Real-world safety of catheter ablation for atrial fibrillation with contact force or cryoballoon ablation

Catheter Ablation of Atrial Fibrillation: Technique and Future Perspectives

Atrial fibrillation is the most common sustained cardiac arrhythmia with a significant impact on quality of life in terms of symptoms and reduction of functional status. Also, it is associated with an increased risk of mortality, stroke, and peripheral embolism. Catheter ablation for atrial fibrillation has become a well-established treatment, improving arrhythmia outcomes without increasing the risk of serious adverse events compared to antiarrhythmic drug therapy. The field has undergone significant advancements in recent years, yet pulmonary vein isolation continues to be the cornerstone of any atrial fibrillation ablation procedure. The purpose of this review is to provide an overview of the current techniques, emerging technologies, and future directions.

Pulsed-field vs cryoballoon vs radiofrequency ablation: Outcomes after pulmonary vein isolation in patients with persistent atrial fibrillation

BACKGROUND

Pulsed-field ablation (PFA) has shown promising data in terms of safety and procedural efficiency for pulmonary vein isolation (PVI), with similar long-term outcomes compared to radiofrequency ablation (RFA) and cryoballoon ablation (CBA) in patients with paroxysmal atrial fibrillation (AF).

OBJECTIVE

The purpose of this study was to compare the procedural and long-term outcomes in patients with persistent AF undergoing PVI using PFA, CBA, or RFA.

METHODS

Consecutive patients with persistent AF undergoing first PVI with PFA, CBA, or RFA were included. Patients underwent 7-day Holter electrocardiography at 3, 6, and 12 months postablation. The primary outcome was recurrence of any atrial arrhythmia after a 90-day blanking period. Safety outcomes included the composite of in-hospital major adverse events.

RESULTS

A total of 533 patients with persistent AF underwent PVI using PFA (n = 214, 39%), CBA (n = 190, 36%), or RFA (n = 129, 24%). Procedures with PFA guided by fluoroscopy were shorter than those with CBA (median 60 minutes; interquartile range [IQR] 53-80 minutes vs 84 minutes; IQR 68-101 minutes; P ≤ .001), and procedures with PFA in combination with 3-dimensional electroanatomic mapping were shorter than those with RFA (median 101 minutes; IQR 85-126 minutes vs 171 minutes; IQR 141-204 minutes; P < .001). Acute safety events occurred in 2.3%, 2.6%, and 0.8% in the PFA, CBA, and RFA groups, respectively (P = .545). The 1-year confounder-adjusted estimate for freedom from atrial arrhythmias was 62.1% for CBA, 55.3% for PFA, and 48.3% for RFA (CBA vs PFA: P = .79; CBA vs RFA: P = .009; PFA vs RFA: P = .010).

CONCLUSION

In patients with persistent AF undergoing first PVI, 1-year confounder-adjusted outcomes are better with PFA and CBA than with RFA.

Pulmonary vein isolation using pulsed field ablation vs. high-power short-duration radiofrequency ablation in paroxysmal atrial fibrillation: efficacy, safety, and long-term follow-up (PRIORI study)

AIMS

Pulsed field ablation (PFA) is a novel, non-thermal, cardiac tissue-selective ablation modality. To date, radiofrequency (RF)-guided high-power short-duration (HPSD) ablation represents the gold standard besides cryo-ablation for pulmonary vein isolation (PVI). This single-centre, retrospective study investigated the efficacy of PFA-PVI vs. HPSD-RF PVI in terms of single-procedure arrhythmia-free outcome and safety in a real-world setting.

METHODS AND RESULTS

Consecutive, paroxysmal atrial fibrillation (AF) patients who underwent PVI using PFA or HPSD-RF were enrolled. In group PFA, PVI was performed using a pentaspline PFA catheter. The ablation procedure in group HPSD-RF was performed with RF energy (45 W, ablation index). A total of 410 patients (group PFA, 201; group HPSD-RF, 209) were included. There was no difference between both groups regarding age, gender, and CHA2DS2-VASc score. The procedure time was significantly shorter in group PFA [61 (44-103) vs. 125 (105-143) min; P < 0.001]; fluoroscopy time and dose area product were significantly higher in group PFA [16 (13-20) vs. 4 (2-5) min; P < 0.01 and 412 (270-739) vs. 129 (58-265) μGym2; P < 0.01]. The overall complication rates were 2.9% in group PFA and 6.2% in group HPSD (P = 0.158). There was one fatal stroke in the PFA group. The 1-year Kaplan-Meier estimated freedom from any atrial tachyarrhythmia was 85% with PFA and 79% with HPSD-RF (log-rank P = 0.160). In 56 repeat ablation procedures, the PV reconnection rate was 30% after PFA and 38% after HPSD-RF (P = 0.372).

