6-Month Outcomes in Patients With Implantable Cardioverter-Defibrillators Undergoing Renal Sympathetic Denervation for the Treatment of Refractory Ventricular Arrhythmias.

OBJECTIVES: This study aimed to assess 6-month outcomes in patients with implantable cardioverter-defibrillators (ICDs) undergoing renal sympathetic denervation (RSD) for refractory ventricular arrhythmias (VAs). BACKGROUND: ICDs are generally indicated for patients at high risk of malignant VAs. Sympathetic hyperactivity plays a critical role in the development, maintenance, and aggravation of VAs. METHODS: A total of 10 patients with refractory VA underwent RSD. Underlying conditions were Chagas disease (n = 6), nonischemic dilated cardiomyopathy (n = 2), and ischemic cardiomyopathy (n = 2). Information on the number of ventricular tachycardia (VT)/ventricular fibrillation (VF) episodes and device therapies (antitachycardia pacing/shocks) in the previous 6 months as well as 1 and 6 months post-treatment was obtained from ICD interrogation. RESULTS: The median number of VT/VF episodes/antitachycardia pacing/shocks 6 months before RSD was 28.5 (range 1 to 106)/20.5 (range 0 to 52)/8 (range 0 to 88), respectively, and was reduced to 1 (range 0 to 17)/0 (range 0 to 7)/0 (range 0 to 3) at 1 month and 0 (range 0 to 9)/0 (range 0 to 7)/0 (range 0 to 3) at 6 months afterward, respectively. There were no major procedure-related complications. Two patients experienced sustained VT within the first week; in both cases, no further episodes occurred during follow-up. Two patients were nonresponders: 1 with persistent idioventricular rhythm and 1 with multiple renal arteries and incomplete ablation. Three patients died during follow-up. None of the deaths was attributed to VA. CONCLUSIONS: In patients with ICDs and refractory VAs, RSD was associated with reduced arrhythmic burden with no procedure-related complications. Randomized controlled trials investigating RSD for treatment of refractory VAs in patients with increased sympathetic activity are needed.

Denervação simpática renal em pacientes com cardiodesfibrilador implantável e tempestade elétrica / Renal sympathetic denervation in patients with implantable cardioverter-defibrillator and electrical storm

Introdução: Cardiodesfibriladores implantáveis (CDIs) são geralmente indicados para pacientes com arritmias malignas considerados de alto risco. A hiperatividade simpática desempenha um papel crítico no desenvolvimento, na manutenção e no agravamento de arritmias ventriculares. Novas opçõesde tratamento nessa população representam uma necessidade clínica. Nosso objetivo foi relatar osresultados de pacientes com CDIs e tempestade elétrica submetidos à denervação simpática renal paracontrole da arritmia. Métodos: Oito pacientes com CDIs internados por tempestade elétrica refratária ao tratamento médico otimizado foram submetidos à denervação simpática renal. Condições subjacentes foram: doença de Chagas (n = 6), cardiomiopatia dilatada não isquêmica (n = 1) e cardiomiopatia isquêmica (n = 1). As informações sobre o número de taquicardias ventriculares/fibrilações ventriculares e episódios de terapiasantitaquicardia na última semana pré-procedimento e nos 30 dias pós-tratamento foram obtidas por meiode interrogação dos CDIs. Resultados: As medianas dos episódios de taquicardias ventriculares/fibrilações ventriculares, sobreestimulaçãoe choques na semana que antecedeu a denervação simpática renal foram de 29 (9 a 106), 23 (2 a 94) e 7,5 (1 a 88), sendo significativamente reduzidas para 0 (0 a 12), 0 (0 a 30) e 0 (0 a 1), respectivamente, 1 mês após o procedimento (p = 0,002; p = 0,01; p = 0,003). Nenhum paciente morreu durante o acompanhamento. Não ocorreram complicações maiores relacionadas ao procedimento.Conclusões: Em pacientes com CDIs e tempestade elétrica refratária ao tratamento médico otimizado, a denervação simpática renal reduziu significativamente a carga de arritmia e, consequentemente, as sobre-estimulações e os choques. Ensaios clínicos randomizados, no contexto de denervação simpática renal para controle de arritmias cardíacas refratárias, são necessários para trazer maior robustez aos nossos achados.

Background: Implantable cardioverter-defibrillators (ICDs) are usually indicated for patients with malignant arrhythmias considered as high risk. Sympathetic hyperactivity plays a critical role in thedevelopment, maintenance, and worsening of ventricular arrhythmias. New treatment options in thispopulation represent a clinical necessity. This study’s objective was to report the outcomes of patients with ICDs and electrical storm submitted to renal sympathetic denervation for arrhythmia control. Methods: Eight patients with ICDs admitted for electrical storm refractory to optimal medical therapy underwent renal sympathetic denervation. Underlying diseases included Chagas disease (n = 6), non-ischemic dilated cardiomyopathy (n = 1), and ischemic cardiomyopathy (n = 1).Information on the number of episodes of ventricular tachycardia/ventricular fibrillation and antitachycardia therapies in the week before the procedure and 30 days after treatment were obtained through interrogation of the ICDs.Results: The median numbers of episodes of ventricular achycardia/ ventricular fibrillation,antitachycardia pacing, and shocks in the week before renal sympathetic denervation were 29 (9 to 106), 23 (2 to 94), and 7.5 (1 to 88), and significantly reduced to 0 (0 to 12), 0 (0 to 30), and 0 (0 to 1), respectively, 1 month after the procedure (p = 0.002; p = 0.01; p = 0.003, respectively). No patients diedduring follow-up. There were no major complications related to the procedure.Conclusions: In patients with ICDs and electrical storm refractory to optimal medical treatment, renal sympathetic denervation significantly reduced arrhythmia load and, consequently, antitachycardia pacing and shocks. Randomized clinical trials in the context of renal sympathetic denervation tocontrol refractory cardiac arrhythmias are needed to further support these findings.

Denervação simpática renal: um novo cateter em um novo cenário / Renal sympathetic denervation: a new catheter in a new scenario

A denervação simpática renal (DSR) surgiu como uma estratégia terapêutica adjunta no tratamento da hipertensão arterial sistêmica resistente. Diversas outras condições clínicas cursam com hiperatividade simpática, às quais, teoricamente, a DSR seria benéfica. Relatamos o primeiro caso realizado no Brasil de DSR em paciente com doença de Chagas e arritmia refratária, tratada por meio do cateter multieletrodo EnligHTN®.

Renal sympathetic denervation (RSD) has emerged as an adjunct strategy in the treatment of resistant hypertension. Several other clinical conditions are characterized by sympathetic hyperactivity and could theoretically benefit from RSD. We report the first case of RSD performed in Brazil in a patient with Chagas' disease and refractory arrhythmia, treated by the EnligHTN® multi-electrode catheter.