Catheter Ablation Of Paroxysmal Atrial Fibrillation Research Articles

The role of high density mapping in cathether ablation of paroxysmal atrial fibrillation - preliminary results

Abstract Introduction Despite technical progress and numerous approaches in ablation strategies, long-term success in paroxysmal atrial fibrillation (PAF) treatment is still suboptimal. Non-transmural ablation lesions in antral isolation lines, causing late electrical reconnection between pulmonary veins (PVs) and left atrium (LA) could present one of the potenital issues for reduced effectiveness of radiofrequency cathether ablation (RFCA). Potentially, these lesions can be identified with high-density (HD) mapping as low voltage, fragmented electrocardiograms (LFEGMs) representing gaps in antral isolation lines. Purpose To compare the long-term pulmonary vein isolation (PVI) durability of two PVI verification methods (circumferential vs high-density mapping catheter) after catheter ablation of PAF. Methods Thirty-three patients with PAF were prospectively randomized to PVI verification by either circumferential mapping catheter (CM group) or HD mapping catheter (HD group). Patients in both groups underwent PVI according to the CLOSE protocol with PVI verification after a 30 minute waiting period. Additionally, in the HD group antral ablation lines were mapped to search for LFEGMs that were defined as fragmented signals (at least 3 deflections) and/or conduction to the LA during stimulation on the ablation line (10 mA at 1 msec) and/or voltage amplitude above 0.1 mV. If LFEGMs were found, additional ablations were performed until electrical inactivity was confirmed with the HD catheter. To monitor AF reccurence 6-day continuous holter ECG was performed after 3, 6, and 12 months after the initial procedure. Arrhythmia recurrence was defined as any atrial tachyarrhythmia lasting more than 30 seconds. Patients also underwent a mandatory second procedure 12 months after the initial PVI, during which HD re-mapping was performed to test durability of PVI and absence of conducting gaps in antral isolation lines. Results There were 16 patients in the CM group and 17 patients in the HD group. Baseline characteristics (gender, age, body mass index, LA volume index, left ventricular ejection fraction, CHA2DS2VASc score) did not significantly differ between the groups. Procedural characteristic are summarized in Table 1. There were significantly more isolated PVs at the remapping procedure in the HD group compared to the CM group (91.2% (62/68) vs 75.0% (48/64); P=0.021). There were also significantly more patients with all PVs durably isolated in the HD group (82.4% (14/17) vs 37.5% (6/16); P=0.008). However, arrhythmia recurrence rate was similiar between the CM and HD group (43.8% (7/16) vs 35.3% (6/17); P=0.640). Conclusion HD mapping improved PVI durability after 12 months compared to standard CM verification. However, lower number of isolated PVs in the HD group did not have an impact on arrhythmia reccurence.

Evaluation of an Optimized Workflow for the Radiofrequency Catheter Ablation of Paroxysmal Atrial Fibrillation.

BACKGROUND A significant number of atrial fibrillation (AF) recurrences occur after initial ablation, often due to pulmonary vein reconnections or triggers from non-pulmonary veins. MATERIAL AND METHODS Patients with paroxysmal AF who underwent radiofrequency catheter ablation for the first time were enrolled. Base on propensity score matching (1: 1 matching), 118 patients were selected for an optimized workflow for the radiofrequency catheter ablation of paroxysmal AF (OWCA) group and a conventional group. Comparative analysis of the acute and 12-month clinical outcomes was conducted. Moreover, an artificial intelligence analytics platform was used to evaluate the quality of pulmonary vein isolation (PVI) circles. RESULTS PVI was successfully achieved in all patients. Incidence of first-pass isolation of bilateral PVI circles was higher (P=0.009) and acute pulmonary vein reconnections was lower (P=0.027) in the OWCA group than conventional group. The OWCA group displayed a significant reduction in the number of fractured points (P<0.001), stacked points (P=0.003), and a greater proportion of cases in which the radiofrequency index achieved the target value (P=0.003). Additionally, the contact force consistently met the force over time criteria (P<0.001) for bilateral PVI circles in the OWCA group, accompanied by a shorter operation time (P=0.017). During the 12-month follow-up period, the OWCA group exhibited a higher atrial arrhythmia-free survival rate following the initial ablation procedure than did the conventional group. CONCLUSIONS The optimized workflow for radiofrequency catheter ablation of paroxysmal AF could play a crucial role in creating higher quality PVI circles. This improvement is reflected in a significantly elevated 12-month atrial arrhythmia-free survival rate.

