Symptomatic Paroxysmal Atrial Fibrillation Research Articles

Predictors of neuromodulation during single-shot thermal atrial fibrillation ablation: a computed tomography imaging analysis

Abstract Background Ganglionated plexi (GPs) are part of the cardiac autonomic nervous system (CANS), which play an important role in the induction and maintenance of atrial fibrillation (AF). Because of the anatomic proximity of the pulmonary veins with GPs, pulmonary vein isolation (PVI) using thermal (radiofrequency (RF) or cryo) ablation, has been shown to concomitantly affect the GPs, as suggested by increased heart rate (HR) after ablation. Right superior pulmonary vein (RSPV) isolation has been reported to have the most evident inhibitory responses to the CANS via modulation of the anterior right ganglionated plexus. Nonetheless, there are also cases with little to no effect on neuromodulation post-ablation. Purpose To assess the clinical and anatomical predictors of thermal ablation-induced CANS changes, as assessed via variations in resting HR post-ablation. Methods We retrospectively analyzed consecutive patients with symptomatic paroxysmal AF who underwent first-time PVI by cryoballoon (CB) or RF balloon (RFB) between January 2022 to November 2022. Patients who were not in sinus rhythm, had cardiac implantable electronic devices, or did not have a contrast-enhanced computed tomography before the ablation were excluded. Pre-ablation and 24-hour post-ablation ECGs in sinus rhythm were collected and analyzed to assess HR. Results A total of 83 patients (CB group, n = 43 vs RFB group, n = 40) were included in the analysis. Baseline patients’ characteristics were similar between the two groups (Table 1). A significant HR increase (ΔHR ≥ 15 bpm) at 24h post-ablation occurred in 31 patients [CB group 16 (52 %), RFB group 15 (48 %)]. Predictors of increased HR were the distance between superior vena cava (SVC) and RSPV (OR 0.51, CI 0.35 - 0.75, p value < 0.01) and age (OR 0.94, CI 0.89 - 0.99, p value < 0.01) (Table 2). Conclusions Single-shot thermal PVI influences the CANS, especially in patients with a shorter SVC - RSPV distance and in younger patients.Table 1Table 2

Pulmonary vein isolation with the radiofrequency balloon catheter: long-term results and predictors of ablation success

Abstract Background The novel multielectrode radiofrequency balloon catheter (RFB) has been demonstrated to achieve safe and effective pulmonary vein isolation (PVI). However, data on long-term ablation outcomes is lacking. Purpose This single-centre study aimed to evaluate the efficacy of the RFB beyond 1-year follow-up and define predictors of arrhythmia recurrence. Methods All consecutive patients with symptomatic paroxysmal atrial fibrillation (AF) undergoing first-time PVI with the RFB between January 2021 and November 2022 were prospectively included. Post-ablation remapping was systematically employed to confirm PVI at the end of the procedure. Procedural failure was defined as any atrial tachyarrhythmias (ATas) lasting >30 s occurring during the follow-up after a 3-month blanking period (BP). Patient characteristics, procedural parameters, and ATas recurrence during BP were analysed with respect to ablation outcome. Results A total of 120 consecutive patients (50 female, 42%; mean age 65±12 years) were enrolled. After a mean follow-up of 16.1±7.9 months, ATas recurrence occurred in 30 patients (25%). ATas were adjudicated as AF in 25 patients (83.3%) and as atrial tachycardia/atrial flutter in 5 patients (16.7%). The mean time from the index procedure to ATas recurrence was 203±130 days. A redo procedure was performed in 17 patients (56.7%) and at least one PV reconnection was observed in 12 patients (70.6%). Patients with ATas recurrence presented higher values of body mass index (31.0 ±5.7 vs. 28.1±4.9 kg/m2, p=0.048), larger left atria (43±11 vs. 35±9 ml/m2, p=0.003), and increased rates of ATas recurrence during the BP (53.3% vs. 2.2 %, p<0.001) compared to patients with persistent sinus rhythm. At multivariable Cox regression analysis, left atrial end-systolic volume index and ATas recurrence during the BP were independently associated with procedural failure (HR 1.05, 95%CI 1.00-1.11, p=0.048 and HR 23.88, 95%CI 7.71-73.99, p<0.001, respectively). Conclusion At 16 months follow-up, PVI with the RFB resulted in freedom from arrhythmia relapse in 75% of patients. Left atrial end-systolic volume index and ATas recurrence during the BP were independent predictors of arrhythmia recurrence.ATas-free survivalPredictors of ATas recurrence

An economic evaluation of first-line cryoballoon ablation versus antiarrhythmic drug therapy for the treatment of paroxysmal atrial fibrillation from a Danish healthcare perspective

