Pulmonary Vein Isolation In Patients Research Articles

Long-term success after catheter ablation of atrial fibrillation

Ablation is an established treatment option for atrial fibrillation (AF) and is associated with convincing success rates and areasonable safety profile. Ablation strategies going beyond pulmonary vein isolation in patients with chronic forms of AF are less well established and reproducible. Especially in patients with progressed AF forms multiple ablation procedures might be mandatory to achieve reasonable clinical success. An early ablation strategy might stop or prolong the progress from paroxysmal to persistent AF. In addition, ablation is more effective than drug-based treatment and comparably safe. Long-term success rates after asingle and after multiple ablation procedures in paroxysmal AF are reported with 60-70% and up to 80%, while success rates in persistent or long-standing persistent AF are less favorable (single procedure 40-50%, multiple procedures 70%). However, currently non-recurrence of AF is the most established but potentially not the best endpoint. The burden of AF after ablation as assessed by novel monitoring modalities might gain further clinical importance.

Dynamics of left and right atrial strain after radiofrequency ablation in patients with paroxysmal and persistent atrial fibrillation

Aim. To assess the dynamics of left (LA) and right atrium (RA) strain after antral pulmonary vein isolation in patients with paroxysmal and persistent atrial fibrillation.Methods. The study included 57 subjects (31 men and 26 women) aged of 55.4±9.8 years. Patients were divided into 2 groups: group 1 with paroxysmal atrial fibrillation (n=40; 70%) and group 2 with persistent atrial fibrillation (n=17; 30%). All patients were treated (were undergone) with antral isolation of the pulmonary veins. Speckle-tracking echocardiography at sinus rhythm was performed before interventional treatment, after 3 days, 3 months and one year. The reservoir, conduit and contractile LA function and peak longitudinal RA strain were analyzed.Results. In both groups, reservoir (p<0.001), conductive (p<0.001) and contractile LA functions (p<0.001 and p=0.001) decreased significantly in the early postoperative period. LA mechanics recovered after 3 months in all patients and were comparable to the level before and one year after radiofrequency ablation. RA strain was significantly increased in the early postoperative period. RA strain was significantly higher at one year follow-up period compared with baseline.Conclusion. Catheter ablation has a damaging effect on the LA - inhibition of reservoir, conductive and contractile functions in the early postoperative period, while the RA strain is intensified. LA strain is recovered in 3 months after radiofrequency ablation and remains comparable with the baseline level at one year follow-up. Reservoir and conduction function of LA and longitudinal deformation of RA are better in the patients with a stable sinus rhythm for a year after ablation compared with patiens who had a tachyarrhythmia recurrence.

TCT-3 Renal Artery Denervation Combined With Pulmonary Vein Isolation in Patients With Heart Failure and Atrial Fibrillation: Pilot Study

TCT-3 Renal Artery Denervation Combined With Pulmonary Vein Isolation in Patients With Heart Failure and Atrial Fibrillation: Pilot Study

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

BackgroundPulsed-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).MethodsConsecutive 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.ResultsA 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).ConclusionIn 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.Graphical

Four typical pulmonary venous pressure curves displaying the level of occlusion during atrial fibrillation ablation by cryoballoon.

Cryoballoon ablation is safe and effective for pulmonary vein isolation in patients with symptomatic drug-refractory paroxysmal atrial fibrillation. To monitor adhesion between the balloon and the pulmonary vein, an alternative technique to pulmonary venography is to analyze changes in the pressure curve. We have described the adhesion level characterized by four types of pressure waveforms. These correlated with the extent of contrast agent leakage (Cohen's kappa of 0.81 [IC 95%: 0.63-0.99]). Monitoring the venous pressure curve is easy to perform and has the advantage of being able to detect balloon movement during the first few seconds of treatment.

