Paroxysmal and persistent atrial fibrillation ablation outcomes with the pulmonary vein ablation catheter GOLD duty-cycled phased radiofrequency ablation catheter: quality of life and 12-month efficacy results from the GOLD Atrial Fibrillation Registry

Aims

The GOLD AF Registry has been designed to prospectively assess the population, indications, and outcomes using second-generation phased radiofrequency (RF) ablation (pulmonary vein ablation catheter GOLD) in a global examination of standard-of-care use for the treatment of paroxysmal and persistent atrial fibrillation (AF).

Methods and results

GOLD AF (NCT02433613) is a prospective, observational, multi-centre registry designed to characterize efficacy and safety of phased RF ablation in patients with AF. The primary endpoint was freedom from AF recurrence at 12-month follow-up after a 90-day blanking period. Ancillary objectives include safety, procedural efficiency, and quality of life (QoL). The QoL assessment using the Atrial Fibrillation Effect on QualiTy-of-Life (AFEQT) and the European Heart Rhythm Association (EHRA) Score of AF-related symptoms was collected at baseline and 12 months. In total, 1054 patients were included in this analysis (age 60.6, 67.6% male, 26.5% PersAF). Kaplan–Meier estimate of freedom from AF recurrence was 77.7% at 12 months. Peri-procedural device or procedure-related complications were observed in 26 (2.5%) patients, with a low stroke rate of 0.3%. One-year post-ablation, the EHRA AF Symptom score decreased in 68% of patients. The AFEQT score improvement was observed in 88.4% and 90.4% of patients who completed the questionnaire in-person or interviewed by phone at 12 month follow-up, respectively.

Conclusion

Phased RF ablation for the treatment of paroxysmal and persistent AF demonstrated a 77.7% freedom from AF recurrence at 12 months in addition to a significant reduction in arrhythmia symptoms and clinically meaningful improved QoL. Low peri-procedural complication rate of <3% was reported.

Evaluation of stroke incidence with duty-cycled multielectrode-phased radiofrequency ablation of persistent atrial fibrillation results of the VICTORY AF Study

INTRODUCTION

The VICTORY AF Study was designed to evaluate the risk of the procedure and/or device-related strokes in patients with PersAF on warfarin undergoing ablation with a phased radiofrequency (RF) system.

METHODS

The VICTORY AF trial was a prospective, multicenter, single-arm, investigational study. PersAF patients on vitamin K antagonism without major structural heart disease or history of stroke/transient ischemic attack undergoing phased RF ablation for atrial fibrillation (AF) were included. The primary outcome was the incidence of the procedure and/or device-related stroke within 30 days of the ablation by a board-certified neurologist's assessment. The secondary outcomes were an acute procedural success, 6 months effectiveness (defined as the reduction in AF/atrial flutter episodes lasting ≥10 minutes by 48-hour Holter 6 months postablation) and the number of patients with pulmonary vein (PV) stenosis.

RESULTS

A total of 129 (108 PersAF, 21 long-standing PersAF) patients were treated (mean age: 60.6 ± 7.7; 79.8% male, 54.3% CHA2Ds2-VASc score ≥ 2). Two nondisabling strokes were reported (1.6%); one before discharge and the second diagnosed at the 30-day visit. Due to slow enrollment, the study was terminated before reaching the 95% one-sided upper confidence boundary for stroke incidence. Acute procedural success was 93.8%, and at 6 months, 72.8% of patients demonstrated ≥90% reduction in AF burden, 78.9% were off all antiarrhythmic drugs. There were no patients with PV stenosis of greater than 70%.

CONCLUSIONS

VICTORY AF demonstrated a 1.6% incidence of stroke in PersAF undergoing ablation with a phased RF system which did not meet statistical confidence due to poor enrollment. The secondary outcomes suggest comparable efficacy to phased RF in the tailored treatment of permanent AF trial. Rigorous clinical evaluation of the stroke risk of new AF ablation technologies as well as restriction to Vitamin K antagonist anticoagulation appears to be unachievable goals in a clinical multicenter IDE trial of AF ablation in the current era.

