Adjunctive Left Atrial Posterior Wall Isolation in Treating Atrial Fibrillation: Insight From a Large Secondary Analysis.

OBJECTIVES: This study evaluated the role of adjunctive left atrium posterior wall isolation (PWI) in preventing atrial fibrillation (AF) recurrence. BACKGROUND: The left atrium posterior wall is an arrhythmogenic substrate that contributes to the development of AF. METHODS: This was an updated pooled analysis that included clinical data regarding PWI plus pulmonary vein isolation (PVI) in treating AF. The primary outcome was recurrence of atrial tachyarrhythmias. RESULTS: A total of 26 studies with 3,287 patients with AF (age 61.7 ± 10.8 years) were included. Mean follow-up was 15.2 ± 8.4 months. Procedural success to achieve PWI was 92.8%. In paroxysmal AF, adjunctive PWI did not reduce the recurrence of all atrial arrhythmias (P = 0.21) or AF (P = 0.37); however, in persistent AF, adjunctive PWI was associated with substantially lower recurrence of all atrial arrhythmias (risk ratio: 0.74; P < 0.001) and AF (risk ratio: 0.67; P = 0.01), particularly when randomized data were included. Subgroup analyses based on meta-regression demonstrated that patients with older age, a larger left atrial diameter, and persistent AF benefited more significantly from the adjunctive PWI. Adjunctive PWI using either radiofrequency or a cryoballoon reduced AF recurrence, whereas using radiofrequency seemed to be associated with higher recurrence rate of atrial tachycardias and/or atrial flutter. Non-BOX adjunctive PWI rather than BOX PWI was associated with significantly lower recurrence of AF. The incidence of procedural adverse events between the PVI+PWI (3.2%) and PVI (2.8%) groups was low and similar. PVI+PWI needed longer ablation and/or procedural time but had similar fluoroscopy time. CONCLUSIONS: Adjunctive PWI can be achieved in most patients without compromising safety. Patients with persistent AF appear to benefit from this approach. The ablation technology and/or approach may affect the clinical outcome of PWI.

Microvascular changes at different stages of chronic kidney disease.

Patients with progressing chronic kidney disease (CKD) are more likely to experience cardio- and cerebrovascular events than progressing to end-stage renal disease. The authors explored whether retinal microvascular calibers differed with the degree of renal impairment and between the standard and extended optic disk and may serve as a simple additional tool for risk stratification in this highly vulnerable patient cohort. The authors analyzed central retinal arteriolar and venular equivalent calibers (CRAE, CRVE) at different retinal zones (zone B&C) using digital retinal imaging in hypertensive patients with stage 2 (n = 66) or stage 3 CKD (n = 30). Results were adjusted for age, sex, HbA1c, and 24-hour diastolic blood pressure. Mean eGFR was 77.7 ± 8.9 and 48.8 ± 7.9 ml/min/1.73 m2 for stage 2 and 3 CKD, respectively. CRAE and CRVE in zones B and C were significantly lower in patients with stage 3 CKD compared to patients with stage 2 CKD (CRAE-B:141.1 ± 21.4 vs. 130.5 ± 18.9 µm, p = .030; CRAE-C:137.4 ± 19.4 vs 129.2 ± 18.2 µm, p = .049; CRVE-B:220.8 ± 33.0 vs. 206.0 ± 28.4 µm, p = .004; and CRVE-C:215.9 ± 33.0 vs. 201.2 ± 25.1µm, p = .003). In patients with stage 2 CKD, CRAE-B was higher than CRAE-C (141.1 ± 21.4 vs. 137.4 ± 19.4µm, p < .001). In contrast, such a difference was not found in patients with stage 3 CKD. CRAE of both retinal zones correlated with eGFR for the entire cohort. In patients with stage 3 CKD, retinal narrowing is more pronounced compared to patients with stage 2 CKD. Whether the novel observation of difference in arteriolar caliber between zones B and C in stage 2 CKD could serve as an early marker of CKD progression warrants further investigation.

Sympathetic Activation in Hypertensive Chronic Kidney Disease - A Stimulus for Cardiac Arrhythmias and Sudden Cardiac Death?

