Ablation Strategy For Atrial Fibrillation Research Articles

Effectiveness and safety of single transseptal ablation for atrial fibrillation in real-word practice.

BackgroundWe have previously reported that unilateral groin‐single transseptal (ST) ablation in patients with paroxysmal atrial fibrillation (AF) was safe and significantly reduced patient discomfort compared with bilateral groin‐double transseptal (DT) ablation.HypothesisIn the present study, we hypothesized that ST ablation would be as effective and safe as DT ablation in real‐world practice like previous study. Among the 1765 consecutive patients in the Yonsei AF ablation cohort from October 2015 to January 2020, 1144 patients who underwent radiofrequency ablation were included for the analysis. Among them, 450 underwent ST ablation and 694 underwent DT ablation.ResultsThe total procedure time, ablation time, and fluoroscopy time were longer in the ST group than in the DT group (p < .05 for all). The hospital stay after catheter ablation was 1.3 ± 1.1 days which was longer in DT group than ST group (p = .001). No significant difference was observed in the complication rate (p = .263) and AF‐free survival rate (log‐rank p = .19) between the groups. However, after excluding patients who used antiarrhythmic drugs when AF recurred, the AF‐free survival rates were lower in the DT group than in the ST group before and after propensity score matching (log‐rank p = .026 and .047, respectively).ConclusionAlthough the ST approach increases the procedure time compared with the DT approach owing to the need for more frequent catheter exchanges, the ST approach is a feasible and safe strategy for AF ablation in terms of rhythm outcomes and risk of complications.

Abstract 12970: High Power Short Duration and Low Power Long Duration in Atrial Fibrillation Ablation: A Systematic Review and Meta-analysis

Background: Although high power, shorter duration (HPSD) ablation and low power, longer duration (LPLD) ablation strategies for atrial fibrillation (AF) are frequently advocated to enhance safety and efficacy, there exists a need for comparative data from large populations. We performed a meta-analysis to compare arrhythmia-free survival, procedure time and complications rates between the two strategies. Methods: We searched the databases of MEDLINE and EMBASE from inception to April 2020. Included studies were case-control studies, cohort studies, or randomized controlled trials that compared patients undergoing HPSD and LPLD strategies for AF ablation and reported either of the following outcomes: freedom from atrial tachyarrhythmia (AT) including AF and atrial flutter, procedure time, or periprocedural complications. Data from each study were combined using the random-effects model to calculate odds ratio (OR) and weighted mean difference (WMD) with 95% confidence interval (CI). Results: Ten studies from 2006 to 2020 involving 2,189 patients were included (1,350 patients underwent HPSD strategy and 839 patients underwent LPLD strategy). Both HPSD and LPLD strategies resulted in a similar freedom from AT at 12-month follow-up (OR=1.36, 95% CI:0.91-2.04, p=0.13, Figure 1A). HPSD strategy did result in a significant reduction in total procedure time (WMD=47.34, 95% CI:29.47-65.21, p&lt;0.001, Figure 1B) compared to LPSD. HPSD wasn’t associated with reduction in esophageal ulcer/arterioesophageal fistula (OR=0.35, 95%CI=0.12-1.06, p=0.06) or pericardial effusion/cardiac tamponade (OR=0.96, 95%CI: 0.24-3.79, p=0.95) Conclusions: In this large meta-analysis both LPLD and HPSD are equally effective and safe. Although HPSD is often advocated to reduce esophageal injury, risk was similar between approaches. However, HPSD strategy significantly lowers procedure times.

Abstract 16499: Hybrid Cryoballoon Pulmonary Vein Isolation and Radiofrequency Posterior Wall Isolation for Persistent Atrial Fibrillation