Vein of Marshall ethanol infusion for persistent atrial fibrillation: VENUS and MARS clinical trial design

BACKGROUND

Although pulmonary vein isolation (PVI) is effective in the treatment of paroxysmal atrial fibrillation (AF), its success rates in persistent AF are suboptimal. Ablation strategies to improve outcomes including additional lesions beyond PVI have not consistently shown benefit. Recurrence as perimitral flutter (PMF) is a common form of ablation failure. The vein of Marshall (VOM) contains myocardial connections and abundant sympathetic and parasympathetic innervation implicated in the genesis and maintenance of AF, and is anatomically co-localized with the mitral isthmus, the ablation target of PMF. VOM ethanol infusion is effective in targeting these arrhythmia substrates.

OBJECTIVE

To test the safety and efficacy of VOM ethanol infusion when added to PVI in patients undergoing either de novo ablation of persistent AF or after a previous ablation failure.

STUDY DESIGN

VENUS-AF and MARS-AF are prospective, multicenter, randomized, controlled trials. VENUS-AF will enroll patients undergoing their first catheter ablation of persistent AF. MARS-AF will enroll patients undergoing ablation after previous ablation failure(s). Patients (n = 405) will be randomized to PVI alone or in combination with VOM ethanol infusion. The primary endpoints include procedural safety and freedom from AF or atrial tachycardia (AT) of more than 30 seconds on 30-day continuous event monitors at 6 and 12 months after randomization procedure (single-procedure success), off antiarrhythmic drugs. Key secondary endpoints include AF burden, freedom from AF/AT after repeat procedures and quality of life.

CONCLUSIONS

The VENUS-AF and MARS-AF will determine the safety and potential rhythm control benefit of VOM ethanol infusion when added to PVI in patients with persistent AF undergoing de novo or repeat ablation, respectively.

Comparison of the Efficacy of PVAC® and nMARQ™ for paroxysmal atrial fibrillation

Pulmonary vein isolation (PVI) has become the mainstay of therapy for atrial fibrillation (AF) and one of the most frequently performed procedures in the cardiac electrophysiology laboratory. PVI by a single-tip radiofrequency (RF) ablation catheter remains a complex and time-consuming procedure, especially in centers with limited experience. In order to simplify the PVI procedure, to shorten it and reduce the complication rate, circular multi-electrode catheters were introduced for simultaneous mapping and ablation. The common concept of these "single-shot" AF ablation technologies is the creation of circular lesions for PVI by placing the ablation device at the antrum of the pulmonary veins without the need for continuous repositioning. In this review we describe the main features of two circular non-balloon ablation catheters- PVAC^®, which is based on the phased RF, duty-cycled ablation technology, and nMARQ^™, the irrigated multi-electrode electro-anatomically guided catheter - and compare the clinical outcomes of these technologies, mainly for paroxysmal AF patients, based on current available data.

Who Needs Catheter Ablation And Which Approach?

Catheter ablation therapy for atrial fibrillation (AF) has gained a significant role during maintenance of sinus rhythm compared to anti-arrhythmic medication. Catheter ablation techniques are also improved and progressed over years in parallel to better understanding of disease mechanisms and technological advancements. However, due to invasive nature of the therapy with its pertinent procedural risks, both appropriate patient selection and use of relevant approach should be considered by all electrophysiologists before decide to perform catheter ablation.

Persistent Atrial Fibrillation Ablation using the Tip-Versatile Ablation Catheter

BACKGROUND

The mechanisms by which persistent atrial fibrillation (PsAF) develops are incompletely understood. Consequently, the optimal strategy for the ablative management of PsAF remains debated. Current methods are often time consuming, complex and non-reproducible. We assessed the Tip-Versatile Ablation Catheter (T-VAC) technique, a rapidly delivered, empirical technique based on the box-set concept using duty-cycled linear catheter ablation technology.

