A cohort study of cardiac resynchronization therapy in patients with chronic Chagas cardiomyopathy.

Aims: Cardiac resynchronization therapy (CRT) is an established procedure for patients with heart failure. However, trials evaluating its efficacy did not include patients with chronic Chagas cardiomyopathy (CCC). We aimed to assess the role of CRT in a cohort of patients with CCC. Methods and results: This retrospective study compared the outcomes of CCC patients who underwent CRT with those of dilated (DCM) and ischaemic cardiomyopathies (ICM). The primary endpoint was all-cause mortality and the secondary endpoints were the rate of non-advanced New York Heart Association (NYHA) class 12 months after CRT and echocardiographic changes evaluated at least 6 months after CRT. There were 115 patients in the CCC group, 177 with DCM, and 134 with ICM. The annual mortality rates were 25.4%, 10.4%, and 11.3%, respectively (P < 0.001). Multivariate analysis adjusted for potential confounders showed that the CCC group had a two-fold [hazard ratio 2.34 (1.47-3.71), P < 0.001] higher risk of death compared to the DCM group. The rate of non-advanced NYHA class 12 months after CRT was significantly higher in non-CCC groups than in the CCC group (DCM 74.0% vs. ICM 73.9% vs. 56.5%, P < 0.001). Chronic Chagas cardiomyopathy and ICM patients had no improvement in the echocardiographic evaluation, but patients in the DCM group had an increase in left ventricular ejection fraction and a decrease in left ventricular end-diastolic diameter. Conclusion: This study showed that CCC patients submitted to CRT have worse prognosis compared to patients with DCM and ICM who undergo CRT. Studies comparing CCC patients with and without CRT are warranted.

Functional IL18 polymorphism and susceptibility to Chronic Chagas Disease.

BACKGROUND: Chronic Chagas Disease cardiomyopathy (CCC), a life-threatening inflammatory dilated cardiomyopathy, affects 30% of the approximately 8 million patients infected by Trypanosoma cruzi, the rest of the infected subjects remaining asymptomatic (ASY). The Th1 T cell-rich myocarditis plays a pivotal role in CCC pathogenesis. Local expression of IL-18 in CCC myocardial tissue has recently been described. IL-18 could potentially amplify the process by inducing increased expression of IFN-γ which in turn can increase the production of IL-18, thereby creating a positive feedback mechanism. In order to assess the contribution of the IL-18 to susceptibility to Chronic Chagas Disease, we investigated the association between a single nucleotide polymorphism (SNP) located in the IL-18 gene with the risk of developing Chagas cardiomyopathy. METHODS AND RESULTS: We analyzed the rs2043055 marker in the IL18 gene in a cohort of Chagas disease cardiomyopathy patients (n=849) and asymptomatic subjects (n=202). We found a significant difference in genotype frequencies among moderate and severe CCC patients with ventricular dysfunction. CONCLUSIONS: Our analysis suggests that the IL18 rs2043055 polymorphism- or a SNP in tight linkage disequilibrium with it- may contribute to modulating the Chagas cardiomyopathy outcome.

Mortality risk score for patients with Chagas cardiomyopathy and pacemaker.

BACKGROUND: Prognosis of Chronic Chagasic Cardiomyopathy (CCC) patients depends on functional and clinical factors. Bradyarrhythmia requiring pacemaker is a common complication. Prognosis of these patients is poorly studied, and mortality risk factors are unknown. We aimed to identify predictors of death and to define a risk score for mortality in a large cohort of CCC patients with pacemaker. METHODS: It was an observational, unicentric and prospective study. The endpoint was all-cause mortality. Cox regression was used to identify predictors of death and to define a risk score. Bootstrapping method was used to internal score validation. RESULTS: We included 555 patients and after a mean follow-up of 3.7±1.5 years, 100 (18%) deaths occurred. Predictors of death were: right ventricular dysfunction (HR [hazard ratio] 2.24; 95%CI 1.41-3.53; P = 0.001); heart failure class III or IV (HR 2.16; 95% confidence interval [95%CI] 1.16-4.00; P = 0.014); renal disease (HR 2.14; 95%CI 1.24-3.68; P = 0.006); left ventricular end-systolic diameter > 44mm (HR 1.97; 95%CI 1.26-3.05; P = 0.003); atrial fibrillation (HR 1.94; 95%CI 1.25-2.99; P = 0.003) and cardiomegaly on X-ray (HR 1.87; 95%CI 1.10-3.17; P = 0.020). The score identified patients with: low (0-20 points), intermediate (21-30 points) and high risk (>31points). The optimism-corrected C-statistic of the predictive model was 0.751 (95% CI 0.696-0.806). Internal validation with bootstrapping revealed a calibration slope of 0.946 (95% CI 0.920-0.961), reflecting a small degree of over-optimism and C-statistic of 0.746 (95% CI 0.692-0.785). CONCLUSIONS: This study identified predictors of mortality in CCC patients with pacemaker defining a simple, validated and specific risk score.

