Pulsed Field Versus Cryoballoon Pulmonary Vein Isolation for Atrial Fibrillation: Efficacy, Safety, and Long-Term Follow-Up in a 400-Patient Cohort.

BACKGROUND: The cryoballoon (CB) represents the gold standard single-shot device for pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). Single-shot pulsed field PVI ablation (nonthermal, cardiac tissue selective) has recently entered the arena. We sought to compare procedural data and long-term outcome of both techniques. METHODS: Consecutive AF patients who underwent pulsed field ablation (PFA) and CB-based PVI were enrolled. CB PVI was performed using the second-generation 28-mm CB; PFA was performed using a 31/35-mm pentaspline catheter. Success was defined as freedom from atrial tachyarrhythmia after a 3-month blanking period. RESULTS: Four hundred patients were included (56.5% men; 60.8% paroxysmal AF; age 70 [interquartile range, 59-77] years), 200 in each group (CB and PFA), and baseline characteristics did not differ. Acute PVI was achieved in 100% of PFA and in 98% (196/200) of CB patients (P=0.123; 4 touch-up ablations). Median procedure time was significantly shorter in PFA (34.5 [29-40] minutes) versus CB (50 [45-60] minutes; P<0.001), fluoroscopy time was similar. Overall procedural complications were 6.5% in CB and 3.0% in PFA (P=0.1), driven by a higher rate of phrenic nerve palsies using CB. The 1-year success rates in paroxysmal AF (CB, 83.1%; PFA, 80.3%; P=0.724) and persistent AF (CB, 71%; PFA, 66.8%; P=0.629) were similar for both techniques. CONCLUSIONS: PFA compared with CB PVI shows a similar procedural efficacy but is associated with shorter procedure time and no phrenic nerve palsies. Importantly, 12-month clinical success rates are favorable but not different between both groups.

Impact of body mass index on cryoablation of atrial fibrillation: Patient characteristics, procedural data, and long-term outcomes.

INTRODUCTION: Ablation of atrial fibrillation in the context of obesity can be challenging. We sought to evaluate the role of cryoballoon pulmonary vein isolation (CB-PVI) in obese patients with symptomatic atrial fibrillation (AF). METHODS: Patients with a BMI ≥ 25 kg/m2 and symptomatic AF who underwent CB-PVI were retrospectively enrolled. Three groups were defined (G1: BMI of 25-29 kg/m2 ; G2: BMI of 30-34 kg/m2 ; G3: BMI ≥ 35 kg/m2 ). RESULTS: 600 patients were included (59% male; 66 ± 11 years old); 337, 149, and 114 were assigned to G1, G2, and G3, respectively. Acute procedural success was recorded in 99.7% of patients. Procedural and fluoroscopy time were comparable but the radiation dose was significantly higher in G3. Procedural complications were 3% in G1, 5.4% in G2, and 8.8% in G3 (p = .01). The overall freedom from AF after 1-year was 77%. G3 had a significantly worse 1-year success rate compared to G1 and G2 (G3: 66.5% vs. G1: 78.4%; p = .015 and vs. G2: 82.5%; p = .008) with reduced 1-year success in paroxysmal AF (G1: 84.0%; G2: 86.3%; and G3: 69.6%) but not in persistent AF (G1: 68.7%; G2: 77.4%; and G3: 62.1%). G3 showed similar success rates irrespective of AF form (PAF: 69.6% vs. persAF 62.1%; p = .501). CONCLUSION: Cryoballoon ablation in obese patients can be effective with an acceptable safety profile, 77% of patients were in stable SR at 1 year. Severe obese patients (BMI ≥ 35) showed reduced procedural safety and 1-year success rate. In association with life style modification, CB ablation may represent a strategy to enhance rhythm control in the context of obesity.

Cryoballoon Ablation for the Treatment of Atrial Fibrillation in Patients With Concomitant Heart Failure and Either Reduced or Preserved Left Ventricular Ejection Fraction: Results From the Cryo AF Global Registry.

