EUropean real-world outcomes with Pulsed field ablatiOn in patients with symptomatic atRIAl fibrillation: lessons from the multi-centre EU-PORIA registry

AIMS

Pulsed field ablation (PFA) is a new, non-thermal ablation modality for pulmonary vein (PV) isolation in patients with atrial fibrillation (AF). The multi-centre EUropean Real World Outcomes with Pulsed Field AblatiOn in Patients with Symptomatic AtRIAl Fibrillation (EU-PORIA) registry sought to determine the safety, efficacy, and learning curve characteristics for the pentaspline, multi-electrode PFA catheter.

METHODS AND RESULTS

All-comer AF patients from seven high-volume centres were consecutively enrolled. Procedural and follow-up data were collected. Learning curve effects were analysed by operator ablation experience and primary ablation modality. In total, 1233 patients (61% male, mean age 66 ± 11years, 60% paroxysmal AF) were treated by 42 operators. In 169 patients (14%), additional lesions outside the PVs were performed, most commonly at the posterior wall (n = 127). Median procedure and fluoroscopy times were 58 (interquartile range: 40-87) and 14 (9-21) min, respectively, with no differences due to operator experience. Major complications occurred in 21/1233 procedures (1.7%) including pericardial tamponade (14; 1.1%) and transient ischaemic attack or stroke (n = 7; 0.6%), of which one was fatal. Prior cryoballoon users had less complication. At a median follow-up of 365 (323-386) days, the Kaplan-Meier estimate of arrhythmia-free survival was 74% (80% for paroxysmal and 66% for persistent AF). Freedom from arrhythmia was not influenced by operator experience. In 149 (12%) patients, a repeat procedure was performed due to AF recurrence and 418/584 (72%) PVs were durably isolated.

CONCLUSION

The EU-PORIA registry demonstrates a high single-procedure success rate with an excellent safety profile and short procedure times in a real-world, all-comer AF patient population.

Cryoballoon ablation of atrial fibrillation in octogenarians: one year results from the Cryo Global Registry

Background

A few studies have demonstrated the safety and efficacy of cryoballoon ablation (CBA) in elderly patients (≥75 years old) with atrial fibrillation (AF). However, global utilization and outcomes of CBA in the octogenarian population (≥80 years old) have not been reported.

Purpose

To evaluate the efficacy and safety of CBA of AF in patients ≥80 years old.

Methods

The Cryo Global Registry (NCT02752737) is an ongoing, prospective, multicenter registry. In this analysis, 1674 patients with paroxysmal or persistent AF were included in 37 global centers who treated at least one octogenarian with CBA. Analysis cohorts were defined as patients ≥80 and patients <80 years old (control). To address safety issues of CBA in octogenarians, serious procedure-related complications were assessed. Utilizing Kaplan-Meier estimates, 12-month freedom from a ≥30sec AF/atrial flutter (AFL)/atrial tachycardia (AT) recurrence following a 90-day blanking period was evaluated.

Results

The average age of the octogenarians (n=101) was 82±2 years vs 62±10 years in the control group (n=1573). More females were found in the octogenarian population (51.5% vs 35.7%, p<0.01). The ≥80-year-old cohort had lower BMI (26±4 kg/m2 vs 27±5 kg/m2), higher CHA2DS2-VASc-Scores (4.2±1.3 vs 2.0±1.5), and a higher proportion of heart failure (all p<0.01). The patient cohort ≥80 years was similar compared to the control group regarding the AF history (70.3% vs 74.4% paroxysmal AF), years diagnosed with AF (2.9±4.9 vs 3.2±4.8), and left atrial diameter (43±8 mm vs 42±8 mm) (all p>0.05). Success rates of acute pulmonary vein isolation did not differ between the groups (95.0% vs 96.2%, p=0.59). No differences were observed between ≥80- (5.9%) and <80-year-old patients (3.5%) with respect to serious adverse events (p=0.26). Rhythm monitoring, comprising of Holter and 12-lead ECG, was performed on average 3.1±3.1 times in the elder population and 3.2±3.1 times in the control group through 12 months (p=0.84). Efficacy at 12 months was not different between groups, resulting in 80.6% (95% CI: 71.0–87.3%) freedom from AF/AFL/AT recurrence at 12 months in the octogenarians compared to 78.9% (95% CI: 76.7–80.9%) in the control group (p=0.70). Fewer patients were prescribed AADs at 12 months (32.2%, 23.7%) compared to discharge (47.8%, 49.1%), octogenarians and control, respectively. Further, octogenarians were less likely to receive a repeat ablation 3.3% (95% CI: 1.1–9.7%) in comparison to the control cohort 9.2% (95% CI: 7.8–10.8%) (p=0.052). The 12-month Kaplan-Meier estimate of freedom from cardiovascular-related hospitalization was 81.1% (95% CI: 71.7–87.7%) in the octogenarian and 84.8% (95% CI: 82.9–86.6%) in the control group, respectively (p=0.21).

Conclusion

Cryoballoon ablation for the treatment of AF is a safe procedure in octogenarians, with efficacy and complication rates comparable to younger patients.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Medtronic, Inc.

Regional variations in patient selection and procedural characteristics for cryoballoon ablation of atrial fibrillation

Background

Cryoballoon ablation is a well-established anatomical approach for pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). Although widely adopted, regional variations in standards of care have not been well characterized.