The Six Pillars of Lifestyle Medicine in Managing Noncommunicable Diseases - The Gaps in Current Guidelines. / Os Seis Pilares da Medicina do Estilo de Vida no Manejo de Doenças Não Transmissíveis ­ As Lacunas nas Diretrizes Atuais.

BACKGROUND: Noncommunicable diseases (NCDs), also known as chronic diseases that are long-lasting, are considered the major cause of death and disability worldwide, and the six pillars of lifestyle medicine (nutrition, exercise, toxic control, stress management, restorative sleep, and social connection) play an important role in a holistic management of their prevention and treatment. In addition, medical guidelines are the most accepted documents with recommendations to manage NCDs. OBJECTIVE: The present study aims to analyze the lack of lifestyle pillars concerning the major Brazilian medical guidelines for NCDs and identify evidence in the literature that could justify their inclusion in the documents. METHOD: Brazilian guidelines were selected according to the most relevant causes of death in Brazil, given by the Mortality Information System, published by the Brazilian Ministry of Health in 2019. Journals were screened in the PUBMED library according to the disease and non-mentioned pillars of lifestyle. RESULTS: Relevant causes of deaths in Brazil are acute myocardial infarction (AMI), diabetes mellitus (DM), and chronic obstructive pulmonary diseases (COPD). Six guidelines related to these NCDs were identified, and all address aspects of lifestyle, but only one, regarding cardiovascular prevention, highlights all six pillars. Despite this, a literature search involving over 50 articles showed that there is evidence that all the pillars can help control each of these NCDs. CONCLUSION: Rarely are the six pillars of lifestyle contemplated in Brazilian guidelines for AMI, DM, and COPD. The literature review identified evidence of all lifestyle pillars to offer a holistic approach for the management and prevention of NCDs.

FUNDAMENTO: As doenças crônicas não transmissíveis (DCNT), também conhecidas como doenças crônicas de longa duração, são consideradas a principal causa de morte e incapacidade em todo o mundo, e os seis pilares da medicina do estilo de vida (nutrição, exercício, controle de tóxicos, manejo do estresse, saúde do sono e conexão social) desempenham um papel importante na gestão holística da sua prevenção e tratamento. Além disso, as diretrizes médicas são os documentos mais aceitos com recomendações para o manejo das DCNT. OBJETIVO: O presente estudo tem como objetivo analisar a ausência de pilares de estilo de vida nas principais diretrizes médicas brasileiras sobre as DCNT e identificar evidências na literatura que possam justificar sua inclusão nos documentos. MÉTODO: As diretrizes brasileiras foram selecionadas de acordo com as causas de morte mais relevantes no Brasil, informadas pelo Sistema de Informações sobre Mortalidade publicado pelo Ministério da Saúde em 2019. Os periódicos foram selecionados na biblioteca PUBMED de acordo com a doença e os pilares do estilo de vida não mencionados. RESULTADOS: Causas relevantes de mortes no Brasil são o infarto agudo do miocárdio (IAM), o diabetes mellitus (DM) e as doenças pulmonares obstrutivas crônicas (DPOC). Foram identificadas seis diretrizes relacionadas a essas DCNT e todas abordam aspectos do estilo de vida, mas apenas uma, referente à prevenção cardiovascular, destaca todos os seis pilares. Apesar disso, uma pesquisa bibliográfica envolvendo mais de 50 artigos mostrou que há evidências de que todos os pilares podem ajudar no controle de cada uma dessas DCNT. CONCLUSÃO: Raramente os seis pilares do estilo de vida são contemplados nas diretrizes brasileiras para IAM, DM e DPOC. A revisão da literatura identificou evidências de todos os pilares do estilo de vida para oferecer uma abordagem holística para a gestão e prevenção das DCNT.

CHronic use of Amiodarone aGAinSt Implantable cardioverter-defibrillator therapy for primary prevention of death in patients with Chagas cardiomyopathy Study: rationale and design of a randomized clinical trial.