Comparison of the PolarX and the Arctic Front cryoballoon for pulmonary vein isolation in patients with symptomatic paroxysmal atrial fibrillation (COMPARE CRYO) – Study protocol for a randomized controlled trial

IntroductionSingle-shot devices are increasingly used for pulmonary vein isolation (PVI) in atrial fibrillation (AF). The Arctic Front cryoballoon (Medtronic) is the most frequently used single-shot technology. A recently developed novel cryoballoon has been introduced (PolarX, Boston Scientific) with the aim to address limitations of the Arctic Front system. MethodsCOMPARE CRYO is a multicentre, randomized, controlled trial with blinded endpoint adjudication by an independent clinical events committee. A total of 200 patients with paroxysmal AF undergoing their first PVI are randomized 1:1 between PolarX cryoballoon ablation and Arctic Front cryoballoon ablation. Continuous monitoring during follow-up is performed using an implantable cardiac monitor (ICM) in all patients. The primary endpoint is time to first recurrence of any atrial tachyarrhythmia (AF, atrial flutter, and/or atrial tachycardia) ≥ 120 s between days 91 and 365 post ablation as detected on the (ICM). Procedural safety is assessed by a composite of cardiac tamponade, persistent phrenic nerve palsy >24 h, vascular complications requiring intervention, stroke/transient ischemic attack, atrioesophageal fistula or death occurring during or up to 30 days after the procedure. Key secondary endpoints include (1) procedure and fluoroscopy times, (2) AF burden, (3) proportion of patients with recurrence in the blanking period, (4) proportion of patients undergoing repeat ablation, and (5) quality of life changes at 12 months compared to baseline. ConclusionCOMPARE CRYO will compare the efficacy and safety of the novel PolarX cryoballoon and the standard-of-practice Arctic Front cryoballoon for first PVI performed in patients with symptomatic paroxysmal AF.Trial registration: (ClinicalTrials.gov ID: NCT04704986).

Optimization of high-power short duration catheter radiofrequency ablation for pulmonary veins isolation in patients with artiral septial defect

Objective ‒ to perform the analysis and biophysical substantiation of a new technique of catheter radiofrequency ablation (RFA) with high power and short duration based on mathematical modeling of own clinical data of the electro-thermodynamic effect of RFA on the myocardium; to investigate the morphological characteristics of the myocardium in different areas of the atrium and to determine the morphometric parameters of the display on the electroanatomical model of the heart of the ablation zone in the EnSite Precision navigation system, necessary for effective and safe high-power and short-duration RFA.Materials and methods. Clinical studies were performed in Amosov National Institute of Cardiovascular Surgery NAMS of Ukraine. Specialized high-tech medical equipment was used for the objectivity of clinical data obtained and used in the work. Morphological characteristics of the myocardium (thickness of the wall of the left atrium, distance from the back wall of the heart to the esophagus, diameters of the pulmonary veins) were evaluated on the computed tomography images of the heart of the patients, which were obtained in the radiology department on a Toshiba device (Japan) using a spiral scanning. The morphometric parameters of the ablation zone, which were later used to evaluate the effectiveness of RFA and which formed the basis of standardized protocols for the operation, were determined for display on the electro-anatomical maps of the patients' hearts in the EnSite Precision system (Abbott, USA). Biophysical substantiation of the RFA technique with high power and short duration was performed using mathematical modeling of the electro-thermodynamic effect of RFA on the myocardium and own clinical data in the Comsol Multiphysics automated simulation of biophysical processes.Results. It is proposed for a group of patients with combined atrial fibrillation with an atrial septal defect to perform RFA using a new ablation technique with high power and short duration at one point of application of radio frequency energy. Achieving transmurality of ablation in a shorter time makes it possible to hold the electrode more precisely and stably in this area when isolating the pulmonary veins in a complex geometry and without support for the electrode in case of a defect. The morphological characteristics of the myocardium were studied and the morphometric parameters of the display on the electroanatomical heart model of the ablation zone, necessary for effective and safe RFA, were determined. These include: the diameter of the point-label of radiofrequency ablation on the anatomical model of the heart, which must correspond to the real data of the size of the destruction; the percentage of overlap of RFA points for the formation of an effective transmural line; estimated number of ablation points to standardize the evaluation of the effectiveness of the procedure.Conclusions. The conducted research made it possible to solve the current problems of catheter radiofrequency ablation in patients with atrial fibrillation and atrial septal defect, namely to increase the efficiency and safety of pulmonary vein isolation. Transmurality and integrity of the isolating line was achieved due to the determined morphological characteristics of the myocardium and the calculated morphometric parameters of the ablation zone. The obtained data are adapted to a real display visible to the surgeon on the electro-anatomical map of the heart in the EnSite Precision navigation system. This system is actively used in clinical practice, but it was necessary to optimize the clinical protocols of RFA with high power and short duration, which was achieved as a result of this work.

