Five-Year Follow-Up After Catheter Ablation of Persistent Atrial Fibrillation Using the Stepwise Approach and Prognostic Factors for Success

Rates of pulmonary vein reconnection at repeat ablation for recurrent atrial fibrillation and its impact on outcomes among females and males

BACKGROUND

Several studies have demonstrated that females have a higher risk of arrhythmia recurrence after pulmonary vein (PV) isolation for atrial fibrillation (AF). There are limited data on sex-based differences in PV reconnection rates at repeat ablation. We aimed to investigate sex-based differences in electrophysiological findings and atrial arrhythmia recurrence after repeat AF ablation METHODS: We conducted a retrospective study of 161 consecutive patients (32% female, age 65 ± 10 years) who underwent repeat AF ablation after index PV isolation between 2010 and 2022. Demographics, procedural characteristics and follow-up data were collected. Recurrent atrial tachycardia (AT)/AF was defined as any atrial arrhythmia ≥30 s in duration.

RESULTS

Compared to males, females tended to be older and had a significantly higher prevalence of prior valve surgery (10 vs. 2%; P = .03). At repeat ablation, PV reconnection was found in 119 (74%) patients. Males were more likely to have PV reconnection at repeat ablation compared to females (81 vs. 59%; P = .004). Excluding repeat PV isolation, there were no significant differences in adjunctive ablation strategies performed at repeat ablation between females and males. During follow-up, there were no significant differences in freedom from AT/AF recurrence between females and males after repeat ablation (63 vs. 59% at 2 years, respectively; P = .48).

CONCLUSIONS

After initial PV isolation, significantly fewer females have evidence of PV reconnection at the time of repeat ablation for recurrent AF. Despite this difference, long-term freedom from AT/AF was similar between females and males after repeat ablation.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society (HRS), the Asia Pacific HRS, and the Latin American HRS.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society.

Ablation-induced left atrial mechanical dysfunction recovers in weeks after ablation

BACKGROUND

The immediate impact of catheter ablation on left atrial mechanical function and the timeline for its recovery in patients undergoing ablation for atrial fibrillation (AF) remain uncertain. The mechanical function response to catheter ablation in patients with different AF types is poorly understood.

METHODS

A total of 113 AF patients were included in this retrospective study. Each patient had three magnetic resonance imaging (MRI) studies in sinus rhythm: one pre-ablation, one immediate post-ablation (within 2 days after ablation), and one post-ablation follow-up MRI (≤ 3 months). We used feature tracking in the MRI cine images to determine peak longitudinal atrial strain (PLAS). We evaluated the change in strain from pre-ablation, immediately after ablation to post-ablation follow-up in a short-term study (< 50 days) and a 3-month study (3 months after ablation).

RESULTS

The PLAS exhibited a notable reduction immediately after ablation, compared to both pre-ablation levels and those observed in follow-up studies conducted at short-term (11.1 ± 9.0 days) and 3-month (69.6 ± 39.6 days) intervals. However, there was no difference between follow-up and pre-ablation PLAS. The PLAS returned to 95% pre-ablation level within 10 days. Paroxysmal AF patients had significantly higher pre-ablation PLAS than persistent AF patients in pre-ablation MRIs. Both type AF patients had significantly lower immediate post-ablation PLAS compared with pre-ablation and post-ablation PLAS.

CONCLUSION

The present study suggested a significant drop in PLAS immediately after ablation. Left atrial mechanical function recovered within 10 days after ablation. The drop in PLAS did not show a substantial difference between paroxysmal and persistent AF patients.

Incidence of nausea/vomiting following propofol sedation with adaptive servo-ventilation for atrial fibrillation ablation

Background

Postoperative nausea and vomiting (PONV) following atrial fibrillation (AF) ablation can cause considerable distress.

Aim

Continuous intravenous propofol sedation with adaptive servo-ventilation (ASV) with or without an analgesic, pentazocine, during AF ablation was studied in 272 consecutive patients with paroxysmal, persistent, and long-standing persistent AF. The study objectives were to determine the incidence of PONV after AF ablation and to assess the predictive value of factors for PONV using the area under the receiver operating characteristic curve (AUC).

Results

The present sedation maneuver was successfully accomplished with a low incidence of hypotension and without discontinuation of ablation or switching to general anesthesia, while maintaining an acceptable procedural time (102 ± 32 min). The incidence of PONV was 5.5% (15/272). Nausea occurred in nine patients after an average of 4.6 ± 3.5 h (range: 2-12 h) postablation, and vomiting with nausea occurred in six patients after an average of 4.5 ± 3.1 h (range: 1-9 h) postablation. The postablation interval did not differ significantly between the occurrence of nausea and nausea accompanied by vomiting. AUCs based on various factors, including the Apfel score, ranged from 0.55 to 0.67, indicating low accuracy in predicting PONV occurrence.

Conclusions

The incidence of PONV after propofol sedation with ASV was the lowest (5.5%) reported to date. Scoring systems, which included the Apfel score, were ineffective in predicting PONV. The low PONV incidence in addition to the efficacy of propofol sedation with ASV revealed the adequacy of this regimen for AF ablation.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society .

Atrial fibrillation catheter ablation in endurance athletes: systematic review and meta-analysis

BACKGROUND

Atrial fibrillation (AF) management in endurance athletes (EA) is challenging due to the paucity of data, especially on the efficacy and safety of catheter ablation (CA). The hypothesis is that the efficacy and safety of AF CA in EA are comparable to the non-EA.

METHODS

Databases from EMBASE, Medline, PubMed, and Cochrane were searched from inception through February 2023. Studies with available information on efficacy and safety profiles were included. Effect estimates from the individual studies were extracted and combined using random effect and generic inverse variance method of DerSimonian and Laird.

RESULTS

Nine observational studies with a total of 1129 participants were identified, of whom 51% were EA. Our analysis found that rate of atrial arrhythmia (AA) recurrences following AF CA was not statistically different between EA and non-EA (RR 1.04, I2 = 57.6%, p = 0.54). The AA survival rates after a single ablation in EA was 60.2%, which improved up to 77% after multiple ablations during the follow-up period. Infrequent complication rates ranging from 0 to 7.6% were observed, with no mortality.

CONCLUSIONS

Our meta-analysis suggests that AF CA is as effective and safe in EA as in non-EA. In the future, AF CA should be considered as a first-line therapeutic choice in this patient group.

First clinical data on artificial intelligence-guided catheter ablation in long-standing persistent atrial fibrillation

INTRODUCTION

Despite advanced ablation strategies and major technological improvements, treatment of persistent atrial fibrillation (AF) remains challenging and the underlying pathophysiology is not fully understood. This study analyzed the multiple procedure outcome and safety of catheter ablation of spatiotemporal dispersions (DISPERS) detected by artificial intelligence (AI)-guided software in patients with long-standing persistent AF.

METHODS AND RESULTS

The Volta VX1 software was used for 50 consecutive patients undergoing catheter ablation for persistent AF. First, high-density mapping (78% biatrial) with a multipolar mapping catheter was performed. In addition to pulmonary vein isolation (PVI), ablation of DISPERS was performed aiming at homogenizing, dissecting, isolating, or connecting DISPERS areas to nonconducting anatomical structures. Follow-up contained regular visits at our outpatient clinic at 1, 3, 6, and 12 months including 7-day Holter electrocardiograms. Patients were mainly suffering from long-standing persistent AF (mean AF duration 50.30 ± 54.28 months). Following PVI, ablation of left atrial and right atrial DISPERS areas led to AF cycle length prolongation (mean of 162.0 ± 16.6 to 202.2 ± 21.6 ms after) and AF termination to atrial tachycardia (AT) or sinus rhythm (SR) in 12 patients (24%). No stroke or pericardial effusion occurred; major groin complications (pseudoaneurysm n = 1, atrioventricular fistula n = 1) were detected in two patients. After a blanking period of 6 weeks, recurrence of any atrial arrhythmia was documented in 26 patients (52%). The majority of patients presented with organized AT (n = 15) while AF was present in n = 9 patients and AT/AF was observed in n = 2 patients. Twenty-two patients underwent reablation. During a mean follow-up of 363.14 ± 187.42 days and after an average of 1.46 ± 0.68 procedures, 82% of patients remained in stable SR.