Introduction: Catheter ablation of persistent atrial fibrillation (AF) is associated with less successful outcomes compared to paroxysmal AF. The optimal ablation strategy for persistent AF is not well established. We report our center’s experience utilizing a hybrid ablation approach of cryoballoon (CB) pulmonary vein isolation (PVI) followed by radiofrequency (RF) left atrial posterior wall isolation (LAPWI). Methods: 134 patients with persistent AF who underwent catheter ablation between 2016 and 2019 at our center were retrospectively reviewed. Patients with congenital heart disease or prior left atrial ablation or surgery were excluded. Hybrid ablation (n=62) consisted of CB PVI followed by RF roof and floor lines resulting in LAPWI. The control group (n=72) had PVI ±LAPWI with either CB (n=38) or RF (n=34). Outcomes were monitored with office visits and 7-day Holter monitors at 3, 6, 12, and 24 months post-ablation. The primary endpoint was freedom from any documented atrial tachyarrhythmia over 30 seconds. Results: Concomitant atrial flutter ablation was performed in 19/62 (31%) and 5/72 (7%) of hybrid and control cases, respectively. There was no significant difference in procedure time, however fluoroscopy time was shorter with hybrid ablation compared to control (p&lt;.01). 18-month freedom from atrial tachyarrhythmias was 70.4% with hybrid ablation and 51.6% with PVI±LAPWI with a single energy source (p=.048). Among those with recurrence, mean AF burden was significantly lower with hybrid ablation (7%) than with a single-energy approach (60%). Conclusion: In this single center experience with multiple operators, hybrid CB-RF PVI and LAPWI reduced AF recurrence (incidence and burden) compared to PVI±LAPWI with a single energy source.

Abstract 15553: The Long-term Outcome Beyond Pulmonary Vein Isolation of Ablation Guided by the Online and Real-time Atrial Fibrillation Imaging System: Extra Mapping Project

Introduction: Although modulation of atrial fibrillation (AF) drivers and/or substrates has been proposed as one of the effective ablation strategies for non-paroxysmal AF (Non-PAF), previous meta-analyses showed that ablation, targeting complex fractionated atrial electrogram (CFAE) indirectly-reflecting Non-PAF drivers, had no additional benefit for post-pulmonary vein isolation (PVI) Non-PAF. As an alternative ablation strategy for Non-PAF, rotor ablation has been proposed as one of the potentiated ablation strategies for Non-PAF. However, the optimal ablation strategy is still unclear because reliable method detecting AF drivers remain unsettled in clinical practice. Hypothesis: Because rotors are known as key mechanisms for Non-PAF, we might open the possibility of Non-PAF control by the real-time visualization of wave dynamics during AF ablation. Methods: Consecutive 140 Non-PAF patients were enrolled in this study. The clinically-available online and real-time AF imaging system with high-spatiotemporal density (ExTRa Mapping TM ) developed by our group was applied in case Non-PAF was remained after PVI. Then, we detected and ablated non-passively-activated areas where rotational activations in the form of meandering rotors and/or multiple wavelets assumed to contain Non-PAF drivers were frequently observed (figure, top). The recurrence rate of Non-PAF or atrial tachycardia (AT) after the ablation was compared to that in patients underwent PVI-alone at our hospital. Results: The propensity scores selected each 34 people from ExTRa-strategy group and PVI-alone group (figure, middle). The 24-month freedom ratio from Non-PAF/AT in the matched-ExTRa-strategy group was higher than the matched-PVI-alone group, which was close to significance (p = 0.056) (figure, bottom). Conclusion: The ExTRa Mapping-guided ablation for PVI-refractory Non-PAF might be superior to PVI-alone.

Comparing efficacy and safety in catheter ablation strategies for atrial fibrillation: protocol of a network meta-analysis of randomised controlled trials

IntroductionAtrial fibrillation (AF) is the most common sustained arrhythmia. Catheter ablation (CA) of AF is an increasingly offered therapeutic approach, primary to relieve AF-related symptoms. Despite the development of new...

The impact of left atrium size on selection of the pulmonary vein isolation method for atrial fibrillation: Cryoballoon or radiofrequency catheter ablation