METHODS

Forty-four procedures in 40 patients undergoing PsAF ablation with the novel technique were prospectively entered onto a database: 27 de novo. Primary endpoint was freedom from arrhythmia at over two-year follow-up. Secondary endpoints were time to first arrhythmia recurrence, freedom from atrial fibrillation (AF) on and off antiarrhythmic drugs (AAD), procedural and fluoroscopy duration and complication rate.

RESULTS

At mean follow-up of 33 months, absolute freedom from arrhythmia recurrence was 45% in the de novo group. Overall, at 33 (IQR 24-63) months, 60% of de novo patients were in sustained normal sinus rhythm and a further 15% reported only occasional paroxysms of AF at long-term follow-up. Procedure time was 192±25 mins, total energy delivered 2239±883s and fluoroscopy time was 60±10mins.

CONCLUSION

In selected patients with persistent AF, a long-term rate of 60% arrhythmia free survival off AAD can be achieved using this novel T-VAC technique.

Multielectrode Pulmonary Vein Ablation Catheter (PVAC(®)): current data on results and risks

Electrical isolation of pulmonary veins is the cornerstone of catheter ablation for patients with symptomatic atrial fibrillation. However, uncertainty surrounds the choice of energy source in pulmonary vein isolation (PVI). Various alternative techniques such as the Pulmonary Vein Ablation Catheter (PVAC(®), Medtronic Inc., Minneapolis, MN, USA) have been developed to facilitate PVI. This over-the-wire multielectrode catheter is delivering duty-cycled bipolar and unipolar radiofrequency (RF) energy at relatively low power.PVI with this "one-shot" PVACatheter can shorten the procedure duration and lower fluoroscopy time compared to irrigated RF. It enables mapping and ablation with the same array, but fails to show signals during RF energy delivery. The effectiveness of PVAC is comparable to other technologies in randomized studies. The overall complication rate of PVAC PVI is comparable to irrigated RF and possibly slightly higher for cryoballoon PVI. Special attention has to be paid to an effective anticoagulation throughout the ablation procedure, avoidance of embolic events and pulmonary venous stenosis.The novel catheter design of the PVAC Gold(®) array may improve safety by reducing embolic events through avoidance of electrode 1-to-10 interaction and by better tissue contact due to the 20° forward tilt. Although clinical data with this new array are lacking so far, the PVAC system has been shown to be a promising tool for PVI. However, prospective studies especially with the novel array are required to determine its true role for catheter ablation of atrial fibrillation in the future.

Phased RF Ablation: Results and Concerns

Treatment of atrial fibrillation (AF) with catheter ablation has proven to be a safe and effective treatment modality which is offered to an increasing number of patients in many centers. Pulmonary vein isolation (PVI) is an established cornerstone of AF ablation strategies. Athough the isolation of the pulmonary veins (PVs) with irrigated focal radiofrequency (RF) catheters using a point-by-point method is considered as the gold standard, it can be challenging to create contiguous lesions, time consuming, and require advanced three dimensional (3D) mapping and navigational systems. The phased RF ablation system was designed to address many of these challenges associated with conventional focal RF ablation. In this review, we describe the main features of phased RF ablation and summarize the data available on clinical outcome with this technology.

Variability of P-wave morphology predicts the outcome of circumferential pulmonary vein isolation in patients with recurrent atrial fibrillation

INTRODUCTION

Severe atrial structural remodeling may reflect irreversible damage of the atrial tissue in patients with atrial fibrillation (AF) and is associated with changes of P-wave duration and morphology. Our aim was to study whether variability of P-wave morphology (PMV) is associated with outcome in patients with AF after circumferential PV isolation (CPVI).

