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

Does periprocedural anticoagulation management of atrial fibrillation affect the prevalence of silent thromboembolic lesion detected by diffusion cerebral magnetic resonance imaging in patients undergoing radiofrequency atrial fibrillation ablation with open irrigated catheters? Results from a prospective multicenter study

BackgroundSilent cerebral ischemia (SCI) has been reported in 14% of cases after catheter ablation of atrial fibrillation (AF) with radiofrequency (RF) energy and discontinuation of warfarin before AF ablation procedures.ObjectiveThe purpose of this study was to determine whether periprocedural anticoagulation management affects the incidence of SCI after RF ablation using an open irrigated catheter.MethodsConsecutive patients undergoing RF ablation for AF without warfarin discontinuation and receiving heparin bolus before transseptal catheterization (group I, n = 146) were compared with a group of patients who had protocol deviation in terms of maintaining the therapeutic preprocedural international normalized ratio (patients with subtherapeutic INR) and/or failure to receive pretransseptal heparin bolus infusion and/or ≥2 consecutive ACT measurements <300 seconds (noncompliant population, group II, n = 134) and with a group of patients undergoing RF ablation with warfarin discontinuation bridged with low molecular weight heparin (group III, n = 148). All patients underwent preablation and postablation (within 48 hours) diffusion magnetic resonance imaging.ResultsSCI was detected in 2% of patients (3/146) in group I, 7% (10/134) in group II, and 14% (21/148) in group III (P <.001). “Therapeutic INR” was strongly associated with a lower prevalence of postprocedural silent cerebral ischemia (SCI). Multivariable analysis demonstrated nonparoxysmal AF (odds ratio 3.8, 95% confidence interval 1.5–9.7, P = .005) and noncompliance to protocol (odds ratio 2.8, 95% confidence interval 1.5–5.1, P <.001] to be significant predictors of ischemic events.ConclusionStrict adherence to an anticoagulation protocol significantly reduces the prevalence of SCI after catheter ablation of AF with RF energy

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

478 Clinical outcomes of patients at very high stroke risk undergoing watchman implantation

Abstract Aims Left atrial appendage occlusion (LAAO) with the Watchman device is an effective alternative to oral anticoagulation in patients with non-valvular atrial fibrillation at high thromboembolic risk. We sought to evaluate the safety and effectiveness of LAAO for stroke and bleeding prevention in patients at very high stroke risk. Methods and results Data were extracted from a prospective database of 488 AF patients who underwent LAA closure with a Watchman device. Periprocedural complications, thromboembolic (TE), and bleeding event rates among patients with a CHA2DS2-VASc ≥ 5 were reported. Predicted annual rates of TE or major bleeding events were compared to the annualized observed risk of the population. Overall, 209 patients with a CHA2DS2-VASc ≥5 (CHA2DS2-VASc: 6.0 ± 1.0; HAS-BLED: 3.7 ± 1.1) were included in the study. The mean age was 78 ± 6 years and 52.2% (n = 109) were males. Watchman implantation was successful in all patients. Overall procedure-related complication rate was 3.3% (n = 7). Two major complications were observed (1.0%): one pericardial tamponade requiring surgery and one major bleeding event at 3 days post-procedure. The incidence of minor complications was 2.3% (n = 5). Specifically, two patients experienced a pericardial effusion that required drainage and three had a groin hematoma. During a mean follow-up duration of 12 ± 5 months (193 pt/years), six TE events (2.9%/annualized rate: 3.1%) were documented after a median of 6.3 months (IQR: 2.2–9.6). Based on the estimated annual TE risk according to the CHA2DS2-VASc score (8.5%), the % risk reduction after LAAO was 63.5%. Four major bleeding events [1.9% (median time to event: 2.1 months; IQR: 1.0–3.4)] and five minor bleeding events occurred (2.5%) during follow-up. Compared to the expected rate of bleeding events as assessed by the HAS-BLED of the population (8.03%), LAAO led to a 42% reduction of bleeding risk. Conclusions In a population at very high TE risk, LAAO with the Watchman device was a safe and effective approach, and led to a 63.5% of stroke risk

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