to placebo. The following are the primary outcomes to be measured: (1) the trajectories of the left ventricular ejection fraction in the follow-up period; (2) reduction of heart disease progression rates, with progression defined as a 10% decrease in left ventricular ejection fraction; and (3) rate of hospital admissions attributable to dysrhythmia, heart failure or stroke due to Chagas disease. One hundred thirty patients will be randomly allocated into either the intervention or placebo group at a ratio of 1:1. The sequence allocation concealment and blinding were planned to be conducted with the strategy of numbered boxes. Both patients and health-care providers will remain blinded to the intervention groups during the 5 years of follow-up. DISCUSSION: If Se treatment reduces the progression of Chagas cardiopathy, the inclusion of this micronutrient in the daily diet can improve the therapeutic regimen for this neglected tropical disease at low cost. TRIAL REGISTRATION: Clinical Trials.gov ID: NCT00875173 (registered 20 October 20 2008).

A clinical adverse drug reaction prediction model for patients with chagas disease treated with benznidazole.

Benznidazole (BZN) is the main trypanocidal drug used to treat Chagas disease, and the evidence supporting the benefits of BZN use during the chronic phase of the disease will favor its use in millions of individuals. However, more than 30% of patients treated with BZN may suffer adverse drug reactions (ADRs), and the development of tools to identify those patients at risk is highly desirable. In the present study, we aimed to identify predictive factors for ADRs in Chagas disease patients treated with BZN. Among 195 patients included in the study, 48.7% experienced ADRs and 31.3% had ADRs that caused BZN treatment discontinuation. Overall ADRs and ADRs that caused BZN treatment discontinuation were more common among women and in those who graduated from elementary school. Overall ADRs were also less frequent among black individuals. Based on logistic regression analysis, female sex (odds ratio [OR], 2.9; 95% confidence interval [CI], 1.5 to 5.4), graduation from elementary school (OR, 2.0; 95% CI, 1.1 to 3.8), and white (OR, 5.0; 95% CI, 1.0 to 24.1) and mulatto (OR, 5.6; 95% CI, 1.1 to 28.7) races were considered to predict overall ADRs, and female sex (OR, 2.3; 95% CI, 1.2 to 4.3) was considered to predict ADRs that caused BZN treatment discontinuation. Graduation from elementary school also presented a tendency to predict ADRs that caused BZN treatment discontinuation (OR, 1.8; 95% CI, 0.9 to 3.6). The logistic regression (LR) models to predict ADRs to BZN described in this study may become important tools to minimize ADRs and improve patients' compliance and thus assist physicians treating patients with Chagas disease with BZN.

Swimming training attenuates remodeling, contractile dysfunction and congestive heart failure in rats with moderate and large myocardial infarctions.

1. The aim of the present study was to evaluate the effect of swimming on myocardial remodelling after myocardial infarction (MI) in female rats induced by coronary occlusion, which was not performed in sham rats. 2. Rats were divided in six groups, three sedentary (sham (SSh; n = 14), moderate infarct (SMI; n = 8) and large infarct (SLI; n = 10)) and three trained (sham (TSh; n = 16), moderate infarct (TMI; n = 9) and large infarct (TLI; n = 8)) groups. Training (8 weeks, 60 min/day, 5 days/week) was initiated 4 weeks after MI or sham operation. Training did not affect mortality rate, but attenuated the increases in atrial/bodyweight (SSh: 0.07 +/- 0.02; TSh: 0.07 +/- 0.02; SMI: 0.11 +/- 0.03; TMI: 0.09 +/- 0.03; SLI: 0.17 +/- 0.09; TLI: 0.10 +/- 0.05 mg/g) and right ventricular/bodyweight (SSh: 0.15 +/- 0.02; TSh: 0.17 +/- 0.02; SMI: 0.17 +/- 0.07; TMI: 0.20 +/- 0.03; SLI: 0.29 +/- 0.13; TLI: 0.22 +/- 0.08 mg/g) ratios. Myocardial infarction increased pulmonary and myocardial water content in infarcted sedentary animals, whereas no changes were observed in trained infarcted rats. Sedentary infarcted rats showed inotropic and lusitropic depression proportional to the size of the infarct (SSh > SMI > SLI), whereas no differences were noted in trained rats (TLI = TMI = TSh). Indeed, in sedentary rats there was depression of +dT/dt (SSh: 68 +/- 25; TSh: 72 +/- 21; SMI: 53 +/- 20; TMI: 77 +/- 30; SLI: 33 +/- 15; TLI: 57 +/- 22 g/mm(2) per s) and -dT/dt (SSh: 33 +/- 13; TSh: 36 +/- 11; SMI: 24 +/- 5; TMI: 35 +/- 11; SLI: 15 +/- 4; TLI: 32 +/- 11 g/mm(2) per s) compared with trained rats. 3. In conclusion, swimming clearly favoured post-MI cardiac remodelling, attenuated myocardial hypertrophy, contractile and relaxation dysfunction and prevented pulmonary congestion.