Results From a Single-Blind, Randomized Study Comparing the Impact of Different Ablation Approaches on Long-Term Procedure Outcome in Coexistent Atrial Fibrillation and Flutter (APPROVAL)

2023 Cardiac Society of Australia and New Zealand Expert Position Statement on Catheter and Surgical Ablation for Atrial Fibrillation

Catheter ablation for atrial fibrillation (AF) has increased exponentially in many developed countries, including Australia and New Zealand. This Expert Position Statement on Catheter and Surgical Ablation for Atrial Fibrillation from the Cardiac Society of Australia and New Zealand (CSANZ) recognises healthcare factors, expertise and expenditure relevant to the Australian and New Zealand healthcare environments including considerations of potential implications for First Nations Peoples. The statement is cognisant of international advice but tailored to local conditions and populations, and is intended to be used by electrophysiologists, cardiologists and general physicians across all disciplines caring for patients with AF. They are also intended to provide guidance to healthcare facilities seeking to establish or maintain catheter ablation for AF.

In-hospital complications associated with pulmonary vein isolation with adjunctive lesions: the NCDR AFib Ablation Registry

AIMS

No prior study has been adequately powered to evaluate real-world safety outcomes in those receiving adjunctive ablation lesions beyond pulmonary vein isolation (PVI). We sought to evaluate characteristics and in-hospital complications among patients undergoing PVI with and without adjunctive lesions.

METHODS AND RESULTS

Patients in the National Cardiovascular Data Registry AFib Ablation Registry undergoing first-time atrial fibrillation (AF) ablation between 2016 and 2020 were identified and stratified into paroxysmal (PAF) and persistent AF, and separated into PVI only, PVI + cavotricuspid isthmus (CTI) ablation, and PVI + adjunctive (superior vena cava isolation, coronary sinus, vein of Marshall, atypical atrial flutter lines, other). Adjusted odds of adverse events were calculated using multivariable logistic regression. A total of 50 937 patients [PAF: 30 551 (60%), persistent AF: 20 386 (40%)] were included. Among those with PAF, there were no differences in the adjusted odds of complications between PVI + CTI or PVI + adjunctive when compared with PVI only. Among persistent AF, PVI + adjunctive was associated with a higher risk of any complication [3.0 vs. 4.5%, odds ratio (OR) 1.30, 95% confidence interval (CI) 1.07-1.58] and major complication (0.8 vs. 1.4%, OR 1.56, 95% CI 1.10-2.21), while no differences were observed in PVI + CTI compared with PVI only. Overall, there was high heterogeneity in adjunctive lesion type, and those receiving adjunctive lesions had a higher comorbidity burden.

CONCLUSION

Additional CTI ablation was common without an increased risk of complications. Adjunctive lesions other than CTI are commonly performed in those with more comorbidities and were associated with an increased risk of complications in persistent AF, although the current analysis is limited by high heterogeneity in adjunctive lesion set type.

Generalizable and robust deep learning algorithm for atrial fibrillation diagnosis across geography, ages and sexes

To drive health innovation that meets the needs of all and democratize healthcare, there is a need to assess the generalization performance of deep learning (DL) algorithms across various distribution shifts to ensure that these algorithms are robust. This retrospective study is, to the best of our knowledge, an original attempt to develop and assess the generalization performance of a DL model for AF events detection from long term beat-to-beat intervals across geography, ages and sexes. The new recurrent DL model, denoted ArNet2, is developed on a large retrospective dataset of 2,147 patients totaling 51,386 h obtained from continuous electrocardiogram (ECG). The model's generalization is evaluated on manually annotated test sets from four centers (USA, Israel, Japan and China) totaling 402 patients. The model is further validated on a retrospective dataset of 1,825 consecutives Holter recordings from Israel. The model outperforms benchmark state-of-the-art models and generalized well across geography, ages and sexes. For the task of event detection ArNet2 performance was higher for female than male, higher for young adults (less than 61 years old) than other age groups and across geography. Finally, ArNet2 shows better performance for the test sets from the USA and China. The main finding explaining these variations is an impairment in performance in groups with a higher prevalence of atrial flutter (AFL). Our findings on the relative performance of ArNet2 across groups may have clinical implications on the choice of the preferred AF examination method to use relative to the group of interest.

