Benefit of pulmonary vein isolation guided by loss of pace capture on the ablation line: results from a prospective 2-center randomized trial

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.

Colchicine Prevents Post-Ablation Atrial Fibrillation Recurrence: A Systematic Review and Meta-Analysis

Catheter ablation for atrial fibrillation (AF) is a commonly performed procedure, however, post-ablation AF recurrence is often observed due to inflammation and oxidative stress. Colchicine is a potent anti-inflammatory agent with conflicting efficacy in preventing post-ablation AF recurrence. A comprehensive literature search of the major bibliographic databases was conducted to retrieve studies comparing colchicine use versus placebo in AF patients post-ablation. Odds ratios (ORs) with 95% confidence intervals (CIs) were pooled using the DerSimonian-Laird random-effects model. Statistical significance was set at P < 0.05. Six studies were included with 1791 patients (721 in the colchicine group and 1070 in the placebo group). Patients who received colchicine had significantly lower odds of AF recurrence on follow-up (OR, 0.62; 95% CI, 0.48-0.79; P = 0.0001) but had higher gastrointestinal side effects (OR, 2.67; 95% CI, 1.00-7.12; P = 0.05). There were no statistically significant differences in acute pericarditis (OR, 0.54; 95% CI, 0.27-1.05; P = 0.07) or hospitalization (OR, 1.03; 95% CI, 0.73-1.45; P = 0.87). Prophylactic use of colchicine after catheter ablation in patients with AF leads to a reduction in AF recurrence, albeit with increased gastrointestinal side effects. Colchicine use did not lead to a reduction in the rates of pericarditis and hospitalization after ablation. Large randomized controlled trials are necessary to evaluate the efficacy of colchicine in preventing AF recurrence, particularly focusing on the dose and duration of treatment to optimize the side effect profile.

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 .

Identification of recurrent atrial fibrillation using natural language processing applied to electronic health records

AIMS

This study aimed to develop and apply natural language processing (NLP) algorithms to identify recurrent atrial fibrillation (AF) episodes following rhythm control therapy initiation using electronic health records (EHRs).

METHODS AND RESULTS

We included adults with new-onset AF who initiated rhythm control therapies (ablation, cardioversion, or antiarrhythmic medication) within two US integrated healthcare delivery systems. A code-based algorithm identified potential AF recurrence using diagnosis and procedure codes. An automated NLP algorithm was developed and validated to capture AF recurrence from electrocardiograms, cardiac monitor reports, and clinical notes. Compared with the reference standard cases confirmed by physicians' adjudication, the F-scores, sensitivity, and specificity were all above 0.90 for the NLP algorithms at both sites. We applied the NLP and code-based algorithms to patients with incident AF (n = 22 970) during the 12 months after initiating rhythm control therapy. Applying the NLP algorithms, the percentages of patients with AF recurrence for sites 1 and 2 were 60.7% and 69.9% (ablation), 64.5% and 73.7% (cardioversion), and 49.6% and 55.5% (antiarrhythmic medication), respectively. In comparison, the percentages of patients with code-identified AF recurrence for sites 1 and 2 were 20.2% and 23.7% for ablation, 25.6% and 28.4% for cardioversion, and 20.0% and 27.5% for antiarrhythmic medication, respectively.

CONCLUSION

When compared with a code-based approach alone, this study's high-performing automated NLP method identified significantly more patients with recurrent AF. The NLP algorithms could enable efficient evaluation of treatment effectiveness of AF therapies in large populations and help develop tailored interventions.

Comparison of pulsed-field ablation versus very high power short duration-ablation for pulmonary vein isolation

BACKGROUND

The newly introduced nonthermal pulsed field ablation (PFA) is a promising technology to achieve fast pulmonary vein isolation (PVI) with high acute success rates and good safety features. However, previous studies have shown that very high power short duration ablation (VHPSD) is also highly effective and fast to achieve PVI with potentially less arrhythmia recurrence compared to conventional radiofrequency ablation. Data comparing PFA to VHPSD-PVI is lacking.

OBJECTIVE

This study compared procedural and outcome data for PFA-PVI to VHPSD-PVI in patients with paroxysmal or persistent atrial fibrillation (PAF/persAF).

METHODS

Consecutive patients undergoing de novo PVI (PFA or VHPSD) were included in this analysis. For PFA-PVI a pentaspline 20 electrode catheter was used. For VHPSD-PVI an enhanced irrigated catheter with a power setting of 70 W/7 s (70 W/5 s at posterior wall) was employed in conjunction with electro-anatomical mapping. All procedures were performed in deep analgo-sedation.

RESULTS

A total of n = 114 patients (n = 57[50%] PFA, n = 17[30%] PAF; n = 40[70%] persAF) were included in this analysis. PVI was successful in all patients. The PFA group revealed a significantly shorter procedure duration (65 ± 17 min vs. 95 ± 23 min, p < 0.01) but longer fluoroscopy time (PFA 15 ± 5 min and VHPSD 12 ± 3 min; p < 0.001). At follow-up after median 125 days (interquartile range: 109-162) n = 46 PFA (80.7%) and n = 44 VHPSD pts (77.2%) were free from atrial arrhythmia after a single procedure (p = 0.819). Two tamponades occurred in the PFA while in VHPSD two pts suffered groin bleedings. One clinically nonsignificant PV stenosis occurred in the VHPSD group.

CONCLUSION

Pulsed-field ablation and VHPSD-PVI seem to be highly effective and safe to achieve PVI in the setting of PAF and persAF with comparable arrhythmia-free survival. However, procedure duration for PFA PVI is significantly shorter and therefore may be of potential benefit. Compared to PFA VHPSD-PVI might ensure information on left atrial substrate allowing to target concomitant secondary tachycardias.

Methods and techniques for increasing the safety and efficacy of pulmonary vein isolation in patients with atrial fibrillation

The most common type of sustained arrhythmia is atrial fibrillation (AF). Pulmonary vein isolation (PVI) is the cornerstone of catheter ablation for atrial fibrillation, which has emerged as the primary therapeutic strategy for atrial fibrillation patients. Unfortunately, about one-third of patients experience recurrent atrial arrhythmias after the procedure.

Ablation of residual potentials along the circumferential line reduces acute pulmonary vein reconnection

INTRODUCTION

Acute pulmonary vein (PV) reconnection is frequently encountered in patients undergoing PV isolation (PVI) procedure for the treatment of atrial fibrillation. In this study, we investigated whether the identification and ablation of residual potentials (RPs), after the initial achievement of PVI, reduces acute PV reconnection rate.

METHODS

Following PVI in 160 patients, mapping along the ablation line was performed to identify RPs, defined as bipolar amplitude ≥0.2 mV or 0.1-0.19 mV combined with a negative component of the unipolar electrogram. Ipsilateral PV sets with RPs were randomized to either no further ablation (Group B) or to additional ablation of the identified RPs (Group C). The primary study endpoint was spontaneous or adenosine-mediated acute PV reconnection after a 30-min waiting period and was also evaluated in ipsilateral PV sets without RPs (Group A).