Purpose

To evaluate regional variations in patient selection and procedural characteristics for PVI with cryoablation in the Cryo Global Registry (NCT02752737).

Methods

Patients with AF were enrolled from May 2016 to October 2021 at 128 sites in 37 countries. Patients were treated with cryoballoon ablation according to local clinical practice. Baseline subject and procedural characteristics were summarized for 8 regions (Central Asia and Russia, East Asia, Europe, Middle East, North America, South Africa, South America, and Southeast Asia). Procedure-related serious adverse events (SAEs) were evaluated in a subset of patients with ≥7 days of follow-up.

Results

A total of 3680 patients undergoing initial PVI for AF were included. Cryoballoon ablation was more commonly performed in patients with paroxysmal vs. persistent AF in all regions, and in males vs. females in all regions except Central Asia and Russia. Mean age ranged from 47±12 in the Middle East to 64±11 in East Asia. Regional variations were observed in the proportion of patients with common AF comorbidities undergoing cryoablation (Table 1). Median procedure time ranged from 61 (49–68) minutes in Central Asia and Russia to 95 (76–120) minutes in Southeast Asia. Median fluoroscopy time was ≤20 minutes in all regions. The use of 3D mapping was relatively uncommon except in North America (63.3%). Large variation was observed in the use of esophageal monitoring, whereas phrenic nerve monitoring was used in ≥97.7% of cases in all regions (Table 2). Same-day discharge was uncommon except in North and South America (37.8% and 26.5% of cases, respectively). Average freeze duration ranged from 153±41 seconds in Southeast Asia to 230±29 seconds in Central Asia and Russia. Mean number of applications per vein ranged from 1.2±0.4 in Central Asia and Russia to 2.1±1.0 in North America. Acute procedural success was ≥94.7% in all geographies and focal radiofrequency touch-up was required in ≤13.0% of cases. In 3126 subjects with ≥7 days of follow-up, 122 procedure-related SAEs were reported in 111 patients (3.6%), and 1 procedure-related death was reported during data collection.

Conclusion(s)

Despite regional variations in patient selection and procedural characteristics, PVI using cryoballoon ablation is performed with high acute success and short procedural times around the world.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Medtronic, Inc.

Quality of life after first-line cryoablation of atrial fibrillation: results from the Cryo AF Global Registry

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): The registry was sponsored Medtronic, Inc., Minneapolis, MN.

Background

Atrial fibrillation (AF), the most common cardiac arrhythmia, burdening patients with a myriad of symptoms. Three recent randomized trials demonstrated that cryoballoon ablation (CBA) is superior to antiarrhythmic drugs (AADs) as a first-line treatment for the prevention of arrhythmia reoccurrence in patients with paroxysmal AF. However, the global outcome of CBA performed according to local standard of care as a first-line therapy for AF is not reported.

Purpose

To compare safety, efficacy, and quality of life outcomes in patients treated with CBA for first-line management of AF against patients treated with CBA following failed AAD therapy.

Methods

The Cryo AF Global Registry, an ongoing, prospective, multicenter registry, of AF patients undergoing index CBA performed according to local standards at 58 centers in 26 countries worldwide. In this analysis, subjects undergoing first-line cryoablation were compared to patients who were refractory to AAD therapy and/or taking AADs at baseline. Safety was assessed utilizing a composite of serious procedure-related complications. To evaluate efficacy, time-to-first atrial fibrillation, -flutter and/or -tachycardia (AF/AFL/AT) recurrence post a 90-day blanking period was compared between groups using Kaplan-Meier estimates. Quality of life was evaluated using the EQ-5D-3L questionnaire at baseline and at 12 months following CBA. Log-rank, two-sample t-test, and exact binomial tests were utilized to test difference between groups.

Results

Of 1,394 total patients, 433 (31.1%) were drug naïve prior to CBA. Patients in the AAD therapy cohort failed a mean of 1.2 ± 0.5 AADs before CBA. Freedom from AF/AFL/AT recurrence at 12 months was 87.8% in first-line patients compared to 81.6% in AAD-refractory patients (p<0.01). Serious adverse event rates were not statistically different (p=0.32) between first-line (2.3%) and AAD-refractory (3.4%) patients. First-line CBA resulted in a larger mean decline in symptoms upon follow-up, with 81% of patients reported to be symptom-free at 12 months. Further, first-line patients were prescribed AADs at a lower rate at discharge (18.6% vs.62.8%) and at 12-months (9.7% vs.29.9%) in comparison to patients in the AAD cohort. However, cryoablation did result in AAD prescriptions being reduced by approximately 50% in both cohorts from discharge to 12-months. As determined by the EQ-5D-3L score, quality of life improved for patients in both groups, with no significant difference between first-line and AAD-refractory patients (p=0.29).

Conclusion

This real-world global evaluation supports CBA as a safe and efficacious first-line treatment that improves the quality of life for patients with symptomatic AF.

The triangle correlation among the impact on serum S100B protein release, incidence of the silent cerebral ischemic phenomena and pulsed field ablation for patients with atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Backgrounds: Pulsed field ablation (PFA) represents a cardiac specific energy source for atrial fibrillation (AF) ablation. The correlation among this remarkable technique, the incidence of silent cerebral ischemic phenomena (SCIP), and the clinical impact on serum S100B release, a well-known neural injury relevant biomarker concomitant to denervation of the intrinsic cardiac autonomic nervous system during AF ablation, has been unclear.