Impedance-guided modified CLOSE protocol ablation can reduce ablation index necessary for pulmonary vein isolation in patients with atrial fibrillation

BackgroundReal-time monitoring of generator impedance drop is not considered in CLOSE protocol pulmonary vein (PV) isolation (PVI) in patients with atrial fibrillation (AF). We verified whether additional information of impedance drop could minimize ablation index required for PVI using modified CLOSE protocol (target ablation index ≥ 500 on anterior wall and ≥400 on posterior wall along with inter-lesion distance of 3–6 mm and maximum power of 35 W) without any adverse effect of procedural data and efficacy. MethodsSixty consecutive Japanese AF patients [paroxysmal AF: 43 (72 %) patients] underwent first-time PVI with modified CLOSE protocol with real-time monitoring of impedance drop (impedance-guided modified CLOSE protocol). Ablation tags were colored according to impedance drop and ablation was immediately terminated before reaching target ablation index if impedance drop of ≥10 Ω was confirmed. Ablation index needed for PVI, first-pass PVI rate, other procedural data, and atrial tachyarrhythmia recurrence were evaluated. ResultsMean ablation index and impedance drop on anterior and posterior walls were 437.6 ± 43.5 Ω and 10.2 ± 2.6 Ω and 393.3 ± 27.4 Ω and 9.3 ± 2.2 Ω, respectively. First-pass PVI per PV pair was accomplished in 90/120 (75 %). No complications occurred. PV gaps after first-pass ablation were locationally most often found on right posterior wall than on the other parts (p < 0.001). There were no differences in mean contact force, impedance drop, and ablation index between walls with and without PV gaps after first-pass PV ablation. During a mean follow-up of 24 ± 9 months, survival from atrial tachyarrhythmia recurrence was 51/60 (85 %) patients. ConclusionsUsing additional generator impedance drop information may be useful to minimize radiofrequency current application to accomplish PVI with modified CLOSE protocol while maintaining efficacy and safety in Japanese AF population.

Tailored ablation index based on left atrial wall thickness assessed by computed tomography for pulmonary vein isolation in patients with atrial fibrillation.

Although left atrial wall thickness (LAWT) is known to be varied, a fixed target Ablation Index (AI) based pulmonary vein isolation (PVI) has been suggested in catheter ablation for atrial fibrillation (AF). We aimed to evaluate the efficacy and safety of PVI applying tailored AI based on LAWT assessed by cardiac computed tomography (CT). The thick segment was defined as the segment including ≥LAWT grade 3 (≥1.5 mm). The fixed AI strategy was defined as AI targets were 450 on the anterior/roof segments and 350 on the posterior/inferior/carina segments regardless of LAWT. The tailored AI strategy consisted of AI increasing the targets to 500 on the anterior/roof segments and to 400 on the posterior/inferior/carina segments when ablating the thick segment. After PVI, acute pulmonary vein (PV) reconnection, defined by the composite of residual potential and early reconnection, was evaluated. A total of 156 patients (paroxysmal AF 72%) were consecutively included (86 for the fixed AI group and 70 for the tailored AI group). The tailored AI group showed a significantly lower rate of segments with acute PV reconnection than the fixed AI group (8% vs. 5%, p = .007). The tailored AI group showed a trend for shorter ablation time for PVI. One-year AF/atrial tachycardia free survival rate was similar in two groups (87.2% in the fixed AI group and 90.0% in the tailored AI group, p = .606). Applying tailored AI based on the LAWT was a feasible and effective strategy to reduce acute PV reconnection after PVI.

Differences in atrial substrate localization using late gadolinium enhancement-magnetic resonance imaging, electrogram voltage, and conduction velocity: a cohort study using a consistent anatomical reference frame in patients with persistent atrial fibrillation.