RESULTS

After isolation of 287 PV pairs, 135 had no RPs (Group A), whereas the remaining PV pairs were randomized to either Group B (n = 75) or Group C (n = 77). Ablation of RPs resulted in a reduction of spontaneous or adenosine-mediated PV reconnection rate (16.9% in Group C vs 48.0% in Group B; p < 0.001). Group A was associated with a significantly lower percentage of acute PV reconnection as compared to Group B (5.9% vs 48.0%; p < 0.001) and Group C (5.9% vs 16.9%; p = 0.016).

CONCLUSION

After PVI achievement, the absence of RPs along the circumferential line is associated with a low likelihood of acute PV reconnection rate. Ablation of RPs significantly reduces spontaneous or adenosine-mediated acute PV reconnection rate.

Pulmonary vein isolation for atrial fibrillation using true high-power short-duration vs. cryoballoon ablation

AIMS

Pulmonary vein isolation (PVI) is achievable and effective using radiofrequency (RF) catheter (CA) or cryoballoon (CB) ablation. The newly introduced high RF-power short-duration ablation (HPSD) technique has shown promising results. Data comparing HPSD- to CB-PVI is sparse. We sought to investigate success rates and procedural differences of HPSD-PVI vs. CB-PVI in patients undergoing ablation for PAF and persAF.

METHODS

Consecutive patients undergoing de novo PVI (HPSD or CB) were included. A power setting of 70W/7 s (70W/5 s at posterior wall) using a flexible tip catheter with enhanced irrigation was considered as true HPSD. Follow-up consisted of out-clinic pts visits, tele-consultation, 48-h Holter ECG, app-based telemonitoring and cardiac implanted electronic devices (CIED) interrogation.

RESULTS

721 patients (46 HPSD, 675 CB) were analyzed. In all HPSD (27 persAF [59%]) and CB patients (423 persAF [63%]), PVI was successfully achieved. Procedure duration was significantly longer for HPSD (91 ± 19 min vs. 72 ± 18 min, p < 0.01). Ablation time was similar in both groups (HPSD: 44 ± 19 min vs. CB: 40 ± 17 min; p = 0.347). No major complications occurred in HPSD. For CB-PVI, in 25 (3.7%; p = 0.296) patients, complications occurred. At a follow-up of 290 ± 135 days, arrhythmia-free survival using HPSD was non-inferior to CB-PVI in the Kaplan-Meier survival analysis (p = 0.096).

CONCLUSION

PVI using HPSD is equally effective and safe to CB-PVI. This analysis revealed a similar arrhythmia-free survival after HPSD and CB with low complication rates. Procedure duration for CB was significantly shorter while LA dwell time excluding mapping was equal. Currently, a prospective trial is conducted to corroborate these findings.

Procedural and outcome impact of obesity in cryoballoon versus radiofrequency pulmonary vein isolation in atrial fibrillation patients

PURPOSE

Cryoballoon (CB) ablation and radiofrequency (RF) ablation are the most common techniques for pulmonary vein isolation (PVI) in patients with symptomatic atrial fibrillation (AF). An increasing number of patients undergoing PVI are obese. To address the paucity of data on outcomes of CB- vs. RF-based PVI in relation to body mass index (BMI) of AF patients.

METHODS

All patients undergoing de novo PVI between 01/2018 and 08/2019 at University Hospital Cologne were included in this retrospective analysis. Patients of each group (CB-PVI vs. RF-PVI) were analyzed based on their BMI. Hereafter, procedural characteristics and AF recurrence rate were compared regarding different BMI groups.

RESULTS

A total of 526 patients (62% male, 65±11 years) underwent successful de novo PVI (320 CB and 206 RF). In obese patients, two differences in procedural characteristics were noted: A significantly increased contrast medium volume in CB group and a lower fluoroscopy dose in RF group: contrast medium: CB 50 [40-80] vs. RF 20 [20-30], p<0.001; fluoroscopy dose: CB 392.4 [197.9-995.9] vs. RF 282.5 [139.8-507.2], p<0.001. The complication rate was equal throughout all BMI groups, regardless of CB or RF usage. For obese patients, a trend toward a higher AF recurrence rate was revealed after RF-PVI as compared to CB-PVI. In line with previous studies, the overall procedure time was significantly shorter with CB-PVI regardless of BMI.

CONCLUSION

For obese patients, CB-PVI is similarly safe and effective as RF-PVI. The significantly shorter procedure time for CB-PVI may minimize potential obesity-related complications. However, the lower contrast medium quantity and fluoroscopy dose in RF-PVI must be considered. AF recurrence rates were comparable between CB-PVI and RF-PVI.

What we have learned: is pulmonary vein isolation still the cornerstone of atrial fibrillation ablation?

Ablation of atrial fibrillation (AF) is an established treatment option for symptomatic patients. The cornerstone of all ablation strategies is electrical isolation of the pulmonary veins (PVs). Ablation strategies going beyond PV isolation (PVI) might be considered in the setting of recurrent AF despite durably isolated PVs. The lack of persistent PVI, however, limits the opportunities to perceive the real impact of this endpoint on AF suppression and to fully understand the benefit of extended ablation strategies going beyond. To overcome this limitation, novel and innovative ablation systems have been developed to facilitate acute PVI and to increase its durability. These systems include balloon-based ablation devices incorporating different energy sources such as cryo energy, laser, or radiofrequency current, but also new energy sources such as pulsed field ablation as a non-thermal energy source. These technologies could advance catheter ablation of AF to an early stage of the disease and to the primary treatment tool. The current manuscript focuses on the past, the present, and the future value of PVI as the cornerstone for interventional treatment of AF and on how to achieve durable PVI during the first procedure and to further improve the clinical success rates of AF ablation. It also analyses extended ablation strategies going beyond PVI and their impact.

Radiofrequency ablation to achieve durable pulmonary vein isolation

Pulmonary vein isolation (PVI) by radiofrequency (RF) ablation is an important alternative to antiarrhythmic drugs in the treatment of symptomatic atrial fibrillation. However, the inability to consistently achieve durable isolation of the pulmonary veins hampers the long-term efficacy of PVI procedures. The large number of factors involved in RF lesion formation and the complex interplay of these factors complicate reliable creation of durable and transmural ablation lesions. Various surrogate markers of ablation lesion formation have been proposed that may provide information on RF lesion completeness. Real-time assessment of these surrogates may aid in the creation of transmural ablation lesions, and therefore, holds potential to decrease the risk of PV reconnection and consequent post-PVI arrhythmia recurrence. Moreover, titration of energy delivery until lesions is transmural may prevent unnecessary ablation and subsequent adverse events. Whereas several surrogate markers of ablation lesion formation have been described over the past decades, a 'gold standard' is currently lacking. This review provides a state-of-the-art overview of ablation strategies that aim to enhance durability of RF-PVI, with special focus on real-time available surrogates of RF lesion formation in light of the biophysical basis of RF ablation.

Durable pulmonary vein isolation but not complex substrate ablation determines the type of arrhythmia recurrence after persistent atrial fibrillation ablation

BACKGROUND

Complex ablation for persistent atrial fibrillation (AF) aims to modify the arrhythmogenic substrates to become incapable to perpetuate the arrhythmia. Ablation-associated determinants of atrial tachycardia (AT) rather than AF recurrences are unknown. The aim of the study was to evaluate the association between the type of arrhythmia recurrence and electrophysiological findings during redo procedures.