Pulmonary vein isolation (PVI) is the cornerstone of ablation strategies for atrial fibrillation (AF), and noninferiority of cryoballoon (CB) over radiofrequency (RF) ablation has been previously reported. One of the risk factors of recurrence is left atrium (LA) enlargement. This study aimed to analyze the impact of LA enlargement on the selection of CB or RF ablation for AF patients. A total of 2,224 AF patients (64.4 ± 10.7 years, 65.5% male) who underwent PVI were analyzed retrospectively. Left atrial diameter (LAD) and volume (LAV) were measured using echocardiography before the procedures. LA enlargement was defined as LAD ≥40 mm and LAV index (LAVI) ≥35 mL/m2. Patients undergoing CB and RF ablation were propensity score matched, and 376 matched pairs were evaluated. Cox proportional hazard analysis revealed that LAD (95% CI, 1.01-1.05), LAV (95% CI, 1.01-1.02), and LAVI (95% CI, 1.01-1.03) were independent predictors of recurrence. CB showed equivalent clinical outcomes to those of RF with shorter procedure time required for patients without LA enlargement. CB was inferior to RF in patients with LA enlargement (LAD, 74.5% vs 84.6%, P = .028; LAVI, 74.7% vs 83.4%, P = .015), and large LAVI was associated with a higher prevalence of non-PV foci (35% vs 29%, P = .008). CB ablation may be recommended for patients without enlarged LA based on the short procedure time and efficacy, whereas RF would be more appropriate in large LAs. LAVI may be a valuable reference to predict PVI outcomes and in selecting the ablation method.

Atrial fibrillation ablation strategies and technologies: past, present, and future.

Catheter ablation is an established treatment option for atrial fibrillation (AF), and pulmonary vein isolation (PVI) has become the gold standard in AF ablation. AF recurrence after PVI remains an important clinical problem. Recovery of conduction from the pulmonary veins (PVs) is considered the dominant mechanism for AF recurrence in paroxysmal AF. However, the underlying mechanism of AF recurrence after PVI is more complex in patients with persistent and longstanding persistent AF. Different ablation technologies and energy sources have been developed aimed at improving lesion quality and durability with an acceptable safety profile. Novel technologies are under evaluation which have a great potential to produce permanent PVI after a single ablation procedure. However, clinical value of these novel devices needs to be tested in adequately powered randomized controlled trials. In this article, we review the history of catheter ablation for AF and discuss the present and future ablation technologies.

Fractionated Mapping-Guided Ablation Strategy in Patients with Long-Standing Persistent Atrial Fibrillation: a Case Series

Although pulmonary vein isolation (PVI) remains the cornerstone of ablation for paroxysmal atrial fibrillation (AF), optimal ablation strategy for long-standing persistent AF (LSPAF) remains unclear. This article presents two patients with LSPAF in whom acute AF termination was achieved during ablation by using fractionated-guided extended PVI, posterior wall isolation, and mitral isthmus.

Catheter vs thoracoscopic ablation for atrial fibrillation: Meta-analysis of randomized trials.

BackgroundWe meta‐analyzed the efficacy and safety of catheter (CA) vs thoracoscopic (TA) ablation for atrial fibrillation (AF).MethodsPubMed, Embase, and Cochrane databases were searched until 31/12/2019 for relevant randomized trials and subsequent pooled analyses.ResultsIn six trials totaling 465 patients (254 CA/211 TA), 1‐year AF recurrences were higher for CA (46% vs 26%, odds ratio 2.90 [95% CI 1.32‐6.38]), whereas total adverse events were lower (10% vs 25%, 0.35 [0.14‐0.86], respectively).ConclusionCA has lower efficacy but higher safety than TA. CA should remain the first‐line AF ablation strategy, and TA reserved for selected CA‐resistant patients where rhythm control is clinically necessary.

Esophageal visualization changes atrial fibrillation ablation strategy: from encircling to segmental approach.

Esophageal visualization changes atrial fibrillation ablation strategy: from encircling to segmental approach.

Results of a survey concerning atrial fibrillation ablation strategies in Poland.

