Veronika Bulkova

Background and Aims: In the PRAGUE-25 study, the effect of lifestyle modification (LFM) in combination with antiarrhythmic drugs (AAD) in patients with atrial fibrillation (AF) and BMI 30-40 was smaller than that of catheter ablation (CA). The presented sub-analysis aims to assess the relationship between the actual weight reduction and the AF burden 12 months after randomization. Methods: Per-protocol analysis of the PRAGUE-25 trial. Patients in the LFM+AAD group were stratified into tertiles based on the extent of relative weight reduction, and a comparison of AF burden was performed between the LFM+AAD tertiles and the CA group. Results: The study analyzed 83 LFM+AAD patients (age 60 ±9 years, 31% women, 54% paroxysmal AF, mean weight 109±17 kg) and 99 CA patients (age 60±9 years, 32% women, 56% paroxysmal AF, weight 109±15 kg). Within the LFM+AAD group, 28 patients achieved a weight reduction of >8.3% (−15.46±6.16 kg), 27 patients were between 3.1–8.1% (−6.56±2.28 kg), and 28 patients were <3.1% (+1.38±4.03 kg). Compared to the CA group, the AF burden at 12 months (0 [IQR 0–0]) was significantly higher in the second (3.5% [0; 52] and third (1[0; 47] LFM-ADD tertiles, but did not differ from CA in the first tertile (0% [0; 11.], p=0.17). Conclusion: In obese patients, the maintenance of SR on AADs is related to the level of weight reduction. The efficacy of AADs in obese patients with a significant weight loss at 12-months follow-up is close to catheter ablation, although the overall AF burden is still non-significantly higher.

Funding Acknowledgements: Type of funding sources: None. Background: Pulsed field ablation (PFA) is a promising method to reduce procedure time and improve ablation safety and efficacy in all types of atrial fibrillation (AF). Purpose: To present ablation approach and medium-term outcomes of PFA in all AF types. Methods: Between 9/2021-10/2022, PFA using Farawave catheter was performed in 250 patients (63±11 years, 65 females). Patients with paroxysmal AF were basically scheduled for simple pulmonary vein isolation (PVI) (Farawave, ICE), patients with longstanding AF (LSPAF) underwent complex left atrial (LA) PFA (Farawave, CS 10-pole catheter, ICE); ablation extent varied in persistent AF. Results: Paroxysmal AF (n=131; 115 ablated in SR), persistent AF (n=39; 11 ablated in SR), and LSPAF (n=64) were ablated with procedure times 58±20, 105±28, and 116±32 minutes, respectively, and fluoroscopy times 9±5, 14±7, and 17±7 minutes, respectively. Additional 16 patients underwent PFA for atrial tachycardia (AT). Ongoing AF was terminated by PFA in 13/16 (81%), 16/28 (57%), and 23/64 (36%) patients with paroxysmal AF, persistent AF, and LSPAF, respectively. In groups of paroxysmal AF ablated in SR, paroxysmal AF ablated in AF, persistent AF ablated in SR, persistent AF, and LSPAF, simple PVI was performed in 100%, 50%, 73%, 11%, and 0 patients respectively; and freedom from AF/AT was present in 86/99 (87%), 11/14 (79%), 7/10 (70%), 11/12 (92%), and 40/52 (77%) patients, respectively, of total 187 patients with follow-up ≥3 months (≥6 months in 139 patients). In 8 patients with repeat ablation post-PFA for paroxysmal AF (n=4), persistent AF (n=2), LSPAF (n=2), extra-PV AF/AT sources dominated in all groups. Complications included one tamponade with pericardiocentesis, and prolonged ST elevation with negative coronary angiography. Conclusion: PFA using Farawave catheter was associated with reduced procedure times and favourable medium-term outcome for all AF types. Early experience specifically suggests improved outcome after extensive LA ablation for persistent AF/LSPAF.

Funding Acknowledgements: Type of funding sources: None. Background: Benefits of pulsed field ablation (PFA) compared to radiofrequency ablation (RFA) are not known in patients with longstanding persistent atrial fibrillation (LSPAF). Purpose: To present interim procedural and short-term clinical results of an ongoing prospective randomized comparison of PFA vs. RFA in patients with LSPAF. Methods: In 9/2021-10/2022, 125 patients underwent catheter ablation for LSPAF using PFA (n=64, 69±8 years, 11 F, continuous AF 32±20 months) vs. RFA (n=61, 68±8 years, 17 F, continuous AF 29±23 months). PFA included pulmonary vein isolation (PVI) and extra-PV left atrial (LA) ablation. RFA included stepwise PVI, electrogram-guided LA ablation, CS isolation, and electrogram-guided right atrial ablation. Intermediate endpoints were PVI, mitral isthmus, LA roof and CTI blocks); sinus rhythm (SR) restoration by ablation was the desired procedural endpoint. Follow-up included 7-day ECG monitoring every 3 months during the first year, and every 6 months afterwards. Results: In groups PFA vs. RFA, procedure and fluoroscopy times were 116±32 vs. 204±44 minutes, and 17±5 vs. 8±2 minutes, respectively (both p30 s) was achieved in 38 (79%) vs. 23 (46%) patients. Conclusion: Interim results of ongoing comparison suggest procedure time reduction and improved AF/AT free survival after PFA as compared to RFA in patients with LSPAF.

Purpose: Single center retrospective analysis of complications of catheter ablation for paroxysmal atrial fibrillation (PAF).