METHODS

A total number of 384 consecutive patients with persistent AF underwent complex ablation consisting of PV isolation (PVI), biatrial electrogram-guided ablation, and linear ablation with the desired procedural endpoint of AF termination. Electrophysiological findings during redo procedures and its relation to AR type are the subject of this study.

RESULTS

Overall, 177 (46%) patients underwent a second procedure. Patients with AT recurrences had significantly more often persistent PVI (47 vs. 25%; P = 0.002). Moreover, a higher number of recovered PVs were associated with AF recurrence (3 PVs recovered, AF = 16.1% vs. AT = 5.2%; P = 0.02; 4 PVs recovered, AF = 18.5% vs. AT = 6.3%; P = 0.01), regardless of the extent of substrate ablation during the first procedure.

CONCLUSIONS

Durable PV isolation but not the extent of atrial substrate ablation determines the type of arrhythmia recurrence. Thus, the PVs may represent dominant perpetuators (and not only triggers) of persistent AF even in the presence of a significantly modified atrial substrate.

Comparison of lesion characteristics between conventional and high-power short-duration ablation using contact force-sensing catheter in patients with paroxysmal atrial fibrillation

Background

Transmural lesion creation is essential for effective atrial fibrillation (AF) ablation. Lesion characteristics between conventional energy and high-power short-duration (HPSD) setting in contact force-guided (CF) ablation for AF remained unclear.

Methods

Eighty consecutive AF patients who received CF with conventional energy setting (power control: 25–30 W, force–time integral = 400 g s, n = 40) or with HPSD (power control: 40–50 W, 10 s, n = 40) ablation were analyzed. Of them, 15 patients in each conventional and HPSD group were matched by age and gender respectively for ablation lesions analysis. Type A and B lesions were defined as a lesion with and without significant voltage reduction after ablation, respectively. The anatomical distribution of these lesions and ablation outcomes among the 2 groups were analyzed.

Results

1615 and 1724 ablation lesions were analyzed in the conventional and HPSD groups, respectively. HPSD group had a higher proportion of type A lesion compared to conventional group (P < 0.01). In the conventional group, most type A lesions were at the right pulmonary vein (RPV) posterior wall (50.2%) whereas in the HPSD group, most type A lesions were at the RPV anterior wall (44.0%) (P = 0.04). The procedure time and ablation time were significantly shorter in the HPSD group than that in the conventional group (91.0 ± 12.1 vs. 124 ± 14.2 min, P = 0.03; 30.7 ± 19.2 vs. 57.8 ± 21 min, P = 0.02, respectively). At a mean follow-up period of 11 ± 1.4 months, there were 13 and 7 patients with recurrence in conventional and HPSD group respectively (P = 0.03).

Conclusion

Optimal ablation lesion characteristics and distribution after conventional and HPSD ablation differed significantly. HPSD ablation had shorter ablation time and lower recurrence rate than did conventional ablation.

[Pulmonary vein isolation using radiofrequency ablation]

Catheter ablation represents the primary treatment for most arrhythmias. The effectiveness of catheter ablation for the treatment of atrial fibrillation is superior to drug therapy. Therefore, catheter ablation has been established as an increasingly common procedure in clinical routine. In this context, the electrical isolation of the pulmonary veins (PVI) constitutes the cornerstone of the interventional therapy of paroxysmal and persistent atrial fibrillation. This article describes the procedure of pulmonary vein isolation utilizing radiofrequency point-by-point ablation. It shall be a practical guide for the staff in the electrophysiological laboratory. This article continues a series of manuscripts focusing on interventional electrophysiology topics in the course of EP (electrophysiology) training.This article describes the procedure of pulmonary vein isolation utilizing radiofrequency point-by-point ablation. It shall be a practical guide for the staff in the electrophysiological laboratory. This article continues a series of manuscripts dealing with topics of interventional electrophysiology in the course of EP training.

Integrated 3D intracardiac ultrasound imaging with detailed pulmonary vein delineation guided fluoroless ablation of atrial fibrillation

BACKGROUND

Intracardiac echocardiography (ICE) has become an all-round tool for ablation of atrial fibrillation (AF) since it plays an important role in all procedural steps. The key upgrade to the usefulness of ICE is its integration into three-dimensional (3D) electroanatomic mapping (EAM) system (ICE/EAM automatic integration system). The aim of this single-center retrospective study was to evaluate feasibility, safety and acute efficacy of ICE/EAM automatic integration system guided fluoroless ablation of AF.

METHODS

The study included patients with symptomatic paroxysmal or persistent AF undergoing first pulmonary vein isolation (PVI) radiofrequency (RF) catheter ablation (RFCA) from September 2017 to August 2020. All procedures were performed without the use of fluoroscopy. A detailed 3D virtual anatomy of the left atrium (LA) and structures relevant to AF ablation was constructed from ultrasound contours obtained with ICE probe inside the LA. Pulmonary veins (PVs) and antral regions were additionally mapped with fast anatomical mapping (FAM). PVI was performed with contact force (CF) sensing catheter. Procedural endpoint was successful PVI.

RESULTS

A total of 98 consecutive patients underwent RFCA (34.7% females, median age 64.4 years, 64.3% paroxysmal AF). Acute PVI was achieved in all patients (100%). Forty-three patients (43.9%) underwent additional ablations for concomitant arrhythmias. Adverse events were detected in four patients (4.1%). The median procedure duration was 130 min (IQR 103.8-151.3). If only PVI was done the median procedure duration was 110.5 (IQR 100.0-133.8) CONCLUSIONS: ICE/EAM automatic integration system guided fluoroless ablation of AF is feasible, safe and acutely effective method for treatment of symptomatic AF.

Nicht invasive Vagusstimulation zur Behandlung von paroxysmalem Vorhofflimmern: eine vielversprechende Alternative?

Autonome Dysbalance kann die Wahrscheinlichkeit für das Auftreten von paroxysmalem Vorhofflimmern beeinflussen. Frühere Studien haben gezeigt, dass die Ablation autonomer Ganglien im linken Vorhof Rezidive von Vorhofflimmern reduzieren kann. Die bisherige Therapie von Vorhofflimmern besteht aus wenig effektiven medikamentösen Ansätzen und potenziell mit Risiken behafteten invasiven Verfahren, wie der katheterbasierten Isolation der Pulmonalvenen. Eine einfach durchzuführende nicht invasive Stimulation des N. vagus könnte eine mögliche Therapieoption sein. Die Effektivität dieses Verfahrens ist in einer kürzlich erschienenen randomisierten Arbeit mit einer relativ geringen Anzahl von Patienten untersucht worden. Der vorliegende Artikel gibt einen Überblick über die Therapie und ordnet den Stellenwert perspektivisch ein.

Optimizing Durability in Radiofrequency Ablation of Atrial Fibrillation

Radiofrequency ablation (RFA) remains a highly effective therapy in the management of paroxysmal atrial fibrillation (PAF) and is an important therapeutic option in the management of persistent atrial fibrillation (PeAF) when clinically indicated. Lesion size is influenced by many parameters, which include those related to energy application (RFA power, temperature, and time), delivery mechanism (electrode size, orientation, and contact force), and the environment (blood flow and local tissue contact, stability, and local impedance). Successful durable RFA is dependent on achieving lesions that are reliably transmural and contiguous, whilst also avoiding injury to the surrounding structures. This review focuses on the variables that can be adjusted in connection with RFA to achieve long-lasting lesions that enable patients to derive the maximum sustained benefit from pulmonary vein isolation and additional lesion sets if utilized.