BACKGROUND: The implantable cardioverter defibrillator (ICD) is better than antiarrhythmic drug therapy for the primary and secondary prevention of all-cause mortality and sudden cardiac death in patients with either coronary artery disease or idiopathic dilated cardiomyopathy. This study aims to assess whether the ICD also has this effect for primary prevention in chronic Chagas cardiomyopathy (CCC). METHODS: In this randomized (concealed allocation) open-label trial, we aim to enroll up to 1,100 patients with CCC, a Rassi risk score for death prediction of ≥10 points, and at least 1 episode of nonsustained ventricular tachycardia on a 24-hour Holter monitoring. Patients from 28 centers in Brazil will be randomly assigned in a 1:1 ratio to receive an ICD or amiodarone (600 mg/d for 10 days, then 200-400 mg/d until the end of the study). The randomization sequence will be generated by computer, and the members of the committees responsible for end point validation and data analysis will be blinded to study assignment. The primary end point is all-cause death, and enrolment will continue until 256 patients have reached this end point. Key secondary end points include cardiovascular death, sudden cardiac death, hospitalization for heart failure, and quality of life. We expect follow-up to last 3 to 6 years, and data analysis will be done on an intention-to-treat basis. This trial is registered with ClinicalTrials.gov number NCT01722942. CONCLUSION: CHAGASICS is the first large-scale trial to assess the benefit of ICD therapy for the primary prevention of death in patients with CCC and nonsustained ventricular tachycardia, who have a moderate to high risk of death.

Conventional versus biventricular pacing in heart failure and bradyarrhythmia: the COMBAT study.

BACKGROUND: Worsening in clinical and cardiac status has been noted after chronic right ventricular pacing, but it is uncertain whether atriobiventricular (BiVP) is preferable to atrio-right ventricular pacing (RVP). Conventional versus Multisite Pacing for BradyArrhythmia Therapy study (COMBAT) sought to compare BiVP versus RVP in patients with symptomatic heart failure (HF) and atrioventricular (AV) block. METHODS AND RESULTS: COMBAT is a prospective multicenter randomized double blind crossover study. Patients with New York Heart Association functional class (FC) II-IV, left ventricular ejection fraction (LVEF) <40%, and AV block as an indication for pacing were enrolled. All patients underwent biventricular system implantation and then were randomized to receive successively (group A) RVP-BiVP-RVP, or (group B) BiVP-RVP-BiVP. At the end of each 3-month crossover period, patients were evaluated according to Quality of Life (QoL), FC, echocardiographic parameters, 6-Minute Walk Test (6MWT), and peak oxygen consumption (VO(2 max)). Sixty patients were enrolled, and the mean follow-up period was 17.5 +/- 10.7 months. There were significant improvements in QoL, FC, LVEF, and left ventricular end-systolic volume with BiVP compared with RVP. The effects of pacing mode on 6MWT and VO(2 max) were not significantly different. Death occurred more frequently with RVP. CONCLUSION: In patients with systolic HF and AV block requiring permanent ventricular pacing, BiVP is superior to RVP and should be considered the preferred pacing mode.

Os Seis Pilares da Medicina do Estilo de Vida no Manejo de Doenças Não Transmissíveis - As Lacunas nas Diretrizes Atuais / The Six Pillars of Lifestyle Medicine in Managing Noncommunicable Diseases - The Gaps in Current Guidelines

Resumo Fundamento: As doenças crônicas não transmissíveis (DCNT), também conhecidas como doenças crônicas de longa duração, são consideradas a principal causa de morte e incapacidade em todo o mundo, e os seis pilares da medicina do estilo de vida (nutrição, exercício, controle de tóxicos, manejo do estresse, saúde do sono e conexão social) desempenham um papel importante na gestão holística da sua prevenção e tratamento. Além disso, as diretrizes médicas são os documentos mais aceitos com recomendações para o manejo das DCNT. Objetivo: O presente estudo tem como objetivo analisar a ausência de pilares de estilo de vida nas principais diretrizes médicas brasileiras sobre as DCNT e identificar evidências na literatura que possam justificar sua inclusão nos documentos. Método: As diretrizes brasileiras foram selecionadas de acordo com as causas de morte mais relevantes no Brasil, informadas pelo Sistema de Informações sobre Mortalidade publicado pelo Ministério da Saúde em 2019. Os periódicos foram selecionados na biblioteca PUBMED de acordo com a doença e os pilares do estilo de vida não mencionados. Resultados: Causas relevantes de mortes no Brasil são o infarto agudo do miocárdio (IAM), o diabetes mellitus (DM) e as doenças pulmonares obstrutivas crônicas (DPOC). Foram identificadas seis diretrizes relacionadas a essas DCNT e todas abordam aspectos do estilo de vida, mas apenas uma, referente à prevenção cardiovascular, destaca todos os seis pilares. Apesar disso, uma pesquisa bibliográfica envolvendo mais de 50 artigos mostrou que há evidências de que todos os pilares podem ajudar no controle de cada uma dessas DCNT. Conclusão: Raramente os seis pilares do estilo de vida são contemplados nas diretrizes brasileiras para IAM, DM e DPOC. A revisão da literatura identificou evidências de todos os pilares do estilo de vida para oferecer uma abordagem holística para a gestão e prevenção das DCNT.