Electro-anatomical voltage, conduction velocity (CV) mapping, and late gadolinium enhancement (LGE) magnetic resonance imaging (MRI) have been correlated with atrial cardiomyopathy (ACM). However, the comparability between these modalities remains unclear. This study aims to (i) compare pathological substrate extent and location between current modalities, (ii) establish spatial histograms in a cohort, (iii) develop a new estimated optimized image intensity threshold (EOIIT) for LGE-MRI identifying patients with ACM, (iv) predict rhythm outcome after pulmonary vein isolation (PVI) for persistent atrial fibrillation (AF). Thirty-six ablation-naive persistent AF patients underwent LGE-MRI and high-definition electro-anatomical mapping in sinus rhythm. Late gadolinium enhancement areas were classified using the UTAH, image intensity ratio (IIR >1.20), and new EOIIT method for comparison to low-voltage substrate (LVS) and slow conduction areas <0.2 m/s. Receiver operating characteristic analysis was used to determine LGE thresholds optimally matching LVS. Atrial cardiomyopathy was defined as LVS extent ≥5% of the left atrium (LA) surface at <0.5 mV. The degree and distribution of detected pathological substrate (percentage of individual LA surface are) varied significantly (P < 0.001) across the mapping modalities: 10% (interquartile range 0-14%) of the LA displayed LVS <0.5 mV vs. 7% (0-12%) slow conduction areas <0.2 m/s vs. 15% (8-23%) LGE with the UTAH method vs. 13% (2-23%) using IIR >1.20, with most discrepancies on the posterior LA. Optimized image intensity thresholds and each patient's mean blood pool intensity correlated linearly (R2 = 0.89, P < 0.001). Concordance between LGE-MRI-based and LVS-based ACM diagnosis improved with the novel EOIIT applied at the anterior LA [83% sensitivity, 79% specificity, area under the curve (AUC): 0.89] in comparison to the UTAH method (67% sensitivity, 75% specificity, AUC: 0.81) and IIR >1.20 (75% sensitivity, 62% specificity, AUC: 0.67). Discordances in detected pathological substrate exist between LVS, CV, and LGE-MRI in the LA, irrespective of the LGE detection method. The new EOIIT method improves concordance of LGE-MRI-based ACM diagnosis with LVS in ablation-naive AF patients but discrepancy remains particularly on the posterior wall. All methods may enable the prediction of rhythm outcomes after PVI in patients with persistent AF.

Changes in Heart Rate after Pulmonary Vein Isolation in Patients with Paroxysmal Atrial Fibrillation and Sinus Bradycardia.

This study aimed to evaluate the effect of circumferential pulmonary vein isolation (CPVI) on autonomic nervous function and prognosis in patients with paroxysmal atrial fibrillation (AF) with or without sinus bradycardia.A total of 66 patients with paroxysmal AF accompanied by sinus bradycardia and who underwent CPVI were recruited as the sinus bradycardia group. A total of 91 patients with paroxysmal AF but without sinus bradycardia and who underwent catheter ablation were selected as the control group. After surgical contraindications were eliminated, CPVI was performed by three-dimensional mapping system. 24-hour dynamic electrocardiogram was used to observe the changes of heart rate before and 2 days after surgery.A total of 45 (68%) and 51 (56%) patients in the sinus bradycardia and control groups, respectively, maintained sinus rhythm. There was an increase in heart rate after CPVI in both groups. The standard deviation of normal-to-normal (NN) intervals (SDNN), standard deviation of the average NN intervals (SDANN), low frequency (LF), and LF/high frequency (HF) in the sinus bradycardia and control groups decreased after CPVI (P < 0.01). Moreover, SDANN was higher in patients with sinus bradycardia treated by successful ablation than in those with recurrence (P < 0.01), while SDNN, a standard statistical measure of heart rate variability (rMSSD), LF, and HF were significantly lower in patients with sinus bradycardia (P < 0.05).CPVI was able to produce a significant reduction effect on vagal nerve and sympathetic activity regardless of whether patients with paroxysmal AF had sinus bradycardia. Moreover, CPVI exerted a certain influence on the success rate of AF catheter ablation.

Fractal complexity alternations in paroxysmal atrial fibrillation patients with and without recurrence after pulmonary vein isolation.