Catheter ablation in general anesthesia reduces atrial fibrillation recurrence regardless of atrial fibrillation type

Abstract Background Treatment with catheter ablation (CA) as rhythm control is increasingly used in atrial fibrillation (AF). Short-term AF recurrence after first-time CA varies from 10-30% in paroxysmal AF (PAF) and up to 50% in persistent AF (PeAF). Strategies to optimize outcome is still an ongoing challenge. Whether the sedation strategy, conscious sedation (CS) or general anesthesia (GA), has any impact on AF recurrence has yet to be determined. Currently no guidelines are available regarding sedation strategy. Objective To investigate the impact of sedation strategy in CA for PAF and PeAF on AF recurrence. Method This nationwide retrospective registry study was conducted using large real-life data from Danish mandatory registries. All patients above 18 years, that underwent CA for AF from January 1st 2010 to December 31st 2018, were identified and included at the date of ablation. Exposure of interest was type of anesthesia, and patients were stratified into CS or GA. Primary endpoint was recurrent AF after a 3-months blanking period, defined by a composite endpoint of first-reached endpoint of either use of antiarrhythmic drugs (AAD), AF-admission, electrical cardioversions or AF re-ablation. 5-year risk of recurrent AF was examined by the Aalen-Johansen estimator, taking the competing risk of death into account. Subgroup analysis of PAF and PeAF was performed. Results The study cohort consisted of 6,423 patients with first-time CA. 3,958 patients with PAF and 2,465 patients with PeAF. 5,058 patients underwent the procedure in CS, and 1,365 in GA. 5-year cumulative incidence of recurrent AF was higher in the CS group for both PAF and PeAF with 49,3% and 58,9% respectively, compared to 39,0% for PAF and 46,2% for PeAF in the GA group (Figure 1). A total of 3,242 patients reached the primary endpoint. Admissions for AF was the predominant endpoint for both CS and GA (1323, 42,0%). When subdivided into PAF and PeAF, admission for AF was still the predominant endpoint (Table 1). Conclusion Reduction of AF recurrence after CA is a continuing challenge. This study shows that the sedation strategy is important, and that the risk of recurrence is significantly lower for CA performed in GA. Subgroup analysis of PAF and PeAF, shows that regardless of AF type, recurrence rates are significantly lower in the GA group.Figure 1Table 1

Atrial fibrillation progression after cryoablation vs. radiofrequency ablation: the CIRCA-DOSE trial.

Atrial fibrillation (AF) is a chronic progressive disorder. Persistent forms of AF are associated with increased rates of thromboembolism, heart failure, and death. Catheter ablation modifies the pathogenic mechanism of AF progression. No randomized studies have evaluated the impact of the ablation energy on progression to persistent atrial tachyarrhythmia. Three hundred forty-six patients with drug-refractory paroxysmal AF were enrolled and randomly assigned to contact-force-guided RF ablation (CF-RF ablation, 115), 4 min cryoballoon ablation (CRYO-4, 115), or 2 min cryoballoon ablation (CRYO-2, 116). Implantable cardiac monitors placed at study entry were used for follow-up. The main outcome was the first episode of persistent atrial tachyarrhythmia. Secondary outcomes included atrial tachyarrhythmia recurrence and arrhythmia burden on the implantable monitor. At a median of 944.0 (interquartile range [IQR], 612.5-1104) days, 0 of 115 patients (0.0%) randomly assigned to CF-RF, 8 of 115 patients (7.0%) assigned to CRYO-4, and 5 of 116 patients (4.3%) assigned to CRYO-2 experienced an episode of persistent atrial tachyarrhythmia (P = .03). A documented recurrence of any atrial tachyarrhythmia ≥30 s occurred in 56.5%, 53.9%, and 62.9% of those randomized to CF-RF, CRYO-4, and CRYO-2, respectively; P = .65. Compared with that of the pre-ablation monitoring period, AF burden was reduced by a median of 99.5% (IQR 94.0%, 100.0%) with CF-RF, 99.9% (IQR 93.3%-100.0%) with CRYO-4, and 99.1%% (IQR 87.0%-100.0%) with CRYO-2 (P = .38). Catheter ablation of paroxysmal AF using radiofrequency energy was associated with fewer patients developing persistent AF on follow-up.