Abstract Background As demonstrated in three randomized clinical trials (RCTs), initial rhythm control with first-line pulmonary vein isolation (PVI) using cryoballoon ablation decreases atrial arrhythmia recurrence compared to antiarrhythmic drug (AAD) therapy in patients with symptomatic paroxysmal atrial fibrillation (PAF). Purpose To assess the cost-effectiveness of first-line cryoablation versus first-line AADs in a Danish healthcare setting. Methods Data from 703 participants with symptomatic PAF enrolled into Cryo-FIRST, STOP AF First and EARLY-AF RCTs were used to estimate risk equations (rate of ablation, AF recurrence and resolution, AF-related hospital attendance in addition to health-related quality-of-life (HRQoL) utilities). These were then incorporated into a cost-effectiveness model (CEM) . The Danish cost data was derived from published Danish literature, DRG tariffs and pharmaceutical list prices in Denmark. Where parameters could not be derived, inputs were sourced from published literature or expert opinion. The CEM consisted of a decision tree (one-year time horizon) and a Markov model (three-month cycle length) hybrid, with a lifetime (40 years) time horizon. The CEM is from the perspective of the Danish healthcare system. Health benefits were expressed in quality-adjusted life-years (QALYs), and all costs and benefits were discounted at 3%. As there is no official cost-effectiveness threshold in Denmark, the UK threshold of £20,000 (~€23,200) was assumed. Input uncertainty within the CEM was explored using probabilistic sensitivity analysis. The results presented include data from the initial 12-week blanking period for all studies. Results The three-monthly rate of AF symptom recurrence had a reduction, on average, of 46.7% (p<0.001) in those treated with cryoablation. In addition, the cryoablation arm had a 72.8% (p<0.001) reduction in the monthly rate of receiving an ablation following initial treatment. The average cryoablation patient was also associated with a 4.3% (p=0.025) increase in their HRQoL. Finally, there was no difference in the rate of AF symptom resolution in those who failed initial treatment. Base case results per patient are presented in Table 1. Cryoablation was shown to be dominant when compared to AADs (0.159 more QALYs and €2,519 less costly), with a 99.96% probability of being cost-effective at a willingness-to-pay threshold of ~€23,200 per QALY gained. Individuals in both arms of the model were also expected to receive ~1.2 ablations over a lifetime horizon. Nonetheless, there was a 45% relative reduction in time spent in symptomatic AF states for individuals who were initially treated with cryoablation. Scenario analysis results are presented in Table 2. Cryoablation remained cost-effective over AADs in all scenarios conducted. Conclusions Initial rhythm control with cryoballoon ablation is cost-effective (dominant) when compared to AADs in the Danish healthcare system.Table 1:Key results (per patient)Table 2.Deterministic scenario analysis

Comparison of the novel radiofrequency-balloon and the cryo-balloon in pulmonary vein isolation

Abstract Background Balloon catheters are often used for pulmonary vein isolation (PVI) in atrial fibrillation (AF) because of their procedural efficiency. Apart from the established cryo-balloon (CB) catheter, there is a novel multi-electrode radiofrequency balloon catheter (RFB) with 3D mapping integration available. There is currently no data regarding a direct comparison of the RFB-PVI and the CB-PVI in a matched population. Objective Aim of this study was to assess the procedural data, the safety profile, and the outcome of the RFB-PVI and the CB-PVI. Methods This prospective registry study included patients with symptomatic paroxysmal or persistent AF, who underwent first-time PVI between January 2019 and April 2023, either with the RFB or the CB. For reduction of potential confounders patients were matched in a 1:2 ratio. Results In total 171 consecutive RFB patients and 342 matched CB patients were included. The baseline characteristics were comparable. The estimated recurrence free survival after 12 months was 81.3% in the RFB group and 76.8% in the CB group (p = 0.359). Longer procedural duration (p < 0.001) and longer fluoroscopy time was observed in the RFB group (p < 0.001). Except for the left inferior pulmonary vein, the single-shot isolation rate was comparable. In the RFB group no major complications occurred. In the CB group one transient ischemic attack, one pericardial tamponade, and two persistent phrenic nerve palsies occurred. Conclusion Although longer procedural duration was observed in the RFB group, both technologies enable an efficient and a safe PVI. Despite the 3D mapping integration of the RFB, no reduction in the fluoroscopy time was seen in comparison to the CB.

First-time catheter ablation outcomes for atrial fibrillation are dependent on low-voltage areas rather than paroxysmal vs. persistent classifications: a REAL-AF study