CONCLUSION

DISPERS-guided ablation using machine learning software (the Volta VX1 software) in addition to PVI in long-standing persistent AF ablation resulted in high long-term success rates regarding AF and AT elimination. Most arrhythmia recurrences were reentrant AT. After a total of 1.46 ± 0.68 procedures, freedom from AF/AT was 82%. Despite prolonged procedure times complication rates were low. Randomized studies are necessary to evaluate long-term efficacy of dispersion-guided ablation using AI.

Effects of colchicine on the prevention of AF recurrence after atrial ablation: a systematic review and meta-analysis

BACKGROUND

Catheter ablation has become a widely accepted treatment for atrial fibrillation, but early recurrences remain a challenge, often attributed to inflammatory responses triggered during the procedure. This systematic review and meta-analysis aimed to evaluate the effectiveness of colchicine in preventing short-term AF recurrence post-ablation.

METHOD

PubMed, Embase, and Cochrane Library were searched for studies comparing use of colchicine and placebo in patients after AF ablation. Outcomes included AF recurrence, GI side effects, and hospitalization. R program (version 4.3.2) was used for statistical analysis. Heterogeneity was assessed with I2 statistics.

RESULTS

Five studies, including 1592 patients, were analyzed. Pooled results revealed no statistically significant decrease in AF recurrence (OR 0.74; 95% CI 0.48-1.12; p = 0.153) and pericarditis rates (OR 0.67; 95% CI 0.26-1.72; p = 0.403) with colchicine use. No significant difference in hospitalization rates was observed between colchicine and placebo groups (OR 1.00; 95% CI 0.63-1.59; p = 0.996). In addition, gastrointestinal side effects were notably higher in the colchicine group (OR 4.84; 95% CI 2.58-9.05; p < 0.001).

CONCLUSION

Prophylactic use of colchicine after atrial ablation was not associated with a reduction in AF recurrence and pericarditis rates. In addition, there was no difference in the rate of all-cause hospitalization between the groups, and colchicine use was associated with gastrointestinal adverse events.

Treatment of atrial fibrillation with second-generation cryoballoon followed by contact-sensing radiofrequency catheter ablation for arrhythmia recurrences-results of a 5-year follow-up

INTRODUCTION

The aim of this study was to report the long-term follow-up results of cryoballoon (CB) ablation in patients with atrial fibrillation.

METHODS

All consecutive patients who underwent second-generation CB ablation from February 2015 to December 2017 were included in our study. In all procedures, we used a 28-mm CB placed via a single transseptal puncture guided by intracardiac ultrasound. A 20-mm octapolar intraluminal circular catheter was used for intracardiac recordings. A single 180-s freeze strategy was employed. Repeated procedures were performed with a 3D mapping system and radiofrequency catheters.

RESULTS

A total of 126 patients (69.8% male, mean age 57 ± 11 years), of which 77.0% had paroxysmal atrial fibrillation (PAF), were included in the study. After a 5-year period, 52.4% of patients were in sinus rhythm without AF recurrence, off antiarrhythmic drugs. A total of 61.9% of patients were free of AF recurrence when redo PVI procedures were performed. When accounting for redo pulmonary vein isolation and antiarrhythmic drugs, a total of 73.8% of the patients were without AF recurrence in long-term follow-up. The patients who underwent redo pulmonary vein isolation procedures had statistically significant lower rates of AF recurrence (p = 0.006). In patients with PAF, long-term success rates improved from 62.9 to 79.4% for patients who underwent the redo procedure (p = 0.020). In patients with persistent atrial fibrillation (PersAF), success rates went up from 41.4 to 55.1% for patients with single or repeated PVI procedure (p = 0.071). In the whole cohort, a total of 3 (2.4%) procedure-related major complications occurred which included persistent PNP, arterial pseudoaneurysm, and arteriovenous fistula.

CONCLUSION

Our data suggest a favorable long-term safety and efficacy profile of second-generation CB ablation. In the mixed paroxysmal and persistent population, up to 73.8% of patients remained free of AF recurrence in the 5-year follow-up, when accounting for redo procedures and AADs. Only 2.4% of patients experienced major complications of the ablation procedure, none with permanent sequelae.

Including hemoglobin levels and female sex provide the additional predictive value of the APPLE score for atrial fibrillation recurrence post-catheter ablation

OBJECTIVE

We probed whether the addition of hemoglobin (HGB) or the female sex (SEX) as variables would provide additional prognostic value to the APPLE score.

METHODS

An optimized APPLE score was used to evaluate the AF recurrence risk in the consecutive populations with AF post-catheter ablation including the development (n = 562) and validation (n = 239) cohorts.

RESULTS

In the populations of AF recurrence, most patients were female sex (103/164, 62.8%), and had the lower HGB levels. After adjusting for the APPLE score, HGB level (Odds Ratio [OR], 0.828; 95% Confidence Interval [CI], 0.749-0.915; P < 0.001) and female sex (OR, 1.596; 95% CI, 1.140-2.235; P = 0.006) independently predicted AF recurrence. Adjusting the APPLE score by HGB variable improved its predictive ability for AF recurrence (C-statistic value from 0.675 to 0.711, P = 0.010), which also increased the C-indexes in the external validation (from 0.653 to 0.725, p = 0.023). The female sex variable also enhanced the C-statistic value of the APPLE score for AF recurrence at both development and external validation (C-indices from 0.675 to 0.691, P = 0.004; C-indices from 0.653 to 0.704, p = 0.037, respectively). Decision curve analysis showed that the HGB plus APPLE score was better than the SEX plus APPLE score in predicting AF recurrence in two following AF populations.

CONCLUSION

The inclusion of HGB level and female sex variables improved the predictability and clinical usefulness of adjusted APPLE score. Adjustment of the APPLE score by HGB levels may provide better predictive value than inclusion of the female sex variable.

Electrographic flow mapping of persistent atrial fibrillation: intra- and inter-procedure reproducibility in the absence of 'ground truth'

AIMS

Validating mapping systems that identify atrial fibrillation (AF) sources (focal/rotational activity) is confounded by the absence of ground truth. A key concern of prior mapping technologies is spatiotemporal instability, manifesting as poor map reproducibility. Electrographic flow (EGF) employs a novel algorithm that visualizes atrial electrical wavefront propagation to identify putative AF sources. We analysed both intra- (3 min) and inter- (>3 months) procedure EGF map reproducibility.

METHODS AND RESULTS

In 23 persistent AF patients, after pulmonary vein isolation (PVI), EGF maps were generated from 3 serial 1 min recordings using a 64-electrode basket mapping catheter (triplets) at right and left atrial locations. Source prevalence from map triplets was compared between recordings. Per protocol, 12 patients returned for 3-month remapping (1 non-inducible): index procedure post-PVI EGF maps were compared with initial EGF remapping at 3-month redo. Intra-procedure reproducibility: analysing 224 map triplets (111 right atrium, 113 left atrium) revealed a high degree of map consistency with minimal min-to-min shifts: 97 triplets (43%), exact match of leading sources on all 3 maps; 95 triplets (42%), leading source within 1 electrode space on 2 of 3 maps; and 32 triplets (14%), chaotic leading source pattern. Average deviation in source prevalence over 60 s was low (6.4%). Inter-procedure reproducibility: spatiotemporal stability of EGF mapping >3 months was seen in 16 of 18 (89%) sources mapped in 12 patients with (re)inducible AF.