Catheter ablation is an effective treatment for patients with atrial fibrillation (AF). Despite the increasing availability of the procedure, current treatment patterns of invasive AF treatment in Poland are unknown. The aim of the study was to assess data on the contemporary approaches to AF ablation in Poland, such as: target population, patients' characteristics, ablation techniques, procedural results, and complication rates. The survey including 36 questions was conducted among 38 representatives of Polish electrophysiology centers performing AF catheter ablation to test the methods and outcomes in their laboratories. The survey was conducted among 38 out of 69 Polish electrophysiology centers performing AF ablation. There were 88 ablation laboratories in 2018 in Poland. They have performed 16 566 ablations, of which 6680 were AF ablations, according to the Polish National Health Fund data. Therefore, 3745 AF ablations analyzed in this study constituted 22.6% of all ablations and 56% of AF ablations performed in Poland in 2018.Paroxysmal AF was the most common type of AF in all surveyed centers. In 69% of the centers, the preferred method was cryoballoon ablation and in 31%, radiofrequency point‑by‑point circumferential pulmonary vein isolation. The reported complication rate was low (6.4%), with localadverse events being the most frequent. The mean reported incidence of atrial flutter or tachycardia after ablation was low (5%). Repeated procedures were performed mainly with radiofrequency ablation (89%). Procedural techniques and the type of venous access did not vary between the centers. Paroxysmal AF was the most common indication for percutaneous ablation of that arrhythmia in Polish electrophysiology laboratories. The preferred method was cryoballoon ablation.

Adjunctive percutaneous ablation targeting epicardial arrhythmogenic structures in patients of atrial fibrillation with recurrence after multiple procedures.

Repeat ablation strategy for atrial fibrillation (AF) recurrence after multiple ablation procedures is known to be challenging. This study evaluated the insights of adjunctive ablation for epicardial arrhythmogenic substrates in those patients via a percutaneous epicardial approach. Thirty-five consecutive patients with AF/atrial tachycardia (AT) recurrence, who had two or more prior ablation procedures, were enrolled from September 2016 to December 2018. In addition to a standard endocardial approach, epicardial mapping and ablation were performed via a percutaneous subxiphoid access in the electrophysiology lab. Adjunctive epicardial ablations for left lateral ridge (LLR) were performed in 31 of 35 patients (88.6%) for efficient transmural lesions with pacing capture loss. Marshall Bundle (MB) potentials were documented on epicardial LLR in three patients and abolished by direct epicardial ablation. Bachmann's bundle (BB) was ablated as an epicardial conduction gap in four patients with a refractory anterior wall line. Two epicardial AT/AF triggers were detected followed by successful termination with epicardial ablation. No periprocedural complications occurred. About 23 of 35 patients (65.7%) remained free from AF/AT after 23.2 ± 9 months of the procedure. Patients with multiple failed prior AF procedures refractory to antiarrhythmic therapy might warrant a percutaneous epicardial mapping and ablation strategy, with adjunctive therapy for targeting LLR/MB, BB, and underlying epicardial triggers in addition to a standard endocardial approach.

Isolating the entire pulmonary venous component versus isolating the pulmonary veins for persistent atrial fibrillation: A propensity-matched analysis.

The outcomes of pulmonary vein isolation (PVI) for persistent atrial fibrillation (AF) are suboptimal. The entire pulmonary venous component (PV-Comp), consisting of the pulmonary veins, their antra, and the area between the antra, provides triggers and substrate for AF. PV-Comp isolation is an alternative strategy for persistent AF ablation. Among 328 patients with persistent AF who underwent a first radiofrequency ablation procedure, 200 patients (PVI, n=100; PV-Comp isolation, n=100) were selected by propensity score matching. Both groups were followed up for 1 year. At 6- and 12-month follow-up, atrial tachyarrhythmia (AF/atrial tachycardia) recurred in 41 and 61 patients in PVI group and 22 (P=.006) and 33 patients (P<.001) in PV-Comp isolation group, respectively. PV-Comp isolation was associated with longer mean time to recurrence (PVI: 8 months, PV-Comp isolation: 10 months, log-rank P<.001) and a lower probability of recurrence (odds ratio [OR]=0.32; 95% confidence of interval [CI]=0.18-0.56, P<.001), with no increase in procedural complications (PVI: 5 of 100, PV-Comp isolation: 6 of 100, P=.76). Procedure duration was longer in PV-Comp isolation group (PVI: 186 ± 42min, PV-Comp isolation: 238 ± 44min, P<.001), as well as fluoroscopy time (PVI: 22 ± 16min, PV-Comp isolation: 31 ± 21min, P=.001). PV-Comp isolation for persistent AF reduced atrial tachyarrhythmia recurrence up to 1 year compared with PVI alone. While procedure and fluoroscopy time increased, there was no difference in procedural complications.

Persistent atrial fibrillation in the setting of pulmonary vein isolation-Where to next?