Aims

This study thought to reveal the "triangle correlation" by investigating the serum S100B increase, incidence of SCIP on cerebral magnetic resonance imaging (MRI), and its interactive correlation in PFA using the FARAPULSE system.

Methods and Results

Pre- and postprocedural serum S100B was analyzed in a total of 85 patients who underwent AF ablation using the FARAPULSE PFA device. Cerebral MRI was performed subsequently 24-48 hours after procedure. All PVs (332 PVs) were successfully isolated solely with PFA. No additional left atrial mapping using other catheters was performed.

The median overall serum S100B increase from the preprocedural value was 0.01μg/l (-0.02 – 0.04μg/l). Asymptomatic SCIP were detected on MRI in 10/53 patients (18.9 %). Of those, the patients with SCIP demonstrated a significantly higher S100B release (0.04, 0.02 – 0.16μg/l vs. without SCIP:0.01, -0.04 – 0.03μg/l, p = 0.0038). Receiver operating characteristic curve revealed a predictive cut-off point for SCIP of 0.04 μg/l (sensitivity:0.7, specificity: 0.49).

Conclusions

We revealed no clear detectable impact of PFA on S100B release, highlighting the cardioselectivity with limited concomitant denervation. SCIP was detected approximately in a one-fifth after procedures and was a potential confounder of the higher S100B increase.

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.

Initial clinical experience of pulmonary vein isolation using the novel ultra-low temperature cryoablation catheter for patients with atrial fibrillation

Background

The high cooling power and ultra-low temperature cryoablation (ULTC) catheter called “Adagio” has been recently launched. A combination of a newly exploited cryogen and interchangeable stylet enables flexible and continuous lesion creation applicable not only for atrial fibrillation (AF) but also for other tachyarrhythmia by optimizing catheter shape. The exclusive esophageal warming balloon in order to preserve esophageal temperature is encouraged to prevent the potential risk of esophageal complication during procedure.

Aim

To assess the initial clinical data on pulmonary vein (PV) isolation for patients with AF using the novel ULTC catheter.

Methods

Consecutive patients who underwent AF ablation using ULTC in our center were enrolled. We assessed the acute procedural data focusing on procedural feasibility and safety comprising “first-pass isolation” defined as successful PV isolation after the initial application.

Results

A total of 16 AF patients (53% male, age 67 years, 59% paroxysmal AF) were analyzed. Sixty-six out of 67 PVs (98.5%) were isolated with ULTC. The mean number of applications per PV was 2.3 1.1. Touch-up catheter was needed in one case at left inferior PV. The mean total procedure and fluoroscopy times were 79±30 and 14±7 mins, respectively. First-pass isolation was achieved in 34 PVs (50.7%) varying across PVs from left superior PV (43.8%) to right superior PV (58.8%). In none of the patients an acute thromboembolic event (stroke or transient ischemic attack), a pericardial effusion/tamponade and postprocedural esophageal complication occurred. A single transient phrenic nerve weakening was observed at right superior PV.

Conclusion

Sequential PV isolation using the novel ULTC catheter was achieved feasibly without compromising safety. First-pass isolation was accomplished about in a half of PVs.

Funding Acknowledgement

Type of funding sources: None.

Evolution in lesion index durability using the new third generation laser balloon catheter for pulmonary vein isolation – does the mechanical innovation mean also clinical innovation?

Background

The new second- and third-generation endoscopic ablation systems (EAS 2 and EAS 3) have been launched in recent years. We aimed to assess the index lesion durability as well as gap localization using the multigenerational novel technologies in patients with recurrent atrial fibrillation (AF).

Methods

Consecutive patients who underwent the second ablation for recurrent AF following the initial pulmonary vein isolation (PVI) with EAS 2 or EAS 3 were investigated. The persistent durability of PVI and gap localization at the second procedure were analyzed using spiral mapping catheter and three-dimensional mapping system.

Results

A total of 34 patients (EAS3: N=13, 50 PVs, EAS2: N=21, 82 PVs) were enrolled. Repeat procedure was performed mean 11.9±9.3 months after the initial procedure. Persistent durable isolation of all four PVs was recorded in 6 (46.2%) patients in EAS3 and 4 (19.1%) patients in EAS2 (P=0.130). Ninety-one out of 132 (68.9%) PVs were persistently isolated with a higher rate in EAS3 (EAS3: 82.0% vs. EAS2: 61.0%, P=0.0113). A total of 45 gaps were recorded in 41 PVs, of which right superior PV (RSPV) was the predominantly common reconnected vein (15 gaps in 14 PVs) irrespective of generation difference (EAS 3: 4 gaps in 3 PVs and EAS 2: 12 gaps in 11 PVs). Anterior-segment of RSPV was the most common gap distribution (EAS 3: 2 gaps and EAS 2: 6 gaps). Logistic multivariate regression analysis revealed high-dose (≥8.5W) only ablation as an independent predictor of durable PVI (adjusted OR: 3.70, 95% CI [1.408 - 10.003], P=0.008)

Conclusion

The multigenerational technical innovation resulted in a higher index lesion durability in EAS3 guided PVI in patients with recurrent AF. The specific gap patterns frequent at RSPV, especially at the anterior-superior segment, and the feasibility of high-dose ablation were confirmed in successor EASs.