Sex differences in paroxysmal atrial fibrillation catheter ablation: A difference-in-difference propensity score matched analysis.

Whether male and female patients with atrial fibrillation (AF) differ in their risk of recurrence after catheter ablation remains controversial. Large differences in baseline characteristics between males and females often affect study results. Patients with drug-refractory paroxysmal AF who received their first catheter ablation procedure between January 2018 and December 2020 were retrospectively enrolled. Propensity score matching was used to adjust for age, body mass index, and AF duration. Our main concerns were sex differences in comorbidities, procedures, arrhythmia recurrences, and procedure-related complications. For this study, 352 patients (176 pairs) were matched, and baseline characteristics were comparable between the two groups. Intraprocedural sex differences were apparent as more male patients received cavotricuspid isthmus ablation (55.00%vs. 31.43%, p=.005). Full follow-up, 1-year, 2-year, and 3-year AF recurrence rates were comparable between male and female groups. Multivariable Cox regression showed that the recurrence risk of paroxysmal AF was similar between male and female patients. AF duration was the only potential risk factor and occurred for only male patients. There were no significant differences in the subgroup analyses. Procedure-related complications were comparable between the male and female groups. We did not observe differences in baseline characteristics, arrhythmia recurrences, or procedure-related complications between male and female patients. Sex differences were reflected mainly in the finding that male patients received more cavotricuspid isthmus ablations, and atrial fibrillation duration was the only potential risk factor for recurrence and only for male patients.

Left atrium substrate and wave speed mapping using Omnipolar technology in patients undergoing paroxysmal atrial fibrillation catheter ablation

Abstract Funding Acknowledgements Type of funding sources: None. Background The new Ensite X Cardiac Mapping (Abbott) system, with the introduction of Omnipolar technology (OT), provides three-dimensional information on voltage, direction of activation and conduction velocity of endocardial potentials, regardless of catheter orientation. OT thus enables the creation of more defined voltage maps and a wave speed map, a color map encoded by the numerical value of conduction velocity. Purpose We aimed to evaluate the feasibility and reliability of left atrium (LA) substrate and wave speed mapsperformed with OT in patients undergoing pulmonary vein isolation of paroxysmal atrial fibrillation (AF). Methods We included 39 patients undergoing catheter ablation for paroxysmal AF with the new Ensite X Cardiac Mapping System at five Italian Institution. In all patients the left atrium (LA) was mapped with the Advisor HD Grid catheter (Abbott). A sinus rhythm high-density voltage map and wave speed map were obtained and analyzed to compare low-voltage areas and to identify high conduction velocity areas. Results Thirty-nine pts were included in this analysis (61±10 years, 64% male, 68% with paroxysmal AF, CHA2DS2-VASc = 1.6±1.1, left atrial diameter = 46±9 mm, left ventricle ejection fraction 63±4%). The voltage maps were obtained by acquiring and, after point validation, analyzing significantly more points in the OT analysis than in the bipolar analysis (11455±8833 vs 8186±5826 and 2611±1728 vs 1753±1324, respectively; p &amp;lt; 0.001). Low-voltage area (&amp;lt; 0.05 mV) was significantly less extensive using OT (low-voltage OT area 8.9 cm2 [5.8; 24.2] vs low-voltage bipolar area 10.8 [6.4; 31.4]; p &amp;lt; 0.05), Fig 1. Considering wave speed maps, the pulmonary veins showed significantly higher values than the atrial values (LSPV: 2.89 ms/s ± 1.99; LIPV 2.86 ms/s ± 1.78; RSPV 3.31 ms/s ± 2.07; RIPV 2.86 ms/s ± 1.96; LA 1.67 ms/s ± 0.80; p&amp;lt; 0.001) while, in the atrium, the area of greatest speed was located on the roof (2.35 ms/s ± 1.53; p 0.02) almost drawing a bundle from the RSPV to the LA appendage that could coincide with the anatomical Bachmann’s bundle location, Fig 2. Conclusion OT makes it possible to obtain voltage maps by analyzing a larger number of points and providing a better substrate definition. Wave speed mapping is a promising new map type, allowing characterization and identification of high velocity areas. Further studies are needed to assess the impact of this new technology on procedural workflow and clinical outcome.