The Effect of the Enhanced Endpoint of Pulmonary Vein Isolation on the Long-Term Success Rate of Radiofrequency Ablation for Atrial Fibrillation

Objective

This study aimed to investigate whether the enhanced endpoint of pulmonary vein isolation (PVI; intravenous injection of adenosine-triphosphate [ATP] + pacing capture + supplemental ablation) after initial PVI can reduce the long-term recurrence rate of atrial fibrillation (AF) after PVI.

Methods

Patients with paroxysmal or persistent AF undergoing catheter ablation treatment were enrolled in this study and divided into three groups according to the surgical endpoint: (1) group 1 (n = 92), in which patients were observed for 30 minutes after the initial PVI and pulmonary vein–left atrium (PV–LA) electrical conduction had not recovered; (2) group 2 (n = 99), in which patients were observed for 30 minutes after the initial PVI, then intravenously injected with ATP, and PV–LA electrical conduction had not recovered; and (3) group 3 (n = 102), in which patients were observed for 30 minutes after the initial PVI, then intravenously injected with ATP + treated with ablation line pacing, and the atrium could not be captured.

Results

Patients were followed up for 12 months after the operation. Twenty-eight patients in group 1 (30.4%), 19 patients in group 2 (19.2%), and 10 patients in group 3 (9.8%) developed a recurrence of AF. The difference between groups 1 and 3 was statistically significant (p < 0.001). At 12 months after the operation, the thickness of the left atrium, the posterior wall of the left ventricle, and the ventricular septum of the three groups of patients were significantly thinner than before the operation. Furthermore, the left ventricular ejection fraction had increased (p < 0.05 for all), and the pulmonary artery pressure had decreased (p < 0.001).

Conclusion

For patients with paroxysmal AF or persistent AF, the enhanced endpoint of PVI after the initial PVI can reduce the long-term recurrence rate of AF after PVI.

Catheter ablation for atrial fibrillation in a low-volume center using contemporary technology

BACKGROUND

Catheter ablation is increasingly being performed worldwide for atrial fibrillation (AF). However, there are concerns of lower success rates and higher complications of AF ablations performed in low-volume centers. Thus, we sought to evaluate the safety and efficacy of AF catheter ablation in a low-volume center using contemporary technologies.

METHODS AND RESULTS

71 consecutive patients (50 paroxysmal AF [pAF] vs 21 persistent AF) who underwent first catheter ablation were studied. Primary outcome was AF recurrence rate. Secondary outcomes included periprocedural complications, hospitalization for symptomatic tachy-arrhythmias post-ablation and number of repeat ablations. Mean age of our cohort was 59.1 ± 9.7 years, of which 56 (78.9%) were males. 1-year AF recurrence was 19.5% in pAF and 23.8% in persistent AF (p = 0.694). Ablation in persistent AF group required longer procedural (197.76 ± 48.60 min [pAF] vs 238.67 ± 70.50 min [persistent AF], p = 0.006) and ablation duration (35.08 ± 15.84 min [pAF] vs 52.65 ± 28.46 min [persistent AF], p = 0.001). There were no significant differences in secondary outcomes. Major periprocedural complication rate was 2.8%.Subset analysis on (i) cryoablation vs radiofrequency, (ii) Ensite vs CARTO navigational system and (iii) circular vs high density mapping catheter did not yield significant differences in primary or secondary outcomes.

CONCLUSIONS

The AF ablation complication and recurrence free rates in both paroxysmal and persistent AF at one year were comparable to high-volume centers. Long-term follow up is needed. In addition, first AF catheter ablation in a low-volume center is realistic with comparable efficacy and safety outcomes to high-volume centers using contemporary ablation technologies.

Multiple procedure outcomes for nonparoxysmal atrial fibrillation: Left atrial posterior wall isolation versus stepwise ablation

OBJECTIVE

To compare multiple-procedure catheter ablation outcomes of a stepwise approach versus left atrial posterior wall isolation (LA PWI) in patients undergoing nonparoxysmal atrial fibrillation (NPAF) ablation.

BACKGROUND

Unfavorable outcomes for stepwise ablation of NPAF in large clinical trials may be attributable to proarrhythmic effects of incomplete ablation lines. It is unknown if a more extensive initial ablation strategy results in improved outcomes following multiple ablation procedures.

METHODS

Two hundred twenty two consecutive patients with NPAF underwent first-time ablation using a contact-force sensing ablation catheter utilizing either a stepwise (Group 1, n = 111) or LA PWI (Group 2, n = 111) approach. The duration of follow-up was 36 months. The primary endpoint was freedom from atrial arrhythmia >30 s. Secondary endpoints were freedom from persistent arrhythmia, repeat ablation, and recurrent arrhythmia after repeat ablation.

RESULTS

There was similar freedom from atrial arrhythmias after index ablation for both stepwise and LA PWI groups at 36 months (60% vs. 69%, p = .1). The stepwise group was more likely to present with persistent recurrent arrhythmia (29% vs. 14%, p = .005) and more likely to undergo second catheter ablation (32% vs. 12%, p < .001) compared to LA PWI patients. Recurrent arrhythmia after repeat ablation was more likely in the stepwise group compared to the LA PWI group (15% vs. 4%, p = .003).

CONCLUSIONS

Compared to a stepwise approach, LA PWI for patients with NPAF resulted in a similar incidence of any atrial arrhythmia, lower incidence of persistent arrhythmia, and fewer repeat ablations. Results for repeat ablation were not improved with a more extensive initial approach.

Catheter Ablation of Low-Voltage Areas for Persistent Atrial Fibrillation: Procedural Outcomes Using High-Density Voltage Mapping

BACKGROUND

Several approaches have been proposed to address the challenge of catheter ablation of persistent atrial fibrillation (AF). However, the optimal ablation strategy is unknown. We sought to evaluate the efficacy of pulmonary vein isolation (PVI) plus low-voltage area (LVA) ablation using contemporary high-density mapping to identify LVA in patients with persistent AF.

METHODS

Consecutive patients accepted for AF catheter ablation were studied. High-density bipolar voltage mapping data were acquired in sinus rhythm using multipolar catheters to detect LVA (defined as bipolar voltage < 0.5 mV). Semiautomated impedance-based software was used to ensure catheter contact during data collection. Patients underwent PVI + LVA ablation (if LVA present).

RESULTS

A total of 145 patients were studied; 95 patients undergoing PVI + LVA ablation were compared with 50 controls treated with PVI only. Average age was 61 ± 10 years, and 80% were male. Baseline characteristics were comparable. Freedom from atrial tachycardia/AF at 18 months was 72% after PVI + LVA ablation vs 58% in controls (P = 0.022). Median procedure duration (273 [240, 342] vs 305 [262, 360] minutes; P = 0.019) and radiofrequency delivery (50 [43, 63] vs 55 [35, 68] minutes; P = 0.39) were longer in the PVI + LVA ablation group. Multivariable analysis showed that the ablation strategy (PVI + LVA) was the only independent predictor of freedom from atrial tachycardia/AF (hazard ratio, 0.53; 95% confidence interval, 0.29-0.96; P = 0.036). There were no adverse safety outcomes associated with LVA ablation.