CONCLUSION

Electrographic flow mapping generates reproducible intra- and inter-procedural maps, providing rationale for randomized clinical trials targeting these putative AF sources.

Long-Term Impact of Additional Ablation After Pulmonary Vein Isolation: Results From EARNEST-PVI Trial

Background An optimal strategy for left atrial ablation in addition to pulmonary vein isolation (PVI) in patients with persistent atrial fibrillation (AF) has not been determined. Methods and Results We conducted an extended follow-up of the multicenter randomized controlled EARNEST-PVI (Efficacy of Pulmonary Vein Isolation Alone in Patients With Persistent Atrial Fibrillation) trial, which compared 12-month rhythm outcomes in patients with persistent AF between patients randomized to a PVI-alone strategy (n=248) or PVI-plus strategy (n=248; PVI followed by left atrial additional ablation, including linear ablation or ablation targeting areas with complex fractionated electrograms). The present study extended the follow-up period to 3 years after enrollment. Outcomes were compared not only between randomly allocated groups but also between on-treatment groups categorized by actually created ablation lesions. Recurrence rate of AF or atrial tachycardia (AT) was lower in the randomly allocated to PVI-plus group than the PVI-alone group (29.0% versus 37.5%, P=0.036). On-treatment analysis revealed that patients with PVI+linear ablation (n=205) demonstrated a lower AF/AT recurrence rate than those with PVI only (26.3% versus 37.8%, P=0.007). In contrast, patients with PVI+complex fractionated electrograms ablation (n=37) had an AF/AT recurrence rate comparable to that of patients with PVI only (40.5% versus 37.8%, P=0.76). At second ablation in 126 patients with AF/AT recurrence, ATs excluding common atrial flutter were more frequent in patients with PVI+linear ablation than in those with PVI only (32.6% versus 5.7%, P<0.0001). Conclusions Left atrial ablation in addition to PVI was efficacious during 3-year follow-up. Linear ablation was superior to other ablation strategies but may increase iatrogenic ATs. Registration URL: http://www.umin.ac.jp/ctr/index-j.htm; Unique identifier: UMIN000019449.

Freedom from atrial arrhythmia and other clinical outcomes at 5 years and beyond after catheter ablation of atrial fibrillation: a systematic review and meta-analysis

AIMS

Catheter ablation of atrial fibrillation (AF) is now a mainstream procedure although long-term outcomes are uncertain. We performed a systematic review and meta-analysis of procedural outcomes at 5 years and beyond.

METHODS AND RESULTS

We searched PubMed and Embase and after the screening, identified 73 studies (67 159 patients) reporting freedom from atrial arrhythmia, all-cause death, stroke, and major bleeding at ≥5 years after AF ablation. The pooled mean age was 59.7y, 71.5% male, 62.2% paroxysmal AF, and radiofrequency was used in 78.1% of studies. Pooled incidence of freedom from atrial arrhythmia at 5 years was 50.6% (95%CI 45.5-55.7%) after a single ablation and 69.7% [95%CI (confidence interval) 63.8-75.3%) after multiple procedures. The incidence was higher among patients with paroxysmal compared with non-paroxysmal AF after single (59.7% vs. 33.3%, p = 0.002) and multiple (80.8% vs. 60.6%, p < 0.001) ablations but was comparable between radiofrequency and cryoablation. Pooled incidences of other outcomes were 6.0% (95%CI 3.2-9.7%) for death, 2.4% (95%CI 1.4-3.7%) for stroke, and 1.2% (95%CI 0.8-2.0%) for major bleeding at 5 years. Beyond 5 years, freedom from arrhythmia recurrence remained largely stable (52.3% and 64.7% after single and multiple procedures at 10 years), while the risk of stroke and bleeding increased over time.

CONCLUSION

Nearly 70% of patients having multiple ablations remained free from atrial arrhythmia at 5 years, with the incidence slightly decreasing beyond this period. Risk of death, stroke, and major bleeding at 5 years were low but increased over time, emphasizing the importance of long-term thromboembolism prevention and bleeding risk management.

Association with the nonparoxysmal atrial fibrillation duration and outcome of ExTRa Mapping-guided rotor ablation

Background

Additional ablation strategies after pulmonary vein isolation (PVI) for patients with nonparoxysmal atrial fibrillation (non-PAF) lasting ≥2 years have not been fully effective. This is presumably because of insufficient identification of non-PAF maintenance mechanisms. In this study, we employed a novel online and real-time phase mapping system, ExTRa Mapping, to identify and modulate rotors as one of the non-PAF maintenance mechanisms in patients with non-PAF sustained after PVI. We investigated the relationship between outcomes of ExTRa Mapping-guided rotor ablation (ExTRa-ABL) and non-PAF duration prior to this procedure.

Methods

This study consisted of 73 non-PAF patients (63 ± 8 years, non-PAF duration 31 ± 37 months) who underwent the first ExTRa-ABL in patients with non-PAF sustained after completion of PVI.

Results

Freedom from non-PAF/atrial tachycardia (AT) recurrence at 12 months after ExTRa-ABL was achieved in 50 (69%) of patients. The non-PAF duration prior to ExTRa-ABL was significantly longer in patients with non-PAF/AT recurrence after ExTRa-ABL compared with those without (56 ± 50 vs. 19 ± 22 months, p = .001). In patients with non-PAF duration of ≤60 months prior to ExTRa-ABL, compared with >60 months, non-PAF/AT-free rate was significantly higher (68.9% vs. 23.1%, p < .001), during the follow-up of 36 ± 18 months.

Conclusions

A non-PAF duration of ≤60 months prior to ExTRa-ABL was associated with a better outcome. The effect of ExTRa-ABL was considered to be limited in patients with >60 months of non-PAF duration.

Electrographic flow mapping for atrial fibrillation: theoretical basis and preliminary observations

Ablation strategies remain poorly defined for persistent atrial fibrillation (AF) patients with recurrence despite intact pulmonary vein isolation (PVI). As the ability to perform durable PVI improves, the need for advanced mapping to identify extra-PV sources of AF becomes increasingly evident. Multiple mapping technologies attempt to localize these self-sustained triggers and/or drivers responsible for initiating and/or maintaining AF; however, current approaches suffer from technical limitations. Electrographic flow (EGF) mapping is a novel mapping method based on well-established principles of optical flow and fluid dynamics. It enables the full spatiotemporal reconstruction of organized wavefront propagation within the otherwise chaotic and disorganized electrical conduction of AF. Given the novelty of EGF mapping and relative unfamiliarity of most clinical electrophysiologists with the mathematical principles powering the EGF algorithm, this paper provides an in-depth explanation of the technical/mathematical foundations of EGF mapping and demonstrates clinical applications of EGF mapping data and analyses. Starting with a 64-electrode basket catheter, unipolar EGMs are recorded and processed using an algorithm to visualize the electrographic flow and highlight the location of high prevalence AF "source" activity. The AF sources are agnostic to the specific mechanisms of source signal generation.

A novel stepwise approach incorporating ethanol infusion in the vein of Marshall for the ablation of persistent atrial fibrillation

Introduction

Apart from pulmonary vein isolation (PVI), several step-by-step procedures that aim to modify left atrial substrate have been proposed for the ablation of persistent atrial fibrillation (AF), yet the optimal strategy remains elusive. There are cumulative data suggesting an incremental benefit of adding vein of Marshall (VOM) ethanol infusion to PVI in patients with persistent AF. We sought to evaluate the feasibility and efficacy of a novel stepwise ablation approach, incorporating a VOM alcoholization step, for persistent AF.