Studies have revealed a robust and independent correlation between chronic kidney disease (CKD) and cardiovascular (CV) events, including death, heart failure, and myocardial infarction. Recent clinical trials extend this range of adverse CV events, including malignant ventricular arrhythmias and sudden cardiac death (SCD). Moreover, other studies point out that cardiac structural and electrophysiological changes are a common occurrence in this population. These processes are likely contributors to the heightened hazard of arrhythmias in CKD population and may be useful indicators to detect patients who are at a higher SCD risk. Sympathetic overactivity is associated with increased CV risk, specifically in the population with CKD, and it is a central feature of the hypertensive state, occurring early in its clinical course. Sympathetic hyperactivity is already evident at the earliest clinical stage of CKD and is directly related to the progression of renal failure, being most pronounced in those with end-stage renal disease. Sympathetic efferent and afferent neural activity in kidney failure is a crucial facilitator for the perpetuation and evolvement of the disease. Here, we will revisit the role of the feedback loop of the sympathetic neural cycle in the context of CKD and how it may aggravate several of the risk factors responsible for causing SCD. Targeting the overactive sympathetic nervous system therapeutically, either pharmacologically or with newly available device-based approaches, may prove to be a pivotal intervention to curb the substantial burden of cardiac arrhythmias and SCD in the high-risk population of patients with CKD.

Efeitos da lidocaína vs. ropivacaína durante anestesia local para implantes de marcapasso / Effects of lidocaine vs. ropivacaine during local anesthesia for pacemaker implants

Introdução: A lidocaína é o anestésico local mais amplamente utilizado durante os procedimentos de implante de marcapasso, principalmente pelo seu perfil seguro e baixo custo. Atualmente, nosso grupo vem utilizando a ropivacaína no lugar da lidocaína. Essa substância é um anestésico local do tipo amida de longa duração com efeitos anestésico e analgésico, proporcionando, assim, maior conforto aos pacientes. Método: O presente estudo transversal foi realizado em 1.178 pacientes que necessitavam de implante de marcapasso dupla-câmara. Durante o implante do dispositivo eletrônico implantável, 450 pacientes foram submetidos a anestesia do músculo peitoral (direito ou esquerdo) com 20 ml de lidocaína 2% sem vasoconstritor, enquanto 728 pacientes foram submetidos a anestesia local na mesma região com 20 ml de ropivacaína 7,5%. Avaliamos o tempo de ausência da sensação dolorosa após o implante do marcapasso e a segurança relacionada ao uso de lidocaína vs. ropivacaína. Resultados: A ausência de dor após o implante avaliada em horas demonstrou que a ropivacaína promove efeito anestésico de 6,5 ± 0,4 horas ao término do procedimento, enquanto a lidocaína só foi capaz de aliviar a dor durante 2,3 ± 0,6 horas (P < 0,0001). Em relação à segurança dos fármacos, a taxa de complicação anestésica foi muito semelhante: 15 pacientes (2,03%) com utilização de ropivacaína e 12 pacientes (2,67%) com uso de lidocaína (P = 0,5482). Conclusão: A ropivacaína parece ser tão segura e mais eficaz que a lidocaína durante a anestesia local, tendo efeitos analgésicos mais prolongados após implante de dispositivos cardíacos eletrônicos implantáveis

Background: Lidocaine is the most widely used local anesthetic during pacemaker implantation procedures, mainly because of its safe profile and low cost. Currently, our group has been using ropivacaine instead of lidocaine. This substance is a long-acting amide-type local anesthetic with anesthetic and analgesic effects, thus providing greater patient comfort. Method: The present cross-sectional study was performed in 1,178 patients who required a dual-chamber pacemaker implantation. During implantation of the implantable electronic device 450 patients underwent right or left pectoral muscle anesthesia with 20 mL of 2% lidocaine without vasoconstrictor, while 728 patients underwent local anesthesia in the same region with 20 mL of 7.5% ropivacaine. We evaluated the time of absence of the pain after the implantation of the pacemaker and the safety of the use of lidocaine vs. ropivacaine. Results: The absence of post-implant pain evaluated in hours showed that ropivacaine promotes an anesthetic effect of 6.5 ± 0.4 hours at the end of the procedure, whereas lidocaine was only able to relieve pain for 2.3 ± 0.6 hours (P < 0.0001). Regarding drug safety, the rate of anesthetic complication was very similar: 15 patients (2.03%) with ropivacaine and 12 patients (2.67%) with lidocaine (P = 0.5482). Conclusion: Ropivacaine seems to be as safe and effective as lidocaine during local anesthesia and has longer analgesic effects after the implantation of implantable electronic cardiac devices