Prophylactic Cavotricuspid Isthmus Ablation in Atrial Fibrillation without Documented Typical Atrial Flutter: A Systematic Review and Meta-analysis

Background: The advantage of prophylactic cavotricuspid isthmus (CTI) ablation for AF patients without documented atrial flutter is still unclear. The present study aimed to evaluate the role of prophylactic CTI ablation in this population. Methods: A systematic review and meta-analysis study was conducted. The overall effects estimation was conducted using random effects models. The pooled effects were presented as the risk difference and standardised mean difference for dichotomous and continuous outcomes, respectively. Results: A total of 1,476 patients from four studies were included. The risk of atrial tachyarrhythmias following a successful catheter ablation procedure was greater in the pulmonary vein isolation + CTI ablation group than pulmonary vein isolation alone group (34.8% versus 28.2%; risk difference 0.08; 95% CI [0.00–0.17]; p=0.04). Prophylactic CTI ablation was associated with a higher recurrent AF rate (33.8% versus 27.1%; risk difference 0.07; 95% CI [0.01–0.13]; p=0.02). Additional prophylactic CTI ablation to pulmonary vein isolation significantly increased the radio frequency application time (standardised mean difference 0.52; 95% CI [0.04–1.01]; p=0.03). Conclusion: This study suggested that prophylactic CTI ablation was an ineffective and inefficient approach in AF without documented typical atrial flutter patients.

Natural History of Arrhythmia After Successful Isolation of Pulmonary Veins, Left Atrial Posterior Wall, and Superior Vena Cava in Patients With Paroxysmal Atrial Fibrillation: A Multi-Center Experience

Background We evaluated long-term outcome of isolation of pulmonary veins, left atrial posterior wall, and superior vena cava, including time to recurrence and prevalent triggering foci at repeat ablation in patients with paroxysmal atrial fibrillation with or without cardiovascular comorbidities. Methods and Results A total of 1633 consecutive patients with paroxysmal atrial fibrillation that were arrhythmia-free for 2 years following the index ablation were classified into: group 1 (without comorbidities); n=692 and group 2 (with comorbidities); n=941. We excluded patients with documented ablation of areas other than pulmonary veins, the left atrial posterior wall, and the superior vena cava at the index procedure. At 10 years after an average of 1.2 procedures, 215 (31%) and 480 (51%) patients had recurrence with median time to recurrence being 7.4 (interquartile interval [IQI] 4.3-8.5) and 5.6 (IQI 3.8-8.3) years in group 1 and 2, respectively. A total of 201 (93.5%) and 456 (95%) patients from group 1 and 2 underwent redo ablation; 147/201 and 414/456 received left atrial appendage and coronary sinus isolation and 54/201 and 42/456 had left atrial lines and flutter ablation. At 2 years after the redo, 134 (91.1%) and 391 (94.4%) patients from group 1 and 2 receiving left atrial appendage/coronary sinus isolation remained arrhythmia-free whereas sinus rhythm was maintained in 4 (7.4%) and 3 (7.1%) patients in respective groups undergoing empirical lines and flutter ablation (P<0.001). Conclusions Very late recurrence of atrial fibrillation after successful isolation of pulmonary veins, regardless of the comorbidity profile, was majorly driven by non-pulmonary vein triggers and ablation of these foci resulted in high success rate. However, presence of comorbidities was associated with significantly earlier recurrence.

Predictors of recurrent atrial fibrillation following catheter ablation

INTRODUCTION

Atrial fibrillation (AF) is a complex and multi-factorial rhythm disorder. Catheter ablation is widely used for the management of AF. However, it is limited by relapse of the arrhythmia necessitating repeat procedures.

AREAS COVERED

This review aims to discuss the predictors of post-ablation recurrent AF including age, gender, genetic predisposition, AF type and duration, comorbidities, lifestyle factors, echocardiographic parameters of heart chambers, left atrial fibrosis and ablation strategies and targets. An extensive literature search was undertaken on PubMed and Google Scholar to obtain full texts of relevant AF-related articles.

EXPERT OPINION

Maintenance of stable sinus rhythm is the main intended outcome of AF ablation. Therefore, it is very crucial to identify the risk factors that may influence the ablation success. Most of these predictors such as comorbidities, ablation strategy and targets and lifestyle factors are either reversible or modifiable. Thus, not only the awareness of these known risk factors by both patients and their physicians but also future research to identify the unknown predictors are critical to optimize care in this multi-faceted morbidity.

Cavotricuspid isthmus line in patients undergoing catheter ablation of atrial fibrillation with or without history of typical atrial flutter: A meta-analysis

BACKGROUND

Pulmonary vein isolation (PVI) is the mainstay of catheter ablation (CA) for paroxysmal atrial fibrillation (AF). However, for persistent and long-standing persistent AF, there are no established strategies to improve the success rate of CA. Despite studies indicating that prophylactic cavotricuspid isthmus (CTI) ablation provides no or limited incremental benefit in patients with AF, it is still routinely performed worldwide.