Background Heart failure (HF) and atrial fibrillation (AF) often coexist; yet, outcomes of ablation in patients with AF and concomitant HF are limited. This analysis assessed outcomes of cryoablation in patients with AF and HF. Methods and Results The Cryo AF Global Registry is a prospective, multicenter registry of patients with AF who were treated with cryoballoon ablation according to routine practice at 56 sites in 26 countries. Patients with baseline New York Heart Association class I to III (HF cohort) were compared with patients without HF. Freedom from atrial arrhythmia recurrence ≥30 seconds, safety, and health care utilization over 12-month follow-up were analyzed. A total of 1303 patients (318 HF) were included. Patients with HF commonly had preserved left ventricular ejection fraction (81.6%), were more often women (45.6% versus 33.6%) with persistent AF (25.8% versus 14.3%), and had a larger left atrial diameter (4.4±0.9 versus 4.0±0.7 cm). Serious procedure-related complications occurred in 4.1% of patients with HF and 2.6% of patients without HF (P=0.188). Freedom from atrial arrhythmia recurrence was not different between cohorts with either paroxysmal AF (84.2% [95% CI, 78.6-88.4] versus 86.8% [95% CI, 84.2-89.0]) or persistent AF (69.6% [95% CI, 58.1-78.5] versus 71.8% [95% CI, 63.2-78.7]) (P=0.319). After ablation, a reduction in AF-related symptoms and antiarrhythmic drug use was observed in both cohorts (HF and no-HF), and freedom from repeat ablation was not different between cohorts. Persistent AF and HF predicted a post-ablation cardiovascular rehospitalization (P=0.032 and P=0.001, respectively). Conclusions Cryoablation to treat patients with AF is similarly effective at 12 months in patients with and without HF. Registration URL: https://www.clinicaltrials.gov; Unique Identifier: NCT02752737.

Safety of cryoballoon ablation for the treatment of atrial fibrillation: First European results from the cryo AF Global Registry.

BACKGROUND: Cryoballoon ablation for the treatment of patients with atrial fibrillation (AF) has been utilized in Europe for >15 years. OBJECTIVES: Report patient and procedural characteristics that influence the safety of cryoablation for the treatment of AF. METHODS: Patients enrolled in the prospective, multicenter Cryo AF Global Registry were treated at 38 European centers. Freedom from a ≥30s episode of AF/atrial flutter (AFL)/atrial tachycardia (AT) at 12-months and serious complications were analyzed. Univariate and multivariable models identified baseline patient and procedural characteristics that predicted a procedure-related complication. RESULTS: Of the 1418 subjects who completed an index procedure, the cohort was 62 ± 11 years of age, 37.7% female, and 72.2% paroxysmal AF (PAF). The mean procedure, left atrial dwell, and fluoroscopy times were 81 ± 34, 54 ± 25, and 14 ± 13 min, respectively. Among the 766 patients with 12-month follow-up, freedom from a ≥30 s AF/AFL/AT recurrence was 83.3% (95% CI: 79.8%-86.3%) and 71.6% (95% CI: 64.6%-77.4%) in patients with PAF and persistent AF. The serious procedure- and device-related adverse event rates were 4.7% and 2.0%. No baseline patient characteristic independently predicted a procedure-related adverse event; however, prolonged procedure duration (OR = 1.01 [95% CI: 1.00-1.01]), use of general anesthesia (OR = 1.71 [95% CI: 1.01-2.92]), and delivery of a cavotricuspid isthmus line (OR = 3.04 [95% CI: 1.01-9.20]) were each independently associated with the occurrence of a serious procedural safety event (all p < .05). CONCLUSIONS: Cryoballoon ablation is safe and effective in real-world use across a broad cohort of patients with AF.

First-line catheter ablation of paroxysmal atrial fibrillation: outcome of radiofrequency vs. cryoballoon pulmonary vein isolation.