Renal sympathetic denervation guided by renal nerve stimulation to treat ventricular arrhythmia in CKD patients with ICD.

Chronic kidney disease (CKD) patients on stage 4 present greater risk rates for malignant ventricular arrhythmia events. This study examined patients with CKD in stages 1, 2, 3 and 4, left ventricular dysfunction and automatic implantable cardioverter-defibrillator (ICD). Our goal was to record the appropriate therapies, "Anti-tachycardia Therapy Pacing" (ATP) and shock events during the 18 months of follow-up and compare the incidence and severity of these at different stages of CKD, mainly in patients with CKD stage 4 underwent renal sympathetic denervation (RSD) guided by renal nerve stimulation (RNS). One hundred and fifteen patients were evaluated once every three months till 18 months of follow-up. The arrhythmic events were assessed at each follow-up visit. Comparing the groups, we can see the number of ATP and shock events recorded by ICD during 18 months of follow-up, and differences in the number of therapeutic events between the various stages of CKD. The hazard ratio (HR), 95% confidence interval (CI) and P value for ATP and shock events between all the CKD stages were evaluated by the log-rank/Mantel-Haenszel test. At the 18th month of follow-up, 75% of patients with CKD stage 4 received ATP, and 70% were treated with shock while only 20% of the subjects with CKD stage 4 that were submitted to RSD received ATP and 20% were treated with shock, P<0.0001 and P=0.0002, respectively. In our study, a decline occurred in the incidence of arrhythmias, and therefore, appropriate ICD therapies in advanced stages of CKD, reducing the risk rates for these events in patients with CKD on stage 4 after RSD guided by RNS in comparison to the other CKD stages. Our results suggest that RSD can control the higher incidence of malignant arrhythmias in advanced CKD stages.

Denervação renal simpática associada a reisolamento de veia pulmonar em pacientes com fibrilação atrial persistente de longa duração e hipertensão resistente: funciona? / Renal sympathetic denervation combined to pulmonary vein re-isolation in patients with long-standing persistent atrial fibrillation and resistant hypertension: does it work?

Relato de 5 casos de pacientes com fibrilação atrial persistente de longa duração refratários ao tratamento com fármacos antiarrítmicos e submetidos a ablação da fibrilação atrial por cateter há pelo menos 12 meses. Os pacientes apresentavam as mesmas queixas, estavam utilizando os mesmos medicamentos, eram portadores de hipertensão resistente e de outras comorbidades, e voltaram a apresentar fibrilação atrial persistente de longa duração. Todos foram submetidos a denervação renal simpática associada a reisolamento das veias pulmonares e passaram a apresentar redução significativa da pressão arterial, tanto sistólica como diastólica, aferida no consultório e por monitorização ambulatorial da pressão arterial de 24 horas após o procedimento. Mesmo após o imediato sucesso do procedimento, com recuperação do ritmo sinusal, em menos de 12 meses os pacientes tiveram recorrência de fibrilação atrial persistente. Observou-se, porém, redução do volume do átrio esquerdo 12 meses após o procedimento. Conclui-se que a denervação renal simpática foi eficaz no controle da pressão arterial, com consequente redução do volume do átrio esquerdo