OBJECTIVE

We sought to examine whether CTI ablation for AF is associated with improvement in recurrence of all-atrial arrhythmias, compared with PVI alone in patients with and without typical atrial flutter (AFL).

METHODS

A systematic review of PubMed, Cochrane, and Embase was performed for clinical studies including AF patients, reporting outcomes of CTI + PVI versus PVI alone. The primary efficacy endpoint was recurrence of all-atrial arrhythmias.

RESULTS

Five studies comprising 1400 patients undergoing CTI + PVI versus PVI alone were included; 1110 patients had AF without AFL, and 290 patients had coexistent AF and AFL. After a mean follow-up of 14.4 ± 4.8 months, CTI + PVI was not associated with improvement in recurrence of all-atrial arrhythmias when compared with PVI alone (risk ratio [RR]: 1.29; 95% confidence interval [CI]: 0.93-1.79;p = .13). In the subgroup analysis, there were no differences between both groups in patients with AF without AFL (RR: 1.55; 95% CI: 0.96-2.48; p = .07), and in patients with AF and AFL (RR: 0.91; 95% CI: 0.6-1.39; p = .68).

CONCLUSION

In AF patients, irrespective of the presence of typical AFL, additional CTI ablation is not associated with improvement in recurrence of all-atrial arrhythmias, compared with PVI alone.

Prophylactic pulmonary vein isolation in typical atrial flutter patients without atrial fibrillation: a systematic review and meta-analysis of randomized trials

BACKGROUND

New-onset atrial fibrillation (AF) is common after cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL) ablation. The meta-analysis was conducted to evaluate the benefit of prophylactic pulmonary vein isolation (PVI) in typical AFL patients.

METHODS

Randomized controlled trials (RCT) comparing prophylactic PVI to CTI ablation alone in typical AFL patients without prior documentation of AF were identified in the MEDLINE, EMBASE, and Cochrane databases.

RESULTS

Four RCTs met the inclusion criteria. A total of 357 patients with follow-up of 20 ± 9 months were included. More patients in prophylactic PVI group were free from atrial arrhythmias (AA) compared with those in CTI group (69% versus 50%, OR = 2.36, 95% CI: 1.51 to 3.68; P = 0.0001). In the subgroup of age > 55, prophylactic PVI showed even higher incidence of freedom from AA. There is a lower occurrence of AF in prophylactic PVI group (27% versus 46%, OR = 0.45, 95% CI: 0.28 to 0.73; P = 0.001) and no difference of complications between prophylactic PVI group and CTI group (4% versus 2%; P = 0.33).

CONCLUSION

Our study indicated the efficacy and safety of prophylactic PVI during CTI ablation in typical AFL patients without AF history, especially for elder patients. Large prospective RCTs are warranted to confirm the benefit of prophylactic PVI in typical AFL.

Smartphone ECG Monitoring System Helps Lower Emergency Room and Clinic Visits in Post-Atrial Fibrillation Ablation Patients

Aim:

To evaluate the effectiveness of using a smartphone-based electrocardiography (ECG) monitoring device (ECG Check) on the frequency of clinic or emergency room visits in patients who underwent ablation of atrial fibrillation (AF).

Methods:

Two groups of patients were identified and compared: The conventional monitoring group (CM group) included patients who were prescribed conventional event monitoring or Holter monitoring systems. The ECG Check group (EC group) included patients who were prescribed the ECG Check device for continuous monitoring in addition to conventional event monitoring. The primary outcome was the number of patient visits to clinic or emergency room. The feasibility, accuracy, and detection rate of mobile ECG Check were also evaluated.

Results:

Ninety patients were studied (mean age: 66.2 ± 11 years, 64 males, mean CHA₂DS₂-VASc score: 2.6 ± 2). In the EC group, forty-five patients sent an average of 52.8 ± 6 ECG records for either routine monitoring or symptoms of potential AF during the follow-up period. The rhythm strips identified sinus rhythm (84.7%), sinus tachycardia (8.4%), AF (4.2%), and atrial flutter (0.9%). Forty-two EC transmissions (1.8%) were uninterpretable. Six patients (13%) in the EC group were seen in the clinic or emergency room over a 100-day study period versus 16 (33%) in the standard care arm (P value < 0.001).