Abstract Background: Noncommunicable diseases (NCDs), also known as chronic diseases that are long-lasting, are considered the major cause of death and disability worldwide, and the six pillars of lifestyle medicine (nutrition, exercise, toxic control, stress management, restorative sleep, and social connection) play an important role in a holistic management of their prevention and treatment. In addition, medical guidelines are the most accepted documents with recommendations to manage NCDs. Objective: The present study aims to analyze the lack of lifestyle pillars concerning the major Brazilian medical guidelines for NCDs and identify evidence in the literature that could justify their inclusion in the documents. Method: Brazilian guidelines were selected according to the most relevant causes of death in Brazil, given by the Mortality Information System, published by the Brazilian Ministry of Health in 2019. Journals were screened in the PUBMED library according to the disease and non-mentioned pillars of lifestyle. Results: Relevant causes of deaths in Brazil are acute myocardial infarction (AMI), diabetes mellitus (DM), and chronic obstructive pulmonary diseases (COPD). Six guidelines related to these NCDs were identified, and all address aspects of lifestyle, but only one, regarding cardiovascular prevention, highlights all six pillars. Despite this, a literature search involving over 50 articles showed that there is evidence that all the pillars can help control each of these NCDs. Conclusion: Rarely are the six pillars of lifestyle contemplated in Brazilian guidelines for AMI, DM, and COPD. The literature review identified evidence of all lifestyle pillars to offer a holistic approach for the management and prevention of NCDs.

Predictors of death in chronic Chagas cardiomyopathy patients with pacemaker.

BACKGROUND: Chronic Chagas cardiomyopathy (CCC) is the most serious and frequent manifestation of Chagas disease. Conduction abnormalities and bradycardia requiring pacemaker are common. The aim of this study was to determine the rate and predictors of death in CCC patients with pacemaker. METHODS: In this single-center prospective cohort study we assessed the outcome of 396 CCC patients with pacemaker, followed-up for at least 24months. All patients underwent a clinical and device assessment, 12-lead electrocardiography and echocardiography. RESULTS: During the median follow-up of 1.9years (Interquartile range 1.6-2.4), there were 65 (16.4%) deaths, yielding an annual mortality rate of 8.6%. The major cause was sudden death (33.8%), followed by heart failure (HF), 32.3%. All the investigated variables were examined as potential predictors of death. The final multivariate logistic regression model included five independent variables: advanced HF functional class (OR [odds ratio] 6.71; 95% confidence interval [95% CI] 1.95-23.2; P=0.003), renal disease (OR 5.71; 95% CI 1.80-18.0; P=0.003), QRS ≥150ms (OR 2.80; 95% CI 1.08-7.27; P=0.034), left atrial enlargement (OR 2.75; 95% CI 1.09-6.95; P=0.032) and left ventricular ejection fraction ≤43% (OR 2.31; 95% CI 1.07-4.97; P=0.032). The model had good discrimination, confirmed by bootstrap validation (optimism-adjusted c-statistic of 0.78) and the calibration curve showed a proper calibration (slope=0.972). CONCLUSIONS: CCC patients with pacemaker have a high annual mortality rate despite that the pacemaker related variables were not predictors of death. The independent predictors of death can help us to identify the poor prognosis patients.

COMBAT--conventional versus multisite pacing for bradyarrhythmia therapy: rationale of a prospective randomized multicenter study.

COMBAT is a prospective, multicenter, randomized, blinded clinical study, with crossover design. The main objective is the comparative evaluation of atrio-biventricular versus conventional atrioventricular stimulation (atrio and right ventricle) in patients with heart failure and bradycardia as the primary indication for pacemaker implantation. After successful atrio-biventricular system implantation, patients will be randomized into two groups: group A--atrioventricular conventional pacing and group B--atrio-biventricular pacing. Both groups will be programmed in DDD mode with AV delay optimized by echocardiogram. After 3 months, New York Heart Association functional class, ventricular arrhythmia density and complexity, echocardiography outcomes, 6-min hall walk distance, quality of life and peak oxygen consumption will be assessed in all patients. Then, all patients will crossover to the other pacing regimen, with an additional AV delay adjustment by echo. Patients will be followed up for another 3 months at the end of which all evaluations will be repeated. Patients will then crossover back to their original pacing regimen for a further 3 months. At the end of this 9-month period, patients will be reprogrammed according to their optimal pacing regime. In an extended follow-up, patient survival will be evaluated after 24 months of the optimal pacing therapy.

Predictors of Arrhythmic Events Detected by Implantable Loop Recorders in Renal Transplant Candidates.