Funding Acknowledgement

Type of funding sources: None.

What Does the Future Hold?: Ideal Device, Newer Devices, and More

Please verify if "pigtail guided" should be "pigtail catheter-guided": Recent design changes for left atrial appendage (LAA) closure devices have led to significant improvement by facilitating the procedural workflow (no need for pigtail guided LAA intubation), moving the workspace from distal LAA to the landing zone (closed distal end design), and improving device stability (different anchor design). The availability of different device types (plug vs disc-lobe design) offers an option to tailor a device type to a patient's anatomy; thereby, sealing results have improved substantially. The issue of device-related thrombus has not been resolved and deserves future research, with the goal of eliminating postprocedural antithrombotic medication without increasing risk for stroke.

Ablation Index guided high power (50W) short duration for anterior line and roof line ablation: feasibility, procedural data and lesion analysis

Funding Acknowledgements

Type of funding sources: None.

Objectives

To evaluate the feasibility, procedural data, and lesion characteristics of anterior line (AL) and roof line (RL) ablation by using ablation index (AI) guided high-power(50W) among patients with recurrent atrial fibrillation (AF) or atrial tachycardia (AT) after pulmonary vein isolation (PVI).

Methods

35 consecutive patients with macro-reentrant left atrial tachycardia (LAT) or substrate at LA anterior wall or roof after previous PVI were enrolled. Ablation power was set to 50W, targeting AI 500 for AL and 400 for RL. First-pass conduction block (FPB) was evaluated. The AL was arbitrarily divided into 3(caudal, middle and cranial) segments to analyze the location of conduction gaps in non-FPB patients.

Results

A total of 32 AL and 17 RL were deployed and FPB was achieved in 24 (75%) and 14 (82%) of them respectively. In non-FPB group, the most frequent gap location along the AL was the middle third. Final block of AL was achieved in 97%, and block of RL was achieved in 100%. The RF ablation time was short (2,9 ± 0,8 min for AL and 46,2 ± 15,6 sec for RL). For AL, female gender was significantly more frequent in FPB than in non-FPB patients(p 0,028); patients with non-FPB were associated with significantly longer RF time as compared to patients with FPB (204 ± 47 sec vs 161 ± 41 sec; p = 0,02). No procedural complications occurred.

Conclusion

AI guided high-power(50W) ablation appears to be a feasible, effective and fast technique for AL and RL ablation.

First insight into a novel irrigated radiofrequency ablation balloon

Funding Acknowledgements

Type of funding sources: None.

Background

A novel irrigated RF balloon (RFB) for pulmonary vein isolation (PVI) was recently released in selected centers . It is a 28 mm open irrigated balloon with 10 unipolar electrodes on its surface to deploy a circular ostial lesion set around the PVs. An inner lumen spiral catheter allows for real time PVI visualization during the ablation.

Methods

Data from consecutive RFB procedures were collected and analysed. After a single transseptal puncture and selective PV angiograms a 3D map of the left atrium was acquired. Sequential PVI was performed using the RFB: each application lasted 60 seconds, the posterior electrodes were identified to stop the energy delivery after 20 seconds. Real time to isolation data were acquired. A 3D bipolar remap was finally performed to observe the level of isolation. A temperature probe was used to monitor the local esophageal temperature (LET) with a cut off of 39°C. Acute procedural data and complication were collected. Endoscopy was scheduled the day after procedure.

Results

Data from 10 consecutive RFB procedures were analyzed: 6/10  patients were male, 67 ± 9 years old, 8/10 with history of paroxysmal AF. A total of 36 PVs were targeted and isolated with the RFB, with a mean of 7,3 ± 4,0 applications per patient and 2,0 ± 1,2 applications per PV. First pass "single shot"  isolation was achieved in 22/36 (61%), time to isolation during the first application was observed in 29/36 (80%) PVs, but an acute reconnection was observed in  10/29 (35%) isolated PVs. Mean time to sustained isolation was 13 ± 5 sec., mean time to non-sustained isolation was significantly longer (29 ± 17 sec; p = 0,001). Procedure time was 57 ± 16 min., left atrial dwell time 50 ± 14 min, ablation phase time 29 ± 14 min and fluoroscopy time was 10 ± 4 minutes. An esophageal temperature above 39°C was recorded in 2/36 PVs. No phrenic nerve palsy was recorded. 7/10 patients underwent endoscopy and no thermal lesions were detected. No other complications were recorded.

Conclusion

The novel irrigated RFB seems to allow an effective, safe and fast pulmonary vein isolation. More studies are needed to optimize energy dosing to possibly increase the rate of durable single shot PVI.

Healthcare utilization after cryoballoon ablation for treatment of atrial fibrillation in patients with heart failure: real-world results from the Cryo AF Global Registry

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Medtronic, Inc.