Abstract Background Left atrial low-voltage areas (LA LVA) measured at time of catheter ablation for atrial fibrillation (AF) have been increasingly recognized as an indicator of atrial fibrosis [1]. However, little is known whether first-time catheter ablation outcomes differ between paroxysmal AF (PAF) and persistent AF (PerAF) in patients with higher LA LVA, which may indicate a more advanced substrate independent of clinical subtype. Purpose To evaluate whether outcomes of first-time catheter ablation for AF are dependent on LA LVA rather than PAF vs. PerAF types in a multicenter registry of patients. Methods The Real-world Experience of Catheter Ablation for the Treatment of Symptomatic PAF and PerAF Using Novel Contact Force Technologies registry (REAL-AF) is a prospective, observational multicenter registry of patients undergoing catheter ablation. We evaluated 4181 patients undergoing first-time catheter ablation for both PAF and PerAF to determine AF recurrence within 12 months. Contact maps were created using a 5-spline high-density catheter. LA LVA was calculated using these contact maps based on a bipolar voltage of <0.50 mV. LA LVA was categorized into low (<5%) vs. high (≥5%) based on preliminary data. Risk of recurrence was analyzed using Cox proportional hazard models. Results Patients with LA LVA ≥5% who underwent first-time catheter ablation for AF (both PAF and PerAF) experienced a higher risk of AF recurrence within 12 months (Hazard ratio (HR): 1.95, p<0.001), see Figure 1. Overall, 82.0% of patients were free of AF in the LA LVA <5% group compared to 69.1% in the LA LVA ≥5% group. This association remained significant in a subpopulation of patients presenting in normal sinus rhythm (N = 2463) at time of ablation (HR: 1.90, p<0.001). 12-month ablation outcomes between PAF and PerAF in patients with LA LVA ≥5% (N = 1590) were not statistically significant (71.0% vs 67.3% respectively, HR: 1.15, p=0.30), see Figure 2. Finally, in the LA LVA <5% group (N = 2591), patients with PerAF had a 1.42 times higher risk for AF recurrence within 12 months after catheter ablation (p=0.04). Conclusion This is the largest real-world registry to date demonstrating that LA LVA ≥5% is associated with a higher risk of AF recurrence within 12 months in patients undergoing first-time catheter ablation for AF. Among patients with LA LVA ≥5%, AF recurrence was not associated with AF type. These findings motivate further studies into using LA LVA as a prognostic tool for patients undergoing first-time catheter ablation for AF and using non-invasive methods to assess this in order to stratify patients further.

Long-term anti-arrhythmic is effective than no anti-arrhythmic in patients with first developed paroxysmal atrial fibrillation

Abstract Background There is no detailed guideline recommendation of AAD treatment for the firstly developed paroxysmal atrial fibrillation (AF). Anti-arrhythmic drugs (AAD) prevent recurrence of AF and short-term AAD treatment would increase drug safety by reducing treatment duration. Introduction We designed the prospective, randomized trial to evaluate the efficacy of short- and long-term AAD (flecainide) compared with no treatment in maintaining sinus rhythm in patients with firstly developed paroxysmal atrial fibrillation (PAF). Methods Definition of the firstly developed PAF was the patients with firstly developed symptomatic PAF without history of palpitation. Sixty patients were randomly assigned into no AAD treatment (Group I; N=21), short-term AAD treatment (flecainide 100mg bid for 4 weeks, Group II; N=20) or long-term AAD treatment (flecainide 100mg bid for 6 months, Group III; N=19). All patients were in sinus rhythm at randomization. Patients received clinical follow up with serial evaluation of rhythm status. Results There were no significant differences in age, gender, cardiovascular comorbidities and echocardiographic parameters. Among the total population, AF recurred in 16 patients (26.7%) during the follow up period. AF free survival was significantly different among groups (p=0.038) (Fig 1). Conclusions Long-term AAD at least 6 months is beneficial in maintaining sinus rhythm than no or shot-term AAD in patients with firstly developed PAF.

Dual energy for pulmonary vein isolation using dual-energy focal ablation technology integrated with a three-dimensional mapping system: SmartfIRE 3-month results.

Contact force (CF)-sensing radiofrequency (RF) catheters with an ablation index have shown reproducible outcomes for the treatment of atrial fibrillation (AF) in large multicentre studies. A dual-energy (DE) focal CF catheter to deliver RF and unipolar/biphasic pulsed field ablation (PFA), integrated with a three-dimensional (3D) mapping system, can provide operators with additional flexibility. The SmartfIRE study assessed the safety and efficacy of this novel technology for the treatment of drug-refractory, symptomatic paroxysmal AF. Results at 3 months post-ablation are presented here. Pulmonary vein isolation (PVI) was performed using a DE focal, irrigated CF-sensing catheter with the recommendation of PFA at posterior/inferior and RF ablation at the anterior/ridge/carina segments. Irrespective of energy, a tag size of 3 mm; an inter-tag distance ≤6 mm; a target index of 550 for anterior, roof, ridge, and carina; and a target index of 400 for posterior and inferior were recommended. Cavotricuspid isthmus ablation was permitted in patients with documented typical atrial flutter. The primary effectiveness endpoint was acute procedural success. The primary safety endpoint was the rate of primary adverse events (PAEs) within 7 days of the procedure. A prespecified patient subset underwent oesophageal endoscopy (EE; 72 h post-procedure), neurological assessment (NA; pre-procedure and discharge), and cardiac computed tomography (CT)/magnetic resonance angiogram (MRA) imaging (pre-procedure and 3 months post-procedure) for additional safety evaluation, and a mandatory remapping procedure (Day 75 ± 15) for PVI durability assessment. Of 149 patients enrolled between February and June 2023, 140 had the study catheter inserted (safety analysis set) and 137 had ablation energy delivered (per-protocol analysis set). The median (Q1/Q3) total procedure and fluoroscopy times were 108.0 (91.0/126.0) and 4.2 (2.3/7.7) min (n = 137). The acute procedural success rate was 100%. First-pass isolation was achieved in 89.1% of patients and 96.8% of veins. Cavotricuspid isthmus ablations were successfully performed in 12 patients [pulsed field (PF) only: 6, RF only: 5, and RF/PF: 1]. The PAE rate was 4.4% [6/137 patients; 2 pulmonary vein (PV) stenoses, 2 cardiac tamponades/perforations, 1 stroke, and 1 pericarditis]. No coronary artery spasm was reported. No oesophageal lesion was seen in the EE subset (0/31, 0%). In the NA subset (n = 30), microemboli lesions were identified in 2 patients (2/30, 6.7%), both of which were resolved at follow-up; only 1 was symptomatic (silent cerebral lesion, 3.3%). In the CT/MRA subset (n = 30), severe PV narrowing (of >70%) was detected in 2 patients (2/30, 6.7%; vein level 2/128, 1.6%), of whom 1 underwent dilatation and stenting and 1 was asymptomatic; both were associated with high index values and a small inter-tag distance. In the PV durability subset (n = 30), 100/115 treated PVs (87%) were durably isolated and 18/30 patients (60.0%) had all PVs durably isolated. A DE focal CF catheter with 3D mapping integration showed a 100% acute success rate with an acceptable safety profile in the treatment of paroxysmal AF. Prespecified 3-month remapping showed notable PVI durability. ClinicalTrials.gov Identifier: NCT05752487.