Methods

In this single-center study, we prospectively enrolled 66 consecutive patients with symptomatic persistent AF and failure of at least one antiarrhythmic drug (ADD). The ablation procedure consisted of (i) PVI, (ii) left atrial segmentation with VOM ethanol infusion and the deployment of linear radiofrequency lesions across the roof and the mitral isthmus and (iii) electrogram-based ablation of dispersion zones. The first two steps were performed in all patients, whereas the third step was carried out only in those still in AF at the end of the second step. Atrial tachycardias during the procedure were mapped and ablated. At the end of the procedure, cavotricuspid isthmus ablation was additionally performed in all patients. The primary endpoint was 12-month freedom from AF and atrial tachycardia after a single procedure and an initial three-month blanking period.

Results

Total procedure time was 153 ± 38.5 min. Fluoroscopy time was 16 ± 6.5 min and the radiofrequency ablation time was 26.14 ± 0.26 min. The primary endpoint occurred in 54 patients (82%). At 12 months, 65% of patients were off any AAD. In the univariate Cox regression analysis, left ventricular ejection fraction < 40% was the only predictor of arrhythmia recurrence (HR 3.56; 95% CI, 1.04-12.19; p = 0.04). One patient developed a pericardial tamponade and another a minor groin hematoma.

Conclusion

A novel stepwise approach, including a step of ethanol infusion in the VOM, is feasible, safe and provides a high rate of sinus rhythm maintenance at 12 months in patients with persistent AF.

Predictors of Maintenance of Sinus Rhythm After Radiofrequency Catheter Ablation for Long-Standing Persistent Atrial Fibrillation

Little has been reported on the predictors of maintenance of sinus rhythm (SR) after radiofrequency catheter ablation (RFCA) for long-standing persistent atrial fibrillation (AF). We enrolled 151 patients with long-standing persistent AF (defined as AF lasting more than 12 months) who underwent an initial RFCA between October 2014 and December 2020 in our hospital. These patients were categorized into 2 groups on the basis of the absence and presence of the late recurrence (LR, defined as a recurrence of atrial tachyarrhythmia between 3 and 12 months after RFCA): SR group and LR group. The SR group comprised 92 patients (61%). In the univariate analysis, there were significant differences in gender and preprocedural average heart rate (HR) between the 2 groups (p = 0.042 and p = 0.042, respectively). A receiver operating characteristics analysis revealed that a cut-off value of preprocedural average HR to predict the maintenance of SR was 85 beats/min (sensitivity: 37%, specificity: 85%, area under curve: 0.58). A multivariate analysis showed that preprocedural average HR ≥85 beats/min was independently associated with the maintenance of SR after RFCA (odds ratio 3.30, 95% confidence interval 1.47 to 8.04, p = 0.003). In conclusion, a relatively high preprocedural average HR might be a prognostic factor of maintenance of SR after RFCA for long-standing persistent AF.

Catheter Ablation for Atrial Fibrillation in Structural Heart Disease: A Review

Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice. Patients with structural heart disease (SHD) are at an increased risk of developing this arrhythmia and are particularly susceptible to the deleterious hemodynamic effects it carries. In the last two decades, catheter ablation (CA) has emerged as a valuable strategy for rhythm control and is currently part of the standard care for symptomatic relief in patients with AF. Growing evidence suggests that CA of AF may have potential benefits that extend beyond symptoms. In this review, we summarize the current knowledge of this intervention on SHD patients.

Temporal trends in atrial fibrillation ablation procedures at an academic medical center: 2011-2021

INTRODUCTION

Radiofrequency ablation technology for treating atrial fibrillation (AF) has evolved rapidly over the past decade. We investigated the impact of technological and procedural advances on procedure times and ablation outcomes at a major academic medical center over a 10-year period.

METHODS

Clinical data was collected from patients who presented to NYU Langone Health between 2011 and 2021 for a first-time AF ablation. Time to redo AF ablation or direct current cardioversion (DCCV) for recurrent AF during a 3-year follow-up period was determined and correlated with ablation technology and practices, antiarrhythmic medications, and patient comorbid conditions.

RESULTS

From 2011 to 2021, the cardiac electrophysiology lab adopted irrigated-contact force ablation catheters, high-power short duration ablation lesions, steady-pacing, jet ventilation, and eliminated stepwise linear ablation for AF ablation. During this time the number of first time AF ablations increased from 403 to 1074, the percentage of patients requiring repeat AF-related intervention within 3-years of the index procedure dropped from 22% to 14%, mean procedure time decreased from 271 ± 65 to 135 ± 36 min, and mean annual major adverse event rate remained constant at 1.1 ± 0.5%. Patient comorbid conditions increased during this time period and antiarrhythmic use was unchanged.

CONCLUSION

Rates of redo-AF ablation or DCCV following an initial AF ablation at a single center decreased 36% over a 10-year period. Procedural and technological changes likely contributed to this improvement, despite increased AF related comorbidities.

Atrial cardiomyopathy: Diagnosis, clinical implications and unresolved issues in anticoagulation therapy

Atrial cardiomyopathy (AC) is an evolving pathophysiological entity that has expanded our understanding regarding the atrium and its role in arrhythmogenesis and cardiac thromboembolism. The pathological myocardium in AC promotes arrhythmogenesis through mechanical dysfunction (hypocontractility, fibrosis), adverse alterations of the endothelium and secretion of prothrombotic factors (IL-6, IL-8, TNF-a). 'Red flags', indicative of AC, can be recognized either non-invasively by electrocardiography, echocardiography and cardiac magnetic resonance imaging or invasively by high-density electroanatomical mapping as low bipolar voltage areas of the affected myocardium. Signs of AC have been strongly associated with an increased risk of ischemic stroke, even embolic strokes of undetermined source, regardless of the coexistence of atrial fibrillation (AF). The underlying existence of AC has been negatively correlated with the success rate of catheter ablation of AF. The clinical value of AC is the provision of a novel pathway regarding the potential mechanisms of cerebrovascular events of cardiac thromboembolic origin. In addition, AC may serve as a risk stratification tool to predict the long-term responders of AF catheter ablation.

His-Purkinje conduction system pacing and atrioventricular node ablation in treatment of persistent atrial fibrillation refractory to multiple ablation procedures: A case report

In patients with symptomatic atrial fibrillation refractory to optimal medical therapy, atrioventricular node ablation followed by permanent pacemaker implantation is an effective treatment option. A 66-year-old woman with symptomatic persistent atrial fibrillation refractory to multiple ablation procedures was referred to our institution. After optimal drug therapy, the patient still had obvious symptoms. Sequential His-Purkinje conduction system pacing and atrioventricular node ablation were performed. Left bundle branch pacing was used as a backup pacing method if thresholds of His bundle pacing were too high or loss of His bundle capture occurred in the follow-up. At the 6-month follow-up, the European Heart Rhythm Association classification for AF was improved, the score of the Atrial Fibrillation Effect on Quality of Life was enhanced, and the 6-Minute Walk Test was ameliorated. The present case was subjected to His-Purkinje conduction system pacing in combination with atrioventricular node ablation as treatment for a symptomatic persistent atrial fibrillation refractory to multiple ablation procedures, and this procedure alleviated symptoms and improved the quality of life in a short-term follow-up.