Case report of 5 patients with persistent long-standing atrial fibrillation refractory to treatment with antiarrhythmic drugs undergoing atrial fibrillation ablation by catheter for at least 12 months. Patients had the same complaints, were using the same drugs, were carriers of resistant hypertension and other comorbidities and resumed persistent long-standing atrial fibrillation. All of them were submitted to renal sympathetic denervation combined to re-isolation of the pulmonary veins and had a significant systolic and diastolic blood pressure reduction, measured at the clinic and by 24-hour outpatient monitoring after the procedure. Even after the immediate success of the procedure, with the recovery of sinus rhythm, in less than 12 months patients had a recurrence of persistent atrial fibrillation. However, a reduction in the volume of the left atrium was observed 12 months after the procedure. It is concluded that sympathetic renal denervation was effective in blood pressure control with consequent reduction of left atrial volume

Doença renal crônica e fatores de risco para morte súbita cardíaca ­ denervação renal simpática: um sopro de esperança? / Chronic kidney disease and risk factors responsible for sudden cardiac death ­ renal sympathetic denervation: a whiff of hope?

Vários estudos têm demonstrado forte associação independente entre doença renal crônica e eventos cardiovasculares, incluindo morte, insuficiência cardíaca e infarto do miocárdio. Ensaios clínicos recentes estendem essa gama de eventos adversos cardiovasculares, incluindo também arritmias ventriculares e morte súbita cardíaca. Além disso, outros estudos sugerem remodelação estrutural do coração e alterações eletrofisiológicas nessa população. Esses processos podem explicar o aumento do risco de arritmia na doença renal crônica e ajudam a identificar os pacientes que possuem maior risco de morte súbita cardíaca. A hiperatividade simpática é bem conhecida por aumentar o risco cardiovascular em pacientes com doença renal crônica e é uma marca registrada do estado hipertensivo essencial, que ocorre precocemente no curso clínico da doença. Nessa afecção, a hiperatividade simpática parece ser expressa em sua fase clínica mais precoce, mostrando relação direta com a gravidade do estágio da insuficiência renal, sendo mais acentuada em sua fase terminal. A atividade nervosa simpática eferente e aferente na insuficiência renal é mediadora-chave para manutenção e progressão da doença. O objetivo desta revisão foi mostrar que o circuito fechado de realimentação do ciclo, em decorrência da hiperatividade adrenérgica, também agrava muitos dos fatores de risco responsáveis por causar morte súbita cardíaca, podendo ser um alvo potencial modificável pela denervação renal simpática percutânea. Pouco se sabe, ainda, sobre a viabilidade e a eficácia da denervação renal simpática percutânea na doença renal terminal

Several studies have shown a strong independent association between chronic kidney disease and cardiovascular events, including death, heart failure, and myocardial infarction. Recent clinical trials extend this array of adverse cardiovascular events, also including ventricular arrhythmias and sudden cardiac death. Furthermore, other studies suggest structural remodeling of the heart and electrophysiological alterations in this population. These processes may explain the increased risk of arrhythmia in kidney disease and help to identify patients who are at increased risk of sudden cardiac death. Sympathetic hyperactivity is well known to increase cardiovascular risk in chronic kidney disease patients and is typical of the essential hypertensive state that occurs early in the clinical course of the disease. In chronic kidney disease, sympathetic hyperactivity seems to be expressed at the earliest clinical stage of the disease, showing a direct relationship with the severity of renal failure, being more pronounced in the end stage of chronic kidney disease. Efferent and afferent sympathetic neural activity in kidney failure is a key mediator for the maintenance and progression of the disease. The aim of this review was to demonstrate that the feedback loop of this cycle, due to adrenergic hyperactivity, also aggravates many of the risk factors for sudden cardiac death and may be a potential target modifiable by percutaneous sympathetic renal denervation. Little is known whether it is feasible and effective in end-stage renal disease.