Pulmonary vein isolation (PVI) is a cornerstone therapy for paroxysmal atrial fibrillation (PAF). The variations in nonlinear heart rate variability (HRV) between patients with and without recurrences remain unclear. We aimed to characterize the nonlinear HRV before and after PVI in patients with and without recurrence. Twenty-five drug-refractory PAF patients (56.0 ± 9.1 years old, 20 males) who received PVI were enrolled. Holter electrocardiography were performed before, 1-3, and 6-12 months after PVI. After 8.2 ± 2.5 months of follow-ups after PVI, patients were divided into two groups: the recurrence (n = 8) and non-recurrence (n = 17) groups. Linear and nonlinear HRV variables were analyzed, including the Poincaré Plot analysis and the Detrended Fluctuation Analysis (DFA). The non-recurrence group, but not the recurrence group, had decreased high-frequency component (HF), the root mean square of successive RR interval differences (RMSSD), and the Poincaré Plot index SD1 1-3 months after PVI and increased DFAslope2 6-12 months after PVI. The non-recurrence group's LF/HF ratio and DFAslope1 decreased significantly 1-3 and 6-12 months after PVI, respectively, whereas there was no significant change in the recurrence group after PVI. Significantly reduced vagal tone 1-3 months after PVI, increased long-term fractal complexity 6-12 months after PVI, and decreased sympathetic tone as well as short-term fractal complexity 1-3 and 6-12 months after PVI led to a better AF-free survival after PVI. These findings suggest that neuromodulation and heart rate dynamics play crucial roles in AF recurrence following PVI.

Characteristics and Efficacy of Cryoablation Versus Radiofrequency Pulmonary Vein Isolation in Patients With Atrial Fibrillation: A Single-Centre Experience

Characteristics and Efficacy of Cryoablation Versus Radiofrequency Pulmonary Vein Isolation in Patients With Atrial Fibrillation: A Single-Centre Experience

Baroreflex activity change after pulmonary vein isolation in patients with atrial fibrillation

Aim. To study the intraprocedural changes in baroreflex activity after catheter pulmonary vein isolation in paroxysmal atrial fibrillation patients.Methods. From October 2021 to June 2022, sinus rhythm was registered at the start of procedure in 21 patients with paroxysmal atrial fibrillation admitted for catheter pulmonary vein isolation. Patients before and after procedure were tested with phenylephrine. Pre- and postoperative baroreflex activity and sinus rhythm rate were analyzed.Results. After catheter pulmonary vein isolation, the baroreflex activity decreased from 5.8 [3.5; 11.3] ms/mmHg to 0.3 [-0.1; 1.8] ms/mmHg, р&lt;0.001, based on systolic arterial pressure, and from 9.5 [5.1; 15.5] ms/mmHg to 0.6 [0; 7.6] ms/mmHg, p=0.033, based on diastolic arterial pressure.Conclusion. Intraprocedural phenylephrine test allows to study the baroreflex activity changes and to assess the modification of cardiac autonomic innervation.

Pulsed-Field Ablation on Mitral Isthmus in Persistent Atrial Fibrillation: Preliminary Data on Efficacy and Safety

BackgroundPulsed-field ablation (PFA) is a new and promising modality of ablation that has been shown to specifically ablate cardiac tissue while sparing other anatomic structures, thus avoiding thermal ablation–related complications. Recent studies have certified safety and efficacy of PFA for pulmonary vein isolation (PVI) in the setting of paroxysmal atrial fibrillation (AF). However, there are very limited data assessing the feasibility and safety of PFA ablation of different substrates within the left atrium in the setting of persistent AF. ObjectivesThe purpose of this study was to evaluate the feasibility and safety of mitral isthmus (MI) ablation in addition to PVI and posterior wall (PW) ablation with PFA in patients with persistent AF. MethodsWe prospectively included all consecutive patients with persistent AF who underwent a first ablation procedure with PFA. We performed in all these patients a substrate ablation strategy comprising PVI, PW, and MI ablation with the use of PFA only. The primary feasibility endpoint was obtaining a persistent MI block at the end of the procedure. The safety endpoint was a composite of major safety events. ResultsFrom November 2021 to September 2022, we included 45 patients. Complete MI block was achieved in all 45 (100%). Three patients presented with complications, among them 2 cases (4.4%) of reversible and nonfatal coronary spasm. During a mean follow-up time of 107.8 ± 59.5 days, a 20% recurrence rate was observed. ConclusionsPFA is a feasible and safe ablation approach for mitral isthmus ablation in addition to PVI in patients with persistent AF.