Conclusions:

Use of smartphone-based ECG monitoring led to a significant reduction in AF-related visits to clinic or emergency department in the postablation period.

Efficacy and safety of catheter ablation combined with left atrial appendage occlusion for nonvalvular atrial fibrillation: A systematic review and meta-analysis

Atrial fibrillation (AF) is currently the most prevalent arrhythmia in clinical practice, with stroke being one of its major complications. Combining catheter ablation and percutaneous left atrial appendage occlusion (LAAO) into a "one-stop" intervention could reduce stroke incidence in selected high-risk patients and, at the same time, relieve AF symptoms in a single procedure. This meta-analysis analyzed the efficacy and safety of catheter ablation combined with LAAO for nonvalvular AF. PubMed, EMBASE, and the Cochrane Library were searched from inception to April 2019 to identify relevant citations. Efficacy indexes were procedural success, AF recurrence, stroke/transient ischemic attacks (TIA), and device-related thrombus (DRT). Safety indexes were all-cause death, major hemorrhagic complications, and pericardial effusion/cardiac tamponade. The incidence rate of events (ratio of events to patients) and 95% confidence interval (CI) were calculated as summary results. A forest plot was constructed to present pooled rates. Eighteen studies (two randomized controlled trials and 16 observational studies) were included. The results showed that one-stop intervention has significant efficacy and safety, with procedural success of .98 (95% CI, .97-1.00), AF recurrence of .24 (95% CI, .15-.35), stroke/TIA of .01 (95% CI, .00-.01), DRT of .00 (95% CI, .00-.01), all-cause mortality of .00 (95% CI, .00-.00), cardiac/neurological mortality of .00 (95% CI, .00-.00), major hemorrhagic complications of .01 (95% CI, .00-.02), and pericardial effusion/cardiac tamponade of .01 (95% CI, .00-.01). A single procedure with catheter ablation and LAAO in AF is a feasible strategy with significant efficacy and safety.

Prophylactic pulmonary vein isolation during cavotricuspid isthmus ablation for atrial flutter: A meta-analysis

BACKGROUND

Atrial arrhythmias (AA), including atrial fibrillation (AF), have been reported in patients after cavotricuspid isthmus (CTI) ablation for typical atrial flutter (AFL). Several studies have examined the effect of performing concomitant pulmonary vein isolation (PVI) with CTI on recurrent AA. These studies were analyzed to determine the overall effect of this approach on recurrent AA.

METHODS

PubMed and Google Scholar were searched for randomized trials comparing the incidence of AA after CTI versus CTI + PVI until June 2018. Only patients without prior history of AF were included in the recurrent AA analysis. All patients were included in the analyses of other clinical outcomes.

RESULTS

Four randomized control trials were included in the meta-analysis. In the recurrent AA analysis, a total of 314 patients were randomized in the studies (n = 158 CTI, n = 156 CTI + PVI). Freedom from AA at 1 year was significantly higher in the CTI + PVI group versus CTI alone (odds ratio [OR] 0.25 [0.14, 0.44] 95% confidence interval [CI], P < 0.00001). A total of 550 patients (n = 336 CTI, n = 214 CTI + PVI) were included in analyses for procedure time, fluoroscopy time, and complications rates. Procedure time and fluoroscopy time were significantly longer in the CTI + PVI group (mean difference [MD]: 103.31 min [94.40, 112.23] 95% CI, P < 0.00001) and (MD: 16.47 min [14.89, 18.05] 95% CI, P < 0.00001), respectively. Total complications were statistically similar between groups.

CONCLUSION

This meta-analysis shows addition of a prophylactic PVI during CTI ablation significantly reduces recurrent AA at 1 year without significantly increasing major complications.

Prophylactic Atrial Fibrillation Ablation in Atrial Flutter Patients without Atrial Fibrillation: A Meta-Analysis with Trial Sequential Analysis

Background

New-onset atrial fibrillation (AF) is common after atrial flutter (AFL) ablation, but it was unclear whether AF ablation could reduce the incidence of AF in AFL patients without AF history. The present meta-analysis was conducted to evaluate the benefit of prophylactic AF ablation in reducing the occurrence of AF in typical AFL patients.

Material/Methods

We systematically searched PubMed, EMBASE, and the Cochrane Library from inception to December 2017 for randomized controlled trials (RCTs) that assessed the efficacy of AF ablation in reducing the occurrence of AF in AFL patients without AF. Trial sequential analysis (TSA) was used to control random errors and calculate the required information size.