PolarX vs Arctic Front for Cryoballoon Ablation of Paroxysmal AF: The Randomized COMPARE CRYO Study.

Pulmonary vein isolation is an effective treatment for atrial fibrillation (AF). Cryoballoon ablation using the Arctic Front cryoballoon (Medtronic) was found to be superior to antiarrhythmic drug treatment. Recently, a novel cryoballoon system was introduced (PolarX, Boston Scientific). The purpose of this study was to compare the efficacy and safety of the 2 cryoballoons in a randomized controlled trial. Patients with symptomatic paroxysmal AF were enrolled in 2 centers and randomized 1:1 to pulmonary vein isolation using the PolarX or the Arctic Front cryoballoon. All patients received an implantable cardiac monitor. The primary endpoint was first recurrence of atrial tachyarrhythmia (AF, atrial flutter, or atrial tachycardia [AT]) between days 91 and 365. Procedural safety was assessed by a composite of tamponade, phrenic nerve palsy lasting >24 hours, vascular complications, stroke/transient ischemic attack, atrioesophageal fistula or death up to 30days. A total of 201 patients were enrolled. At 1 year, recurrence of atrial tachyarrhythmia had occurred in 41 of 99patients (41.6%) assigned to the PolarX group and in 48 of 102 patients (47.1%) assigned to the Arctic Front group (HR: 0.85 [95%CI: 0.56-1.30]; P = 0.03 for noninferiority; P = 0.46 for superiority). The safety endpoint occurred in 5patients (5%) in the PolarX group (n=5 phrenic nerve palsies lasting >24 hours), whereas no safety endpoints occurred in the Arctic Front group (P = 0.03). In this randomized controlled trial using implantable cardiac monitors for continuous rhythm monitoring, the novel PolarX cryoballoon was noninferior compared with the Arctic Front cryoballoon regarding efficacy. However, the PolarX balloon resulted in significantly more phrenic nerve palsies. (Comparison of PolarX and the Arctic Front Cryoballoons for PVI in Patients With Symptomatic Paroxysmal AF [COMPARE-CRYO]; NCT04704986).

Real-world data of radiofrequency catheter ablation in paroxysmal atrial fibrillation: Short- and long-term clinical outcomes from the prospective multicenter REAL-AF Registry

BackgroundThe safety and long-term efficacy of radiofrequency (RF) catheter ablation (CA) of paroxysmal atrial fibrillation (PAF) has been well established. Contemporary techniques to optimize ablation delivery, reduce fluoroscopy use, and improve clinical outcomes have been developed. ObjectiveThe purpose of this study was to assess the contemporary real-world practice approach and long-term outcomes of RF CA for PAF through a prospective multicenter registry. MethodsUsing the REAL-AF (Real-world Experience of Catheter Ablation for the Treatment of Symptomatic Paroxysmal and Persistent Atrial Fibrillation; ClincalTrials.gov Identifier: NCT04088071) Registry, patients undergoing RF CA to treat PAF across 42 high-volume institutions and 79 experienced operators were evaluated. The procedures were performed using zero or reduced fluoroscopy, contact force sensing catheters, wide area circumferential ablation, and ablation index as a guide with a target of 380–420 for posterior and 500–550 for anterior lesions. The primary efficacy outcome was freedom from all-atrial arrhythmia recurrence at 12 months. ResultsA total of 2470 patients undergoing CA from January 2018 to December 2022 were included. Mean age was 65.2 ±11.14 years, and 44% were female. Most procedures were performed without fluoroscopy (71.5%), with average procedural and total RF times of 95.4 ± 41.7 minutes and 22.1±11.8 minutes, respectively. At 1-year follow-up, freedom from all-atrial arrhythmias was 81.6% with 89.7% of these patients off antiarrhythmic drugs. No significant difference was identified comparing pulmonary vein isolation vs pulmonary vein isolation + ablation approaches. The complication rate was 1.9%. ConclusionRefinement of RF CA to treat PAF using contemporary tools, standardized protocols, and electrophysiology laboratory workflows resulted in excellent short- and long-term clinical outcomes.

Comparison of Arctic Front Advance Pro and POLARx cryoballoons for ablation therapy of atrial fibrillation: an intraprocedural analysis.