METHODS AND RESULTS

70 consecutive patients (aged 60±9years, 46 men) undergoing CPVI due to symptomatic AF were studied. After cessation of antiarrhythmic therapy, standard 12-lead ECG during sinus rhythm was recorded for 10min at baseline and transformed to orthogonal leads. Beat-to-beat P-wave morphology was subsequently defined using a pre-defined classification algorithm. The most commonly observed P-wave morphology in a patient was defined as the dominant morphology. PMV was defined as the percentage of P waves with non-dominant morphology in the 10-min sample. At the end of follow-up, 53 of 70 patients had no arrhythmia recurrence. PMV was greater in patients without recurrence (19.5±17.1% vs. 8.2±6.7%, p<0.001). In the multivariate logistic regression model, PMV≥20% (upper tertile) was the only independent predictor of ablation success (OR=11.4, 95% CI 1.4-92.1, p=0.023). A PMV≥20% demonstrated a sensitivity of 41.5%, a specificity of 94.1%, a PPV of 96.7%, and an NPV of 34.0% for free of AF after CPVI.

CONCLUSIONS

We report a significant association between increased PMV and 6-month CPVI success. PMV may help to identify patients with very high likelihood of freedom of AF 6-months after CPVI.

Ablation for atrial fibrillation in combination with left atrial appendage closure: first results of a feasibility study

BACKGROUND

Drug-refractory atrial fibrillation (AF) increasingly is being treated with catheter ablation. However, the long-term success rate, expressed as freedom from AF, is <50%. Therefore, vitamin K antagonists, with all their complications, remain necessary. Recently, left atrial appendage (LAA) occlusion devices were introduced as an alternative to vitamin K antagonists. Here, we investigated whether AF ablation and LAA occlusion could be a feasible and safe combination in patients with symptomatic drug-refractory AF and a CHADS(2) score ≥1 or a contraindication for vitamin K antagonists.

METHODS AND RESULTS

Ablation was performed by using multielectrode catheters with phased radiofrequency energy. LAA was occluded with the Watchman device (Atritech, Inc, Plymouth, MN). Between February 2010 and February 2011, 30 patients were treated (21 male; age, 62.8±8.5 years). Median CHADS(2) score was 2.5 (25th to 75th percentiles: 2 to 3), median CHADS-VASc score was 3 (25th to 75th percentiles: 3 to 5), 77% had prior stroke, and 27% had a contraindication for vitamin K antagonists. Median HAS-BLED score was 2 (range, 1 to 5). Successful device implantation was achieved with a median number of 1.5 devices (median diameter 24 mm [25th to 75th percentiles: 24 to 24 mm]). Total procedure time was 97 minutes (25th to 75th percentiles: 75 to 115 minutes). At 60 days, all patients met the criteria for successful sealing. Follow-up visit at 12 months showed a 30% rate of documented recurrence of AF. A repeated pulmonary vein isolation was performed successfully in 4 patients, without interference of the LAA closure device. No thromboembolic events occurred during 1-year follow-up.

CONCLUSION

LAA occlusion with the Watchman device and AF ablation can be combined successfully and safely in a single procedure. The Watchman does not interfere with a repeated ablation.

2012 HRS/EHRA/ECAS expert consensus statement on catheter and surgical ablation of atrial fibrillation: recommendations for patient selection, procedural techniques, patient management and follow-up, definitions, endpoints, and research trial design

This is a report of the Heart Rhythm Society (HRS) Task Force on Catheter and Surgical Ablation of Atrial Fibrillation, developed in partnership with the European Heart Rhythm Association (EHRA), a registered branch of the European Society of Cardiology and the European Cardiac Arrhythmia Society (ECAS), and in collaboration with the American College of Cardiology (ACC), American Heart Association (AHA), the Asia Pacific Heart Rhythm Society (APHRS), and the Society of Thoracic Surgeons (STS). This is endorsed by the governing bodies of the ACC Foundation, the AHA, the ECAS, the EHRA, the STS, the APHRS, and the HRS.