OnBehalf

Cryo AF Global Registry Investigators

Background

Heart failure (HF) concomitant to atrial fibrillation (AF) can exacerbate the risk of hospitalization, morbidity, mortality, and impairment in quality of life posed by each condition alone. While the reciprocal relationship between HF and AF challenges effective treatment for these patients, catheter ablation for treatment of AF is reasonable for select patients with AF and HF according to guidelines. Purpose: Assess real-world usage and healthcare utilization outcomes of cryoablation for patients with AF and HF. Methods: The Cryo AF Global Registry (NCT02752737) is an ongoing, prospective, multicenter registry. Patients with AF were enrolled and treated with cryoballoon ablation (Arctic Front Advance, Medtronic) according to clinical practice at 56 sites in 26 countries world-wide. Subjects with NYHA class I-III at baseline comprised the HF cohort and were compared to patients without HF (No-HF). Freedom from atrial arrhythmia recurrence ≥30 sec, adverse events associated with the AF ablation procedure, repeat ablations, AAD usage, and cardiovascular rehospitalization over a 12-month follow-up were compared between cohorts. Results: A total of 1,303 patients (318 HF, 985 No-HF) were included. The HF cohort included patients with NYHA Class I (56.3%) and II/III (43.7%) with either preserved (81.6%) or mid/reduced (18.4%) left ventricular ejection fraction. HF patients were more often female (45.6% vs 33.6%) with persistent AF (25.8% vs 14.3%), larger left atrial diameter (4.4 ± 0.9 vs 4.0 ± 0.7 cm), and higher rates of hypertension (67.9% vs 49.1%) and prior myocardial infarction (3.8% vs 1.7%; all, P < 0.05). The rate of serious procedure-related complications was 5.3% in HF and 3.0% in No-HF (P = 0.08). Freedom from atrial arrhythmia recurrence at 12-months was not different between HF and No-HF patients with either paroxysmal (84.2% (95% CI:78.6-88.4) vs 86.8% (95% CI: 84.2 – 89.0)) or persistent AF (69.6% (95% CI: 58.1 – 78.5) vs 71.8% (95% CI: 63.2-78.7)), respectively (p = 0.32, HF vs No-HF). AF-related symptoms and antiarrhythmic drug use were significantly reduced after cryoablation in the HF and No-HF cohorts (P < 0.05). Freedom from repeat ablation at 12-months was similar between HF and No-HF patients. Of patients who had a cardiovascular rehospitalization after cryoablation, 78% presented with a supraventricular tachyarrhythmia. Persistent AF and HF at baseline both increased the risk of cardiovascular rehospitalization after cryoballoon ablation (P < 0.05). Conclusion: Cryoablation is used to treat patients with AF and concomitant HF in real-world practice and is similarly safe and effective at 12-months in patients with and without HF.

Safety of cryoballoon ablation for the treatment of atrial fibrillation: first European results from the Cryo AF Global Registry

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): Medtronic, Inc.

OnBehalf

Cryo AF Global Registry Investigators

Background

Since introduced in Europe over 15 years ago, cryoballoon ablation for the treatment of

patients with atrial fibrillation (AF) has proven to be safe and effective.

Purpose

Report on patient and procedural characteristics, ablation techniques, and outcomes. Also,

determine the independent predictors of a procedural adverse event in real-world usage.

Methods

Patients with AF were enrolled in the prospective, multicenter Cryo AF Global Registry

(NCT02752737) and treated with cryoballoon ablation at 38

European centers according to standard-of-care. The primary efficacy endpoint was freedom from a ≥30 sec episode of AF/atrial flutter (AFL)/atrial tachycardia (AT) at 12-months. The primary safety endpoint was the rate of serious adverse events related to the device and/or procedure. Univariate and

multivariable models identified baseline patient and procedural characteristics that predicted a serious

procedure-related complication. Results: Of 1,418 subjects who completed an index procedure, the cohort was 62 ± 11 years of age, 37.7% female, and 72.2% paroxysmal AF (PAF). In total, 32.2% of patients were treated with cryoablation as a first-line therapy. Non-general anesthesia was used in 76.0% of procedures. Ablation adjunctive to the cryoballoon pulmonary vein isolation was applied in few cases: 2.0% of patients were treated with a cavotricuspid isthmus (CTI) line with focal radiofrequency ablation and 0.8% of patients received other non-PVI ablation. The mean procedure, left atrial dwell, and fluoroscopy times were 81 ± 34, 54 ± 25, and 14 ± 13 minutes, respectively. Among the 766 patients with 12-month follow-up, freedom from AF/AFL/AT recurrence ≥30 sec 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, respectively. The serious procedure- and device-related adverse event rates were 4.7% and 2.0%, respectively. Female sex was significantly associated with the occurrence of an adverse event in univariate analysis (P < 0.05), but (after accounting for patient age and NYHA status) 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 CTI 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 < 0.05). Conclusion: Cryoablation treated patients across the AF disease spectrum with one-third of patients treated prior to antiarrhythmic drug usage and another third treated for persistent AF. The results indicate extra diligence is warranted in patients under general anesthesia and for those who receive adjunctive CTI ablation. Cryoballoon ablation is consistently safe for patients independent of baseline patient characteristics and comorbidities in real-world use.

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.

Safety and efficacy of cryoballoon ablation for the treatment of paroxysmal and persistent AF in a real-world global setting: Results from the Cryo AF Global Registry

BACKGROUND

Cryoballoon ablation is a commonly used approach to treat patients with atrial fibrillation (AF).

OBJECTIVES

Report on the safety and efficacy of cryoballoon ablation for the treatment of AF in the largest global cohort of cryoablated patients prospectively studied within a single registry.