Results

Four trials (n=357 patients) met the inclusion criteria and were included in our meta-analysis. The incidence of AF after AFL ablation was 46.4%. We observed that prophylactic AF ablation reduced the AF incidence compared with simple AFL ablation (26.1% versus 46.4%, RR: 0.57, 95% CIs: 0.42–0.76, P=0.0002) with a prolonged procedure duration (P<0.00001) and fluoroscopy time (P=0.004). Further TSA indicated that more RCTs were needed to reach more conclusive results. There was no significant difference in clinical complications (P=0.33) between the 2 groups.

Conclusions

This meta-analysis provides evidence that prophylactic AF ablation may be more effective than simple AFL ablation in reducing AF incidence after AFL ablation. Large prospective RCTs are warranted to confirm the benefit of prophylactic AF ablation in AFL patients without AF history.

Catheter Ablation of Atrial Fibrillation: An Overview for Clinicians

Catheter ablation (CA) of atrial fibrillation (AF) is currently one of the most commonly performed electrophysiology procedures. Ablation of paroxysmal AF is based on the elimination of triggers by pulmonary vein isolation (PVI), while different strategies for additional AF substrate modification on top of PVI have been proposed for ablation of persistent AF. Nowadays, various technologies for AF ablation are available. The radiofrequency point-by-point ablation navigated by electro-anatomical mapping system and cryo-balloon technology are comparable in terms of the efficacy and safety of the PVI procedure. Long-term success of AF ablation including multiple procedures varies from 50 to 80%. Arrhythmia recurrences commonly occur, mostly due to PV reconnection. The recurrences are particularly common in patients with non-paroxysmal AF, dilated left atrium and the "early recurrence" of AF within the first 2-3 post-procedural months. In addition, this complex procedure can be accompanied by serious complications, such as cardiac tamponade, stroke, atrio-esophageal fistula and PV stenosis. Therefore, CA represents a second-line treatment option after a trial of antiarrhythmic drug(s). Good candidates for the procedure are relatively younger patients with symptomatic and frequent episodes of AF, with no significant structural heart disease and no significant left atrial enlargement. Randomized trials demonstrated the superiority of ablation compared to antiarrhythmic drugs in terms of improving the quality of life and symptoms in AF patients. However, nonrandomized studies reported additional clinical benefits from ablation over drug therapy in selected AF patients, such as the reduction of the mortality and stroke rates and the recovery of tachyarrhythmia-induced cardiomyopathy. Future research should enable the creation of more durable ablative lesions and the selection of the optimal lesion set in each patient according to the degree of atrial remodeling. This could provide better long-term CA success and expand indications for the procedure, especially among the patients with non-paroxysmal AF.

Persistent atrial fibrillation vs paroxysmal atrial fibrillation: differences in management

INTRODUCTION

Atrial fibrillation (AF) is the most common human arrhythmia. AF is a progressive disease, initially being nonsustained and induced by trigger activity, and progressing towards persistent AF through alteration of the atrial myocardial substrate. Treatment of AF aims to decrease the risk of stroke and improve the quality of life, by preventing recurrences (rhythm control) or controlling the heart rate during AF (rate control). In the last 20 years, catheter-based and, less frequently, surgical and hybrid ablation techniques have proven more successful compared with drug therapy in achieving rhythm control in patients with AF. However, the efficiency of ablation techniques varies greatly, being highest in paroxysmal and lowest in long-term persistent AF. Areas covered: In this review, we discuss the fundamental differences between paroxysmal and persistent AF and the potential impact of those differences on patient management, emphasizing the available therapeutic strategies to achieve rhythm control. Expert commentary: Treatment to prevent AF recurrences is suboptimal, particularly in patients with persistent AF. Emerging technologies, such as documentation of atrial fibrosis using magnetic resonance imaging and documentation of electrical substrate using advanced electrocardiographic imaging techniques are likely to provide valuable insights about patient-specific tailoring of treatments.

Is HATCH score a reliable predictor of atrial fibrillation after cavotricuspid isthmus ablation for typical atrial flutter?

OBJECTIVE

We determined the effectiveness of the HATCH score in patients with typical atrial flutter (AFl) undergoing cavotricuspid isthmus (CTI) ablation to predict long-term atrial fibrillation (AF).

METHODS

We conducted an observational retrospective single-center cohort study including all patients admitted to our hospital for a CTI ablation between 1998 and 2010. The patients were divided into four categories: 1) new-onset AF (no prior AF and AF during follow-up (FU)); 2) old AF (prior AF and no AF during FU); 3) prior and post AF (AF prior and post CTI ablation); and 4) no AF.