Registro de arritmias em pacientes com marcapassos e doença renal crônica de leve a moderada (RYCKE): resultados de um estudo de coorte observacional / Register of arrhythmias in patients with pacemakers and mild to moderate chronic kidney disease (RYCKE): results from an observational cohort study

O presente estudo examinou pacientes submetidos a implante de marcapasso dupla-câmara em decorrência de doença do nó sinusal ou bloqueio atrioventricular de 3o ou 2o graus do tipo 2 na doençarenal crônica em estágios 2, 3 e 4. O estudo teve como objetivo registrar os eventos arrítmicos durante 12 mesesde acompanhamento e comparar a incidência e a gravidade deles nas diferentes fases da doença renal crônica.Método: No total, 305 pacientes foram avaliados a cada 4 meses até 12 meses de acompanhamento. Os eventosarrítmicos foram avaliados em cada visita de acompanhamento. Resultados: Dentro do mesmo grupo de estágio da doença renal crônica não houve diferença entre as causas doença do nó sinusal e bloqueio atrioventricular, a respeito da ocorrência de qualquer arritmia. No entanto, menor incidência de taquicardia atrial/fibrilação atrial foi observada para todas as comparações entre todos os pacientes e os mesmos subgrupos em pacientes no estágio 2 (total: 58%; doença do nó sinusal: 63%; bloqueio atrioventricular: 51%), comparativamente aos estágios 3 (total:87%, P < 0,0001; doença do nó sinusal: 89%, P = 0,0020; bloqueio atrioventricular: 84%, P = 0,0019) e 4 (total: 85%, P < 0,0001; doença do nó sinusal: 81%, P = 0,0409; bloqueio atrioventricular: 90%, P < 0,0001). Em relação à taquicardia ventricular não sustentada/taquicardia ventricular sustentada, foi observada incidência mais elevada para todas as comparações entre todos os pacientes e os mesmos subgrupos em pacientes no estágio 4 (total: 32%; doença do nó sinusal: 16%; bloqueio atrioventricular: 16%), comparativamente aos estágios 3 (total: 11%, P = 0,0007; doença do nó sinusal: 9%, P = 0,0110; bloqueio atrioventricular: 14%, P = 0,0441) e 2 (total: 3%, P < 0,0001; doença do nó sinusal: 3%, P < 0,0001; bloqueio atrioventricular: 4%, P < 0,0001). Conclusão: Nossos resultados sugerem que quanto mais avançado o estágio da doença renal crônica maior a incidência de arritmias malignas...

The present study evaluated patients who had received a dual chamber pacemaker implant due to sinus node disease or 3rd/2nd degree type 2 atrioventricular block in chronic kidney disease stages 2, 3 and 4. The study was aimed at registering arrhythmic events for 12 months of follow-up and comparing their incidence and severity in different stages of chronic kidney disease. Method: Three hundred and five patients were evaluated every 4 months up to 12 months of follow-up. Arrhythmic events were assessed at each follow-up visit. Results: Within the same chronic kidney disease stage group there was no difference between the causes ofsinus node disease and atrioventricular block for the occurrence of any arrhythmia. However, a lower incidence of atrial fibrillation/tachycardia was observed for all comparisons among all patients and the same subgroups in stage 2 patients (total: 58%; sinus node disease: 63%; atrioventricular block: 51%) compared to stages 3 (total: 87%,P < 0.0001; sinus node disease: 89%, P = 0.0020; atrioventricular block: 84%, P = 0.0019) and 4 (total: 85%,P < 0.0001; sinus node disease: 81%, P = 0.0409; atrioventricular block: 90%, P < 0.0001). Regarding nonsustained/ sustained ventricular tachycardia, a higher incidence was observed for all comparisons among all patients and the same subgroups in stage 4 patients (total: 32%; sinus node disease: 16%; atrioventricular block: 16%) compared to stages 3 (total: 11%, P = 0.0007; sinus node disease: 9%, P = 0.0110; atrioventricular block: 14%, P = 0.0441) and 2 (total: 3%, P < 0.0001; sinus node disease: 3%, P < 0.0001; atrioventricular block: 4%,P < 0.0001). Conclusion: Our findings suggest that the more advanced the stage of chronic kidney disease, thegreater the incidence of malignant arrhythmias...

ICD Leads Extraction and Clearing of Access Way in a Patient With Superior Vena Cava Syndrome: Building A Tunnel.