METHODS

The Cryo AF Global Registry is a prospective, multi-center registry. Patients with paroxysmal AF (PAF) or persistent AF (PsAF) were treated with the cryoballoon catheter according to routine practices at 93 sites across 36 countries. Primary efficacy endpoints included freedom from AF and freedom from AF/atrial flutter (AFL)/atrial tachycardia (AT) ≥30 seconds. The primary safety endpoint was serious device- or procedure-related adverse events over 12 month follow-up.

RESULTS

During this evaluation window, 2922 subjects completed an index cryoballoon procedure, and 1440 completed 12 month follow-up. The cohort was 61 ± 12 years of age, 36.3% female, and 78.7% PAF. Serious device- and procedure-related adverse event rates were 1.5% and 3.4%, respectively. Freedom from AF/AFL/AT after the 90 day blanking period was 86.4% (95% CI: 84.3%-88.3%) in patients with PAF and 70.9% (95% CI: 64.6%-76.4%) in patients with PsAF. Freedom from AF/AFL/AT in first-line PAF and PsAF was 90.0% (95% CI: 86.4%-92.7%) and 72.9% (95% CI: 58.6%-83.0%) at 12 months, respectively.

CONCLUSIONS

The Cryo Global AF Registry is the largest evaluation to demonstrate cryoablation is an efficient, safe, and effective treatment for patients with AF worldwide. Cryoablation was commonly used to treat patients prior to an AAD failure and may facilitate earlier therapy for patients on the AF disease continuum.

Thromboembolism after electrical isolation of the left atrial appendage: a new indication for interventional closure?

AIMS

Left atrial appendage electrical isolation (LAAI) may improve the rhythm outcome in selected patients with atrial fibrillation (AF). Controversy exists if LAAI is associated with an increased rate of thromboembolic complications. We sought to assess the feasibility, efficacy, and safety of interventional left atrial appendage closure (LAAC) in comparison to oral anticoagulation (OAC) after electrical LAAI.

METHODS AND RESULTS

Weeks after index LAAI using the cryoballoon or a linear maze like ablation strategy patients' left atrial appendage was invasively remapped. In case of persistent LAAI, LAAC was performed. Patients who refused invasive remapping continued OAC. The primary endpoint was composed of any stroke or systemic embolism (SE) and the occurrence of intracardiac thrombus. Secondary endpoints included stroke/SE, major bleeding, and all-cause death. Of 166 patients (51% female; mean age 70 ± 8 years; mean CHAD2S2VASc score 3.4 ± 1.8) after LAAI, 94 patients received LAAC (LAAC group) and 72 continued OAC (no LAAC). After LAAC, 83% of patients received dual antiplatelet therapy for 6 weeks and aspirin thereafter. During a mean follow-up of 778 ± 630 days, 5 and 11 primary endpoint events were observed in the LAAC and no LAAC group, respectively [hazard ratio (HR) 0.27, 95% confidence interval (CI) 0.10-0.75; P = 0.010]. The calculated annual thromboembolic event rates were 6.9% (no LAAC) and 2.3% (LAAC), respectively. Left atrial appendage closure significantly reduced the incidence of stroke and SE (HR 0.31, CI 0.1-0.98; P = 0.04).

CONCLUSION

After electrical LAAI for rhythm control in AF patients, interventional LAAC was associated with fewer thromboembolic complications when compared with OAC.

Holter ECG diagnosis of nicotine-spray induced ventricular fibrillation. An unusual case of Prinzmetal variant angina

We report on an interesting case of resuscitated sudden cardiac death (SDC) in a 51-year-old with hypertension and positive family history for SDC. The patient was resuscitated and an emergency angiogram ruled out coronary artery disease. Cardio-MRT ruled structural disease or infection. Holter and telemetry monitoring revealed premature ventricular complexes and transient ST-changes followed by anginaepisodes in correlation with the use of the nicotine-replacement-spray. The patient was urged to quit smoking and smoking-substitutes. Medical therapy with calcium-channelblocker and a long acting nitrate was administered. One-month follow up reported no arrhythmic or angina events.

P1022Upstream therapy using preoperative renin-angiotensin system inhibitors in prevention of postoperative atrial fibrillation and adverse events: a collaborative pooled-analysis over 27,000 patients

Background

Renin-angiotensin-system inhibitors (RASIs) have been suggested as an upstream therapy for selected AF patients; however, the evidence in surgical setting is limited.

Objective

We aimed to evaluate the role of preoperative RASIs in prevention of postoperative atrial fibrillation (POAF) and adverse events for patients undergoing cardiac surgery.

Methods

In this collaborative pooled-analysis, both randomized and nonrandomized controlled trials comparing preoperative RASIs with no preoperative RASIs treatment on the incidence of POAF were identified. Sensitivity and subgroup analyses of RCTs were performed to test the stability of the overall-effect, and meta-regression to explore the potential risk of bias. The primary outcome was POAF, and the secondary outcomes includes rate of stroke, mortality and duration of hospitalization.

Results

Eleven trials involving 27885 patients (male 74%, median age 65yrs) were included. As compared to the control group, preoperative RASIs did not significantly reduce the risk of POAF (OR: 1.04, 95% CI: 0.91–1.19), stroke (OR: 0.86, 95% CI: 0.62–1.19), death (OR: 1.07, 95% CI: 0.85–1.35), composite adverse cardiac events (OR: 1.04, 95% CI: 0.91–1.18), and hospital stay (WMD: −0.04, 95% CI: −1.05 to 0.98). Pooled-analysis of randomized trials showed consistent results. The primary overall-effect was maintained in sensitivity and subgroup analyses. Meta-regression showed that male-gender was a significant risk-factor of POAF and use of Beta-blockers was associated with a significantly reduced risk in developing POAF.