RESULTS

Four hundred and eight patients were included. In patients without prior AF, the hazard ratio (HR) for new-onset AF during FU was 0.98 (CI 95%: 0.65-1.50; p = 0.95) and 1.00 (CI 95%: 0.57-1.77; p = 0.98) for HATCH ≥ 2 and HATCH ≥ 3, respectively. In patients with prior AF, the HR for AF was 1.41 (CI 95%: 0.87-2.28; p = 0.17) and 1.79 (CI 95%: 0.96-3.35; p = 0.06), for HATCH ≥ 2 and HATCH ≥ 3, respectively. Left atrial enlargement was positively correlated with the occurrence of AF during FU, especially in the subgroup without prior AF, which had a HR of 2.44 (CI 95%: 1.35-4.40; p = 0.003), a HR of 2.88 (CI 95%: 1.36-6.10; p = 0.006) and a HR of 3.68 (CI 95%: 1.71-7.94; p = 0.001), for slight, moderate and severely dilated left atrial dimension, respectively, compared with a normal value.

CONCLUSIONS

HATCH score did not predict AF in patients with typical AFl who underwent CTI ablation. Basal left atrium dimension could help predict new-onset AF.

Atrial Flutter, Typical and Atypical: A Review

Clinical electrophysiology has made the traditional classification of rapid atrial rhythms into flutter and tachycardia of little clinical use. Electrophysiological studies have defined multiple mechanisms of tachycardia, both re-entrant and focal, with varying ECG morphologies and rates, authenticated by the results of catheter ablation of the focal triggers or critical isthmuses of re-entry circuits. In patients without a history of heart disease, cardiac surgery or catheter ablation, typical flutter ECG remains predictive of a right atrial re-entry circuit dependent on the inferior vena cava-tricuspid isthmus that can be very effectively treated by ablation, although late incidence of atrial fibrillation remains a problem. Secondary prevention, based on the treatment of associated atrial fibrillation risk factors, is emerging as a therapeutic option. In patients subjected to cardiac surgery or catheter ablation for the treatment of atrial fibrillation or showing atypical ECG patterns, macro-re-entrant and focal tachycardia mechanisms can be very complex and electrophysiological studies are necessary to guide ablation treatment in poorly tolerated cases.

Postoperative atrial tachycardias after mitral valve surgery: Mechanisms and outcomes of catheter ablation

BACKGROUND

Atrial tachycardias (ATs) including atrial fibrillation are common arrhythmias occurring late after mitral valve (MV) surgery, and their management is challenging.

OBJECTIVE

The purpose of this study was to determine the electrophysiological mechanisms of ATs in patients with prior MV surgery and the long-term outcomes of catheter ablation.

METHODS

We studied 67 consecutive patients (mean age 59.4 ± 10.6 years; 41 men [61%]) with prior MV surgery who presented with ATs postoperatively between 2007 and 2015.

RESULTS

AT was clinically documented before the electrophysiology study in 55 patients, whereas in the remaining 12 patients AT was inducible at the study. A total of 99 ATs (35 spontaneous and 64 inducible) were characterized. Overall, the right atrium (RA) was the chamber of origin in 56%. The underlying mechanism was macroreentry in 91 cases and included typical RA flutter (n = 37), mitral annular flutter (n = 21), incisional right AT (n = 16), roof-dependent reentry (n = 12), and local left atrial reentry (n = 5). Eight focal ATs were also documented: 6 from the left atrium and 2 from the RA. Left-sided ATs were more common in patients with prior Maze procedure (53%), and mitral annular flutter was twice as prevalent in this group (42% vs 21%; P = .05). The ablation was acutely successful in 98.5%. Freedom from atrial arrhythmias was 62% at 12 months, with 42% requiring more than 1 procedure.

CONCLUSION

Macroreentry is the predominant AT mechanism in patients with prior MV surgery. Circuits are most often localized to the RA, with left-sided ATs more common in patients with prior Maze procedure. Repeat procedures are common and outcomes with 1 year complete AT control good.

Crucial role of pulmonary vein firing as an initiator of typical atrial flutter: Evidence of a close relationship between atrial fibrillation and typical atrial flutter

Background

Several studies reported that cavotricuspid isthmus-dependent atrial flutter (typical AFL) frequently coexists with atrial fibrillation (AF); however, the underlying mechanisms have not been fully investigated. This study aimed to reveal the mechanisms of the initiation of typical AFL and the association between typical AFL and AF.