CONCLUSION

Both PFA and HPSD-RF were highly efficient and effective in achieving PVI in paroxysmal AF patients. The arrhythmia-free survival is comparable. The PV reconnection rate was not different.

Pulsed-field ablation for repeat procedures after failed prior thermal ablation for atrial fibrillation

Background

Pulsed-field ablation (PFA) is a novel nonthermal ablation technology. Its potential value for repeat procedures after unsuccessful thermal ablation for atrial fibrillation has not been assessed.

Objective

The purpose of this study was to summarize our initial experience with patients undergoing repeat procedures using PFA.

Methods

Consecutive patients with arrhythmia recurrences after a prior thermal ablation undergoing a repeat procedure using a multipolar PFA catheter from May 2021 and December 2022 were included. After 3-dimensional electroanatomic mapping, reconnected pulmonary veins (PVs) were reisolated and veins with only ostial isolation wither ablated to widen antral PV isolation. Posterior wall ablation was performed if all PVs were durably isolated or in case of low-voltage areas on the posterior wall at the discretion of the operator. Patients underwent follow-up with 7-day Holter electrocardiography after 3, 6, and 12 months.

Results

A total of 186 patients undergoing a repeat procedure using PFA were included. The median number of previous ablations was 1 (range 1-6). The prior ablation modality was radiofrequency in 129 patients (69.4%), cryoballoon in 51 (27.4%), and epicardial ablation in 6 (3.2%). At the beginning of the procedure, 258 of 744 PVs (35%) showed reconnections. Additional antral ablations were applied in 236 of 486 still isolated veins (49%). Posterior wall ablation was added in 125 patients (67%). Major complications occurred in 1 patient (transient ischemic attack 0.5%). Freedom from arrhythmia recurrence in Kaplan-Meier-analysis was 78% after 6 months and 54% after 12 months.

Conclusion

PFA is a versatile and safe option for repeat procedures after failed prior thermal ablation.

Pulsed-field vs. cryoballoon vs. radiofrequency ablation: a propensity score matched comparison of one-year outcomes after pulmonary vein isolation in patients with paroxysmal atrial fibrillation

BACKGROUND

Pulsed-field ablation (PFA) has shown favourable data in terms of safety and procedural efficiency for pulmonary vein isolation (PVI). We sought to compare procedural and 1-year follow-up data of patients with paroxysmal atrial fibrillation (AF) undergoing PVI using PFA, cryoballoon ablation (CBA) and radiofrequency ablation (RFA).

METHODS

Consecutive patients with paroxysmal AF undergoing a first PVI with PFA at our institution were included. For comparison, patients with paroxysmal AF undergoing a first PVI with CBA and RFA were selected using a 1:2:2 propensity score matching. The PFA group followed the standard 32-applications lesion-set protocol, the CBA group a time-to-effect plus 2-min strategy, and the RFA group the CLOSE protocol. Patients were followed with 7d-Holter ECGs 3, 6, and 12 months after ablation. The primary endpoint was recurrence of atrial tachyarrhythmia (ATa) following a blanking period of 3 months.

RESULTS

A total of 200 patients were included (PFA n = 40; CBA n = 80; RFA n = 80). Median procedure times were shortest with CBA (75 min) followed by PFA (94 min) and RFA (182 min; p < 0.001). Fluoroscopy dose was lowest with RFA (1.6Gycm2) followed by PFA (5.0Gycm2) and CBA (5.7Gycm2; p < 0.001). After a 1-year follow-up, freedom from ATa recurrence was 85.0% with PFA, 66.2% with CBA and 73.8% with RFA (p = 0.12 PFA vs. CBA; p = 0.27 PFA vs. RFA).

CONCLUSION

In a propensity score matched analysis of patients with paroxysmal AF, freedom from any ATa 1 year after PVI using PFA was favourable and at least as good as for PVI with CBA or RFA.

Catheter ablation versus medical therapy in atrial fibrillation: an umbrella review of meta-analyses of randomized clinical trials

This umbrella review synthesizes data from 17 meta-analyses investigating the comparative outcomes of catheter ablation (CA) and medical treatment (MT) for atrial fibrillation (AF). Outcomes assessed were mortality, risk of hospitalization, AF recurrence, cardiovascular events, pulmonary vein stenosis, major bleeding, and changes in left ventricular ejection fraction (LVEF) and MLHFQ score. The findings indicate that CA significantly reduces overall mortality and cardiovascular hospitalization with high strength of evidence. The risk of AF recurrence was notably lower with CA, with moderate strength of evidence. Two associations reported an increased risk of pulmonary vein stenosis and major bleeding with CA, supported by high strength of evidence. Improved LVEF and a positive change in MLHFQ were also associated with CA. Among patients with AF and heart failure, CA appears superior to MT for reducing mortality, improving LVEF, and reducing cardiovascular rehospitalizations. In nonspecific populations, CA reduced mortality and improved LVEF but had higher complication rates. Our findings suggest that CA might offer significant benefits in managing AF, particularly in patients with heart failure. However, the risk of complications, including pulmonary vein stenosis and major bleeding, is notable. Further research in understudied populations may help refine these conclusions.