BACKGROUND: The recording of arrhythmic events (AE) in renal transplant candidates (RTCs) undergoing dialysis is limited by conventional electrocardiography. However, continuous cardiac rhythm monitoring seems to be more appropriate due to automatic detection of arrhythmia, but this method has not been used. OBJECTIVE: We aimed to investigate the incidence and predictors of AE in RTCs using an implantable loop recorder (ILR). METHODS: A prospective observational study conducted from June 2009 to January 2011 included 100 consecutive ambulatory RTCs who underwent ILR and were followed-up for at least 1 year. Multivariate logistic regression was applied to define predictors of AE. RESULTS: During a mean follow-up of 424 ± 127 days, AE could be detected in 98% of patients, and 92% had more than one type of arrhythmia, with most considered potentially not serious. Sustained atrial tachycardia and atrial fibrillation occurred in 7% and 13% of patients, respectively, and bradyarrhythmia and non-sustained or sustained ventricular tachycardia (VT) occurred in 25% and 57%, respectively. There were 18 deaths, of which 7 were sudden cardiac events: 3 bradyarrhythmias, 1 ventricular fibrillation, 1 myocardial infarction, and 2 undetermined. The presence of a long QTc (odds ratio [OR] = 7.28; 95% confidence interval [CI], 2.01-26.35; p = 0.002), and the duration of the PR interval (OR = 1.05; 95% CI, 1.02-1.08; p < 0.001) were independently associated with bradyarrhythmias. Left ventricular dilatation (LVD) was independently associated with non-sustained VT (OR = 2.83; 95% CI, 1.01-7.96; p = 0.041). CONCLUSIONS: In medium-term follow-up of RTCs, ILR helped detect a high incidence of AE, most of which did not have clinical relevance. The PR interval and presence of long QTc were predictive of bradyarrhythmias, whereas LVD was predictive of non-sustained VT.

Long-term follow-up of implantable cardioverter-defibrillator for secondary prevention in chagas' heart disease.

Assessing the efficacy of implantable cardioverter-defibrillators (ICD) in patients with Chagas' heart disease (ChHD) and identifying the clinical predictors of mortality and ICD shock during long-term follow-up. ChHD is associated with ventricular tachyarrhythmias and an increased risk of sudden cardiac death. Although ChHD is a common form of cardiomyopathy in Latin American ICD users, little is known about its efficacy in the treatment of this population. The study cohort included 116 consecutive patients with ChHD and an ICD implanted for secondary prevention. Of the 116 patients, 83 (72%) were men; the mean age was 54 ± 10.7 years. Several clinical variables were tested in a multivariate Cox model for predicting long-term mortality. The average follow-up was 45 ± 32 months. New York Heart Association class I-II developed in 83% of patients. The mean left ventricular ejection fraction was 42 ± 16% at implantation. Of the 116 patients, 58 (50%) had appropriate shocks and 13 (11%) had inappropriate therapy. A total of 31 patients died (7.1% annual mortality rate). New York Heart Association class III (hazard ratio [HR] 3.09, 95% confidence interval 1.37 to 6.96, p = 0.0064) was a predictor of a worse prognosis. The left ventricular ejection fraction (HR 0.972, 95% confidence interval 0.94 to 0.99, p = 0.0442) and low cumulative right ventricular pacing (HR 0.23, 95% confidence interval 0.11 to 0.49, p = 0.0001) were predictors of better survival. The left ventricular diastolic diameter was an independent predictor of appropriate shock (HR 1.032, 95% confidence interval 1.004 to 1.060, p = 0.025). In conclusion, in a long-term follow-up, ICD efficacy for secondary sudden cardiac death prevention in patients with ChHD was marked by a favorable annual rate of all-cause mortality (7.1%); 50% of the cohort received appropriate shock therapy. New York Heart Association class III and left ventricular ejection fraction were independent predictors of worse prognosis, and low cumulative right ventricular pacing defined better survival.

Predictors of Arrhythmic Events Detected by Implantable Loop Recorders in Renal Transplant Candidates / Preditores de Eventos Arrítmicos Detectados por Loop Recorders Implantáveis em Candidatos a Transplante Renal

AbstractBackground:The recording of arrhythmic events (AE) in renal transplant candidates (RTCs) undergoing dialysis is limited by conventional electrocardiography. However, continuous cardiac rhythm monitoring seems to be more appropriate due to automatic detection of arrhythmia, but this method has not been used.Objective:We aimed to investigate the incidence and predictors of AE in RTCs using an implantable loop recorder (ILR).Methods:A prospective observational study conducted from June 2009 to January 2011 included 100 consecutive ambulatory RTCs who underwent ILR and were followed-up for at least 1 year. Multivariate logistic regression was applied to define predictors of AE.Results:During a mean follow-up of 424 ± 127 days, AE could be detected in 98% of patients, and 92% had more than one type of arrhythmia, with most considered potentially not serious. Sustained atrial tachycardia and atrial fibrillation occurred in 7% and 13% of patients, respectively, and bradyarrhythmia and non-sustained or sustained ventricular tachycardia (VT) occurred in 25% and 57%, respectively. There were 18 deaths, of which 7 were sudden cardiac events: 3 bradyarrhythmias, 1 ventricular fibrillation, 1 myocardial infarction, and 2 undetermined. The presence of a long QTc (odds ratio [OR] = 7.28; 95% confidence interval [CI], 2.01–26.35; p = 0.002), and the duration of the PR interval (OR = 1.05; 95% CI, 1.02–1.08; p < 0.001) were independently associated with bradyarrhythmias. Left ventricular dilatation (LVD) was independently associated with non-sustained VT (OR = 2.83; 95% CI, 1.01–7.96; p = 0.041).Conclusions:In medium-term follow-up of RTCs, ILR helped detect a high incidence of AE, most of which did not have clinical relevance. The PR interval and presence of long QTc were predictive of bradyarrhythmias, whereas LVD was predictive of non-sustained VT.