Long-Term Changes in the Biomarkers of Left Atrial Fibrosis after Pulmonary Vein Isolation for Paroxysmal and Persistent Atrial Fibrillation.

Atrial fibrillation (AF) is accompanied by inflammation and fibrosis to variable extent. The biomarkers of fibrosis were measured in patients with different forms of AF and cardiac status. Herein, we assessed the associations of the baseline concentrations of different biomarkers with the long-term success of pulmonary vein isolation (PVI) in patients with a structurally normal heart. Furthermore, we compared biomarker levels before and 3 years after ablation to gain further insights into the AF mechanism. Patients, undergoing PVI for paroxysmal/persistent AF were enrolled prospectively. Blood samples were obtained 24 hours before and 3 years after ablation. Serum cancer antigen 125 (CA-125), plasma Caspase-3, Galectin-3 and Cathepsin L concentrations were measured. Follow-up visits every 6 months included 12-lead electrocardiogram, 24-hour Holter, trans-telephonic monitoring as well as transthoracic echocardiography after ablation. Biomarker levels, left ventricular ejection fraction and left atrial (LA) diameters at baseline and at the 3-year follow-up were compared in patients with versus without AF recurrence. A total of 63 patients were enrolled (23 women; age 61.4 ( 8.8) years). The acute isolation of all pulmonary veins was achieved in all patients. During a mean follow-up of 36.3 6.3 months, AF recurrence was demonstrated in 26 (41.3%) patients. No significant differences were demonstrated in the levels of CA-125, Galectin-3, Caspase-3 and Cathepsin L pre- and post-ablation in patients with versus without AF recurrence. A significant decrease was detected in the concentrations of Caspase-3, Galectin-3 and Cathepsin L during follow-up with no difference in patients with versus without AF recurrence. A positive correlation was found between Caspase-3 levels and LA diameters in the AF recurrence group both before (r = 0.477; p = 0.018) and after the procedure (r = 0.533; p = 0.019). Our results demonstrated that the levels of CA-125, Caspase-3, Cathepsin L and Galectin-3 are not associated with AF recurrence after PVI in patients with a structurally normal heart and mainly paroxysmal AF. Except for CA-125, all the other biomarkers demonstrated a significant decrease during a 3-year follow-up post-ablation. Furthermore, Caspase-3 levels demonstrated a positive correlation with LA dimensions in patients with AF recurrence.

Obstructive Sleep Apnea as a Predictor of Inducible Atrial Flutter During Pulmonary Vein Isolation in Patients With Atrial Fibrillation: Clinical Significance and Follow-Up Outcomes.

Atrial fibrillation (AF) and atrial flutter (AFL) often coexist in patients and may lead to severe symptoms and complications. Despite their coexistence, prophylactic cavotricuspid isthmus (CTI) ablation has failed to reduce the incidence of recurrent AF or new onset AFL. In contrast, the presence of inducible AFL during pulmonary vein isolation (PVI) has been shown to be predictive of symptomatic AFL during follow-up. However, the potential role of obstructive sleep apnea (OSA) as a predictor of inducible AFL during PVI in patients with AF remains unclear. Therefore, this study aimed to examine the potential role of OSA as a predictor of inducible AFL during PVI in patients with AF and reexamine the clinical significance of inducible AFL during PVI in terms of recurrent AFL or AF during follow-up. We conducted a single-center, non-randomized retrospective study on patients who underwent PVI between October 2013 and December 2020. A total of 192 patients were included in the study after screening 257 patients for exclusion criteria, which included a previous history of AFL or previous PVI or Maze procedure. All patients underwent a transesophageal echocardiogram (TEE) prior to their ablation to rule out a left atrial appendage thrombus. The PVI was performed using both fluoroscopic and electroanatomic mapping derived from intracardiac echocardiography. After the confirmation of PVI, additional electrophysiology (EP) testing was performed. AFL was classified as typical or atypical based on the origin and activation pattern. Descriptive and frequency statistics were performed to describe the demographic and clinical characteristics of the sample, and Chi-square and Fisher's exact tests were used to compare independent groups on categorical outcomes. Logistic regression analysis was performed to adjust for confounding variables. The study was approved by the Institutional Review Board, and informed consent was waived given the retrospective nature of the study. Of the 192 patients included in the study, 52% (n = 100) had inducible AFL after PVI, with 43% (n = 82) having typical right AFL. Bivariate analysis showed statistically significant differences between the groups for OSA (P = 0.04) and persistent AF (P = 0.047) when examining the outcome of any inducible AFL. Similarly, only OSA (P = 0.04) and persistent AF (P = 0.043) were significant when examining the outcome of typical right AFL. Multivariate analysis showed that only OSA was significantly associated with any inducible AFL after controlling for other variables (adjusted odds ratio (AOR) = 1.92, 95% confidence interval (CI): 1.003 - 3.69, P = 0.049). Of the 100 patients with inducible AFL, 89 underwent additional ablation for AFL prior to completion of their procedure. At 1 year, the rates of recurrence for AF, AFL, and either AF or AFL were 31%, 10%, and 38%, respectively. There was no significant difference in the rates of recurrence of AF, AFL, or either AF/AFL at 1 year when accounting for the presence of inducible AFL or the efficacy of additional AFL ablation. In conclusion, our study found a high incidence of inducible AFL during PVI, particularly among patients with OSA. However, the clinical significance of inducible AFL in relation to the recurrence rates of AF or AFL at 1-year post-PVI remains unclear. Our findings suggest that successful ablation of inducible AFL during PVI may not provide clinical benefit in reducing AF or AFL recurrence. To establish the clinical significance of inducible AFL during PVI in various patient populations, further prospective studies with larger sample sizes and longer follow-up periods are necessary.