PO-01-198 DOUBLE TROUBLE: HIGHER COMPLICATIONS AND INCREASED PROCEDURE TIMES WITH DOUBLE TRANSEPTAL PUNCTURE

The three main techniques for transeptal access during catheter ablation (CA) of atrial fibrillation (AF) are double transeptal puncture (DTP), single transeptal puncture (STP), and single transeptal puncture with double access (STP-DA). It is unclear which of these techniques is the safest and most effective. To evaluate the periprocedural outcomes of DTP, STP, and STP-DA in patients undergoing first-time catheter ablation for paroxysmal atrial fibrillation. Consecutive patients undergoing first-time catheter ablation for paroxysmal AF performed by 67 operators in 43 centers were prospectively enrolled in the REAL-AF registry. The primary outcomes were procedural time and periprocedural complications. A total of 2,289 patients were included in the study. 379 underwent DTP, 612 underwent STP, and 1298 underwent STP-DA. The mean age was 65±10 years, 55% were male, the mean BMI was 30±7 kg/m2, and the mean CHA2DS2VASc score was 2.5±1.52 without statistically significant differences among the groups. Procedural time was 137.9±72.5 min. for DTP, 97.7±39.1 min. for STP, and 74±28.9 min. for STP-DA, with significant differences in ANOVA and independent t-test (p<0.001). Similarly, fluoroscopy time was 2.5±3.0 min for DTP, 1.8±2.0 min for STP, and 0.9±1.1 min for STP-DA, with significant differences in ANOVA and independent t-test (p<0.01). The complication rate was significantly higher in DTP compared to STP (1.3% vs. 0.2% | p=0.033), while there was no difference when comparing STP to STP-DA (1.3% vs. 0.7% | p=0.18). The use of DTP is associated with increased procedural time compared to STP or STP-DA. It is also associated with a significantly higher complication rate compared to STP. Interestingly, STP-DA was associated with a significant reduction in procedural times compared to STP, potentially due to the elimination of catheter exchange during the procedure.

PO-01-041 COMPARISON OF DIFFERENT POWER SETTINGS (40W VS 50W) IN HIGH-POWER SHORT-DURATION RADIOFREQUENCY ABLATION FOR PAROXYSMAL ATRIAL FIBRILLATION: ACUTE AND LONG-TERM CLINICAL OUTCOMES

The REAL-AF registry is a prospective multi-center registry designed to obtain real-world clinical experience of atrial fibrillation (AF) ablations. While pulmonary vein isolation (PVI) can be performed successfully with various power settings, there has been a recent surge of interest in delivering higher power short duration (HPSD) lesions using 40W-50W through the irrigated tip ablation catheters. However, the ideal power setting to deliver HPSD lesions is unknown. Compare the procedural characteristics, safety and long-term all-atrial arrhythmia recurrence between patients undergoing HPSD radiofrequency ablation either using 40W or 50W. We analyzed the data derived from subjects in the Real-AF registry from January 2018 through May 2021. The patients enrolled underwent a first-time catheter ablation for paroxysmal AF with a minimum follow-up of 12 months. The sample of patients was dichotomized in procedures using either HPSD 50 W or HPSD 40 W of power, with a target ablation index (AI) in the anterior wall of 500-550 and posterior wall of 400 for both groups. We used unadjusted bivariate analyses to explore the relationship between power delivery, patient characteristics and procedural and 12-month clinical outcomes. A total of 385 patients were included in the analyses. There were no significant differences in patient characteristics between groups (Table 1). The HPSD 50W group had significantly shorter RF time (18.69 vs. 29.21, p<0.001) and procedural time (77.72 vs. 99.98, p<0.01) when compared to the LPLD group. There were no statistically significant differences between HPSD 50 W and HPSD 40W for first-pass PVI and no clinically significant differences in the target ablation index between the groups. When looking at all -atrial arrhythmia recurrence documented post-blanking period at 12 months, there was no statistically significant relationship (p=0.925) between groups. There was no statistically significant relationship between immediate procedural complications, pericarditis, or complications at 12 months post-ablation (p>0.05). The esophageal temperature measurements were not different between groups. HPSD is a safe and effective way of performing radiofrequency ablation of AF. HPSD using 50W was associated with shorter RF ablation and procedural times when compared to HPSD 40W without increase in complications HPSD 50W and HPSD 40W had similar acute and long-term success rates.