ResumoFundamento:A documentação de eventos arrítmicos (EA) em candidatos a transplante renal (CTR) submetidos à diálise é limitada pelo registro de eletrocardiograma convencional. Um monitoramento contínuo do ritmo cardíaco parece ser o procedimento mais adequado para a detecção automática de arritmia, contudo esse método não foi explorado anteriormente.Objetivo:O objetivo deste estudo foi investigar a incidência e os preditores de EA em CTR usando um gravador de eventos implantável, do inglês, “loop recorder implantável” (ILR).Métodos:Um estudo prospectivo observacional foi conduzido entre Junho/2009 a Janeiro/2011. Cem CTR ambulatoriais consecutivos foram submetidos ao ILR e acompanhados pelo menos por um ano. Uma regressão logística multivariada foi aplicada para definir os preditores de EA.Resultados:Durante o tempo médio de acompanhamento de 424 ± 127 dias, EA foram detectados em 98% dos pacientes, sendo que 92% deles tinham mais de um tipo de arritmia, a maioria não considerada potencialmente séria. Taquicardia atrial sustentada e fibrilação atrial ocorreram respectivamente em 7% e 13% dos pacientes; bradiarritmia em 25% e taquicardia ventricular (TV) não-sustentada ou sustentada em 57%. Ocorreram 18 óbitos, 7 por morte cardíaca súbita, 3 por bradiarritmias, 1 por fibrilação ventricular, 1 por infarto do miocárdio e 2 óbitos devido à causas desconhecidas. A presença de QTc longo (Razão de Probabilidade [RP] = 7,28; intervalo de confiança de 95% [IC] 2,01-26,35; p = 0,002) e duração do intervalo PR (RP = 1,05; IC 95%: 1,02-1,08; p < 0,001) foram associados independentemente a bradiarritmias. A dilatação ventricular esquerda (DVE) foi independentemente associada à TV não-sustentada (RP = 2,83; IC 95%: 1,01-7,96; p = 0,041).Conclusões:Em acompanhamento de médio prazo de CTR, o ILR detectou uma alta incidência de EA, a maioria sem relevância clínica. O intervalo PR e a presença de QTc longo foram preditivos de bradiarritmias e DVE de TV não‑sustentada.

ICD patients with elevated defibrillation threshold: clinical behavior and therapeutic alternatives.

BACKGROUND: The ideal programming of the implantable cardioverter defibrillator (ICD) shock energy should be at least 10J above the defibrillation threshold (DFT), requiring alternative techniques when the DFT is elevated. OBJECTIVE: To assess the clinical behavior of ICD patients with DFT>25J and the efficacy of the chosen therapy. METHODS: Patients who had undergone ICD implantation between Jan/00 and Aug/04 (prospective database) and presented intraoperative DFT>25J were selected. The analyzed variables were: clinical characteristics, LVEF, rescue of arrhythmic events from ICD and causes of deaths. RESULTS: among 476 patients, 16 (3.36%) presented DFT>25J. The mean age was 56.5 years, and 13 patients (81%) were men. According to the baseline cardiomyopathy, 09 patients had Chagas' disease, 04 had ischemic cardiomyopathy and 03 had idiopathic cardiomyopathy. Mean LVEF was 0.37 and amiodarone was used by 94% of the patients. Mean follow-up (FU) period was 25.3 months. DFT was higher than maximum energy shock (MES) in 2 patients and it was necessary to implant an additional shock electrode (array). It was programmed MES in ventricular fibrillation zone of ICD therapy in the other patients. In the FU, 03 patients had 67 successful appropriate shock therapies (AST). There were 05 noncardiac and 02 heart failure deaths. The patients who died showed higher DFT levels (p=0.044) without correlation with death because there wasn't unsuccessful AST. CONCLUSION: In this cohort of ICD patients, the occurrence of elevated DFT (>25J) was low, leading to alternative therapies. There was an association with severe ventricular dysfunction, although without correlation to the causes of death.