Cryoballoon (CB) ablation has become a popular method for pulmonary vein isolation (PVI) in atrial fibrillation (AF) treatment. This study aimed to compare the intraprocedural ablation characteristics of two cryoballoons, Arctic Front Advance Pro™ (AFA-Pro, Medtronic) and POLARx™ (Boston Scientific). In this retrospective single-center study, 230 symptomatic paroxysmal or persistent AF patients underwent CB ablation with either AFA-Pro or POLARx. Propensity-score matching resulted in two cohorts of 114 patients each. Baseline and procedural characteristics were comparable between both CBs. POLARx achieved lower minimal temperatures (e.g., left superior pulmonary vein, LSPV: AFA-Pro - 49.0°C vs. POLARx - 59.5°C) and lower temperatures at time-to-isolation (TTI). Additionally, POLARx reached lower temperatures faster, as evidenced by lower temperatures after 40 and 60s, and a larger mean temperature change between 20 and 40s. POLARx also had a greater area under the curve below 0°C and a longer thawing phase. Both CBs achieved comparable high rates of final PV-isolation. TTI, minimal esophagus temperature, and first-pass isolation rates were similar between groups. Periprocedural complications, including phrenic nerve injuries, were comparable. Troponin levels in the left atrium were elevated with both systems. Values and change in troponin were numerically higher in the POLARx group (delta troponin: AFA-Pro 36.3 (26.4, 125.4) ng/L vs. POLARx 104.9 (49.5, 122.2) ng/L), p = 0.077). AFA-Pro and POLARx are both highly effective and safe CB systems for PVI. POLARx exhibited significant faster and lower freezing characteristics, and numerically higher troponin levels might indicate greater myocardial injury. However, these differences did not translate into improved performance, procedural efficiency, or safety.

Current management of atrial fibrillation in routine practice according to the last ESC guidelines: an EHRA physician survey-how are we dealing with controversial approaches?

Although guidelines for the management of atrial fibrillation (AF) are regularly published, many controversial issues remain, limiting their implementation. We aim to describe current clinical practice among European Heart Rhythm Association (EHRA) community according to last guidelines. A 30 multiple-choice questionnaire covering the most controversial topics related to AF management was distributed through the EHRA Research Network, National Societies, and social media between January and February 2023. One hundred and eighty-one physicians responded the survey, 61% from university hospitals. Atrial fibrillation screening in high-risk patients is regularly performed by 57%. Only 42% has access to at least one programme aiming at diagnosing/managing comorbidities and lifestyle modifications, with marked heterogeneity between countries. Direct oral anticoagulants are the preferred antithrombotic (97%). Rhythm control is the preferred strategy in most AF phenotypes: symptomatic vs. asymptomatic paroxysmal AF (97% vs. 77%), low vs. high risk for recurrence persistent AF (90% vs. 72%), and permanent AF (20%). I-C drugs and amiodarone are preferred while dronedarone and sotalol barely used. Ablation is the first-line therapy for symptomatic paroxysmal AF (69%) and persistent AF with markers of atrial disease (57%) and is performed independently of symptoms by 15%. In persistent AF, 68% performs only pulmonary vein isolation and 32% also additional lesions. There is marked heterogeneity in AF management and limited accordance to last guidelines in the EHRA community. Most of the discrepancies are related to the main controversial issues, such as those related to AF screening, management of comorbidities, pharmacological treatment, and ablation strategy.

Economic evaluation of first-line cryoballoon ablation versus antiarrhythmic drug therapy for the treatment of paroxysmal atrial fibrillation from an English National Health Service perspective

IntroductionThree recent randomised controlled trials have demonstrated that pulmonary vein isolation as an initial rhythm control strategy with cryoablation reduces atrial arrhythmia recurrence in patients with symptomatic paroxysmal atrial fibrillation...

Atrial Fibrillation Ablation: Current Practice and Future Perspectives.

Catheter ablation to perform pulmonary vein isolation (PVI) is established as a mainstay in rhythm control of atrial fibrillation (AF). The aim of this review is to provide an overview of current practice and future perspectives in AF ablation. The main clinical benefit of AF ablation is the reduction of arrhythmia-related symptoms and improvement of quality of life. Catheter ablation of AF is recommended, in general, as a second-line therapy for patients with symptomatic paroxysmal or persistent AF, who have failed or are intolerant to pharmacological therapy. In selected patients with heart failure and reduced left-ventricular fraction, catheter ablation was proven to reduce all-cause mortality. Also, optimal management of comorbidities can reduce AF recurrence after AF ablation; therefore, multimodal risk assessment and therapy are mandatory. To date, the primary ablation tool in widespread use is still single-tip catheter radiofrequency (RF) based ablation. Additionally, balloon-based pulmonary vein isolation (PVI) has gained prominence, especially due to its user-friendly nature and established safety and efficacy profile. So far, the cryoballoon (CB) is the most studied single-shot device. CB-based PVI is characterized by high efficiency, convincing success rates, and a beneficial safety profile. Recently, CB-PVI as a first-line therapy for AF was shown to be superior to pharmacological treatment in terms of efficacy and was shown to reduce progression from paroxysmal to persistent AF. In this context, CB-based PVI gains more and more importance as a first-line treatment choice. Non-thermal energy sources, namely pulsed-field ablation (PFA), have garnered attention due to their cardioselectivity. Although initially applied via a basket-like ablation tool, recent developments allow for point-by-point ablation, particularly with the advent of a novel lattice tip catheter.