CONCLUSIONS

An individualized strategy of high-density mapping to assess the atrial substrate followed by PVI combined with LVA ablation is associated with improved outcomes. Adequately powered randomized clinical trials are needed to determine the role of PVI + LVA ablation for persistent AF.

The feasibility and effectiveness of a streamlined single-catheter approach for radiofrequency atrial fibrillation ablation

BACKGROUND

Catheter ablation for atrial fibrillation (AF) traditionally requires the use of circular mapping catheter (CMC) for pulmonary vein isolation (PVI). This study aimed to assess the feasibility and effectiveness of a CMC-free approach for AF ablation performed by a contiguous optimized (CLOSE) ablation protocol.

METHODS

A CLOSE-guided and CMC-free PVI protocol with a single transseptal puncture was attempted in 67 patients with AF. Left atrial (LA) CARTO voltage mapping was performed with the ablation catheter pre- and postablation to demonstrate entry block into the pulmonary veins, and pacing maneuvers were used to confirm exit block.

RESULTS

The CMC-free approach was successful in achieving PVI in 66 (98.5%) cases, with procedure time of 148 ± 32 minutes, ablation time of 27.5 ± 5.7 minutes, and fluoroscopy time of 7.8 ± 1.0 minutes. First-pass PVI was seen in 58(86.5%) patients, and pacing maneuvers successfully identified the residual gap in eight of the other nine cases. No complication was observed. At 12 months follow-up, 60 (89.6%) patients remained free from AF. The CMC-free approach resulted in a cost saving of £47,190.

CONCLUSION

A CMC-free CLOSE-guided PVI approach is feasible, safe, and cost-saving, and is associated with excellent clinical outcomes at 1 year.

A novel local impedance algorithm to guide effective pulmonary vein isolation in atrial fibrillation patients: Preliminary experience across different ablation sites from the CHARISMA pilot study

INTRODUCTION

Recently, a novel technology able to measure local impedance (LI) and tissue characteristics has been made available for clinical use. This analysis explores the relationships among LI and generator impedance (GI) parameters in atrial fibrillation (AF) patients. Characterization of LI among different ablation spots and procedural success were also evaluated.

METHODS AND RESULTS

Consecutive patients undergoing AF ablation from the CHARISMA registry at five Italian centers were included. A novel radiofrequency (RF) ablation catheter with a dedicated algorithm (DIRECTSENSE™) was used to measure LI and to guide ablation. The ablation endpoint was pulmonary vein (PV) isolation. We analyzed 2219 ablation spots created around PVs in 46 patients for AF ablation. The mean baseline tissue impedance was 105.8 ± 14 Ω for LI versus 91.8 ± 10 Ω for GI (p < .0001). Baseline impedance was homogenous across the PV sites and proved higher in high-voltage areas than in intermediate- and low-voltage areas and the blood pool (p < .001). Both LI and GI displayed a significant drop after RF delivery, and absolute LI drop values were significantly larger than GI drop values (14 ± 8 vs. 3.7 ± 5 Ω, p < .0001). Every 5-point increment in LI drop was associated with successful ablation (odds ratio = 3.05, 95% confidence interval: 2.3-4.1, p < .0001). Conversely, GI drops were not significantly different comparing successful versus unsuccessful sites (3.7 ± 5 vs. 2.8 ± 4 Ω, p = .1099). No steam pops or major complications occurred during or after the procedures. By the end of the procedures, all PVs had been successfully isolated in all patients.

CONCLUSIONS

The magnitude of the LI drop was more closely associated with effective lesion formation than the GI drop.

Confirmation of Pulmonary Vein Isolation with High-Density Mapping: Comparison to Traditional Workflows

Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. Yet tools and techniques used for confirmation of PVI vary greatly, and it is unclear whether the use of any particular combination of tools and techniques provides greater sensitivity for identifying gaps periprocedurally. It has been suggested the use of a high-density mapping catheter, which enables simultaneous recording of adjacent bipolar EGMs in two directions, may provide improved sensitivity for gap identification. Anonymized, acute procedural data was prospectively collected in AF ablation cases utilizing various workflows for confirmation of PVI. Post-hoc analysis was performed to evaluate the incidence of gaps detected by different diagnostic catheter technologies, including a high-density mapping catheter and circular mapping catheters (CMCs), and common techniques such as pacing the ablation lines. A total of 139 cases were included across three subgroup analyses: 99 cases were included in an indirect comparison of three mapping catheter technologies, revealing gaps in 36.7%, 38.9%, and 81.8% of cases utilizing a 10-pole CMC, 20-pole CMC, and a high-density mapping catheter, respectively; a direct comparison of diagnostic catheter technologies in 18 cryoballoon ablation cases revealed residual gaps in 22.2% of patients identified by high-density mapping which were missed previously with the use of a 3.3F CMC; in 22 cases utilizing a technique of pacing the ablation lines, high-density mapping identified residual gaps in 68.2% of patients. This proof of concept analysis demonstrated that the use of a high-density catheter which records orthogonal bipoles simultaneously, appears to improve acute detection of gaps in PVI lines relative to other commonly utilized techniques and technologies. The long-term impact of ablating these concealed gaps remains unclear. Further study, including direct comparison of diagnostic catheter technologies in a randomized setting with long-term followup, is warranted.

Impact of single versus double transseptal puncture on outcome and complications in pulmonary vein isolation procedures

BACKGROUND

The aim of the current study was to analyze the impact of single versus double transseptal puncture (TSP) for atrial fibrillation (AF) ablation.

METHODS

Consecutive patients undergoing AF ablation were prospectively included in the AF ablation registry and were analyzed according to single versus double TSP.

RESULTS

A total of 478 patients (female 35%, persistent AF 67%) undergoing AF ablation between 01/2014 and 09/2014 were included. Single TSP was performed in 202 (42%) patients, double TSP in 276 (58%) patients. Age, gender, body mass index, CHA2DS2-VASc score, left ventricular ejection fraction and operator experience (experienced operator defined as ≥ 5 years of experience in invasive electrophysiology) were equally distributed between the two groups. Repeat procedures (re-dos) were more frequently performed using single TSP access (p < 0.001). Left atrial (LA) diameter was larger in patients with double TSP (p = 0.001). Procedure duration in single TSP was identical to double TSP procedures (p = 0.823). Radiation duration was similar between the two groups (p = 0.217). There were 49 (10%) patients with complications after catheter ablation. There were no differences between complication rates and TSP type (p = 0.555). Similarly, recurrence rates were comparable between both TSP groups (p = 0.788).

CONCLUSIONS

There was no clear benefit of single or double TSP in AF ablation.

Epicardial Connections Involving Pulmonary Veins

Background:

The presence of epicardial connections (ECs) between pulmonary veins (PVs) and other anatomic structures may hinder PV isolation. In this study, we analyzed their prevalence, location, associated factors, and clinical implications.

Methods:

Five hundred thirty-four consecutive patients with atrial fibrillation undergoing radiofrequency ablation were included. We considered that an EC was present if: (1) the first pass around the PV antrum did not produce PV isolation and (2) subsequent atrial activation during PV pacing showed that the earliest site was located away from the ablation line and later activation sites were observed near the ablation line. Clinical and electrophysiological variables were collected from all patients. Patients were followed during 12.9±9.4 months, and any documented atrial tachyarrhythmia after the 3-month blanking period was classified as a recurrence.