Efficacy of catheter ablation for atrial fibrillation in patients with significant functional mitral regurgitation.

Catheter ablation has been established to be an effective therapy for paroxysmal atrial fibrillation (AF) and is recommended as the treatment of choice for many patients, including those with clinically significant functional mitral regurgitation (MR). However, there is little information available about the clinical efficacy of catheter ablation for paroxysmal AF in patients with significant functional MR. We performed a retrospective study of 247 patients with paroxysmal AF who underwent AF ablation. The study included 28 (11.3%) patients with significant functional MR and 219 (88.7%) without significant functional MR. AF recurrence was defined as the occurrence of confirmed atrial tachyarrhythmia lasting >30 seconds beyond 3 months after catheter ablation. During a mean follow-up of 20.1 ± 7.4 months (range, 3-36 months), 45 (18.2%) patients developed recurrence of AF. The recurrence rate of AF was higher in patients with significant functional MR than in those without significant functional MR (42.9% vs 15.1%; P < .001). Univariable Cox proportional hazards regression analysis showed that significant functional MR (hazard ratio [HR], 3.46; 95% confidence interval [CI], 1.78-6.72; P < .001), age (HR, 1.04; 95% CI, 1.01-1.08; P = .009), the CHA2DS2-VASc score (HR, 1.28; 95% CI, 1.05-1.56; P = .017), and heart failure (HR, 4.71; 95% CI, 1.85-11.96; P = .001) were associated with the risk of recurrence. Multivariable analysis showed that significant functional MR (HR, 2.48; 95% CI, 1.21-5.05; P = .013), age (HR, 1.04; 95% CI, 1.00-1.07; P = .031), and heart failure (HR, 3.39; 95% CI, 1.27-9.03; P = .015) were independent predictors of AF recurrence. Patients with significant functional MR have an increased risk of AF recurrence after catheter ablation.

Periodontitis was associated with worse clinical outcomes after catheter ablation for paroxysmal atrial fibrillation.

Periodontitis (PD), a common chronic inflammatory disease, may be associated with the subsequent development of atrial fibrillation (AF) through a mechanism of systemic inflammation. However, little is known about the impact of PD on the recurrence of atrial fibrillation after catheter ablation (CA). A total of 132 patients (age 62.2 ± 10.6 years; 72.7% male) who underwent periodontal examinations and the first CA for paroxysmal atrial fibrillation (PAF) were investigated. Clinical periodontal examination was performed by independent trained periodontists, and patients were diagnosed with PD when the maximum periodontal probing depth was equal to or greater than 4 mm and bleeding on probing was evident. Of these, 71 patients (54%) were categorized as those with PD (PD group) and the other 61 (46%) as those without PD (non-PD group). Pulmonary vein isolation was performed in a standard fashion. Kaplan-Meier curve analysis revealed worse atrial arrhythmia recurrence-free survival probabilities after CA for PAF in the PD group than in the non-PD group (64.8% versus 80.3%, respectively; p = 0.024) during a median follow-up period of 3.0 (interquartile range: 1.1-6.4) years. Cox regression analysis revealed PD as a significant predictor of arrhythmia recurrence (hazard ratio: 2.063, 95% confidence interval: 1.018-4.182), after adjusting for age and gender. Periodontitis was independently associated with an increased risk of arrhythmia recurrence after the first CA for PAF. Our results may suggest that the periodontal status is potentially a modifiable determinant of the outcomes after PAF ablation, and further prospective studies are warranted.