Predicting acute termination and non-termination during ablation of human atrial fibrillation using quantitative indices

Background: Termination of atrial fibrillation (AF), the most common arrhythmia in the United States, during catheter ablation is an attractive procedural endpoint, which has been associated with improved long-term outcome in some studies. It is not clear, however, whether it is possible to predict termination using clinical data. We developed and applied three quantitative indices in global multielectrode recordings of AF prior to ablation: average dominant frequency (ADF), spectral power index (SPI), and electrogram quality index (EQI). Methods: In N = 42 persistent AF patients (65 ± 9 years, 14% female) we collected unipolar electrograms from 64-pole baskets (Abbott, CA). We studied N = 17 patients in whom AF terminated during ablation ("Term") and N = 25 in whom it did not ("Non-term"). For each index, we determined its ability to predict ablation by computing receiver operating characteristic (ROC) and calculated the area under the curve (AUC). Results: The ADF did not differ for Term and Non-term patients at 5.28 ± 0.82 Hz and 5.51 ± 0.81 Hz, respectively (p = 0.34). Conversely, the SPI for these two groups was. 0.85 (0.80-0.92) and 0.97 (0.93-0.98) and the EQI was 0.61 (0.58-0.64) and 0.56 (0.55-0.59) (p < 0.0001). The AUC for predicting AF termination for the SPI was 0.85 ([0.68, 0.95] 95% CI), and for the EQI, 0.86 ([0.72, 0.95] 95% CI). Conclusion: Both the EQI and the SPI may provide a useful clinical tool to predict procedural ablation outcome in persistent AF patients. Future studies are required to identify which physiological features of AF are revealed by these indices and hence linked to AF termination or non-termination.

Ethanol Infusion of Vein of Marshall for the Treatment of Persistent Atrial Fibrillation: The Basics and Clinical Practice

Catheter ablation for persistent atrial fibrillation (PeAF) is particularly challenging, as the clinical outcomes are modest. Pulmonary vein isolation (PVI) plus linear ablation is one of the main strategies for PeAF ablation. Completely durable transmural lesions are difficult to achieve by catheter ablation during mitral isthmus ablation. The ligament of Marshall contains the vein of Marshall (VOM), myocardial tracts and innervation, and serves as arrhythmogenic foci that make it an attractive target in catheter ablation of atrial fibrillation. Additionally, it co-localizes with the mitral isthmus, and may serve as a part of the perimitral isthmus reentrant circuit. Ethanol infusion into the VOM results in rapid ablation of the neighboring myocardium and its innervation. Its incorporation into PVI significantly increases the success rate of mitral isthmus block and the clinical outcome of PeAF ablation.

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.

Sex Differences in the Outcomes of Cryoablation for Atrial Fibrillation

Background

The literature data on the outcomes of radiofrequency catheter ablation for atrial fibrillation (AF) in women are contradictory.

Aim

To determine and compare the outcomes and complications of cryoballoon pulmonary vein isolation (cryo-PVI) in men vs. women, and to identify predictors of atrial tachyarrhythmia (ATa) recurrence.

Methods

We included all consecutive patients having undergone cryo-PVI for the treatment of symptomatic AF in our center since 2012. Peri-operative complications were documented. All patients were prospectively monitored for the recurrence of ATa, and predictors were assessed.

Results

A total of 733 patients were included (550 men (75%) and 183 (25%) women). Paroxysmal AF was recorded in 112 (61%) female patients and 252 male patients (46%; p < 0.001). Female patients were older (p < 0.001) and had a greater symptom burden (p = 0.04). Female patients were more likely to experience complications (p = 0.02). After cryo-PVI for paroxysmal AF, 66% of the female patients and 79% of the male patients were free of ATa at 24 months (p = 0.001). Female sex was the only independent predictive factor for ATa recurrence (hazard ratio [95% confidence interval] = 1.87 [1.28; 2.73]; p = 0.001). After cryo-PVI for non-paroxysmal AF, 37% of the male patients and 39% of the female patients were free of ATa at 36 months (p = 0.73). Female patients were less likely than male patients to undergo repeat ablation after an index cryo-PVI for non-paroxysmal AF (p = 0.019).

Conclusion

A single cryo-PVI procedure for paroxysmal AF was significantly less successful in female patients than in male patients. Overall, the complication rate was higher in women than in men.

Ten year experience with the concomitant Maze IV procedure for atrial fibrillation

OBJECTIVE

The Maze IV (M-IV) procedure is regarded as the golden standard in treatment for surgical ablation of atrial fibrillation (AF); however, long-term follow-up results are scarce. We present our institutional 10-year experience.

METHODS

We collected data of 117 consecutive patients who have undergone a concomitant M-IV procedure between April 2006 and April 2016. Primary endpoints are freedom of atrial arrhythmias and freedom of atrial arrhythmias off antiarrhythmic drugs (AAD).

RESULTS

Forty-seven patients (40.2%) had paroxysmal AF. Two-thirds of the procedures included mitral valve surgery. The average follow-up time per patient was 3.8 years (SD 2.8). Freedom of AF at 1 year was 79%, at 5 years freedom of AF was 69% and freedom of AF off AAD was 56%. Predictors of AF recurrence in multivariate analysis were age, preoperative pacemakers, redo cardiac surgery and in-hospital AF. Preoperative PVI ablation was found to be a protective factor.

CONCLUSIONS

The long-term outcomes of the M-IV procedure are good and remain stable over the years. Results could be improved if follow-up were to be intensified and recurrences dealt with aggressively. Key question: How many patients are free from AF in a 10-year period after concomitant M-IV surgical ablation? Key findings: In the long term around 70% of patients are free of AF with an increasing need for anti-arrhythmic drugs. Take home message: Early to midterm freedom from AF after concomitant M-IV procedure is high and remains stable after 3 years.

Recurrence of atrial fibrillation post-ablation: which is the most effective approach for detection?

Over the last 20 years, catheter ablation of atrial fibrillation (AF) has evolved from a research tool into a fundamental therapeutic measure, with the potential to improve symptoms, quality of life, and even risk of major adverse cardiac events (among patients with heart failure and a reduced ejection fraction). Notwithstanding the tremendous evolution in techniques and tools, risk of AF recurrences post-ablation is not negligible, and a comprehensive structured follow-up is highly needed to deliver optimal patient care. In this follow-up process, monitoring of heart rhythm is quintessential to detect recurrences, and may be accomplished by means of symptoms-triggered, intermittent, or continuous monitors. In recent years, the development and widespread adoption of implantable cardiac monitors, by allowing continuous long-term rhythm assessment, has surged to become the gold-standard strategy, both in research settings and in clinical practice. In this review, we both summarize the present state-of-the art on the detection of post-ablation AF recurrences, and provide future perspectives on this emerging yet often neglected topic, aiming to give practical hints for evidence-based, personalized patient care.

Classification of Fibrillation Organisation Using Electrocardiograms to Guide Mechanism-Directed Treatments

Background: Atrial fibrillation (AF) and ventricular fibrillation (VF) are complex heart rhythm disorders and may be sustained by distinct electrophysiological mechanisms. Disorganised self-perpetuating multiple-wavelets and organised rotational drivers (RDs) localising to specific areas are both possible mechanisms by which fibrillation is sustained. Determining the underlying mechanisms of fibrillation may be helpful in tailoring treatment strategies. We investigated whether global fibrillation organisation, a surrogate for fibrillation mechanism, can be determined from electrocardiograms (ECGs) using band-power (BP) feature analysis and machine learning. Methods: In this study, we proposed a novel ECG classification framework to differentiate fibrillation organisation levels. BP features were derived from surface ECGs and fed to a linear discriminant analysis classifier to predict fibrillation organisation level. Two datasets, single-channel ECGs of rat VF (n = 9) and 12-lead ECGs of human AF (n = 17), were used for model evaluation in a leave-one-out (LOO) manner. Results: The proposed method correctly predicted the organisation level from rat VF ECG with the sensitivity of 75%, specificity of 80%, and accuracy of 78%, and from clinical AF ECG with the sensitivity of 80%, specificity of 92%, and accuracy of 88%. Conclusion: Our proposed method can distinguish between AF/VF of different global organisation levels non-invasively from the ECG alone. This may aid in patient selection and guiding mechanism-directed tailored treatment strategies.