Conclusion and relevance

This study demonstrates that preoperative RASIs do not offer additional benefit in reducing the risk of postoperative AF, stroke, death and hospitalization in the setting of cardiac surgery. The results provide no support for use of RASIs for the prevention of POAF and adverse events in patients undergoing cardiac surgery.

P1921Impact of cryoballoon freeze duration on long-term durability of pulmonary vein isolation in atrial fibrillation: insights from Re-mapping procedures (the ICE Re-map study)

Background

Second-generation cryoballoon (CB2) represents a powerful pulmonary vein isolation (PVI) tool. Recently, the randomized time-to-effect guided (ICE-T) CB2 strategy targeting a 240s single freeze demonstrated fast and efficient PVI. To further optimize safety and efficacy, a shortened 3min freeze duration has been suggested but PVI durability remains unclear.

Methods

Between May 2013 and December 2017 all CB2 ablations followed the ICE-T concept (target-freeze: 240s or 180s). Patients undergoing a second procedure for arrhythmia recurrence were analyzed. Two groups were defined based on the index freeze duration (group 240s vs. group 180s). In all repeat procedures a 3D left-atrial map was obtained. Durability of PVI and localization of conduction gaps were compared.

Results

A total of 106/788 (13%) patients underwent a second procedure (group 240s: 80/604 vs. group 180s: 26/184) after a mean of 377 days. There was no difference regarding PV occlusion and time-to-isolation in the index procedure between two groups. No major complications occurred. During the second procedure significantly more patients demonstrated durable isolation of all PVs in group 240 (61% vs 35%, p=0.02) along with a significantly increased rate of PVI durability (88% vs. 69%, per vein, p<0.001). Left sided PVs did significantly benefit from 240s freezes (reconnection LSPV: 6% vs 27%, p=0.004, LIPV: 14 vs. 39%, p=0.006).

Conclusions

The ICE-T strategy is associated with a high rate of durable PVI in patients with arrhythmia recurrence. Target freeze duration of 240s vs. 180s is associated with significantly increased lesion durability, particularly at left sided PVs, without increasing complications.

P2841Atrial fibrillation ablation using ablation index guided high power (50W) smart touch technology for quantifiable and efficient circumferential pulmonary vein lesions (the FAFA power-touch study)

Background

High-power short-duration ablation appears a promising concept. The so-called ablation index (AI) integrating power, contact force and time have demonstrated increased pulmonary vein isolation (PVI) durability. However, feasibility and safety of AI guided high-power ablation is unknown.

Methods and results

Symptomatic AF patients (n=50) underwent circumferential PVI using AI guided high-power point-by-point ablation (CARTO Smart-Touch). Ablation was set to 50W targeting AI values (550: anterior wall/roof, 400: posterior wall) with an inter-lesion distance of 6mm using a non-steerable sheath. An esophageal probe monitored luminal temperature rises (limit: 39°C).

Acute PVI was obtained in all patients; first-pass efficacy was 92%. Mean ablation time per procedure was 11.2±2.2 min, mean procedure time was 55.6±6.6 min.

A total of 2105 lesions were analyzed, comparing left anterior wall vs. left posterior wall and right anterior wall vs. right posterior wall, the mean ablation time (sec.) was 20.5±8.2 vs. 8.6±3.2, and 12.2±4 vs 9.3±3.4; the mean contact force (g): 17.1±12 vs 25.4±14.2 and 33.7±13.1 vs 21.0±10.5, the mean AI: 546.8±48.2 vs 444.6±55 and 554.8±56 vs. 439.8±47.1 (all P<0.0001). Audible steam pops were noted in in 4 (8%) patients. Esophageal temperature rise >39°C were noted in 25 (50%) patients. In 1/50 (2%) patient a minor esophageal lesion after ablation was observed without requiring specific therapy. No major complications such as death, stroke, tamponade or atria-esophageal -fistula occurred.

Conclusion

The novel AI guided high power ablation appears to be a feasible, safe, quantifiable and efficient strategy for PVI.

Witnessed pulmonary vein arrest-endoscopically observed conversion of atrial fibrillation into sinus rhythm by laser balloon ablation

The endoscopic laser balloon ablation system affords a unique view of the beating heart for visual guidance in pulmonary vein (PV) isolation. A 66-year-old patient was admitted for catheter ablation of atrial fibrillation (AF). While encircling the left superior PV, AF terminated into sinus rhythm, which was diagnosed by observing sudden regularization of previously rapidly fibrillating atrial tissue demonstrating the unique endoscopic video function.

Role of Remote Navigation Systems in AF Ablation

During the past decade atrial fibrillation (AF) ablation has developed from being an experimental treatment option to an evidence based therapy implemented in current guidelines.[1-2] Irrigated radiofrequency current guided ablations remain the golden standard of pulmonary vein isolation (PVI) procedures. Although practiced more frequently, it remains a demanding procedure requiring skilful operators. Novel technologies such as balloon based catheters or remote navigation (RN) systems have been developed to overcome the pitfalls of manual ablation procedures.