Biophysical Behavior of Very High-Power Short-Duration Radiofrequency Ablation in Pulmonary Vein Isolation: Fast but Gently—Implications for a Successful Procedure

The very high-power short-duration (vHP-SD) ablation strategy is an alternative for pulmonary vein isolation (PVI) in patients with paroxysmal atrial fibrillation (PAF). However, the acute procedural biophysical behavior of successful lesion creation by means of this technique is still unexplored. We performed a retrospective case–control study aimed at evaluating the behavior of vHP-SD ablation parameters with the QDOT MICRO™ ablation catheter (Biosense Webster) compared with standard radiofrequency (RF) ablation with the THERMOCOOL SMARTTOUCH® ablation catheter. Twenty consecutive cases of symptomatic PAF treated with the QDOT MICRO™ ablation catheter from December 2022 to March 2023 were compared with cases treated with the standard technique. The acute procedural success of PVI was obtained in all cases with 2192 RF applications, and no adverse events occurred. Compared with the controls, vHP-SD cases featured a significant reduction in procedural time (47 ± 10 vs. 56 ± 12 min, p = 0.023), total RF time (3.8 [CI 3.4–4.6] vs. 21.2 [CI 18.4–24.9] min, p < 0.001), ablation phase time (25 ± 5 vs. 39 ± 9 min, p < 0.001), and irrigation volume (165 [CI 139–185] vs. 404 [CI 336–472] ml, p < 0.001). In vHP-SD RF ablation, a contact force of 5 g minimum throughout the 4 s of RF application appeared to be statistically significant in terms of an impedance drop of at least 10 Ohm (OR 2.63 [CI 1.37; 5.07], p = 0.003). In contrast, in the control group, the impedance drop depended linearly on the contact force. This suggests a different biophysical behavior of vHP-SD ablation. A maximum temperature and minimum contact force of >5 g independently predicted an effective impedance drop in vHP-SD. Increasing the contact force over 5 g during 4 s of vHP RF application might not be necessary to achieve a successful lesion.

An economic evaluation of first-line cryoballoon ablation versus antiarrhythmic drug therapy for the treatment of paroxysmal atrial fibrillation from a German healthcare service payer perspective

Abstract Background Three recent randomized controlled trials demonstrated that, in patients with symptomatic paroxysmal atrial fibrillation (PAF), first-line pulmonary vein isolation (PVI) with cryoballoon ablation reduces atrial arrhythmia recurrence when compared to initial antiarrhythmic drug (AAD) therapy. Purpose To evaluate the cost-effectiveness of initial rhythm control therapy from a German healthcare service payer perspective. Methods The cost-effectiveness model (CEM) structure consisted of a hybrid decision tree and Markov model, where the decision tree informed the initial health state allocation in the first cycle of the Markov model and had a one-year time horizon. The Markov model had a 40-year time horizon using a three-month cycle length. Health benefits were expressed in quality-adjusted life years (QALYs). Costs and benefits were discounted at 3.5% p.a. Individual patient-level data from 703 participants with untreated PAF enrolled into Cryo-FIRST (NCT01803438), STOP AF First (NCT03118518) and EARLY-AF (NCT02825979) were used to estimate efficacy, resource use and health-related quality of life parameters. Cost inputs were sourced from diagnosis-related groups and the Institute for the Hospital Remuneration System (InEK). Where parameters could not be derived, inputs were sourced from available published literature or determined through clinical expert opinion. Probabilistic sensitivity analyses were conducted to explore the impact of any assumptions on model outputs. Results In those treated with cryoablation, the three-month rate of AF recurrence was reduced by 46.7% (p<0.001) on average. Similarly, the average monthly rate of receiving an ablation following initial treatment was reduced by 72.8% (p<0.001). Cryoablation was also associated with a 4.3% (p=0.025) increase in health-related quality of life at 12 months, assessed through the standard EQ-5D-3L instrument. There was no difference in the rate of AF resolution in those who failed initial treatment. CEM results are shown in Table 1. Analysis shows that cryoablation is cost-effective, incurring a cost of ∼€1,000 per patient over a lifetime compared to AADs, while offering an increase in QALYs. Cryoablation attains an average ICER of ∼€5,500, with a 94.1% probability of being cost-effective at a willingness-to-pay threshold of €35,000 per QALY gained. Through 5,000 iterations, the probabilistic sensitivity analysis indicates that cryoablation has ∼20% probability of being cost-saving. Individuals are expected to receive a total of ∼1.2 ablations over a lifetime, regardless of initial treatment. Although, those initially treated with cryoablation as opposed to AADs experience a 45% reduction in time spent in AF health states. Conclusion Initial rhythm control with cryoballoon ablation in PAF is a cost-effective treatment option in a German healthcare setting.Table 1:Key results (per patient)

Impact of atrial fibrillation type on outcomes following aerobic exercise training: analysis from the ACTIVE-AF Trial