Ablation index-guided pulmonary vein isolation can reduce early recurrences of atrial tachyarrhythmias: a propensity score-matched analysis

PURPOSE

Early recurrence of atrial tachyarrhythmias (ERAT) cause various symptoms and predict worse outcomes after pulmonary vein isolation (PVI). This study aimed to clarify whether ablation index (AI)-guided PVI, which is a novel technology of radiofrequency ablation, could reduce ERAT as compared to conventional contact force (CF)-guided PVI.

METHODS

Consecutive atrial fibrillation (AF) patients who underwent initial PVI from September 2014 to August 2019 were enrolled. We divided the patients into two groups: patients who underwent AI-guided PVI (AI group) and those who underwent CF-guided PVI (CF group). Using propensity score matching (PSM), we adjusted for the patient backgrounds. We compared the incidence of ERAT and late reconnection rate of isolated pulmonary veins (PVs) during second session between the two groups. ERAT was defined as any atrial tachyarrhythmias ≥ 30 s during a 90-day blanking period.

RESULTS

A total of 697 AF patients (paroxysmal 51%) were enrolled. After the PSM, both groups included 229 patients. The incidence of ERAT was significantly lower in the AI group than that in the CF group (21.5% vs. 36.1%, P < 0.001). Total 118 patients (25.7%) experienced late recurrence of atrial tachyarrhythmias (LRAT) after blanking period. LRAT free survival rate was significantly higher in patients without ERAT than those with ERAT (88.1% vs. 42.0%, P < 0.001). The rate of PV reconnection was lower in the AI group than that in the CF group (45.8% vs. 71.4%, P = 0.028). Multivariate analysis demonstrated that AI-guided PVI was independently correlated with ERAT (OR = 0.415, 95%CI = 0.269-0.639, P < 0.001).

CONCLUSIONS

AI-guided PVI can reduce ERAT as compared to conventional CF-guided PVI.

Multi-catheter cryotherapy compared with radiofrequency ablation in long-standing persistent atrial fibrillation: a randomized clinical trial

AIMS

Restoring sinus rhythm (SR) by ablation alone is an endpoint used in radiofrequency (RF) ablation for long-standing persistent atrial fibrillation (AF) but not with cryotherapy. The simultaneous use of two cryotherapy catheters can improve ablation efficiency; we compared this with RF ablation in chronic persistent AF aiming for termination to SR by ablation alone.

METHODS AND RESULTS

Consecutive patients undergoing their first ablation for persistent AF of >6 months duration were screened. A total of 100 participants were randomized 1:1 to multi-catheter cryotherapy or RF. For cryotherapy, a 28-mm Arctic Front Advance was used in tandem with focal cryoablation catheters. Open-irrigated, non-force sensing catheters were used in the RF group with a 3D mapping system. Pulmonary vein (PV) isolation and non-PV triggers were targeted. Participants were followed up at 6 and 12 months, then yearly. Acute PVI was achieved in all cases. More patients in the multi-catheter cryotherapy group were restored to SR by ablation alone, with a shorter procedure duration. Sinus rhythm continued to the last available follow-up in 16/49 patients (33%) in the multi-catheter at 3.0 ± 1.6 years post-ablation and in 12/50 patients (24%) in the RF group at 4.0 ± 1.2 years post-ablation. The yearly rate of arrhythmia recurrence was similar.

CONCLUSION

Multi-catheter cryotherapy can restore SR by ablation alone in more cases and more quickly than RF ablation. Long-term success is difficult to achieve by either methods and is similar with both.

Atrial Remodeling in Atrial Fibrillation. Comorbidities and Markers of Disease Progression Predict Catheter Ablation Outcome

Atrial fibrillation is the most common supraventricular arrhythmia affecting an increasing proportion of the population in which mainstream therapy, i.e. catheter ablation, provides freedom from arrhythmia in only a limited number of patients. Understanding the mechanism is key in order to find more effective therapies and to improve patient selection. In this review, the structural and electrophysiological changes of the atrial musculature that constitute atrial remodeling in atrial fibrillaton and how risk factors and markers of disease progression can predict catheter ablation outcome will be discussed in detail.

Role of the Ambulatory Assessed Apnea-Hypopnea Index for Predicting Recurring Atrial Fibrillation After Ablation Therapy

Catheter ablation is an effective treatment for atrial fibrillation (AF). Obstructive sleep apnea (OSA) is a known risk factor for recurrent AF. The apnea-hypopnea index (AHI) is a measurement tool to screen patients for OSA. We sought to evaluate if the ambulatory assessed AHI is associated with AF recurrence following AF catheter ablation. 187 patients with paroxysmal (n = 155) or early persistent (n = 32) AF presenting for catheter ablation were included in the study. AHI was determined prior to ablation using an ambulatory screening device. All patients underwent pulmonary vein isolation (PVI). In patients with early persistent AF (17%) additional ablation of complex fractionated atrial electrograms (CFAE) was performed. Clinical follow-up was available after 3 and 12 months including 7-day Holter-ECG. All 187 patients (60.3 ± 11.4 years, 64.2% male) completed the 3 months follow-up and 170 patients the 12 months follow-up. A pathological AHI ≥15 was found in 45/187 (24.1%) patients. Additional CFAE did not differ between patients with an AHI ≥15 and AHI <15 (p = 0.663). After 3 months, 12/41 (29.3%) patients with AHI ≥15 showed recurrent AF compared to 24/146 (16.4%) patients with AHI <15 (p = 0.066). After 12 months, AHI ≥15 was associated with a significant higher rate of AF recurrence of 47.4% (18/38) versus 26.5% (35/132) in patients with AHI <15 (p = 0.014). In the logistic regression analysis AHI ≥15 was an independent predictor of recurrent AF at 12 months (p = 0.011). In conclusion, ambulatory assessed AHI ≥15 is associated with increased risk for AF recurrence following catheter ablation. OSA screening should be performed in AF patients as it might influence catheter ablation success.

Subjective assessment of complexity and prognosis after pulmonary vein isolation as significant predictor for procedural success

PURPOSE

Subjective estimation of recurrence after atrial fibrillation ablation is an important tool in clinical use. The aim of this study is to evaluate (1) if the subjective complexity of an atrial fibrillation ablation procedure is correlated with rhythm stability and (2) if the subjective prognosis of the operator has a predictive value.

METHODS

We prospectively enrolled patients admitted for ablation of atrial fibrillation. Two scores were given immediately after the procedure by the operator: the complexity and the prognosis scores. With routine follow-ups, we tried to evaluate the correlation between the subjective scores and measured outcome.

RESULTS

The study population included 611 patients (63 ± 10 years, 37% females, 61% persistent AF). During follow-up (FU) (median 24, IQR 7-36 months), recurrences occurred in 44% patients. Both scores (prognosis and complexity) correlated significantly with age, persistent AF, LA diameter, procedural characteristics, and recurrences. On multivariable analysis, complexity (OR 1.304, 95%CI 1.016-1.675, p = 0.037) and prognosis (OR 1.443, 95%CI 1.080-1.982, p = 0.013) scores remained significant predictors for arrhythmia recurrences. On ROC analysis, both scores showed significant predictive value for rhythm outcomes after catheter ablation (AUC 0.599 and 0.613, both p < 0.001 for complexity and prognosis scores, respectively).

CONCLUSIONS

Complexity and prognosis scores are significant predictors for arrhythmia recurrences after AF catheter ablations and even independent when competing with simple risk factors.