High epicardial fat volume is associated with atrial fibrillation recurrences after catheter ablation

Abstract Background Pulmonary vein isolation (PVI) is the cornerstone of catheter ablation therapy for atrial fibrillation (AF). However, even with important technological improvements, AF recurrences are common in long-term follow-up. Recently, epicardial fat tissue (EFT) has been proposed as a potential AF modulator promoting and sustaining atrial arrhythmogenic milieu. Aim In this retrospective single-centre study, we sought to evaluate the association between CT-quantified EFT volume and long-term primary PVI outcome assed by means of continuous ECG monitoring with implantable loop recorders (ILR) in paroxysmal AF patients. Methods A cohort of 92 patients (median age 60.2 [IQR 51.9–64.0]; 74% male) with paroxysmal AF (a single persistent AF episode was accepted) undergoing catheter ablation targeted at PVI was analysed. Prior to CA all patients underwent cardiac CT imaging with subsequent implantation of implantable loop recorder (ILR). Radiofrequency CA ablation with electro-anatomical mapping for PVI was used in 79 patients, balloon cryoablation was used in 13 patients. Verified complete PVI was defined as procedural endpoint. EFT volume was semi-automatically segmented and quantified on contrast enhanced CT studies. AF recurrence, defined as AF burden &amp;gt;0.1% after the blanking period (90 days), was continuously assessed by ILR. Kaplan-Meier analysis of AF recurrence-free survival at 1-year, 2-year and 3-year follow-up periods compared patients stratified into EFT volume tertiles. Results During a median follow-up of 52.6 months [IQR 43–64], AF recurrence was detected in 58 (63%) patients, 29 (50%) of them underwent a repeat ablation. Patients in high, mid, and low total EFT volume tertiles had a median time to late AF recurrence of 154, 373, and 284 days (Fig. 1A). At a 1-year follow-up, patients in the high EFT volume tertile had the worst AF ablation outcome (p=0.023). However, this difference gradually faded-out and became non-significant at 2 and 3 years. ROC analysis revealed an EFT of 95 ml as an optimal cut-off (p=0.002) for expected arrhythmia recurrence post acutely successful PVI (Fig. 1B). Conclusion EFT volume quantification in a relatively homogenous, continuously monitored cohort of patients undergoing catheter ablation for paroxysmal AF revealed a significant association between AF recurrence at 1 year post ablation and volume of epicardial fat. These results suggest a possible role of epicardial adipose tissue as an adverse pro-fibrillatory factor. Identified EFT volume cut-offs have to be validated prospectively on a larger and balanced patient population. Funding Acknowledgement Type of funding sources: None.

The hemodynamic effect of simulated atrial fibrillation on left ventricular function.

Atrial fibrillation (AF) is the most common sustained arrhythmia in humans. The onset of the arrhythmia can significantly impair cardiac function. This hemodynamic deterioration has been explained by several mechanisms such as the loss of atrial contraction, shortening of ventricular filling, or heart rhythm irregularity. This study sought to evaluate the relative hemodynamic contribution of each of these components during in vivo simulated human AF. Twelve patients undergoing catheter ablation for paroxysmal AF were paced simultaneously from the proximal coronary sinus and the His bundle region according to prescribed sequences of irregular R-R intervals with the average rate of 90and 130 bpm, which were extracted from the database of digital ECG recordings of AF from other patients. The simulated AF was compared to regular atrial pacing with spontaneous atrioventricular conduction and regular simultaneous atrioventricular pacing at the same heart rate. Beat-by-beat left atrial and left ventricular pressures, including LV dP/dT and Tau index were assessed by direct invasive measurement; beat-by-beat stroke volume and cardiac output (index) were assessed by simultaneous pulse-wave doppler intracardiac echocardiography. Simulated AF led to significant impairment of left ventricular systolic and diastolic function. Both loss of atrial contraction and heart rate irregularity significantly contributed to hemodynamic impairment. This effect was pronounced with increasing heart rate. Our findings strengthen the rationale for therapeutic strategies aiming at rhythm control and heart rate regularization in patients with AF.

Outcome of catheter ablation for paroxysmal atrial fibrillation in patients with stable coronary artery disease.