Functional IL18 polymorphism and susceptibility to Chronic ChagasDisease

Background: Chronic Chagas Disease cardiomyopathy (CCC), a life-threatening inflammatory dilated cardiomyopathy,affects 30% of the approximately 8 million patients infected by Trypanosoma cruzi, the restof the infected subjects remaining asymptomatic (ASY). The Th1 T cell-rich myocarditis plays a pivotalrole in CCC pathogenesis. Local expression of IL-18 in CCC myocardial tissue has recently been described.IL-18 could potentially amplify the process by inducing increased expression of IFN-c which in turn canincrease the production of IL-18, thereby creating a positive feedback mechanism. In order to assess thecontribution of the IL-18 to susceptibility to Chronic Chagas Disease, we investigated the associationbetween a single nucleotide polymorphism (SNP) located in the IL-18 gene with the risk of developingChagas cardiomyopathy.Methods and results: We analyzed the rs2043055 marker in the IL18 gene in a cohort of Chagas diseasecardiomyopathy patients (n = 849) and asymptomatic subjects (n = 202). We found a significant differencein genotype frequencies among moderate and severe CCC patients with ventricular dysfunction.Conclusions: Our analysis suggests that the IL18 rs2043055 polymorphism- or a SNP in tight linkagedisequilibrium with it- may contribute to modulating the Chagas cardiomyopathy outcome.

Efetividade do CDI na taquicardia ventricular sincopal e na parada cardíaca / ICD therapy efficacy is similar in cardiac arrest survivors and in patients with syncope due to ventricular tachycardia

Objetivo: Comparar o comportamento clínico-evolutivo de portadores de CDI por taquicardia ventricular (TV) sincopal ou parada cardíaca (PC) por TV/FV. Método: 585 pacientes foram submetidos a implante de CDI entre jan/2000 e jul/2005 para prevenção secundária de morte súbita cardíaca (MSC). Foram selecionados 415 pacientes de um banco de dados prospectivo, distribuídos em dois grupos: G1, com TV sincopal (n=318) e G2, com PC por TV/FV (n=97). As variáveis analisadas foram: idade, sexo, fração de ejeção do ventrículo esquerdo(FEVE), classe funcional de insuficiência cardíaca (CF IC), medicamentos, terapias de choque apropriadas (TCA) pelo CDI e óbitos. Para análise estatística...

Portadores de CDI com limiar de desfibrilação elevado: evolução clínica e alternativas terapêuticas / ICD patients with elevated defibrillation threshold: clinical behavior and therapeutic alternatives

FUNDAMENTO: A programação ideal da energia de choque do CDI deve ser pelo menos 10 J acima do limiar de desfibrilação (LDF), necessitando de técnicas alternativas quando o LDF é elevado. OBJETIVO: Avaliar o comportamento clínico dos portadores de CDI com LDF>25 J e a eficácia da terapêutica escolhida. MÉTODOS: Foram selecionados portadores de CDI, entre janeiro de 2000 e agosto de 2004 (banco de dados prospectivo), com LDF>25 J intra-operatório, e analisaram-se: características clínicas, FEVE, resgate de eventos arrítmicos pelo CDI e óbitos. RESULTADOS: dentre 476 pacientes, 16 (3,36 por cento) apresentaram LDF>25J. Idade média de 56,5 anos, sendo 13 pacientes (81 por cento) do sexo masculino. Quanto à cardiopatia de base 09 eram chagásicos, 04 isquêmicos e 03 com etiologia idiopática. A FEVE média dos pacientes foi 37 por cento e 94 por cento utilizavam amiodarona. O seguimento médio foi de 25,3 meses. Em 02 pacientes com LDF > Choque Máximo (CM), foi necessário implante de eletrodo de choque adicional (array), sendo mantido programação com CM em zona de FV (>182bpm) nos demais. Durante o seguimento 03 pacientes apresentaram 67 terapias de choque apropriadas (TCA) com sucesso. Ocorreram 07 óbitos sendo 5 por causas não cardíacas e 2 por insuficiência cardíaca avançada. Os pacientes que foram a óbito apresentaram níveis de LDF maiores (p=0,0446), entretanto sem relação com a causa dos mesmos tendo em vista que não ocorreram TCA sem sucesso. CONCLUSÃO: Nessa coorte de pacientes com CDI, a ocorrência de LDF elevado foi baixa, implicando terapêuticas alternativas. Houve associação com disfunção ventricular grave, entretanto sem correlação com as causas de óbito.