Methods

Among 154 consecutive patients undergoing a first catheter ablation of AF, we investigated the appearance and mechanism of spontaneous initiation of typical AFL during catheter ablation. Then, we retrospectively investigated 67 consecutive patients without a previous AF episode who underwent typical AFL ablation. The occurrence and predictors of AF after catheter ablation were evaluated.

Results

During AF ablation, spontaneous initiation of typical AFL occurred during sinus rhythm in eight (5.2%) patients. The initiations of typical AFL were pulmonary vein (PV) firings except in one patient, in whom paroxysmal AF following superior vena cava firing initiated reverse typical AFL after PV isolation. After typical AFL ablation, AF occurred in 23 (34.3%) patients (mean follow up, 28.2±20.3 months). Kaplan-Meier analysis showed the occurrence of AF after typical AFL ablation to be significantly higher in the patients with a larger left atrial diameter over 40 mm (log-rank test, P=0.046).

Conclusions

PV firing through AF played an important role in initiating typical AFL. The occurrence of AF after typical AFL ablation was high, and a dilated left atrium was associated with increased occurrence of AF. These findings disclosed the close relationship between typical AFL and AF, especially PV firing.

Concomitant cryoballoon ablation and percutaneous closure of left atrial appendage in patients with atrial fibrillation

AIMS

Pulmonary veins (PVs) isolation is the cornerstone of atrial fibrillation (AF) ablation and can be achieved either by conventional radiofrequency ablation or by cryoenergy. Left atrial appendage (LAA) closure has been proposed as alternative treatment to vitamin K antagonists (VKA). We aimed to evaluate the feasibility of combining cryoballoon (CB) ablation and LAA occlusion in patients with AF and a high thromboembolic risk or contraindication to antithrombotic therapy.

METHODS AND RESULTS

Thirty-five patients (28 males, 74 ± 2 years) underwent CB ablation. Left atrial appendage occlusion was carried out by using two occluder devices (Amplatz Cardiac Plug, ACP, St. Jude Medical, MN, USA, in 25 patients; Watchman, Boston Scientific, MA, USA, in 10 patients). Thirty patients (86%) had previous stroke/TIA episodes, 6 patients (17%) had major bleeding while on VKA therapy, and 7 patients (20%) had inherited bleeding disorders. Over the follow-up (24 ± 12 months), atrial arrhythmias recurred in 10 (28%) patients. Thirty patients (86%) had complete sealing; 5 patients (14%) showed a residual flow (<5 mm) at first transoesophageal echocardiography (TEE) check, while at 1-year TEE residual flow was detected in 3 patients. In 13 patients (37%), VKA therapy was immediately discontinued. Six patients (17%) received novel oral anticoagulants treatment and then discontinued 3 months thereafter. No device-related complications or clinical thromboembolic events occurred.

CONCLUSION

Combined CB ablation and LAA closure using different devices appears to be feasible in patients with non-valvular AF associated with high risk of stroke or contraindication to antithrombotic treatment.

A Patient With Asymptomatic Cerebral Lesions During AF Ablation: How Much Should We Worry?

Silent brain lesions due to thrombogenicity of the procedure represent recognized side effects of atrial fibrillation (AF) catheter ablation. Embolic risk is higher if anticoagulation is inadequate and recent studies suggest that uninterrupted anticoagulation, ACT levels above 300 seconds and administration of a pre-transeptal bolus of heparin might significantly reduce the incidence of silent cerebral ischemia (SCI) to 2%. Asymptomatic new lesions during AF ablation should suggest worse neuropsychological outcome as a result of the association between silent cerebral infarcts and increased long-term risk of dementia in non-ablated AF patients. However, the available data are discordant. To date, no study has definitely linked post-operative asymptomatic cerebral events to a decline in neuropsychological performance. Larger volumes of cerebral lesions have been associated with cognitive decline but are uncommon findings acutely in post-ablation AF patients. Of note, the majority of acute lesions have a small or medium size and often regress at a medium-term follow-up. Successful AF ablation has the potential to reduce the risk of larger SCI that may be considered as part of the natural course of AF. Although the long-term implications of SCI remain unclear, it is conceivable that strategies to reduce the risk of SCI may be beneficial.

