471 Arrhythmia-free survival in early-persistent atrial fibrillation patients undergoing radiofrequency catheter ablation

Abstract Aims Despite advances in success rate of paroxysmal atrial fibrillation (PAF) ablation, outcomes of radiofrequency catheter ablation (RFCA) in patients with persistent AF are highly variable. Early persistent AF (EPsAF) is defined as AF that is sustained beyond 7 days but is less than 3 months in duration. Arrhythmia-free survival data after RFCA in this specific population are still limited. We sought to report the outcomes of RFCA in the subgroup of patients with EPsAF, compared to those with PAF and with 'late' persistent AF (LPsAF) lasting between 3 and 12 months. Methods and results Data from 1143 consecutive AF patients receiving their first RFCA were prospectively collected. Patients with EPsAF (n = 190) were compared with PAF (n = 531) and LPsAF (n = 422) patients. All patients received pulmonary vein antrum isolation + posterior wall and sustained non-pulmonary vein (PV) trigger ablation. Non-sustained non-PV triggers were ablated based on operator discretion. Non-PV triggers were defined as sites of firing leading to sustained (>30 s) or non-sustained arrhythmias (<30 s, including premature atrial contractions ≥10 beats/min) with earliest activation outside the PVs. Mean age of the population was 64 ± 11 years. Female patients were more in PAF group (39%) compared to EPsAF (26%) and LPsAF (28%) (P < 0.001). There was no difference in other clinical characteristics among populations. Non-PV triggers were detected more in EPsAF [127 (66.8%)], and LPsAF [296 (70.1%)] patients compared to PAF [185 (34.8%)] (P < 0.001).One-year arrhythmia-free survival rate after a single procedure was 75.0% (398), 74.2% (141), and 64.5% (272) in PAF, EPsAF, and LPsAF, respectively. Success rate was significantly higher in PAF {[HR: 0.67 (0.53, 0.84), P = 0.001] and EPsAF [HR: 0.67 (0.49, 0.93)], P = 0.015} compared to LPsAF. Conclusions In patients with EPsAF, RFCA may result in significantly better freedom from atrial arrhythmias, compared to LPsAF. In this cohort, ablation might be reasonable as first line approach to improve outcomes and prevent AF progression

Ablation of Stable VTs Versus Substrate Ablation in Ischemic Cardiomyopathy the VISTA Randomized Multicenter Trial

Background Catheter ablation reduces ventricular tachycardia (VT) recurrence and implantable cardioverter defibrillator shocks in patients with VT and ischemic cardiomyopathy. The most effective catheter ablation technique is unknown. Objectives This study determined rates of VT recurrence in patients undergoing ablation limited to clinical VT along with mappable VTs ("clinical ablation") versus substrate-based ablation. Methods Subjects with ischemic cardiomyopathy and hemodynamically tolerated VT were randomized to clinical ablation (n = 60) versus substrate-based ablation that targeted all "abnormal" electrograms in the scar (n = 58). Primary endpoint was recurrence of VT. Secondary endpoints included periprocedural complications, 12-month mortality, and rehospitalizations. Results At 12-month follow-up, 9 (15.5%) and 29 (48.3%) patients had VT recurrence in substrate-based and clinical VT ablation groups, respectively (log-rank p < 0.001). More patients undergoing clinical VT ablation (58%) were on antiarrhythmic drugs after ablation versus substrate-based ablation (12%; p < 0.001). Seven (12%) patients with substrate ablation and 19 (32%) with clinical ablation required rehospitalization (p = 0.014). Overall 12-month mortality was 11.9%; 8.6% in substrate ablation and 15.0% in clinical ablation groups, respectively (log-rank p = 0.21). Combined incidence of rehospitalization and mortality was significantly lower with substrate ablation (p = 0.003). Periprocedural complications were similar in both groups (p = 0.61). Conclusions An extensive substrate-based ablation approach is superior to ablation targeting only clinical and stable VTs in patients with ischemic cardiomyopathy presenting with tolerated VT