BACKGROUND: The ideal programming of the implantable cardioverter defibrillator (ICD) shock energy should be at least 10J above the defibrillation threshold (DFT), requiring alternative techniques when the DFT is elevated. OBJECTIVE: To assess the clinical behavior of ICD patients with DFT>25J and the efficacy of the chosen therapy. METHODS: Patients who had undergone ICD implantation between Jan/00 and Aug/04 (prospective database) and presented intraoperative DFT>25J were selected. The analyzed variables were: clinical characteristics, LVEF, rescue of arrhythmic events from ICD and causes of deaths. RESULTS: among 476 patients, 16 (3.36 percent) presented DFT>25J. The mean age was 56.5 years, and 13 patients (81 percent) were men. According to the baseline cardiomyopathy, 09 patients had Chagas' disease, 04 had ischemic cardiomyopathy and 03 had idiopathic cardiomyopathy. Mean LVEF was 0.37 and amiodarone was used by 94 percent of the patients. Mean follow-up (FU) period was 25.3 months. DFT was higher than maximum energy shock (MES) in 2 patients and it was necessary to implant an additional shock electrode (array). It was programmed MES in ventricular fibrillation zone of ICD therapy in the other patients. In the FU, 03 patients had 67 successful appropriate shock therapies (AST). There were 05 noncardiac and 02 heart failure deaths. The patients who died showed higher DFT levels (p=0.044) without correlation with death because there wasn't unsuccessful AST. CONCLUSION: In this cohort of ICD patients, the occurrence of elevated DFT (>25J) was low, leading to alternative therapies. There was an association with severe ventricular dysfunction, although without correlation to the causes of death.

Marcapasso atrioventricular. Incidência e causas de reprogramações em seguimento a longo prazo / Atrioventricular pacemaker. Incidence and causes of reprogramming in long-term follow-up

OBJECTIVE: To assess the incidence of problems requiring reprogramming of atrioventricular pacemakers in a long-term follow-up, and also the causes for this procedure. METHODS: During the period from May '98 to December '99, 657 patients were retrospectively studied, An actuarial curve for the event reprogramming of the stimulation mode was drawn. RESULTS: The follow-up period ranged from 12 to 178 months (mean = 81 months). Eighty-two (12.4 percent) patients underwent reprogramming of the stimulation mode as follows: 63 (9.5 percent) changed to VVI,(R/C); 10 (1.5 percent) changed to DVI,C; 6 (0.9 percent) changed to VDD,C; and 3 (0.5 percent) changed to DOO. The causes for the reprogramming were as follows: arrhythmia conducted by the pacemaker in 39 (37.6 percent) patients; loss of atrial sensitivity or capture, or both, in 39 (38.6 percent) patients; and microfracture of atrial electrode in 5 (4.9 percent) patients. The stimulation mode reprogramming free probability after 15 years was 58 percent. CONCLUSION: In a long-term follow-up, the atrioventricular pacemaker provided a low incidence of complications, a high probability of permanence in the DDD,C mode, and the most common cause of reprogramming was arrhythmia conducted by the pacemaker

Ressincronização cardíaca em seguimento tardio: análise de preditores de resposta clínica / Cardiac resynchronization in long-term follow up: analysis of clinical response predictors

Identificar marcadores de melhora clínica no subgrupo de pacientes com bloqueio completo de ramo esquerdo (BRE) da coorte submetida a ressincronização cardíaca (RC) no InCor-SP do HCFMUSP. Material e método: Foram analisadas características clínicas e epidemiológicas prospectivas de 121 pacientes com IC e BRE submetidos a RC. O critério de melhora clínica foi a redução de pelo menos duas classes funcionais (CF-NYHA) durante acompanhamento mínimo de seis meses. As variáveis analisadas pré e pós RC para comparação do comportamento dos grupos foram: CF-NYHA, sexo, idade, drogas, cardiopatia de base, ritmo cardíaco de base, BRE espontâneo X BRE induzido por marcapasso (troca de sistema ou primeiro implante), diâmetro diastólico final do ventrículo esquerdo (DdVE) e fração de ejeção do ventrículo esquerdo (FEVE - ecocardiograma). A análise estatística foi realizada por meio dos testes de Qui-Quadrado, exato de Fisher e regressão logística de Cox. Resultados: Houve redução de duas CF em 36 por cento dos pacientes e de uma CF em 54 por cento (inalterada em 10 por cento). Associaram-se à redução significativa da CF (análise univariada) o ritmo sinusal (p igual a 0,023), BRE espontâneo (p igual a 0,035), cardiomiopatia dilatada (CMD) (p igual a 0,03), não uso de amiodarona (p igual a 0,003) DdVE (p igual a 0,044). DdVE e CMD foram preditores independentes de melhora clínica (análise múltipla). conclusões: 1. A melhora clínica foi maior em pacientes com BRE espontâneo em relação ao BRE induzido. 2. As medidas dio DdVE e CMD discriminaram subgrupos de resposta clínica satisfatória (seguimento tardio) e foram preditores independentes deste comportamento.