Simultaneous pulmonary vein cryoablation and cavotricuspid isthmus radiofrequency ablation in patients with combined atrial fibrillation and typical atrial flutter

Pulmonary vein isolation (PVI) using cryoballoon (CB) technique and cavotricuspid isthmus (CTI) ablation using radiofrequency (RF) are established interventions for drug-resistant atrial fibrillation (AF) and typical atrial flutter (AFL). Twelve patients with a mean age of 62 ± 12 years underwent simultaneous delivery of RF energy at the CTI during CB applications at the PV ostia. Pulmonary vein isolation was achieved in all PVs and sustained bidirectional CTI conduction block obtained in all patients. The reported ablation protocol of combined paroxysmal AF and typical AFL did not result in prolongation of the procedure duration or in prolonged radiation exposure when compared to CB-PVI alone. No interferences between both ablation energy systems were observed. These preliminary results suggest that combined paroxysmal AF and typical AFL can be successfully and safely ablated using hybrid energy sources with simultaneous CTI ablation using RF during CB applications at the PV ostia.

[Catheter ablation of persistent atrial fibrillation : pulmonary vein isolation, ablation of fractionated electrograms, stepwise approach or rotor ablation?]

Catheter ablation is an established treatment option for patients with atrial fibrillation (AF). In paroxysmal AF ablation, pulmonary vein isolation alone is a well-defined procedural endpoint, leading to success rates of up to 80% with multiple procedures over 5 years of follow-up. The success rate in persistent AF ablation is significantly more limited. This is partly due to the rudimentary understanding of the substrate maintaining persistent AF. Three main pathophysiological concepts for this arrhythmia exist: the multiple wavelet hypothesis, the concept of focal triggers, mainly located in the pulmonary veins and the rotor hypothesis. However, the targets and endpoints of persistent AF ablation are ill-defined and there is no consensus on the optimal ablation strategy in these patients. Based on these concepts, several ablation approaches for persistent AF have emerged: pulmonary vein isolation, the stepwise approach (i.e. pulmonary vein isolation, ablation of fractionated electrograms and linear ablation), magnetic resonance imaging (MRI) and rotor-based approaches. Currently, persistent AF ablation is a second-line therapy option to restore and maintain sinus rhythm. Several factors, such as the presence of structural heart disease, duration of persistent AF and dilatation and possibly also the degree of fibrosis of the left atrium should influence the decision to perform persistent AF ablation.

Monitoring Atrial Fibrillation After Catheter Ablation

Although catheter ablation is an effective treatment for recurrent atrial fibrillation (AF), there is no consensus on the definition of success or follow-up strategies. Symptoms are the major motivation for undergoing catheter ablation in patients with AF, however it is well known that reliance on perception of AF by patients after AF ablation results in an underestimation of recurrence of the arrhythmia. Because symptoms of AF occurrence may be misleading, a reliable assessment of rhythm outcome is essential for the definition of success in both clinical care and research trials. Continuous rhythm monitoring over long periods of time is superior to intermittent recording using external monitors to detect the presence of AF episodes and to quantify the AF burden. Today, new devices implanted subcutaneously using a minimally invasive technique have been developed for continuous AF monitoring. Implantable devices keep detailed information about arrhythmia recurrences and might allow identification of very brief episodes of AF, the significance of which is still uncertain. In particular, it is not known whether there is any critical value of daily AF burden that has a prognostic significance. This issue remains an area of active discussion, debate and investigation. Further investigation is required to determine if continuous AF monitoring with implantable devices is effective in reducing stroke risk and facilitating maintenance of sinus rhythm after AF ablation.

Exploring the Potential Role of Catheter Ablation in Patients with Asymptomatic Atrial Fibrillation: Should We Move away from Symptom Relief?

Although silent atrial fibrillation (AF) accounts for a significant proportion of patients with AF, asymptomatic patients have been excluded from AF ablation trials. This population presents unique challenges to disease management. Recent evidence suggests that patients with asymptomatic AF may have a different risk profile and even worse long-term outcomes compared to patients with symptomatic AF. For the same reasons they might be more prone to side-effects of antiarrhythmic drugs, including pro-arrhythmias. The poor correlation between symptoms and AF demonstrated in several studies should caution physicians against making clinical decisions depending on symptoms. Although current guidelines recommend AF ablation only in patients with symptoms, more attention should be paid to the AF burden and a rhythm control strategy has the potential to improve morbidity and mortality in AF patients. However, limited data exist regarding the use of catheter ablation for asymptomatic AF patients. As ablation techniques have improved, AF ablation has become more widespread and complication rate decreased. As a result, referrals of asymptomatic patients for catheter ablation of AF are on the rise. In this review we discuss the many unresolved questions concerning the role of the ablative approach in asymptomatic patients with AF.