Francisca Tatiana Moreira Pereira

Long-Term Follow-Up of Patients with Chronic Chagas Disease and Implantable Cardioverter-Defibrillator

Chronic Chagas heart disease (ChHD) is associated with ventricular tachyarrhythmias and an increased risk of sudden cardiac death. Little is known about the effectiveness of implantable cardioverter‐defibrillator (ICD) therapy in this population. The objective of this study was to evaluate the efficacy of ICD in patients with ChHD and to identify predictors of mortality and appropriate ICD shocks.

Clinical Course After Cardioverter-Defibrillator Implantation: Chagasic Versus Ischemic Patients

Background: The outcome of Chagas disease patients after receiving implantable cardioverter defibrillator (ICD) is still controversial. Objective: To compare clinical outcomes after ICD implantation in patients with chronic Chagas cardiomyopathy (CCC) and ischemic heart disease (IHD). Methods: Prospective study of a population of 153 patients receiving ICD (65 with CCC and 88 with IHD). The devices were implanted between 2003 and 2011. Survival rates and event-free survival were compared. Results: The groups were similar regarding sex, functional class and ejection fraction. Ischemic patients were, on average, 10 years older than CCC patients (p < 0.05). Patients with CCC had lower schooling and monthly income than IHD patients (p < 0.05). The number of appropriate therapies was 2.07 higher in CCC patients, who had a greater incidence of appropriate shock (p < 0.05). Annual mortality rate and electrical storm incidence were similar in both groups. There was no sudden death in CCC patients, and only one in IHD patients. Neither survival time (p = 0.720) nor event-free survival (p = 0.143) significantly differed between the groups. Conclusion: CCC doubles the risk of receiving appropriate therapies as compared to IHD, showing the greater complexity of arrhythmias in Chagas patients.

Who Are the Super-Responders to Cardiac Resynchronization Therapy?

Fundamento: Pacientes submetidos a ressincronizacao cardiaca podem evoluir com padroes de resposta acima do esperado, com normalizacao dos parâmetros clinicos e ecocardiograficos. Objetivo: Analisar as caracteristicas clinicas e ecocardiograficas desta populacao de super-respondedores, comparando-as com os demais pacientes submetidos a terapia de ressincronizacao cardiaca. Metodos: Estudo de coorte observacional, prospectivo, envolvendo 146 pacientes, consecutivamente submetidos a implantes de ressincronizador cardiaco. Para comparacao das variaveis, foram realizados o teste exato de Fisher e o teste de Mann-Whitney. Foram considerados super-respondedores os pacientes com fracao de ejecao > 50 % e classe funcional I/II (New York Heart Association) apos 6 meses da terapia de ressincronizacao cardiaca. Resultados: A idade media foi de 64,8 ± 11,1 anos, sendo 69,8% do sexo masculino, com mediana da fracao de ejecao de 29%, sendo 71,5% com bloqueio de ramo esquerdo, 12% com bloqueio de ramo direito associado a bloqueios divisionais; 16,3% com marca-passo cardiaco definitivo, 29,3% com miocardiopatia isquemica, 59,4% com miocardiopatia dilatada e 11,2% com miocardiopatia chagasica. Foram observados 24 (16,4%) super-respondedores, sendo que 13 (8,9%) apresentaram normalizacao da fracao de ejecao, dos diâmetros diastolicos do ventriculo esquerdo e da classe funcional. Quando comparados com os pacientes nao super-respondedores, em relacao as caracteristicas pre-implante, os super-respondedores apresentaram-se mais no sexo feminino (58,3% vs. 22,8%; p = 0,002), maior indice de massa corporal (26,8 vs. 25,5; p = 0,013), maior fracao de ejecao basal (31,0 vs. 26,9; p = 0,0003) e menores diâmetros diastolicos do ventriculo esquerdo (65,9 mm vs. 72,6 mm; p = 0,0032). Dez pacientes (41,6% dos super-respondedores) com bloqueio de ramo direito e bloqueio divisional evoluiram como super-respondedores, entretanto apenas um paciente com doenca de Chagas e apenas na primeira avaliacao. Conclusoes: Os super-respondedores apresentaram cardiopatia de base menos avancada e sem diferencas em relacao ao tipo de disturbio de conducao basal. Pacientes com bloqueio de ramo direito e bloqueio divisional, mas sem cardiopatia chagasica podem tambem evoluir como super-respondedores.

Development and Validation of Predictive Models of Cardiac Mortality and Transplantation in Resynchronization Therapy

Background 30-40% of cardiac resynchronization therapy cases do not achieve favorable outcomes. Objective This study aimed to develop predictive models for the combined endpoint of cardiac death and transplantation (Tx) at different stages of cardiac resynchronization therapy (CRT). Methods Prospective observational study of 116 patients aged 64.8 ± 11.1 years, 68.1% of whom had functional class (FC) III and 31.9% had ambulatory class IV. Clinical, electrocardiographic and echocardiographic variables were assessed by using Cox regression and Kaplan-Meier curves. Results The cardiac mortality/Tx rate was 16.3% during the follow-up period of 34.0 ± 17.9 months. Prior to implantation, right ventricular dysfunction (RVD), ejection fraction < 25% and use of high doses of diuretics (HDD) increased the risk of cardiac death and Tx by 3.9-, 4.8-, and 5.9-fold, respectively. In the first year after CRT, RVD, HDD and hospitalization due to congestive heart failure increased the risk of death at hazard ratios of 3.5, 5.3, and 12.5, respectively. In the second year after CRT, RVD and FC III/IV were significant risk factors of mortality in the multivariate Cox model. The accuracy rates of the models were 84.6% at preimplantation, 93% in the first year after CRT, and 90.5% in the second year after CRT. The models were validated by bootstrapping. Conclusion We developed predictive models of cardiac death and Tx at different stages of CRT based on the analysis of simple and easily obtainable clinical and echocardiographic variables. The models showed good accuracy and adjustment, were validated internally, and are useful in the selection, monitoring and counseling of patients indicated for CRT.

Echocardiographic Predictors of Worse Outcome After Cardiac Resynchronization Therapy

Background Cardiac resynchronization therapy (CRT) is the recommended treatment by leading global guidelines. However, 30%-40% of selected patients are non-responders. Objective To develop an echocardiographic model to predict cardiac death or transplantation (Tx) 1 year after CRT. Method Observational, prospective study, with the inclusion of 116 patients, aged 64.89 ± 11.18 years, 69.8% male, 68,1% in NYHA FC III and 31,9% in FC IV, 71.55% with left bundle-branch block, and median ejection fraction (EF) of 29%. Evaluations were made in the pre-implantation period and 6-12 months after that, and correlated with cardiac mortality/Tx at the end of follow-up. Cox and logistic regression analyses were performed with ROC and Kaplan-Meier curves. The model was internally validated by bootstrapping. Results There were 29 (25%) deaths/Tx during follow-up of 34.09 ± 17.9 months. Cardiac mortality/Tx was 16.3%. In the multivariate Cox model, EF < 30%, grade III/IV diastolic dysfunction and grade III mitral regurgitation at 6-12 months were independently related to increased cardiac mortality or Tx, with hazard ratios of 3.1, 4.63 and 7.11, respectively. The area under the ROC curve was 0.78. Conclusion EF lower than 30%, severe diastolic dysfunction and severe mitral regurgitation indicate poor prognosis 1 year after CRT. The combination of two of those variables indicate the need for other treatment options.