AIMS: First-line ablation prior to antiarrhythmic drug (AAD) therapy is an option for symptomatic paroxysmal atrial fibrillation (PAF); however, the optimal ablation technique, radiofrequency (RF), or cryoballoon (CB) has to be determined. METHODS AND RESULTS: The FREEZE Cohort Study compares RF and CB ablation. Treatment-naïve patients were documented in the FREEZEplus Registry. Periprocedural data and outcome were analysed. From 2011 to 2014, a total of 373/4184 (8.9%) patients with PAF naïve to AAD were identified. Pulmonary vein isolation (PVI) was performed with RF (n = 180) or CB (n = 193). In the RF group, patients were older (65 vs. 61 years, P < 0.01) compared with the CB group. The procedure time was significantly shorter and radiation exposure higher in the CB group. Major adverse events occurred in 1.6% (CB) and 3.7% (RF) of patients (P = 0.22). AF/atrial tachycardia (AT) recurrence until discharge was 4.5% (RF) and 8.5% (CB, P = 0.2). Follow-up (FU) ≥12 months was available in 99 (RF) and 107 (CB) patients. After 1.4 years of FU, freedom from AF/atrial tachycardia (AT) was 61% (RF) and 71% (CB, P = 0.11). In the RF group, more patients underwent cardioversion, and a trend for more repeat ablations was observed. Persistent phrenic nerve palsy was observed in one patient treated by CB. CONCLUSION: First-line ablation for PAF is safe and effective with either RF or CB. The procedure was faster with the CB, but the radiation exposure was higher. Although there was a trend for more recurrences and complications in the RF group, a more favourable risk profile in patients undergoing CB ablation might have biased the results. CLINICALTRIALSGOV IDENTIFIER: NCT01360008.

High rate of durable pulmonary vein isolation after second-generation cryoballoon ablation: analysis of repeat procedures.

AIMS: Pulmonary vein isolation (PVI) using the first-generation cryoballoon (CB1) was characterized by a high rate of recovered pulmonary vein (PV) conduction along with a typical conduction gap pattern in patients with recurrent atrial tachyarrhythmia (ATa). Second generation (CB2) enables more uniform freezing. However, the rate of chronic PVI and PV conduction gap pattern is unknown. METHODS AND RESULTS: All patients with ATa recurrence undergoing a second procedure after CB2 or (historical) CB1 PVI (28 mm) were enrolled. In all patients, a left atrial three-dimensional electronatomic reconstruction was performed. The rates of chronic PVI and localization of PV conduction gaps were determined and compared between CB1 and CB2. Antral PV re-isolation was performed using irrigated-tip radiofrequency current energy ablation. Of 206 patients (CB2), 18 patients underwent the repeat procedure after 192 (75:245) days. In 6 of 18 (33%) patients, all PVs were electrically isolated whereas in the remaining 12 patients (66%) at least one PV demonstrated PV reconduction. Of 71 PVs [1 left common PV (LCPV)], 55 PVs (77%) were chronically isolated. The right superior PV (RSPV) was characterized by the lowest rate of chronic PVI (RSPV: 56%, LSPV: 76%, RIPV: 83%, LIPV: 94%, LCPV: 100%). Compared with CB1, CB2 ablation resulted in a significantly higher rate of chronic PVI (CB2: 77% vs. CB1: 32%; P < 0.0001) with the greatest improvement along both inferior PVs. CONCLUSION: Second-generation cryoballoon atrial fibrillation ablation is associated with a high rate of durable PVI in patients with ATa recurrence. The RSPV represents the PV with the greatest risk for left atrium-pulmonary vein reconnection.

Differences of two cryoballoon generations: insights from the prospective multicentre, multinational FREEZE Cohort Substudy.