Results:

Out of the 534 patients included, 72 (13.5%) were found to have 81 ECs. There was a significant association between the presence of ECs and structural heart disease (15.3% in patients without ECs versus 36.5% in patient with ECs; P <0.001) and patent foramen ovale (4.6% versus 13.5%; P =0.002). The presence of a left common trunk was significantly associated with the absence of ECs (29.6% in patients without ECs versus 16.2% in patients with ECs; P =0.014). Patients with ECs had lower acute success in PV isolation compared with patients without ECs (99.1% versus 86.1%; P <0.001). After adjusting for age, sex, type of atrial fibrillation, left atrium area, hypertension, structural heart disease, presence of left common trunk, patent foramen ovale, and time for atrial fibrillation diagnosis to the ablation, we found a significantly higher risk of atrial tachyarrhythmia recurrences in patients with ECs compared with patients without ECs (hazard ratio, 1.7 [95% CI, 1.1–2.9]; P =0.04).

Conclusions:

ECs between PVs and other adjacent structures are frequent in patient with atrial fibrillation (prevalence: 13.5%). Structural heart disease and a patent foramen ovale are strongly associated with the presence of ECs. ECs reduce the acute and chronic success of PV isolation.

Predictors of Recurrence of AF in Patients After Radiofrequency Ablation

Catheter ablation is a well-known treatment for patients with AF. Despite the growing knowledge in the field, the identification of predictors of recurrence of AF after catheter ablation is one of the primary goals and is of major importance to improve long-term results of the procedure. The aim of this article is to provide an overview of what has been published in recent years and to summarise the major predictors, helping cardiac electrophysiologists in the selection of the right candidates for catheter ablation.

Contact-force radiofrequency ablation of non-paroxysmal atrial fibrillation: improved outcomes with increased experience

INTRODUCTION

Clinical trials have failed to reliably show improved outcomes with utilization of contact-force sensing (CFS) radiofrequency (RF) ablation catheters. It is unknown whether the unfavorable outcomes observed in these trials are attributable to inexperience with CFS technology.

OBJECTIVES

To compare catheter ablation outcomes of stepwise linear ablation with versus without CFS technology and to assess the impact of operator experience with CFS technology on procedural outcomes.

METHODS

Clinical outcomes were evaluated in 228 consecutive NPAF patients undergoing first-time left atrial ablation using a stepwise linear approach. Arrhythmia recurrence was assessed using 2-week event monitors at 3-month intervals following index ablation.

RESULTS

A total of 228 patients were included in our study. There was no statistically significant difference in risk of recurrent atrial arrhythmias at 12 and 24 months between CFS and non-CFS patients (p = 0.5 and p = 0.169). The time to recurrence of atrial arrhythmias at 24 months in the second half of CFS patients was significantly lower when compared to both the first half of CFS patients (p = 0.002) and non-CFS patients (p = 0.005).

CONCLUSION

While there was no difference in overall outcomes between CFS and non-CFS ablation using a stepwise linear approach in patients with NPAF, procedural efficacy of the second half of CFS patients was significantly improved compared to both the first half of CFS patients and all non-CFS patients. Lack of benefit seen in clinical trials using CFS technology may be related to operator inexperience with CFS ablation catheters at the time of the trials.

Role of Contact Force Sensing in Catheter Ablation of Cardiac Arrhythmias: Evolution or History Repeating Itself?

Adequate catheter-tissue contact facilitates efficient heat energy transfer to target tissue. Tissue contact is thus critical to achieving lesion transmurality and success of radiofrequency (RF) ablation procedures, a fact recognized more than 2 decades ago. The availability of real-time contact force (CF)-sensing catheters has reinvigorated the field of ablation biophysics and optimized lesion formation. The ability to measure and display CF came with the promise of dramatic improvement in safety and efficacy; however, CF quality was noted to have just as important an influence on lesion formation as absolute CF quantity. Multiple other factors have emerged as key elements influencing effective lesion formation, including catheter stability, lesion contiguity and continuity, lesion density, contact homogeneity across a line of ablation, spatiotemporal dynamics of contact governed by cardiac and respiratory motion, contact directionality, and anatomic wall thickness, in addition to traditional ablation indices of power and RF duration. There is greater appreciation of surrogate markers as a guide to lesion formation, such as impedance fall, loss of pace capture, and change in unipolar electrogram morphology. In contrast, other surrogates such as tactile feedback, catheter motion, and electrogram amplitude are notably poor predictors of actual contact and lesion formation. This review aims to contextualize the role of CF sensing in lesion formation with respect of the fundamental principles of biophysics of RF ablation and summarize the state-of-the-art evidence behind the role of CF in optimizing lesion formation.

Second Generation Cryoballoon vs. Radiofrequency Ablation in Paroxysmal Atrial Fibrillation: Outcomes Beyond One-Year Follow-up

Aims

Pulmonary vein isolation (PVI) can be accomplished using radiofrequency (RF) or second generation cryoballoon (CB2). We aimed to compare the freedom from very late recurrence (VLR) defined as recurrence beyond one year in patients who were AF-free during the first post-procedural year after PVI using CB2 or RF.

Methods

Consecutive patients who underwent PVI by RF or CB2 ablation between August 2014 and December 2015 were included. The primary endpoint was the occurrence of VLR in follow-up after 12 months. Patients who experienced recurrence between the first 3 to 12 months after PVI and those who did not complete 15-month follow-up time were excluded.

Results

139 patients were included: 68 underwent PVI by CB2 and 71 using RF. The global VLR rate was of 22.15%. The freedom from VLR beyond 12-month follow-up was of 84.5% (57 patients) for the CB2 group vs. 71% (50 patients) in the RF group (p=0.037). 15 patients underwent re-ablation (11 of the RF group and 4 of the CB2 group): all of the patients who had undergone PVI by RF in the index procedure were found to have vein reconnection, whereas none of the CB2 group had reconnected veins (3 cavotricuspid isthmus and 1 mitral isthmus).

Conclusion

In patients free of recurrence during the first post-procedural year after pulmonary vein isolation for the treatment of paroxysmal atrial fibrillation: second generation cryoballoon ablation showed a significantly lower very late recurrence rate compared to radiofrequency ablation.

Condensed abstract

The present study evaluates the freedom from very late recurrence (VLR), defined as recurrence in patients who were arrhythmia-free during the first post-procedural year after pulmonary vein isolation using second generation cryoballoon (CB2) or radiofrequency (RF). CB2 ablation had a lower VLR rate compared to RF.

Touch-up and recurrence rates after voltage mapping for verification of pulmonary vein isolation following cryoablation of paroxysmal atrial fibrillation

PURPOSE

The procedural endpoint following cryoballoon ablation (CA) for paroxysmal atrial fibrillation (PAF) is pulmonary vein isolation (PVI), which is typically confirmed by entrance/exit block using a circular mapping catheter. The present study added an assessment of ablation gaps with high-density voltage mapping after standard confirmation of PVI. Relationships between the need for touch-up ablation, patient characteristics, and atrial arrhythmia recurrence were explored.

METHODS

PAF patients received CA through standard of care treatment, with PVI assessed by bidirectional block confirmation, followed by voltage mapping. Radiofrequency ablation was performed as needed for voltage breakthrough and or additional rhythms. Freedom from atrial arrhythmia recurrence through 12-month follow-up was analyzed retrospectively with statistical survival models.