18F-fluorodeoxyglucose positron emission tomography/computed tomography imaging in atrial fibrillation: a pilot prospective study

AIMS

This prospective study explored relevant factors and clinical significance of atrial 18F-fluorodeoxyglucose (FDG) uptake in patients with atrial fibrillation (AF).

METHODS AND RESULTS

One hundred AF patients underwent baseline FDG imaging prior to radiofrequency catheter ablation (RFCA). Of those, 30 subjects underwent additional FDG imaging at 3 months post-RFCA. Voltage mapping of the left atrium was analysed as a voltage score. Patients who received RFCA were followed for 26 months (17-31 months) to assess recurrence. At baseline FDG imaging, 74% of patients with persistent AF (PsAF) and 24% of patients with paroxysmal AF showed increased atrial FDG uptake. The prevalence was higher in the right atrium (49%) than in the left atrium (15%, P < 0.001) or left atrial appendage (21%, P < 0.001). Multivariate analysis demonstrated that PsAF and elevated B-type natriuretic peptide (BNP) were related to enhanced right atrial (RA) activity, and increased epicardial adipose tissue (EAT) activity was predictive of left atrial (LA) activity. LA activity was inversely associated with voltage score, while increased FDG uptake in the right atrium was predictive of successful AF termination by RFCA. Atrial FDG activities decreased significantly post-RFCA, but none of the FDG parameters were predictive of AF recurrence.

CONCLUSIONS

Enhanced RA activity was associated with elevated BNP level, whereas LA activity was related to the increased activity of EAT and inversely correlated with LA fibrosis. Increased RA activity was predictive of successful AF termination by RFCA in PsAF patients.

Functional electrographic flow patterns in patients with persistent atrial fibrillation predict outcome of catheter ablation

Aims

Electrographic flow (EGF) mapping is a method to detect action potential sources within the atria. In a double‐blinded retrospective study we evaluated whether sources detected by EGF are related to procedural outcome.

Methods

EGF maps were retrospectively generated using the Ablamap® software from unipolar data recorded with a 64‐pole basket catheter from patients who previously underwent focal impulse and rotor modulation‐guided ablation. We analyzed patient outcomes based on source activity (SAC) and variability. Freedom from atrial fibrillation (AF) was defined as no recurrence of AF, atypical flutter or atrial tachycardia at the follow‐up visits.

Results

EGF maps were from 123 atria in 64 patients with persistent or long‐standing persistent AF. Procedural outcome correlation with SAC peaked at >26%. S‐type EGF signature (source‐dependent AF) is characterized by stable sources with SAC > 26% and C‐type (source‐independent AF) is characterized by sources with SAC ≤ 26%. Cases with AF recurrence at 3‐, 6‐, or 12‐month follow‐up showed a median final SAC 34%; while AF‐free patients had sources with significantly lower median final SAC 21% (p = .0006). Patients with final SAC and Variability above both thresholds had 94% recurrence, while recurrence was only 36% for patients with leading source SAC and variability below threshold (p = .0001). S‐type EGF signature post‐ablation was associated with an AF recurrence rate 88.5% versus 38.1% with C‐type EGF signature.

Conclusions

EGF mapping enables the visualization of active AF sources. Sources with SAC > 26% appear relevant and their presence post‐ablation correlates with high rates of AF recurrence.

Intraprocedural arrhythmia termination as an end point for hybrid ablation in patients with long-standing persistent atrial fibrillation: a 2-year follow-up study

OBJECTIVES

Hybrid catheter and surgical ablation has emerged as an effective therapy for patients with persistent atrial fibrillation (AF). The aims of this study were to evaluate the relationship between intraprocedural arrhythmia termination and the long-term outcomes of hybrid ablation in patients with long-standing persistent AF.

METHODS

From May 2015 through April 2019, 50 patients with persistent AF with a mean duration of 73.3 ± 62.1 (median 54) months underwent single-step hybrid ablation. Pulmonary vein isolation, left atrial posterior wall isolation and left atrial appendage excision or closure were performed through a left-sided thoracoscopic approach. Subsequently, all patients underwent high-density endocardial mapping and electrogram-based ablation with the end point of AF termination.

RESULTS

We achieved intraprocedural AF termination in 84% (42/50) patients; this end point was reached in 16 patients during surgical ablation and in 26 patients during catheter ablation. Seven patients underwent repeat catheter ablation. After a mean follow-up period of 29 ± 13 months, the freedom from atrial tachyarrhythmia of a single procedure without the use of antiarrhythmic drugs was 70% (35/50). In the Cox regression model, intraprocedural termination of AF (hazard ratio 0.205, 95% confidence interval 0.058-0.730; P = 0.014) was the sole predictor of success.

CONCLUSIONS

The 2-year outcomes of a one-stop hybrid ablation with an end point of AF termination are promising in patients with long-standing persistent AF.

Ablation of Atrial Fibrillation in Patients With Hypertrophic Cardiomyopathy: Treatment Strategy, Characteristics of Consecutive Atrial Tachycardia and Long-Term Outcome

Background

Atrial fibrillation (AF) is common in patients with hypertrophic cardiomyopathy (HCM) and is associated with a deterioration of clinical status. Ablation of symptomatic AF is an established therapy, but in HCM, the characteristics of recurrent atrial arrhythmias and the long‐term outcome are uncertain.

Methods and Results

Sixty‐five patients with HCM (aged 64.5±9.9 years, 42 [64.6%] men) underwent AF ablation. The ablation strategy included pulmonary vein isolation in all patients and ablation of complex fractionated atrial electrograms or subsequent atrial tachycardias (AT) if appropriate. Paroxysmal, persistent AF, and a primary AT was present in 13 (20.0%), 51 (78.5%), and 1 (1.5%) patients, respectively. Twenty‐five (38.4%) patients developed AT with a total number of 54 ATs. Stable AT was observed in 15 (23.1%) and unstable AT in 10 (15.3%) patients. The mechanism was characterized as a macroreentry in 37 (68.5%), as a localized reentry in 12 (22.2%), a focal mechanism in 1 (1.9%), and not classified in 4 (7.4%) ATs. After 1.9±1.2 ablation procedures and a follow‐up of 48.1±32.5 months, freedom of AF/AT recurrences was demonstrated in 60.0% of patients. No recurrences occurred in 84.6% and 52.9% of patients with paroxysmal and persistent AF, respectively (P<0.01). Antiarrhythmic drug therapy was maintained in 24 (36.9%) patients.

Conclusions

AF ablation in patients with HCM is effective for long‐term rhythm control, and especially patients with paroxysmal AF undergoing pulmonary vein isolation have a good clinical outcome. ATs after AF ablation are frequently observed in HCM. Freedom of atrial arrhythmia is achieved by persistent AF ablation in a reasonable number of patients even though the use of antiarrhythmic drug therapy remains high.

Biatrial ablation vs. Pulmonary vein isolation in atrial fibrillation patients undergoing cardiac surgery: a retrospective study

OBJECTIVES

Surgical ablation is an established treatment for patients with atrial fibrillation undergoing cardiac surgery. This study aimed to compare postoperative rhythm outcomes and pacemaker implantation rates after biatrial ablation or pulmonary vein isolation (PVI) concomitantly with other cardiac surgery. Design: In a retrospective study, we included patients who underwent biatrial ablation or PVI. Postoperative rhythm status was assessed by Holter monitoring. All data on outcomes and patient characteristics were collected retrospectively. Results: In total 109 patients had a biatrial procedure whereas 337 had PVI performed. In patients with persistent/long-standing persistent atrial fibrillation, freedom from atrial fibrillation was more common after biatrial ablation than after PVI (63% and 45%, respectively; p = .039). Postoperative permanent pacemaker implantation was more common after biatrial ablation (12% and 6%, respectively; p = .039), compared to PVI. Age < 65 years (OR:2.0, 95% CI:1.1-3.6) was a predictor of freedom from atrial fibrillation in the biatrial group, whereas absence of left atrial dilatation (OR:1.8, 95% CI:1.1-3.2) and HAS-BLED score < 2 (OR:1.9, 95% CI:1.0-3.8) were significant predictors of freedom from atrial fibrillation in the PVI group. Conclusions: In patients with persistent/long-standing persistent atrial fibrillation, biatrial ablation is more effective than PVI in terms of obtaining freedom from postoperative atrial fibrillation. Although our groups were heterogenic in terms of concomitant surgery, our study also indicates that the risk of needing a permanent pacemaker is higher after biatrial ablation, compared to PVI. Therefore, our study highlights that the decision between biatrial ablation or PVI should be performed on an individual basis.