Catheter ablation for atrial fibrillation (AF) is indicated in symptomatic patients who are intolerant or refractory to antiarrhythmic therapy. However, outcomes from catheter ablation remain suboptimal in patients with persistent AF. Pulmonary vein antral isolation (PVAI) is established as the cornerstone of AF ablation strategies. The landmark STAR AF II study demonstrated a lack of incremental benefit with adjunctive linear and complex fractionated electrogram ablation beyond PVAI. Randomized studies thus far have failed to consistently show favorable outcomes from other trigger/substrate-based ablation approaches over PVAI alone. In this issue of the journal, we pose an interesting clinical scenario-of a middle-aged female who presents with recurrent persistent AF but was found to have enduring PVAI on repeat electrophysiologic study. Which approach should be undertaken next? In this review article, we aim to provide an overview of ablation strategies beyond PVAI. Finally in light of scant randomized data to guide decision making we have approached leading experts in the field to provide their approach to this scenario.

Toward a Uniform Ablation Protocol for Paroxysmal, Persistent, and Permanent Atrial Fibrillation.

Atrial fibrillation catheter ablation has emerged as the most effective strategy to restore and maintain sinus rhythm. The cornerstone of atrial fibrillation ablation is elimination of triggers from the pulmonary veins by pulmonary vein isolation. Nevertheless, some patients may experience atrial tachyarrhythmia recurrences even with permanent pulmonary vein antral isolation. Whether and in which patients pulmonary vein antral isolation should be considered as the only ablation strategy remains a matter of debate. This review aims to summarize the rationale and effectiveness of different ablation approaches and identify key points for a uniform atrial fibrillation ablation strategy.

Feasibility, Safety, and Efficacy of Posterior Wall Isolation During Atrial Fibrillation Ablation: A Systematic Review and Meta-Analysis.

The posterior left atrium is an arrhythmogenic substrate that contributes to the initiation and maintenance of atrial fibrillation (AF); however, the feasibility, safety, and efficacy of posterior wall isolation (PWI) as an AF ablation strategy has not been widely reported. We undertook a systematic review and meta-analysis of studies performing PWI to assess (1) acute procedural success including the ability to achieve PWI and the number of procedure-related complications, (2) Long-term, clinical success including rates of arrhythmia recurrence and posterior wall reconnection, and (3) The efficacy of PWI compared with pulmonary vein isolation on preventing arrhythmia recurrence. MEDLINE, EMBASE, and Web of Science databases were searched in May 2018 to retrieve relevant studies. Results were pooled using a random effects model. Seventeen studies (13 box isolation, 3 single ring isolation, and 1 debulking ablation) comprising 1643 patients (31.3% paroxysmal AF, left atrial diameter 41±3.1 mm) were included in the final analysis. In studies focusing specifically on PWI, the acute procedural success rate for achieving PWI was 94.1% (95% CI, 87.2%-99.3%). Single-procedure 12-month freedom from atrial arrhythmia was 65.3% (95% CI, 57.7%-73.9%) overall and 61.9% (54.2%-70.8%) for persistent AF. Randomized control trials comparing PWI to pulmonary vein isolation (3 studies, 444 patients) yielded conflicting results and could not confirm an incremental benefit to PWI. Fifteen major complications (0.1%), including 2 atrio-esophageal fistulas, were reported. PWI as an end point of AF ablation can be achieved in a large proportion of cases with good rates of 12-month freedom from atrial arrhythmia. Although the procedure-related complication rate is low, it did not eliminate the risk of atrio-esophageal fistula. Registration: URL: http://www.crd.york.ac.uk/prospero. PROSPERO registration number: CRD42018107212.

Reasons for successful clinical outcome following pulmonary vein isolation despite lack of persistent LA-PV conduction block.

The mechanisms of atrial fibrillation (AF) induction and maintenance, including those involved in paroxysmal atrial fibrillation, are not completely known; this limits our ablation strategies and prevents us from understanding what we are actually doing when performing pulmonary vein isolation. In this report, we focus on the commonly used ablation strategies for AF and question the importance of complete pulmonary vein isolation in achieving lasting success in the ablation of AF. We also discuss in detail the absence of durable pulmonary vein isolation in patients without arrhythmic recurrences after AF ablation and the possibility to cure paroxysmal AF without concomitant pulmonary vein isolation, provocatively questioning the dogma of pulmonary vein isolation as the cornerstone of AF ablation. Finally, a prospective personalized approach in the individual patient is advocated.