AIMS: Cryoballoon (CB) ablation with the second-generation cryoballoon (CBG2) seems to be more effective than its predecessor [first-generation cryoballoon (CBG1)], but phrenic nerve palsies were observed more frequently. The aim of this study was to compare the safety and efficacy of CBG1 and CBG2 in a substudy of the prospective multicentre, multinational FREEZE Cohort Study. METHODS AND RESULTS: Periprocedural data were analysed, and a total of 532 patients with paroxysmal atrial fibrillation (AF) were examined (n = 224 for CBG1 and n = 308 for CBG2). Procedure time decreased significantly from 149 to 130 min when comparing CBG1 with CBG2 (P < 0.0001), and pulmonary vein isolation (PVI) was achieved in 97.8 and 97.6% of PVs with CBG1 and CBG2 (P = 0.77), respectively. The need for dual-balloon usage within a procedure dropped (20.1 vs. 9.0%, P < 0.001), and the fluoroscopy time was reduced when operating the CBG2. Atrial fibrillation recurrence rates until discharge were similar (5.0 vs. 5.8%, P = 0.69). Comparable low rates of major complications were observed with both CBs, and there was a non-significant trend for more phrenic nerve palsies. CONCLUSION: Second-generation cryoballoon demonstrated a high rate of acute PVI in a significant faster procedure, which also utilized less radiation exposure and less dual-balloon usage during an average procedure. The safety profile remains favourable with a non-significant trend for more phrenic nerve palsies. If the enhancements lead to a higher clinical benefit has to be determined. The 1-year outcome data from the ongoing FREEZE Cohort Study comparing radiofrequency and CB ablation will shed some light on that issue. CLINICAL TRIALS GOV IDENTIFIER: NCT01360008.

Endoscopic ablation systems.

Pulmonary vein (PV) isolation for ablation of atrial fibrillation is a well-accepted therapy option for high symptomatic patients refractory to antiarrhythmic drugs. Radiofrequency point-by-point ablation is the gold-standard technique; however, in the last two decades, many new technologies have been developed. The endoscopic ablation system makes direct PV ostium visualization possible, despite the large anatomy variation thanks to its compliant balloon. The laser generator delivers precise lesions that in the first clinical studies seem to be durable, with a safety and efficacy profile similar to the other PV isolation techniques. If these early results are confirmed by larger clinical studies, the endoscopic ablation system will offer a new paradigm in ablation of cardiac arrhythmias by directly visualizing the target substrate.

Energy titration strategies with the endoscopic ablation system: lessons from the high-dose vs. low-dose laser ablation study.

AIMS: To assess the effects of low-dose (LD) and high-dose (HD) ablation on acute and chronic success in patients with atrial fibrillation (AF). While the concept of visually guided pulmonary vein isolation (PVI) has been established little is known on energy titration using laser ablation. METHODS AND RESULTS: In 60 patients with AF, PVI using the endoscopic ablation system (EAS) was performed in two groups. Visually guided ablation was carried out after obtaining optimal tissue contact with 5.5-8.5 W in the LD group and with >8.5 W in the HD group. Acute PVI after a single visually guided circular lesion set was achieved in 89% (HD) and 69% (LD), respectively, (P = 0.0004). In 70 and 39% of patients all PVs were isolated after a single ablation circle in the HD and LD group, respectively, (P = 0.009). After gap ablation all PVs were isolated with the EAS. More energy was deployed (6483 ± 1834 vs. 5306 ± 2258 Ws; P ≤ 0.0001) with less applications (31.6 ± 8 vs. 35.2 ± 15 applications per PV; P = 0.03) leading to shorter procedure times (128 ± 17 vs. 154 ± 38 min; P = 0.001). During median follow-up of 311 days (261-346) recurrence rate was 17 and 40% in the HD and LD group, respectively. In both groups one phrenic nerve palsy was observed. CONCLUSION: For the first time, it was demonstrated that high ablation power affects acute and chronic outcomes. High-dose laser balloon ablation allows for an acute PVI rate of 89% solely by visually guided circular ablation and is associated with a chronic success rate of 83% after a single procedure.

Two versus one repeat freeze-thaw cycle(s) after cryoballoon pulmonary vein isolation: the alster extra pilot study.