ATE Score Diagnostic Accuracy for Predicting the Absence of Intra-Atrial Thrombi Before AF Ablation

BACKGROUND

In a preliminary study in patients hospitalized for catheter ablation of atrial fibrillation (AF), the atrial thrombus exclusion (ATE) score (stroke, hypertension, heart failure, and D-dimers >270 ng/mL) was developed to rule out the diagnosis of intra-atrial thrombus, with a negative predictive value (NPV) of 100%, and to avoid performing transesophageal echocardiography (TEE).

OBJECTIVES

The present study was designed to prospectively confirm the NPV of the ATE score in an independent population.

METHODS

Consecutive patients hospitalized for catheter ablation of AF or left atrial tachycardia (LAT) were prospectively enrolled in a multicenter study. D-dimer levels were measured within 48 hours before ablation. An ATE score of 0 was considered predictive of no thrombus. TEE was routinely performed at the beginning or just before the ablation procedure. The primary endpoint was the presence of atrial thrombus diagnosed by TEE.

RESULTS

The analysis included 3,072 patients (53.3% paroxysmal AF, 36.7% persistent AF, and 10% LAT). A thrombus was detected in 29 patients (0.94%; 95% CI: 0.63%-1.35%), all on appropriate anticoagulant therapy. An ATE score of 0 was observed in 818 patients (26.6%), and the sensitivity, specificity, positive predictive value, and NPV were 93.1%, 26.8%, 1.2%, and 99.8%, respectively. Follow-up of the 2 false negative patients revealed the persistence of chronic organized thrombi.

CONCLUSIONS

In patients hospitalized for catheter ablation of AF or LAT, the ATE score identifies a population at very low risk for atrial thrombus. In consultation with the patient, the cardiologist may consider not performing a preoperative TEE in case of an ATE score of 0.

Implementation of the multielectrode radiofrequency-balloon in real-world clinical practice-operator learning curve and procedural outcome at a high-volume center

Background

The novel multielectrode radiofrequency (RF) balloon catheter (HELIOSTAR™, Biosense Webster) is a new technology for pulmonary vein isolation (PVI) in atrial fibrillation (AF), combining RF-ablation and 3D-mapping visualization with the concept of a "single-shot"-ablation device. This study evaluates the operator learning curve und procedural outcome during implementation of the multielectrode RF-balloon at a high-volume center.

Methods

The first 40 patients undergoing PVI by multielectrode RF-balloon catheter at Heidelberg University Hospital were included in this prospective study. Procedural outcome was analyzed over the course of increasing experience with the device.

Results

157/157 pulmonary veins (PVs) were successfully isolated with the RF-balloon catheter, in 73.2% by a single RF-application. Median time to isolation (TTI) was 11.0 s (Q1 = 8.0 s; Q3 = 13.8 s). Median procedure time was 62.5 min (Q1 = 50.0 min; Q3 = 70.5 min). LA-dwell time was 28.5 min (Q1 = 23.3 min; Q3 = 36.5 min). Median fluoroscopy duration was 11.6 min (Q1 = 10.1 min; Q3 = 13.7 min). No serious procedure-related complications were observed, apart from one case of unclear, post-procedural acute-on-chronic kidney injury. With increasing operator experience, an additional reduction in procedure duration was observed.

Conclusion

Rapid implementation of a "single shot"-ablation device combining RF-ablation and 3D-mapping can be achieved with high acute procedural efficacy and safety at a high-volume center. Previous experience with "single-shot" ablation devices may be advantageous for time-efficient introduction of the novel RF-balloon catheter into clinical practice.

Clinical Trial Registration

ClinicalTrials.gov; Identifier NCT0560361.

Catheter ablation of atrial fibrillation: anticipating and avoiding complications

INTRODUCTION

Atrial fibrillation (AF) ablation is being performed more frequently and more widely at more centers. This stems from several factors including 1) demographic forces leading to an increased prevalence of the arrhythmia; 2) greater availability of ambulatory monitoring making diagnosis more frequent; 3) relative inefficacy of medications; and 4) improved safety and efficacy of the procedure. Ablation has become much more streamlined and reproducible than a decade ago, but life-threatening complications may still arise.

AREAS COVERED

This review will focus on awareness, avoidance, and early recognition and management of complications of AF ablation. This literature review is challenged by differing approaches to ablation of AF both within a center and between centers, the rapid improvement of technology making the outcomes associated with a therapeutic strategy begun a few years prior relatively obsolete, as well as the heterogeneity of the population being studied.