RESULTS

A total of 77 PAF patients (age 66.1 ± 11.6, CHADS₂ 1.8 ± 1.0) were followed for 1.2 ± 0.3 years after CA. During the index procedure, pulmonary vein (PV) touch-up was required in 59 patients (76.6%) and ablation of additional atrial fibrillation targets beyond PV was required in 26 patients (33.8%). Kaplan-Meier estimates of freedom from atrial arrhythmia recurrence at 1 year were 62 ± 6%. Rates were lower for patients requiring touch-up ablation (58 ± 6% vs. 78 ± 10%) or with CHADS₂ scores > 2 (33 ± 12% vs. 69 ± 6%). Cox regression models showed that the need for touch-up ablation increased recurrence (p = .045, HR = 2.6) after adjusting for hypertension and heart failure.

CONCLUSION

The high rate of PV touch-up suggests that initial CA lesions may be less durable than previously assumed, while the higher recurrence rate in patients requiring touch-up may indicate that additional factors make these patients more difficult to treat.

Pace capture and adenosine triphosphate provocation are complementary rather than mutually exclusive methods to ensure durable pulmonary vein isolation

INTRODUCTION

Adenosine triphosphate (ATP)-provoked dormant conduction (DC) and pacing for unexcitability are used to identify conduction gaps along the ablation lines after circumferential pulmonary vein isolation (CPVI). We aim to determine whether ATP provocation and pacing are interchangeable as endpoints for ablation of paroxysmal atrial fibrillation (PAF).

METHODS AND RESULTS

A total of 107 patients with PAF were randomly divided into two groups after completion of CPVI. In group I (A-P group, n = 53), ATP was administered first. If DC was uncovered, additional ablation was performed until ATP tests were negative. Bipolar pacing along the ablation line was performed subsequently. In group II (P-A group, n = 54), the same protocol was used, but the pacing and the ATP tests were performed in the opposite sequence. The 12-month ablation outcomes of all patients were compared with those of a historical control group of 107 patients with PAF in whom only ATP test was performed. Regardless of which test was performed first, the other modality still identified conduction gaps. In group I, pacing maneuvers identified gaps in 49% (n = 26) of patients who had negative ATP tests. In group II, ATP tests uncovered DC in 18.5% (n = 10) of patients in whom pacing identified no gaps. After 12 months, a higher proportion of patients (91.6%) were free from atrial tachyarrhythmias compared with the historical control group (81.3%; P = 0.031).

CONCLUSION

Pacing along the ablation lines and ATP provocation are complementary tests for evaluating the durability of CPVI and can lead to better long-term outcomes when used in combination.

Influence of energy source on early atrial fibrillation recurrences: a comparison of cryoballoon vs. radiofrequency current energy ablation with the endpoint of unexcitability in pulmonary vein isolation

Introduction

Comparative data of early recurrence rates of atrial fibrillation (ERAF) following second-generation cryoballoon (CB-G2) and radiofrequency current (RFC) ablation for pulmonary vein isolation (PVI) in paroxysmal AF (PAF) are rare. We randomized PAF patients into either PVI with CB-G2 (group 1) or PVI with a combined RFC-approach applying contact force (CF) with the endpoint of unexcitability (group 2) to investigate ERAF.

Methods and results

In group 1 (n = 30), CB-G2-PVI was performed. After CF-PVI in group 2 (n = 30), bipolar pacing on the ablation line and additional ablation until unexcitability was conducted. Follow-up included 48 h of in-hospital monitoring followed by 5-day Holter ECGs 1, 2, 3, 6, 12 months postablation to evaluate ERAF. Acute PVI was reached in 100% of group 2 and in 99% of group 1. Shorter procedure durations (98.0 ± 21.9 vs. 114.3 ± 18.7 min, P < 0.05) but extended fluoroscopy times (15.4 ± 3.9 vs. 10.0 ± 4.3 min, P < 0.05) were found in the CB-G2 group. Ten non-severe complications occurred (6 vs. 4 in group 1 and 2, P = 0.73). In group 2, five patients suffered from ERAF vs. seven patients in group 1 (P = 0.67). The time until the occurrence of ERAF was shorter in group 2 (1 day (q1-q3: 1-4.5)) when compared with group 1 (22 (q1-q3: 6-54) days, P = 0.025).

Conclusion

ERAF rates were equal among groups; however, they occurred earlier in the initial phase after RFC ablation when compared with CB-G2. PVI utilizing cryoablation is associated with shorter procedure durations but extended fluoroscopy time while being similarly secure.

Repeat ablation for paroxysmal atrial fibrillation - Does adenosine play a role in predicting pulmonary vein reconnection patterns?

BACKGROUND

Pulmonary vein (PV) reconduction after PV isolation (PVI) unmasked by adenosine is associated with a higher risk for paroxysmal atrial fibrillation (PAF) recurrence. It is unknown if the reconnected PVs after adenosine testing and immediate re-ablation can predict reconnection and reconnection patterns of PVs at repeat procedures. We assessed reconnection of PVs with and without dormant-conduction (DC) during the first and the repeat procedure.

METHODS

We included 67 patients undergoing PVI for PAF and a second procedure for PAF recurrence. DC during adenosine administration at first procedure was seen in 31 patients (46%). 264 PVs were tested with adenosine; DC was found in 48 PVs (18%) and re-ablated during first procedure. During the second procedure, all PVs where checked for reconnection.

RESULTS

Fifty-eight patients (87%) showed PV reconnection during the second procedure. Reconnection was found in 152/264 PVs (58%). Of 216 PVs without reconnection during adenosine testing at the first ablation, 116 PVs (53.7%) showed reconnection at the repeat procedure. Overall, 14.9% of patients showed the same PV reconnection pattern in the first and second procedure, expected statistical probability of encountering the same reconnection pattern was only 6.6%(p = 0.012).

CONCLUSIONS

In repeat procedures PVs showed significantly more often the same reconnection pattern as during first procedure than statistically expected. More than 50% of initial isolated PVs without reconnection during adenosine testing showed a reconnection during repeat ablation. Techniques to detect susceptibility for PV re-connection like prolonged waiting-period should be applied. Elimination of DC should be expanded from segmental to circumferential re-isolation or vaster RF application.

Simultaneous pace-ablate during CARTO-guided pulmonary vein isolation with a contact-force sensing radiofrequency ablation catheter

PURPOSE

Elimination of pace-capture along pulmonary vein isolation (PVI) lesion sets reduces atrial fibrillation (AF) recurrence in catheter ablation of paroxysmal AF. Pacing from the RF ablation electrode during RF application is prevented within the CARTO electroanatomic mapping system (Biosense Webster, Inc.) due to theoretical safety considerations. We evaluated a method of pacing the distal ablation electrode during RF application in the CARTO system, thus avoiding repeated activation and inactivation of the pacing channel and facilitating immediate recognition of pace-capture loss. We investigated the safety, feasibility, and utility of simultaneous pace-ablate (SPA) during AF ablation with the CARTO-3 system and a contact-force sensing RF ablation catheter.

METHODS

Safety of feasibility of SPA was evaluated in 250 patients undergoing first-time AF ablation. Frequency and regional distribution of pace-capture following PVI was evaluated in a cohort of 50 consecutive patients undergoing catheter ablation of paroxysmal AF.