Central vein disease is defined as at least 50% narrowing up to total occlusion of central veins of the thorax including superior vena cava, brachiocephalic, subclavian, and internal jugular vein. Thrombosis due to intravascular leads occurs in approximately 30% to 45% of patients early or late after implantation of a pacemaker by transvenous access.In this case, we report a male patient, 65-years old, hypertensive, type 2 diabetic, with atherosclerotic disease, coronary artery disease, underwent coronary artery bypass surgery in the past 10 years, having already experienced an acute myocardial infarction, bearer automatic implantable cardioverter defibrillator for 8 years after an episode of aborted sudden death due to ischemic cardiomyopathy, presenting left superior vena cava syndrome. The use of clopidogrel and rivaroxaban for over a year had no benefit on symptoms improvement.After atrial and ventricular leads extraction, a new shock lead was positioned in the right ventricle using active fixation and a new atrial lead was positioned in the right atrium, passing inside of the stents. Two days after the procedure the patient was asymptomatic and was discharged.

Heart Rate Variability Correlates to Functional Aerobic Impairment in Hemodialysis Patients.

BACKGROUND: Autonomic dysfunction (AD) is highly prevalent in hemodialysis (HD) patients and has been implicated in their increased risk of cardiovascular mortality. OBJECTIVE: To correlate heart rate variability (HRV) during exercise treadmill test (ETT) with the values obtained when measuring functional aerobic impairment (FAI) in HD patients and controls. METHODS: Cross-sectional study involving HD patients and a control group. Clinical examination, blood sampling, transthoracic echocardiogram, 24-hour Holter, and ETT were performed. A symptom-limited ramp treadmill protocol with active recovery was employed. Heart rate variability was evaluated in time domain at exercise and recovery periods. RESULTS: Forty-one HD patients and 41 controls concluded the study. HD patients had higher FAI and lower HRV than controls (p<0.001 for both). A correlation was found between exercise HRV (SDNN) and FAI in both groups. This association was independent of age, sex, smoking, body mass index, diabetes, and clonidine or beta-blocker use, but not of hemoglobin levels. CONCLUSION: No association was found between FAI and HRV on 24-hour Holter or at the recovery period of ETT. Of note, exercise HRV was inversely correlated with FAI in HD patients and controls.

Heart Rate Variability Correlates to Functional Aerobic Impairment in Hemodialysis Patients / Variabilidade RR ao Esforço Correlaciona-se com Déficit Funcional Aeróbico em Pacientes em Hemodiálise

Background: Autonomic dysfunction (AD) is highly prevalent in hemodialysis (HD) patients and has been implicated in their increased risk of cardiovascular mortality. Objective: To correlate heart rate variability (HRV) during exercise treadmill test (ETT) with the values obtained when measuring functional aerobic impairment (FAI) in HD patients and controls. Methods: Cross-sectional study involving HD patients and a control group. Clinical examination, blood sampling, transthoracic echocardiogram, 24-hour Holter, and ETT were performed. A symptom-limited ramp treadmill protocol with active recovery was employed. Heart rate variability was evaluated in time domain at exercise and recovery periods. Results: Forty-one HD patients and 41 controls concluded the study. HD patients had higher FAI and lower HRV than controls (p<0.001 for both). A correlation was found between exercise HRV (SDNN) and FAI in both groups. This association was independent of age, sex, smoking, body mass index, diabetes, and clonidine or beta-blocker use, but not of hemoglobin levels. Conclusion: No association was found between FAI and HRV on 24-hour Holter or at the recovery period of ETT. Of note, exercise HRV was inversely correlated with FAI in HD patients and controls. (Arq Bras Cardiol. 2015; [online]. ahead print, PP.0-0) .