Left Atrial Appendage Electrical Isolation as a Target in Atrial Fibrillation.

Although the benefit of catheter ablation of the pulmonary veins is well established in paroxysmal atrial fibrillation (AF), the optimal ablation strategy for persistent AF is yet to be determined. Pulmonary vein isolation in persistent AF often results in AF recurrence and the success rate may be low even after multiple procedures. Recurrent AF risk may besecondary to non-pulmonary vein triggers, and adjunctive therapies to better control persistent AF are under investigation. The left atrial appendage (LAA) is a complex structure with distinct physiological and electrical properties, and multiple studies have implicated the LAA as a potential contributor to persistence of AF. Therapies targeting the LAA for electrical isolation have demonstrated potential efficacy in freedom from AF. The overarching concept of this therapy is to isolate the atria electrically from the LAA via catheter ablation, surgical excision or ligation, or percutaneous ligation. LAA electrical isolation has already demonstrated benefit in reducing AF recurrence and AF burden. LAA electrical isolation has the potential to form a foundational piece in the optimal rhythm control management of AF and thereforewarrants further study and is the focus of this review.

Atrial fibrillation ablation strategies and outcome in patients with heart failure: insights from the German ablation registry.

Heart failure (HF) and atrial fibrillation (AF) often coexist, but data on the prognostic value of differing ablation strategies according to left ventricular ejection fraction (LVEF) are rare. From January 2007 until January 2010, 728 patients with HF were enrolled in the multi-center German ablation registry prior to AF catheter ablation. Patients were divided into three groups according to LVEF: HF with preserved LVEF (≥ 50%, HFpEF, n = 333), mid-range LVEF (40-49%, HFmrEF, n = 207), and reduced LVEF (< 40%, HFrEF, n = 188). Ablation strategies differed significantly between the three groups with the majority of patients with HFpEF (83.4%) and HFmrEF (78.4%) undergoing circumferential pulmonary vein isolation vs. 48.9% of patients with HFrEF. The latter underwent ablation of the atrioventricular (AV) node in 47.3%. Major complications did not differ between the groups. Kaplan-Meier survival analysis demonstrated a significant mortality increase in patients with HFrEF (6.1% in HFrEF vs. 1.5% in HFmrEF vs. 1.9% in HFpEF, p = 0.009) that was limited to patients undergoing ablation of the AV node. Catheter ablation strategies differ significantly in patients with HFpEF, HFmrEF, and HFrEF. In almost 50% of patients with HFrEF AV-node ablation was performed, going along with a significant increase in mortality rate. These results should raise efforts to further evaluate the prognostic effect of ablation strategies in HF patients.

Atrial fibrillation ablation using cryoballoon technology: Recent advances and practical techniques.

Atrial fibrillation (AF) affects 1-2% of the population, and its prevalence is estimated to double in the next 50 years as the population ages. AF results in impaired patients' life quality, deteriorated cardiac function, and even increased mortality. Antiarrhythmic drugs frequently fail to restore sinus rhythm. Catheter ablation is a valuable treatment approach for AF, even as a first-line therapy strategy in selected patients. Effective electrical pulmonary vein isolation (PVI) is the cornerstone of all AF ablation strategies. Use of radiofrequency (RF) catheter in combination of a three-dimensional electroanatomical mapping system is the most established ablation approach. However, catheter ablation of AF is challenging even sometimes for experienced operators. To facilitate catheter ablation of AF without compromising the durability of the pulmonary vein isolation, "single shot" ablation devices have been developed; of them, cryoballoon ablation, is by far the most widely investigated. In this report, we review the current knowledge of AF and discuss the recent evidence in catheter ablation of AF, particularly cryoballoon ablation. Moreover, we review relevant data from the literature as well as our own experience and summarize the key procedural practical techniques in PVI using cryoballoon technology, aiming to shorten the learning curve of the ablation technique and to contribute further to reduction of the disease burden.