Value of robotic navigation and ablation

Catheter ablation has been established as a potentially curative treatment modality for various arrhythmias. Over the past years, catheter ablation has progressed from focal ablation to complex ablations within a three-dimensional anatomy for the treatment of ventricular tachycardia or atrial fibrillation. Complex ablation relies on reproducible catheter navigation in conjunction with stable catheter position and contact force, which depends on the operators´ individual experience and manual skills. Therefore, it would be desirable that technical innovations pursue the goal to minimize the physician's physical demands and exposure to scattered fluoroscopy, to improve catheter stability and, most importantly, to increase procedural safety. This review will discuss the role of remote controlled robotic navigation systems in catheter ablation with particular focus on safety, efficacy and novel applications.

Drug-eluting stents for the treatment of pulmonary vein stenosis after atrial fibrillation ablation

AIMS

Pulmonary vein (PV) stenosis (PVS) is a complication of radiofrequency PV isolation (PVI). Reported restenosis rates after balloon dilatation and bare-metal stent implantation are high. Drug-eluting stent implantation (DES) has not been reported in the setting of PVS.

METHODS AND RESULTS

Patients suspected of having PVS after PVI based on clinical symptoms and transesophageal echocardiography (TEE) follow-up (FU) were referred for PV DES. One or more branches of the affected PV as documented by angiography were stented (paclitaxel or zotarolimus DES). Follow-up consisted of repeat PV angiography and TEE. Over a period of 2 years, five patients were treated with a total of eight DES. A paclitaxel DES was used in seven of eight implants. Mean FU was 12 ± 14 months during which all patients remained asymptomatic. Transesophageal echocardiography Doppler maximal flow velocity (V(max)) of the affected PVs rose from 58 ± 6 cm/s pre-PVI to 207 ± 20 cm/s pre-DES (+358%, P < 0.0001). After DES, V(max) decreased acutely with 86 ± 15 cm/s (-58%, P < 0.01). During FU, V(max) remained stable in three patients and increased moderately in one. Angiography at 3 months confirmed absence of restenosis in the first three patients and moderate (40%) restenosis in one patient. In one patient, an increase of V(max) back to pre-DES values correlated with a 65% peri-stent stenosis, treated with a redo DES. In total, after seven primary DES only one (asymptomatic) proximal margin restenosis required re-stenting.

CONCLUSION

Initial experience with DES for PV stenosis suggests an excellent stent patency rate. Transesophageal echocardiography Doppler measurements provide a viable way of monitoring stent patency.

Pulmonary vein isolation with high-intensity focused ultrasound: results from the HIFU 12F study

AIMS

High-intensity focused ultrasound (HIFU) applied via a balloon catheter (BC) is a novel technology for simplified pulmonary vein isolation (PVI). Safety and efficacy of the third generation HIFU-BC were assessed.

METHODS AND RESULTS

In 22 patients (10 male, mean age 65 +/- 6 years) with paroxysmal atrial fibrillation (PAF), a PVI during real-time PV spike registration and oesophageal temperature measurement was attempted. In 15 patients, a steerable sheath was used along with the HIFU-BC. In 67 of 83 PVs (81%), PVI was achieved exclusively using HIFU. Using the steerable sheath, the acute PVI rate rose from 50% (10/20 PVs) to 90% (57/63 PVs). In the latter, PVI was achieved with a single HIFU application in 60% (38/63 PVs) and mean sonication time of 11 +/- 7 s. The mean procedure time was 166 +/- 74 min including 58 +/- 25 min of HIFU-BC left atrial indwelling time. In four patients, peri-procedural complications occurred (one transient ischaemic attack, one phrenic nerve palsy, and two vascular access complications). During a median follow-up of 342 days (range 272-378 days), 71% patients remained free of any AF/AT recurrence without antiarrhythmic drugs after a single procedure.

CONCLUSION

The novel defocused 12F HIFU-BC used in conjunction with a steerable sheath allows for very rapid PVI in patients with PAF. The enthusiasm for rapid PVI is still dampened by the potential risk of collateral damage.

Expression of the IKr components KCNH2 (rERG) and KCNE2 (rMiRP1) during late rat heart development

To understand molecular mechanisms that regulate formation and maintenance of cardiac IKr (rapidly activating component of the delayed rectifier K+ current), we have investigated the spatiotemporal expression pattern of two rat potassium voltage-gated channels, namely subfamily H (eag-related), member2 (KCNH2) (alias name: rERG) and Isk-related family, member2 (KCNE2) (alias name: rMiRP1) during late embryonic development by means of the in situ hybridization technique. KCNE2 is transcribed predominantly in atrial und ventricular myocardium at stages E14.5-E18.5dpc and only a minor signal emerged in the tongue at E16.5dpc. In contrast, KCNH2 transcripts appeared in a less confined pattern with intense signals in atrial and ventricular myocardium, somites, spinal cord, bowel system, central nervous system and thymus at stages E14.5-E18.5dpc. Non-cardiac expression even exceeds the intensity of the cardiac signal, indicating that KCNH2 contributes to K+ currents in non-cardiac tissue as well. Transcription of the rat b-subunit KCNE2 is present in all regions of the fetal myocardium and co-distributes perfectly with transcription of the pore forming a-subunit KCNH2. It seems likely that KCNH2 and KCNE2 are linked to form cardiac IKr channels, associated to cardiogenesis and cardiomyocyte excitability.