Background: Long-term efficacy of catheter ablation for atrial fibrillation (AF) greatly declines with time.

Aims Identifying patients who benefit from restored sinus rhythm (SR) would optimize the selection of candidates for ablation of long-standing persistent atrial fibrillation (LSPAF). This prospective study sought to identify the hitherto unknown factors associated with global functional improvement after successful radiofrequency catheter ablation of LSPAF. Methods and results In 171 LSPAF patients (84% of the total consecutive 203 patients) who were examined in SR 12 months after ablation, the individual per cent change from baseline value in maximum oxygen consumption at exercise test (VO₂ max), left ventricular ejection fraction (LVEF), N-terminal prohormone of brain natriuretic peptide (NT-proBNP), and five-dimensional descriptive system (EQ-5D) of quality-of-life questionnaire were classified in quartiles by 0 (worse) to 3 (best) grades. The individual grades were summed into a composite score (SCORE, 0 … 12) reflecting global functional improvement. Significant improvement in VO₂ max (3.4 ± 4.7 mL/kg/min), LVEF (7.5 ± 9.1%), NT-proBNP (−861 ± 809 pg/mL), and EQ-5D (0.7 ± 0.12) was observed (all P < 0.0001). On multivariable analysis, younger age (P = 0.001), male gender (P = 0.02), timely post-ablation left atrial appendage (LAA) outflow (P = 0.005) with improvement in outflow velocity (P = 0.0002), and withdrawal of Class I/III antiarrhythmic drugs (P < 0.05) were positively and independently correlated with the SCORE. Conclusions Younger male patients benefited most from catheter ablation of LSPAF. Delayed or non-improved LAA outflow and inability to discontinue Class I/III antiarrhythmic medication reduced the post-ablation functional improvement.

Purpose: Retrospective analysis of freedom from recurrent atrial fibrillation (AF) or atrial tachycardia (AT) after single catheter ablation for paroxysmal AF (PAF) in relation to procedural endpoint Methods: At first ablation in consecutive 946 patients (32% females, age 57 ± 10 years) it was at discretion of 4 involved operators whether they pursued AF/AT noninducibility following simple pulmonary vein isolation (PVI) performed during sinus rhythm (SR), or following termination of ongoing/induced AF/intermediate AT by simple PVI, or following termination of AF/AT continuing after completing PVI by ablation outside PVs. Noniducibility was tested by atrial pacing, isoproterenol and adenosine. Non-termination might be accepted after simple PVI or after PVI with extra-PV ablation. Three patients were excluded from analysis (ablation not performed: n = 2, no follow-up: n = 1). Results: PVI was completed in all patients. At the end of 69 ± 42 month follow-up after 1.36 procedures/patient stable SR was present in 85% patients (71% patients off drugs). No AF/AT recurrence vs. AF/AT recurrence after single ablation occurred in 71 vs. 29% of patients (p < 0.00001) in the group with proved noninducibility (n = 303), in 51 vs. 49% patients (p = 0.75) in the group of patients with non-tested/non-proved noninducibilty (n = 537), and in 31 vs. 69% patients (p = 0.001) in the group of non-terminated ongoing/induced AF/AT (n = 103) (Table). Conclusion: Noniducibility endpoint at first PAF ablation was associated with better single procedure arrhythmia-free outcome disregard presence or absence of AF during procedure. AF/AT non-termination was associated with the worst outcome.

Purpose: To assess possible left ventricular (LV) structural changes that might be behind long-lasting arrhythmia-induced cardiomyopathy related to long-standing persistent atrial fibrillation (LSPAF), delayed-enhancement magnetic resonance imaging (DE-MRI) in detecting abnormal LV tissue was performed in LSPAF patients with severe depression of LV ejection fraction (LVEF). Methods: Of 210 consecutive patients with first LSPAF ablation in years 2006-12, 41 (20%) subjects (58 ± 9 years, 12% females) presented with consistent LVEF ≤40% for 23 ± 20 pre-ablation months. Resting/peak heart rates of 97 ± 18/152 ± 26 bpm were significantly higher for only resting heart rate as compared to LSPAF patients with normal LVEF. In years 2014-5, the patients were contacted to undergo DE-MRI. Results: At the end of 59 ± 18 month follow-up (1.6 ± 0.6 procedures/patient) 39 (95%) patients were in stable SR and LVEF was ≤40% in 7 (17%) patients. At 1 year post-ablation, LVEF improved from baseline by 22 ± 8% (increase to ≥50% in 85% patients), accompanied by improvement in NT-proBNP (-711 ± 562 pg/ml), VO2 max (+3.9 ± 5.1 mL/kg/min), and quality of life (all p < 0.00001). DE-MRI was not available in 18 patients (death 2, ICD 7, PM 2, claustrophobia 3, declined 3). DE-MRI performed 54 ± 17 (25-89) months after initial ablation in remaining 23 patients with SR proved durable ablation effect on LVEF (57 ± 9% by MRI vs. 59 ± 5% by echocardiography at 1 year) with LVEF impairment from ≥50 to ≤40% (54 to 29%) in 1 patient with no DE deposit. Discrete LV DE deposits were found in basal septum (n = 3), basal lateral wall (n = 1), and anterolateral papillary muscle (n = 1) in 3 patients (LVEF 62, 67, and 55%, respectively). Conclusion: Successful LSPAF ablation reversed related long-lasting LVEF depression in a majority of patients. The adverse LV response to arrhythmia was not related to concealed intramural structural (e.g. post-myocarditis) changes.