Implementation of CLOSE protocol for pulmonary vein isolation in paroxysmal atrial fibrillation by young electrophysiologists in real world clinical practice

Abstract Funding Acknowledgements Type of funding sources: None. Background Paroxysmal atrial fibrillation (AF) is widely treated by radiofrequency (RF) catheter ablation. The CLOSE protocol has been proposed and accepted to guide a successful, safe and durable pulmonary vein isolation in patients with paroxysmal AF. However, the reproducibility of the protocol in real clinical practice and on less experienced hands is less established. Objective To assess the acute effectiveness, safety and reproducibility of RF catheter ablation based on the CLOSE protocol for pulmonary vein isolation in paroxysmal AF patients, performed by young electrophysiologists with less than 5 years of experience. Methods Fifty consecutive patients (25 men, aged 61±11 years) with symptomatic paroxysmal AF were enrolled during the period 2020- 2021. RF catheter ablation based on the CLOSE protocol, using a conventional contact force sensing catheter (Thermocool SmartTouch ST D/F) and a circumferential multipolar catheter (Lasso) after double transseptal puncture (2 SL0 long sheaths), under general anesthesia and oesophageal temperature monitoring was performed in all patients. Results Pulmonary vein isolation demonstrated by entrance and exit block was achieved in all patients. Total procedure time was 147 ± 29 minutes, exposure X-ray time was 5.36 ± 4.46 minutes and exposure dose was 922 ± 1616 cGy*cm2. Left pulmonary veins (LPVs) first pass isolation (94%) was numerically higher than the right pulmonary veins (RPVs) first pass isolation (82%). There were not safety issues. In comparison with the results reported by the authors of the CLOSE protocol, the procedure time was similar (p= 0.84), however, the exposure X-ray time and the exposure dose were significantly lower in our study (p&amp;lt;0.0001 and p=0.01, respectively). The rates of first pass isolation of left and right pulmonary veins did not differ when compared to the respective rates reported by the CLOSE protocol authors (82% vs CLOSE 100% for RPVs and 94% vs CLOSE 97% for LPVs, p&amp;gt; 0.05 for both). Conclusions RF catheter ablation in paroxysmal AF patients using the CLOSE protocol is highly effective, safe and reproducible not only by experienced but also by young electrophysiologists. Adaptation of an ablation strategy for pulmonary vein isolation based on the CLOSE protocol may improve the workflow of the procedure and the training curve of young electrophysiologists without compromising the efficacy and safety.