Abstract Background The ACTIVE-AF study demonstrated that aerobic exercise prescription promotes the maintenance of sinus rhythm in patients with atrial fibrillation (AF). However, it is unclear whether these benefits are observed in patients with both paroxysmal and persistent AF. Purpose Compare efficacy of exercise intervention on arrhythmia recurrence between paroxysmal (ParAF) and persistent (PerAF) patients. Methods This study was a prospective, randomized, controlled trial of patients with symptomatic paroxysmal or persistent AF, referred for consideration of AF ablation. Randomization was 1:1 to either aerobic exercise intervention or usual medical care for a period of 6 months with a further 6 months follow-up. The exercise intervention was delivered in a hybrid format of weekly supervised exercise sessions coupled with prescribed home exercise, up to a total of 210 minutes per week. The intervention was led by a clinical exercise physiologist. Management of arrhythmia was at the discretion of a cardiologist blinded to patient randomisation. The primary endpoint reported here is recurrent AF without rhythm control strategies. Results Of the 120 patients enrolled in the study, 74 (62%) had a history of ParAF. Patients with PerAF typically had higher body mass index (32.0±6.6 versus 29.5±5.2 Kg/m2, p=0.02) and left atrial volume (38.0±9.4 versus 28.1±6.5 mL/m2, p<0.001) but similar prevalence of hypertension, diabetes mellitus, coronary artery disease and obstructive sleep apnea. Baseline peak oxygen consumption (VO2peak) was similar between ParAF and PerAF groups (20.0±6.0 versus 19.6±5.4mL/kg/min). Over the 12-month follow-up, AF recurrence in the ParAF patients was lower in the exercise group compared to control group (Hazard Ratio 0.42, 95% CI: 0.23-0.77, p=0.005). However, we did not find evidence of any between-group difference amongst patients with PerAF (HR 0.65, 95% CI: 0.34-1.23). Conclusions In this post-hoc analysis of a randomised controlled trial comparing the efficacy of exercise intervention versus standard medical care amongst patients with symptomatic AF, we observed a reduction in AF recurrence for patients with ParAF, but not amongst those with PerAF. These findings support the need for early lifestyle modification amongst patients with AF, before progression to PerAF occurs. Future studies should explore whether the exercise prescription can be modified to improve outcomes for patients with more advanced AF.

Lower cardiorespiratory fitness is associated with left atrial structural, functional and electrical remodelling in patients with symptomatic atrial fibrillation

Abstract Background Preserved cardiorespiratory fitness (CRF) is associated with improved rhythm control in patients with symptomatic atrial fibrillation (AF). However, the pathophysiological features associated with low cardiorespiratory fitness are not well described. Purpose Evaluate the association between cardiorespiratory fitness and structural, functional and electroanatomical features of the left atrium (LA) amongst patients with symptomatic AF. Methods Consecutive patients with symptomatic paroxysmal or persistent AF undergoing AF ablation were recruited. CRF was assessed objectively by peak oxygen consumption (VO2peak) assessed during maximal cycle ergometry. Invasive assessment of LA remodelling involved direct assessment of resting LA pressures (LAP), LA stiffness during saline infusion and LA electrical function using high-density electroanatomical maps. Non-invasive assessment involved 2D transthoracic echocardiography at rest and during exercise. The association between VO2PEAK and atrial parameters were determined using multivariable linear regression models adjusted for age and sex. Results In total, 110 participants were recruited. Mean age was 63±11 and 74.5% of the cohort was male. In adjusted analyses, higher VO2PEAK was associated with lower mean LAP (p<0.001) and invasively assessed LA stiffness (p=0.005). On non-invasive testing, VO2PEAK was positively associated with left atrial emptying fraction (LAEF) (p=0.001) and reservoir strain (p<0.001) at rest. During exercise, VO2PEAK remained associated with LAEF (p<0.001) and LA reservoir strain (p=0.007). Higher VO2peak was positively associated with LA bipolar voltages (p=0.035) but not LA conduction velocities (p=0.131) or LA fractionation (p=0.452) Conclusions In patients with symptomatic AF, lower cardiorespiratory fitness is independently associated with extensive LA remodelling involving impaired LA haemodynamics, increased LA stiffness, LA mechanical dysfunction and LA electrical remodeling.

Abstract 13916: Patient Outcomes 6 Months Following Pulmonary Vein Isolation for Atrial Fibrillation With a Novel RF Catheter: Initial Data From NEwTON AF