Catheter ablation of atrial fibrillation: Randomized controlled trials and registries, a look back and the view forward

Atrial fibrillation (AF) is a growing epidemic associated with a variety of adverse outcomes, including death, stroke, impaired quality of life, and increased rate of hospitalizations. Achieving a definite cure for this disease is highly desirable, as this would have outstanding social and economic implication. Catheter ablation is the only treatment demonstrated capable of eliminating AF in a substantial proportion of patients. Over the years, intense research has been directed toward the identification of the optimal ablation strategy, with the aim of increasing procedural success while minimizing complications. Multiple clinical trials have established pulmonary vein antrum isolation (PVAI) as the mainstay of treatment for paroxysmal AF patients. In these patients, the addition of superior vena cava isolation has been demonstrated to increase long-term freedom from AF recurrence compared to PVAI alone. In patients with persistent and long-standing persistent AF, a more extensive set of lesions targeting the entire left atrial posterior wall and complex fractionated electrograms (CFAE) is necessary, while those presenting for redo procedure may also benefit from ablation of other trigger sites of AF initiation, such as the left atrial appendage. With regard to safety, the most notable advances have been the introduction of open-irrigated ablation catheters and of ablation without interruption of oral anticoagulation. Both strategies have been demonstrated to reduce dramatically periprocedural thromboembolic complications, without increasing the risk of bleeding. Beyond outstanding advances in defining the optimal ablation strategies to increase the effectiveness and safety of catheter ablation, in recent years outcomes of AF treatment trials have been widely reconsidered. In addition to the prevention of AF recurrence, additional end-points have been considered important. These include reduction of hospitalization, stroke, and mortality, as well as economic factors. A correct evaluation of such end-points has required the introduction of AF ablation registries, and the design of new trials with adequate power to address such issues. This article will provide an overview of AF ablation trials that have constituted the basis for current clinical practice and will discuss the contribution of ongoing studies and registries to the future of AF ablation. © 2011 Springer Science+Business Media, LLC

Novel single-nucleotide polymorphisms predict the risk of recurrence in patients with atrial fibrillation undergoing catheter ablation

background: Genome-wide association studies have identified several atrial fibrillation (AF)-associated single-nucleotide polymorphisms (SNPs). This study tested the hypothesis that selected SNPs are linked with AF recurrence following catheter ablation. Methods: Four hundred AF patients (67% male, 62\ub112 year, left atrial size 45.3\ub17 mm, 64% non-paroxysmal) undergoing catheter ablation were prospectively enrolled. DNA extraction and genotyping for AF-associated SNPs, rs6843082 and rs1448817 were performed from collected blood samples using Qiagen QiaAMP kit and TaqMan assay respectively. Three hundred seventy-two DNA samples were available for genotyping. Multivariate logistic regression analysis (adjusted covariates: age, gender, non-paroxysmal AF, hypertension and diabetes) was used for assessing predictive role of individual SNP with AF recurrence and false discovery rate (FDR) was computed for the candidate SNPs to address multiple testing. Patients were followed up for 1 year. Recurrence was defined as any episode of AF/ Aflutter/ AT lasting >30 seconds and was acquired by event-recorder for the first 5 months followed by series of 7-day Holter recordings at 3 months interval. results: Of 371, 207 patients (55.8%) experienced recurrence after the first procedure. In the overall AF population, rs6843082 showed significant inverse association (OR 0.536 [95%CI 0.338-0.849], p=0.008) with arrhythmia recurrence whereas rs1448817 predicted increased risk of post-ablation recurrence (OR 1.761 [95%CI 1.112-2.788], p=0.016). FDR was controlled at 1.58% for both SNPs to adjust for multiple testing. Conclusion: Our study identified two novel SNPs, rs6843082 and rs1448817 on chromosome 4q25 that are associated with the risk for arrhythmia recurrence after catheter ablation for AF; while rs6843082 confers lower risk; rs1448817 predicts increased chance of recurrence. This finding provides possible evidence of differential influence of the two SNPs on the nearby functional genes in modulating ablation outcome in atrial fibrillation patients