Fundamento: A disfunção autonômica (DA) é altamente prevalente em pacientes em hemodiálise (HD) e tem sido implicada no risco aumentado de mortalidade cardiovascular. Objetivo: Correlacionar a variabilidade RR (VRR) durante o teste ergométrico (TE) com o déficit funcional aeróbico (FAI) em pacientes em HD e em um grupo controle. Métodos: Trata-se de um estudo transversal no qual as variáveis analisadas foram obtidas através de exame clínico, coleta de sangue, ecocardiograma transtorácico, Holter de 24 horas e TE. Foi realizado TE em esteira pelo protocolo de rampa, limitado por sintomas, com recuperação ativa. A VRR foi avaliada no domínio do tempo no exercício e na recuperação separadamente. Resultados: Quarenta e um pacientes em HD e 41 controles concluíram o estudo. Pacientes em HD tinham maior FAI e menor VRR do que os controles (p <0,001 para ambos). Houve correlação entre FAI e VRR no exercício (SDNN) em ambos os grupos. Esta associação foi independente de idade, sexo, tabagismo, índice de massa corporal, diabetes, clonidina, betabloqueador, mas não dos níveis de hemoglobina. Conclusão: A VRR no exercício foi inversamente correlacionada com o FAI em pacientes em HD e controles. Não foram observadas associações do FAI com VRR no Holter ou no período de recuperação do TE. .

Eficacia y seguridad de la terapia de resincronización cardíaca combinada con cardiodesfibrilador implantable para el tratamiento de la insuficiencia cardíaca: metaanálisis de 5.674 pacientes

Objetivo: el propósito de este estudio fue evaluar la eficacia y seguridad de la resincronización cardíaca agregada a la terapia con cardiodesfibrilador implantable (TRC-D) y la terapia con desfibrilador automático implantable (DAI) para el tratamiento de la insuficiencia cardíaca. A esos efectos se realizó un examen sistemático de ensayos controlados aleatorizados. Métodos y resultados: se revisaron las bases de datos de Medline, Embase y la Biblioteca Cochrane en busca de estudios publicados hasta el 31 de mayo de 2012. Se buscó también en las páginas web de clinicaltrials.gov y de la Administración de Alimentos y Medicamentos de EEUU. En el metaanálisis solo se incluyeron ensayos controlados aleatorizados que compararan la eficacia de la TRC-D con la terapia con DAI. Finalmente se incluyeron ocho ensayos controlados aleatorizados de 5.674 pacientes. El metaanálisis puso en evidencia que la terapia con TRC-D se acompañaba de una importante mejoría de las condiciones clínicas [odds ratio (OR): 1,66; 95% intervalo de confianza (IC) 1,33-2,07] y una reducción de la hospitalización (OR: 0,7; IC 95%: 0,6-0,81) y la mortalidad por todas las causas (OR: 0,8; IC 95%: 0,67-0,95). Si bien las ventajas de TRC-D con respecto a DAI resultaron obvias, los eventos adversos periimplantación de TRC-D siguen planteando inquietud. Conclusión: comparado con la terapia con DAI, los pacientes sometidos a TRC-D tienen resultados favorables en cuanto a las mejoras de las condiciones clínicas, la tasa de internaciones y la supervivencia global, pero presentan un riesgo significativamente mayor de eventos adversos periimplantación. Se requieren estudios adicionales para optimizar la aplicación clínica de TRC-D.

Aims: the purpose of this study was to evaluate the efficacy and safety of cardiac resynchronization plus implantable cardioverter defibrillator (CRT-D) therapy and implantable cardioverter defibrillator (ICD) therapy in treating heart failure by systematically reviewing randomized controlled trials. Methods and results: databases of Medline, Embase, and Cochrane Library were searched for published studies up to 31 May 2012. Clinicaltrials.gov and US Food and Drug Administration websites were searched as well. Only randomized controlled trials comparing the efficacy of CRT-D therapy with ICD therapy were enrolled in meta-analysis. Eight randomized controlled trials characterizing 5674 patients were finally included. Meta-analysis found that CRT-D therapy was associated with significant improvement in clinical conditions [odds ratio (OR): 1.66; 95% confidence interval (CI):1.33-2.07] and a reduction in hospitalization (OR: 0.7; 95% CI: 0.6 -0.81) and all-cause mortality (OR: 0.8; 95% CI: 0.67-0.95). Although advantages of CRT-D therapy over ICD therapy were obvious, the peri-implantation adverse events of CRT-D therapy remained to be concerns. Conclusion: compared with ICD therapy, patients receiving CRT-D therapy have favourable outcomes regarding improvement in clinical conditions, hospitalization rate, and overall survival, but at a significantly higher risk of peri-implantation adverse events. Future studies are warranted to optimize the clinical application of CRT-D.