BACKGROUND: Repeated freezing (bonus applications) during cryoballoon pulmonary vein isolation (PVI) has been suggested to improve lesion durability. However, the long-term clinical effects of repeated freezing have not been investigated. METHODS AND RESULTS: A total of 51 patients (pts) with paroxysmal atrial fibrillation (AF) underwent PVI using the single big (28 mm) cryoballoon technique. One (27 pts, group I) or 2 bonus applications (24 pts, group II) were performed at all PVs subsequent to PVI. Clinical follow-up consisted of continuous rhythm monitoring by an implantable cardiac monitor (ICM, 24 pts) and serial 7-day Holter-ECG recording (7DH, 27 pts). The primary endpoint was defined as recurrent AF or atrial tachycardia. Acute PVI of all PVs was obtained in 50/51 pts (98%). The median (Q1;Q3) follow-up duration in this study was 384 (213;638) days. The primary endpoint occurred in 48% (group I, 15 pts ICM, 12 pts 7DH) and 46% (group II, 9 pts ICM, 15 pts 7DH), P = 0.84. Procedure- and fluoroscopy-time for group I versus group II was 193 ± 56 minutes versus 207 ± 27 and 33 ± 13 minutes versus 34 ± 11 minutes, respectively. Right phrenic nerve palsy (PNP) occurred in 3 pts (all group II, time to resolution: 128 ± 112 days). In 2 of these pts, PNP occurred during the second bonus application. CONCLUSION: Application of 2 when compared to 1 freeze-thaw cycle(s) following cryoballoon PVI did not result in improved clinical success but was associated with a higher complication rate.

Pulmonary vein isolation after left-sided pneumonectomy: technically challenging but feasible and instructive.

We present a technically challenging case of pulmonary vein isolation (PVI) after complete left-sided pneumonectomy, resulting in uncommon cardiac rotation. Wide area circumferential PVI after pneumonectomy is technically challenging but feasible in experienced centres. Correct identification of the PV ostia is crucial before ablation.

The 'single big cryoballoon' technique for acute pulmonary vein isolation in patients with paroxysmal atrial fibrillation: a prospective observational single centre study.

AIMS: Cryothermal energy (CTE) ablation via a balloon catheter (Arctic Front, Cryocath) represents a novel technology for pulmonary vein isolation (PVI). However, balloon-based PVI approaches are associated with phrenic nerve palsy (PNP). We investigated whether 'single big cryoballoon'-deployed CTE lesions can (i) achieve acute electrical PVI without left atrium (LA) imaging and (ii) avoid PNP in patients with paroxysmal atrial fibrillation (PAF). METHODS AND RESULTS: After double transseptal punctures, one Lasso catheter and a big 28 mm cryoballoon catheter using a steerable sheath were inserted into the LA. PV angiography and ostial Lasso recordings from all PVs were obtained. Selective PV angiography was used to evaluate balloon to LA-PV junction contact. CTE ablation lasted 300 s, and the PN was paced during freezing at right-sided PVs. Twenty-seven patients (19 males, mean age: 56 +/- 9 years, LA size: 42 +/- 5 mm) with PAF (mean duration: 6.6 +/- 5.7 years) were included. PVI was achieved in 97/99 PVs (98%). Median (Q(1); Q(3)) procedural, balloon, and fluoroscopy times were 220 min (190; 245), 130 min (90; 170), and 50 min (42; 69), respectively. Three transient PNP occurred after distal PV ablations. No PV stenosis occurred. Total median (Q(1); Q(3)) follow-up time was 271 days (147; 356), and 19 of 27 patients (70%) remained in sinus rhythm (3-month blanking period). CONCLUSION: Using the single big cryoballoon technique, almost all PVs (98%) could be electrically isolated without LA imaging and may reduce the incidence of PNP as long as distal ablation inside the septal PVs is avoided.

Remote navigation systems in electrophysiology.

Today, atrial fibrillation (AF) is the dominant indication for catheter ablation in big electrophysiologists (EP) centres. AF ablation strategies are complex and technically challenging. Therefore, it would be desirable that technical innovations pursue the goal to improve catheter stability to increase the procedural success and most importantly to increase safety by helping to avoid serious complications. The most promising technical innovation aiming at the aforementioned goals is remote catheter navigation and ablation. To date, two different systems, the NIOBE magnetic navigation system (MNS, Stereotaxis, USA) and the Sensei robotic navigation system (RNS, Hansen Medical, USA), are commercially available. The following review will introduce the basic principles of the systems, will give an insight into the merits and demerits of remote navigation, and will further focus on the initial clinical experience at our centre with focus on pulmonary vein isolation (PVI) procedures.