Introduction: The combination of local impedance (LI), a direct measure of electrical resistance at the catheter tip, and contact force (CF) may facilitate treatment of atrial fibrillation (AF). This trial is designed to examine the safety and effectiveness of a novel RF catheter that allows measurement of both LI and CF. Hypothesis: Demonstrate the safety and effectiveness of a novel radiofrequency catheter with LI and CF for treatment of drug refractory, recurrent, symptomatic Paroxysmal AF (PAF). Methods: NEwTON AF is a multi-center, global, prospective, single arm study. Patients received index treatment for PAF with the study catheter. The present 6-month endpoint analysis was prospectively planned. Results: The study treated 299 patients at 45 sites in North America, Europe, and Asia. Patients were 39.5% female with a mean age of 62yrs (±12), and had a mean LVEF of 59% and an LA diameter of 3.9cm. Procedure time, LA dwell, and fluoroscopy times were 166, 136, and 15 minutes, respectively. High-power short-duration (HSPD, 45-50W) was exclusively used in 210 cases, which had notably shorter procedure times than the 82 cases that used conventional power, 148 vs 208 min, respectively. Acute procedural success was observed in 98.3% of cases. As of 6 months, freedom from documented recurrence of any atrial arrhythmia was 79.9% (Figure). Recurrence in relation to LI shows that pts with a 20Ω LI drop (in at least 60% of lesions) had better 6m outcomes (84.2% vs 73.3, p=0.04). The freedom from safety event rate at 30d was 96.0%; events included pericarditis (6), access complications (2), pulmonary edema (2), embolism (2), cerebrovascular accident (1), tamponade (1). Pericarditis was higher in pts with a history of COVID at enrollment, 16.3% vs 5.9%, p=0.025. Conclusions: This data suggests that patient outcomes and safety for this novel catheter are promising. Further data from this study, including 12m outcomes, and detailed analysis of local impedance data are forthcoming.

Abstract 18727: Outcomes of Utilization of Transesophageal Echocardiogram (TEE) vs Intracardiac Echocardiogram (ICE) for Atrial Fibrillation Ablations in the Real-AF Registry

Introduction: Transesophageal (TEE) and intracardiac (ICE) echocardiogram are widely used strategies to rule out LAA thrombus prior to atrial fibrillation (AF) ablation. We compare the utilization of TEE and ICE, outcomes and complications of each strategy. Methods: The Real-world Experience of Catheter Ablation for the Treatment of Symptomatic Paroxysmal (PAF) and Persistent (PsAF) Atrial Fibrillation registry (Real-AF) is a multicenter prospective registry that is enrolling patients undergoing AF ablation at high-volume centers. We compared complications rates (Table 1) between TEE and ICE in patients with AF underdoing index ablation for AF in the REAL-AF registry. Patients who underwent both TEE and ICE were excluded from the analysis. Bleeding complication was defined as bleeding that occurs within the first 72 hours of the procedure requiring transfusion or resulting in >20% drop in hemoglobin. Vascular access complications included AV fistula or pseudo-aneurysm needing intervention. Results: A total of 1628 patients were included in the analysis.The mean age was 64.78 (SD=11.43) years, 45.7% were women, mean BMI was 30.36 (SD=6.71) and mean CHAD2DS2VASc score was 2.49 (SD=1.51). TEE was used in 911 patients (58.5%) and ICE was used in 717 (46.1%) ] prior to ablation. There were 0% strokes reported in the TEE group vs 0.1% in the ICE group (p = 0.095). Among other complications reported there was no statistical difference between the two groups (Table 1). There was no significant difference between the two groups on recurrence of arrhythmias at 12 months (HR: = 0.983, CI: 0.79,1.3 , p < 0.894) Conclusion: Both TEE and ICE are acceptable strategies for pre-ablation assessment of left atrium and LAA. There are no significant differences in stroke rates between the two groups. Other reported complications are also similar between the two groups. Choice of either TEE vs ICE depend on patient specific characteristics, hospital resources and operator preference.

Abstract 18225: Left Atrial Volume Index and Outcomes in Paroxysmal Atrial Fibrillation (pAF) in the Real-AF Registry

Introduction: Catheter ablation via pulmonary vein isolation Is one of the most commonly performed procedures for treating paroxysmal atrial fibrillation (pAF). Left atrium size affects ablation strategies and outcomes in patients with pAF. We analyzed the left atrium index (LAi) to determine associations with recurrent arrhythmias at 12 months post-ablation and the ablation strategies used. Methods: The Real-world Experience of Catheter Ablation for the Treatment of Symptomatic Paroxysmal (pAF) and Persistent (PsAF) Atrial Fibrillation registry (Real-AF) is a multicenter prospective registry that is enrolling patients undergoing AF ablation at high-volume centers. Left atrial volume was reconstructed using CARTO 3D. LAi was separated into normal range: < 34 ml/m2, mildly enlarged 35 - 41 ml/m2, moderately enlarged 42 - 48 ml/m2, and severely enlarged > 49 ml/m2 based on the American Society of Echocardiogram guidelines. Ablation strategies were divided into pulmonary vein isolation (PVI) alone or PVI+ ablation, including PVI and additional atrial arrhythmogenic substrates. Recurrence of arrhythmias at 12 months post-ablation and ablation strategies were compared. Results: A total of 1824 were included. In patients with pAF 12.2% developed recurrent arrhythmia at 12 months. When compared to normal LAi, patients with pAF with moderately and severely enlarged LAi were more likely to have a recurrence of arrhythmias at 12 months (Table 1). Women with pAF and moderately and severely enlarged LAi were more likely to have recurrence of arrhythmias (Table 1). A total of 1433 underwent PVI only ablations, and 391 underwent PVI+ ablations. Abnormal LAi was also associated with patients undergoing PVI+ ablations compared to PVI only ablations (Table 1). Conclusions: In patients with pAF and abnormal LA size was associated with more recurrent arrhythmias at 12 months post-ablation. Patients with enlarged LAi were more likely to have PVI+ ablations.