RESULTS

SPA was successfully performed in all 250 patients without adverse event. At least one pace-capture site was noted in 22 of 50 PAF patients (44%), and pace-capture following PVI was most common at anterior and superior left atrial sites. There were 2.0 ± 3.3 RF applications during pacing via the distal ablation electrode per patient, and all lesions sets were successfully rendered unexcitable.

CONCLUSIONS

Pace-capture along the completed PVI lesion set remains common despite utilization of contact-force sensing RF ablation catheters and automated lesion annotation. Simultaneous pace-ablate in AF ablation using the CARTO system may be safely used to render atrial lesion sets unexcitable.

The relationship of early recurrence of atrial fibrillation and the 3-month integrity of the ablation lesion set

Early recurrence of atrial fibrillation (ERAF) after catheter-ablation (CA) can be a transient phenomenon due to inflammation, or a harbinger of late AF recurrence due to CA lesion (re)conduction. We studied the relationship between ERAF and the 3-month CA lesions integrity. Forty one consecutive AF patients who underwent a pulmonary vein isolation (PVI), roof line (RL) and mitral isthmus line (MIL) CA were enrolled. At 3 months all patients underwent invasive assessment of the lesion set integrity irrespective of ERAF. The PVI, RL and MIL ablation was successful in 100.0%, 95.1% and 82.9% patients, respectively. At the 3-month remapping, a gap in PVI-lesion(s), RL or MIL was identified in 61.0%, 31.7% and 36.6% patients, respectively. Patients with (n = 17, 41.5%) compared to those without ERAF (n = 24) had a significantly higher rate of any PV-reconnection (88.2% vs. 41.7%), the right PV(s)-reconnection (82.5% vs. 29.2%) and the RL gap (52.9% vs. 16.7%), as well as a higher number of reconnected right PVI-segments, all p < 0.05. On multivariate analysis, only the number of reconnected right PVI-segments was associated with ERAF (OR 4.26, p = 0.004). The ERAF following PVI + RL + MIL ablation was significantly related to 3-month PV-reconnections and the presence of RL gaps.

Efficacy of adjunctive measures used to assist pulmonary vein isolation for atrial fibrillation: a systematic review

PURPOSE OF REVIEW

Pulmonary vein reconnection leading to recurrence of atrial arrhythmias after pulmonary vein isolation (PVI) for atrial fibrillation remains a significant challenge. A number of adjunctive measures during PVI have been used to attempt to reduce pulmonary vein reconnection and recurrence of atrial arrhythmias. We performed a systematic review of the literature and meta-analysis of studies evaluating the efficacy of adjunctive measures used during PVI in reducing recurrent atrial arrhythmias.

RECENT FINDINGS

Our literature search found four interventions that met the prespecified definition of adjunctive measure: adenosine testing post-PVI, contact force-guided PVI, pacing inexcitability of the ablation line during PVI and additional ablation based on the computed tomography thickness of the pulmonary vein-left atrial appendage ridge. Sixteen studies enrolling 3507 patients met all inclusion and exclusion criteria. PVI performed with adjunctive measures was shown to reduce the 1-year recurrence rate of atrial arrhythmias. The point estimate for the combined relative risk of atrial arrhythmia recurrence was 0.56 [95% confidence interval (CI): 0.43-0.73; P value <0.001] in the PVI with adjunctive measures group.

SUMMARY

PVI for atrial fibrillation assisted by adjunctive measures results in clinically significant reduction of recurrent atrial arrhythmias. Additional research is required to assess the relative efficacy of individual or combined adjunctive strategies used during PVI for atrial fibrillation.

High-density mapping and ablation of concealed low-voltage activity within pulmonary vein antra results in improved freedom from atrial fibrillation compared to pulmonary vein isolation alone

BACKGROUND

Despite advancements, the goal of durable pulmonary vein isolation (PVI) in all patients undergoing ablation for atrial fibrillation (AF) remains elusive. New high-density mapping (HDM) allows detection of concealed low-voltage signals (CLVSs) that persist after PVI and may represent vulnerabilities in the lesion set.

OBJECTIVE

The purpose of this study was to determine the incidence of CLVSs after PVI and the effect of CLVS ablation on outcomes.

METHODS

We conducted a case control study comparing 150 patients undergoing HDM-guided PVI and subsequent CLVS mapping and ablation (39 redo, 111 de novo) against 452 historical controls undergoing traditional PVI alone. PVI was similarly performed and confirmed in both groups.

RESULTS

Baseline characteristics were similar, except left atrial size was larger in the HDM-guided group. Acute PVI was achieved in nearly all patients in both groups. In the HDM group, 31 of 150 patients exhibited CLVS after luminal PVI, and all were subsequently eliminated. During mean follow-up of 320 days, after controlling for baseline characteristics, the HDM-guided group exhibited a hazard ratio of 0.19 in freedom from AF (P <.001). De novo patients exhibited a hazard ratio of 0.44 relative to redo patients in the HDM-guided group. Both subgroups exhibited significantly lower event rates compared to controls in log-rank analysis (P <.001).

CONCLUSION

CLVSs are commonly identified with HDM after PVI, likely representing vulnerabilities in antral lesion sets. Ablation of these targets seems to significantly improve freedom from AF compared to PVI alone.

Contact force facilitates the achievement of an unexcitable ablation line during pulmonary vein isolation

AIMS

Contact force (CF) catheters provide catheter-tissue contact information to improve outcome of pulmonary vein isolation (PVI) in paroxysmal atrial fibrillation (PAF). We evaluated different target-CF values for achievement of the additional endpoint of an unexcitable ablation line.

METHODS

A total of 106 patients undergoing PVI were randomized into three groups (G) (G1: target-CF 15 g, G2: target-CF 10 g, G3: CF concealed from operator). The PVI encircling line was divided into predefined sections. Excitable tissue along the PVI-line identified by high output pacing (10 V, 2 ms) was targeted for further ablation.

RESULTS

Mean average CF was 17.4 ± 4.7 g (G1) vs. 12.3 ± 6.0 g (G2) vs. 11.1 ± 6.5 g (G 3) (p < 0.001). Primary unexcitable ablation lines were found in 38.6, 19.4 and 5.7% (G1, G2, G3 respectively; G1 vs. G2 p < 0.05, G1 vs. G3 p < 0.001, G2 vs. G3 ns). Additional radiofrequency (RF)-energy to achieve unexcitability was lowest in G1 (3.6 ± 3.1 kJ vs. 8.6 ± 7.2 kJ (G2) and 10.4 ± 6.7 (G3), p ≤ 0.001, G2 vs. G3 ns) with accordingly lowest additional RF applications in G1 (3.0 ± 2.6 vs. 7.0 ± 5.4 in G2 and 8.4 ± 4.0 in G3; G1 vs. G2 and G3, p < 0.001, G 2 vs. G 3 ns). Sections along ablation lines with low initial CF were most likely to reveal excitability. Single procedure success was 81.9 vs. 73.5 vs. 71.4% (G 1, 2 and 3, p = 0.6) during 437 ± 254 day follow-up.

CONCLUSION

Higher tip-to-tissue CF during PVI facilitates the achievement of an unexcitable ablation line, requiring less additional RF-energy.