EXPERT OPINION

Newer technologies are on the horizon which will allow us to ablate AF with increasing efficacy, efficiency, and hopefully safety. Such new technology and changing usage mandate vigilance to avoid complications.

Comparison of cryoballoon and radiofrequency ablation for persistent atrial fibrillation: a systematic review and meta-analysis

BACKGROUND

There is limited data comparing radiofrequency (RF) and cryoballoon (CB) ablation for persistent atrial fibrillation (AF), which tends to have higher recurrence rates following ablation compared to paroxysmal AF.

METHODS

A systematic search of the Embase, PubMed, and Cochrane database was performed for studies comparing RF vs CB ablation for persistent AF. An inverse-variance random-effects model was used to calculate the composite effects.

RESULTS

One randomized and 9 observational studies were identified, with 1650 patients receiving CB and 1706 patients receiving RF ablation. Mean follow-up time ranged from 12 to 48 months. Freedom from recurrent atrial tachyarrhythmia was similar with the two modalities (HR 0.93, 95% CI 0.80 to 1.08, I² 0%). Total complications were similar in both groups (RR 1.05, 95% CI 0.73 to 1.53, I² 0%) although rates of phrenic nerve palsy (PNP) were greater with CB (RR 4.13, 95% CI 1.49 to 11.46, I² 0%). Shorter procedure times were observed with CB (mean reduction 43.77 min, 95% CI 66.45 to 21.09 min, I² 96%) with no difference in fluoroscopy time (mean difference 0.82 min, 95% CI - 11.92 to 13.55 min, I² 100%).

CONCLUSIONS

In persistent AF patients, CB ablation has similar efficacy and overall safety as compared to RF ablation. While CB is associated with significantly shorter procedure times, the improved procedural efficiency with CB is offset by increased rates of PNP and the potential need for touch-up RF ablation.

Safety and Effectiveness of a Catheter With Contact Force and 6-Hole Irrigation for Ablation of Persistent Atrial Fibrillation in Routine Clinical Practice

IMPORTANCE

The ThermoCool SmartTouch catheter (ablation catheter with contact force and 6-hole irrigation [CF-I6]) is approved by the US Food and Drug Administration (FDA) for paroxysmal atrial fibrillation (AF) ablation and used in routine clinical practice for persistent AF ablation, although clinical outcomes for this indication are unknown. There is a need to understand whether data from routine clinical practice can be used to conduct regulatory-grade evaluations and support label expansions.

OBJECTIVE

To use health system data to compare the safety and effectiveness of the CF-I6 catheter for persistent AF ablation with the ThermoCool SmartTouch SurroundFlow catheter (ablation catheter with contact force and 56-hole irrigation [CF-I56]), which is approved by the FDA for this indication.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective, comparative-effectiveness cohort study included patients undergoing catheter ablation for persistent AF at Mercy Health or Mayo Clinic from January 1, 2014, to April 30, 2021, with up to a 1-year follow-up using electronic health record data.

EXPOSURES

Use of the CF-I6 or CF-I56 catheter.

MAIN OUTCOMES AND MEASURES

The primary safety outcome was a composite of death, thromboembolic events, and procedural complications within 7 to 90 days. The exploratory effectiveness outcome was a composite of AF-related hospitalization events after a 90-day blanking period. Propensity score weighting was used to balance baseline covariates. Risk differences were estimated between catheter groups and averaged across the 2 health care systems, testing for noninferiority of the CF-I6 vs the CF-I56 catheter with respect to the safety outcome using 2-sided 90% CIs.

RESULTS

Overall, 1450 patients (1034 [71.3%] male; 1397 [96.3%] White) underwent catheter ablation for persistent AF, including 949 at Mercy Health (186 CF-I6 and 763 CF-I56; mean [SD] age, 64.9 [9.2] years) and 501 at Mayo Clinic (337 CF-I6 and 164 CF-I56; mean [SD] age, 63.7 [9.5] years). A total of 798 (55.0%) had been treated with class I or III antiarrhythmic drugs before ablation. The safety outcome (CF-I6 - CF-I56) was similar at both Mercy Health (1.3%; 90% CI, -2.1% to 4.6%) and Mayo Clinic (-3.8%; 90% CI, -11.4% to 3.7%); the mean difference was noninferior, with a mean of 0.5% (90% CI, -2.6% to 3.5%; P < .001). The effectiveness was similar at 12 months between the 2 catheter groups (mean risk difference, -1.8%; 90% CI, -7.3% to 3.7%).

CONCLUSIONS AND RELEVANCE

In this cohort study, the CF-I6 catheter met the prespecified noninferiority safety criterion for persistent AF ablation compared with the CF-I56 catheter, and effectiveness was similar. This study demonstrates the ability of electronic health care system data to enable safety and effectiveness evaluations of medical devices.