Simultaneous hybrid maze procedure for long-standing persistent atrial fibrillation with dilated atrium

Background

The efficacy of catheter-based or thoracoscopic ablation for treating long-standing persistent atrial fibrillation (AF) with a dilated atrium remains suboptimal. This study aimed to assess the feasibility and initial results of simultaneous hybrid ablation with a new biatrial lesion set in these patients.

Methods

Twenty-seven consecutive patients with long-standing persistent AF and dilated atrium underwent simultaneous hybrid ablation with a new biatrial lesion set consistent with the principle of the Cox maze procedure at our institution. Patients were followed up at 3, 6, and 12 months after the procedure and annually thereafter.

Results

After thoracoscopic epicardial ablation, endocardial mapping confirmed complete bilateral pulmonary vein isolation in 25 patients (96.2%). All patients were followed for a mean of 18.7 ± 8.9 months. Freedom from atrial tachyarrhythmia at 1 year after the single hybrid procedure was 64% with antiarrhythmic drugs and 60% without antiarrhythmic drugs. Freedom from atrial tachyarrhythmia at latest follow-up after the hybrid procedure and redo catheter ablation was 77.8% with antiarrhythmic drugs and 74.1% without antiarrhythmic drugs. In patients with sinus rhythm restoration, mean left atrial diameter decreased from 54.4 ± 4.3 mm to 45.2 ± 4.1 mm (P < .001), and mean right atrial diameter decreased from 59.4 ± 3.9 mm to 54.9 ± 4.4 mm (P < .001). Postoperative pleural effusion was observed in 3 patients (11.1%), and no adverse events occurred during follow-up.

Conclusions

In patients with long-standing persistent AF and a dilated atrium, simultaneous hybrid ablation with the new biatrial lesion set, in combination with touch-up catheter ablation when necessary, can achieve promising results. More studies are needed to confirm these findings.

Retrospective analysis of FIRM-guided ablation in patients with recurrent atrial fibrillation: a single-center study

BACKGROUND

Ablation of recurrent atrial fibrillation (AF) is common. Studies indicate that AF recurrence is primarily due to pulmonary vein (PV) re-conduction. This retrospective analysis characterized and evaluated recurrent AF patients using focal impulse and rotor mapping (FIRM) plus PV re-isolation, with follow up at 3, 6, 12, and 24 months after the repeat ablation.

METHODS AND RESULTS

Patients (consecutive, n = 100) underwent FIRM-guided ablation followed by conventional PV re-isolation for recurrent AF treatment. All FIRM patients had failed one or more conventional ablation procedures (1.4 ± 0.08) for paroxysmal (14%), persistent (15%), and long-standing persistent (71%) AF. Stable rotors were identified in 97/100 patients: 60% in the right atrium (RA) and 82% in left atrium (LA) (mean 1.5 ± 0.8 and 2.1 ± 1.2 per patient, respectively). No correlation was noted between the previous number of ablations, AF duration, or LA diameter to the number of rotors (R² = 0.0039, R² = 0.0017, and R² = 0.006, respectively). In this limited observation, only 22% of identified rotors were associated with proximity to low voltage areas. The 12- and 24-month arrhythmia free rate was 93% (13/14) and 92% (12/13) for paroxysmal AF, 60% (9/15) and 47% (7/15) for persistent AF, and 70% (48/69) and 64% (43/67) for long-standing persistent AF, respectively, after a single FIRM procedure and re-isolation of the veins.

CONCLUSIONS

The data show a benefit for FIRM-guided ablation in recurrent AF at 12 months. No correlation was found between rotors and tissue characterization, AF duration, or previous number of ablations, suggesting that rotors may play an independent role in maintaining recurrent AF after prior failed ablation.

Toward Mechanism-Directed Electrophenotype-Based Treatments for Atrial Fibrillation

Current treatment approaches for persistent atrial fibrillation (AF) have a ceiling of success of around 50%. This is despite 15 years of developing adjunctive ablation strategies in addition to pulmonary vein isolation to target the underlying arrhythmogenic substrate in AF. A major shortcoming of our current approach to AF treatment is its predominantly empirical nature. This has in part been due to a lack of consensus on the mechanisms that sustain human AF. In this article, we review evidence suggesting that the previous debates on AF being either an organized arrhythmia with a focal driver or a disorganized rhythm sustained by multiple wavelets, may prove to be a false dichotomy. Instead, a range of fibrillation electrophenotypes exists along a continuous spectrum, and the predominant mechanism in an individual case is determined by the nature and extent of remodeling of the underlying substrate. We propose moving beyond the current empirical approach to AF treatment, highlight the need to prescribe AF treatments based on the underlying AF electrophenotype, and review several possible novel mapping algorithms that may be useful in discerning the AF electrophenotype to guide tailored treatments, including Granger Causality mapping.

Efficacy of an Adjunctive Electrophysiological Test-Guided Left Atrial Posterior Wall Isolation in Persistent Atrial Fibrillation Without a Left Atrial Low-Voltage Area

BACKGROUND

Electrical remodeling precedes structural remodeling. In adjunctive left atrial (LA) low-voltage area (LVA) ablation to pulmonary vein isolation of atrial fibrillation (AF), LA areas without LVA have not been targeted for ablation. We studied the effect of adjunctive LA posterior wall isolation (PWI) on persistent AF without LA-LVA according to electrophysiological testing (EP test).

METHODS

We examined consecutive patients with persistent AF with (n=33) and without (n=111) LA-LVA. Patients without LA-LVA were randomly assigned to EP test-guided (n=57) and control (n=54) groups. In the EP test-guided group, an adjunctive PWI was performed in those with positive results (PWI subgroup; n=24), but not in those with negative results (n=33). The criteria for positive EP tests were an effective refractory period ≤180 ms, effective refractory period>20 ms shorter than the other sites, and/or induction of AF/atrial tachycardia (AT) during measurements. LVA ablation was performed in the patients with LA-LVA.

RESULTS

During the follow-up period (62±33 weeks), the EP test-guided group had significantly lower recurrence rates (19%,11/57 versus 41%, 22/54, P=0.012) and higher Kaplan-Meier AF/AT-free survival curve rates than the control group (P=0.01). No significant differences in the recurrence and AF/AT-free survival curve rates between the PWI (positive EP test) and non-PWI (negative EP test) subgroups were observed. Therefore, PWI for positive EP tests reduced the AF/AT recurrence in the EP test-guided group. A stepwise Cox proportional hazard analyses identified EP test-guided ablation as a factor reducing the recurrence rate. The recurrence rates in the LA-LVA ablation group and EP test-guided group were similar.

CONCLUSIONS

This pilot study proposed that an EP test-guided adjunctive PWI of persistent AF without LA-LVA potentially reduced AF/AT recurrences. The results suggest that there is an AF substrate in the LA with altered electrophysiological function even when there is no LA-LVA. Graphic Abstract: A graphic abstract is available for this article.