The safety and efficacy of rotor ablation in right atrium after pulmonary vein isolation in patients with persistent atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Background Phase mapping using software of ExTRa Mapping is a new tool to clarify the localization of rotor in atrial fibrillation (AF), but the spatial distribution of rotor in right atrium (RA) and the effect of ablation is not clear compared with left atrium (LA). Purpose This study sought to investigate the spatial distribution of rotor in RA and the safety and effectiveness of RA rotor ablation after pulmonary vein isolation (PVI) in patients with persistent AF. Methods ExTRa mapping with a 20-polar Reflexion catheter in RA was performed in 2nd or 3rd ablation for recurrent AF after PVI in 16 patients with persistent AF (including 4 patients with long standing &amp;gt;1 year AF, 15 men, mean age 67±7.7years old, mean LAD 42±5.4mm, mean EF 57±11%). Rotor was defined as NPAs (non-passively activated areas) in which the percentage of the non-passively activated period in the recording time of 5 seconds is over 50%. RA was divided into 5 areas of crista terminalis (CT), septum (Sept), free wall of RA appendage (fRAA), septal side of RAA (sRAA), behind aorta (Ao), and distribution of NPAs was investigated. RA minimal ablation to NPAs was performed to avoid sinus node and phrenic nerve. The outcomes of AF recurrence were analyzed. Results NPAs in RA were observed in 15 of 16 cases, and 67% of cases in CT, 75% in Sept, 80% in fRAA, 20% in sRAA, and 43% in Ao. RA minimal ablation was performed in 21 NPAs in 8 patients to avoid sinus node and phrenic nerve. In a mean follow-up of 307±204 days, freedom from any atrial tachyarrhythmias without antiarrhythmic drugs was achieved in 9 of 16 patients (56%). In 4 (80%) of 5 patients in whom more than 75% area of NPAs were eliminated, sinus rhythm was maintained. There was no serious complication. Conclusion Rotor in RA existed relatively frequently in septum, fRAA and CT. RA rotor ablation was safe and could be a new strategy after PVI for persistent AF.

Methods, efficacy and safety on routine clinical use of pulsed field ablation for pulmonary vein isolation in patients with atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Background Pulsed field ablation (PFA) has recently been introduced as a novel routine ablation technology for paroxysmal atrial fibrillation (AF). It is also used as off-label therapy for persistent AF. Only a few small clinical studies have been published on the mid- and long-term outcome. We present data on methods, efficacy and safety on routine clinical use of pulsed field ablation for pulmonary vein isolation in patients with atrial fibrillation. Methods In patients with AF, PVI in conscious sedation using a steerable sheath and a pentaspline over-the-wire basket and flower PFA catheter was performed. In a subset of patients, pre- and post-ablation high-density bipolar voltage 3D maps using a pentaspline diagnostic catheter were performed. Procedural parameters, acute success and in-hospital safety were assessed. Results A total of 5 operators treated 304 patients (mean age 67 years (range 32-85), female 42%, mean BMI 28 kg/m2 (range 20-42), mean CHA2DS2-VaSc score of 2 (range 0-7), first-time ablation 100%, paroxysmal/persistent/longstanding persistent AF 47/17/36%, respectively. Mean duration since first AF diagnosis was 79 months (range 0-332). Most procedures were performed under deep conscious sedation using propofol and midazolam, without intubation (99%). Pre- and post-ablation high-density maps were performed in 27% of cases. Mean procedure time was 75 min. (range 23–245). Mean left atrial dwell time of the PFA catheter was 25 min. (range 8-98). Fluoroscopy time and dose area product were 18 min. (range 6-50) and 5,74 Gy.cm2 (range 0,40-36,50), respectively. Pulmonary vein isolation (PVI) was successful in 100%. There were no phrenic nerve palsies or esophageal complications. Major complications (2,6%) were pericardial tamponade (2,0%) and stroke (0,7%); one of these strokes was lethal (0,3%). Minor complications (1,0%) were vascular access related (0,7%) and transient ischemic attack (TIA) (0,3%). Conclusions In a large, single center cohort of unselected patients, initial experience with de novo PFA for PVI in patients with AF seems to be fast and effective. There were no PFA-specific complications, but the frequency of catheter complications (tamponade, stroke) in this relatively old patient population with a relatively long history of AF demonstrates that there is still room for improvement. The number of complications improved significantly over the course of time, indicating that the learning curve could have negatively influenced the incidence of complications.