Atrial fibrillation (AF) and stable coronary artery disease (SCAD) frequently coexist. This study aimed to assess the long-term outcome of catheter ablation in patients with paroxysmal AF and SCAD. In total, 12,104 patients with paroxysmal AF underwent catheter ablation in the Chinese Atrial Fibrillation Registry between 2011 and 2019 were screened. A total of 441 patients with SCAD were matched with patients without SCAD in a 1:4 ratio. The primary endpoint was AF recurrence after single ablation. The composite secondary endpoints were thromboembolism, coronary events, major bleeding, all-cause death. Over a mean follow-up of 46.0±18.9 months, the recurrence rate in patients with SCAD was significantly higher after a single ablation (49.0%vs. 41.9%, p=.03). The very late recurrence rate of AF in the SCAD group was also significantly higher than that in the control group (38.9%vs. 31.2%;p=.04). In multivariate analysis, adjusted with the female, smoking, duration of AF, previous thromboembolism, COPD, and statins, SCAD was independently associated with AF recurrence (adjusted HR, 1.19 [1.02-1.40], p=.03). The composite secondary endpoints were significantly higher in the SCAD group (12.70%vs. 8.54%, p=.02), mainly due to thromboembolism events (8.16%vs. 4.41%, p<.01). SCAD significantly increased the risk of recurrence after catheter ablation of paroxysmal AF. The incidence of thromboembolic events after catheter ablation of paroxysmal AF in the patients with SCAD was significantly higher than that in those without SCAD.

Long-Term Outcomes of Pulmonary Vein Isolation in Patients With Brugada Syndrome and Paroxysmal Atrial Fibrillation.

BackgroundPharmacological treatment of atrial fibrillation (AF) in the setting of Brugada syndrome (BrS) is challenging. In addition, patients with BrS with an implantable cardioverter‐defibrillator (ICD) might experience inappropriate shocks for fast AF. Long‐term outcome of pulmonary vein isolation in BrS has not been well established yet, and it is still unclear whether pulmonary vein triggers are the only pathophysiological mechanism of AF in BrS. The aim of the study is to assess the long‐term outcomes in patients with BrS undergoing pulmonary vein isolation for paroxysmal AF compared with a matched cohort of patients without BrS.Methods and ResultsSixty patients with BrS undergoing pulmonary vein isolation with cryoballoon catheter ablation for paroxysmal AF were matched with 60 patients without BrS, who underwent the same procedure. After a mean follow‐up of 58.2±31.7 months, freedom from atrial tachyarrhythmias was achieved in 61.7% in the BrS group and in 78.3% in the non‐BrS group (log‐rank P=0.047). In particular, freedom from AF was 76.7% in the first group and in 83.3% in the second (P=0.27), while freedom from atrial tachycardia/atrial flutter was 85% and 95% (P=0.057). In the BrS group, 29 patients (48.3%) had an ICD and 8 (27.6%) had a previous ICD‐inappropriate shock for fast AF. In the BrS cohort, ICD‐inappropriate interventions for AF were significantly reduced after ablation (3.4% versus 27.6%; P=0.01).ConclusionsPulmonary vein isolation in patients with BrS was associated with higher rate of arrhythmic recurrence. Despite this, catheter ablation significantly reduced inappropriate ICD interventions in BrS patients and can be considered a therapeutic strategy to prevent inappropriate device therapies.

Pulmonary vein isolation with high power, short duration ablation leads to shorter procedure times associated with high success rates: a Prospective Randomized Trial

Abstract Funding Acknowledgements Type of funding sources: None. Background The single procedure success rates of durable pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF) varies between 85 and 90 %. This prospective, randomized study investigated the efficacy of high power, short duration ablation in a temperature-controlled mode versus standard power settings in terms of single-procedure arrhythmia-free outcome, safety and procedural time. Methods and results A total number of 176 patients undergoing de-novo catheter ablation for paroxysmal AF were randomized to two different treatment arms. In group-A patients, PVI was performed with RF-energy with standard power settings of 30 Watts in a temperature-controlled mode. The ablation procedure in group B was performed with RF-energy with higher power settings of 45 Watts. In both groups the ablation was performed with ablation index (AI) and following the CLOSE protocol (Biosense Webster Thermocool STSF). A total of 88 patients were randomized into each group without significant differences in baseline characteristics. During a mean follow-up of 12 ± 4 months after a single procedure, 79 (90%) patients of group A were free of arrhythmia recurrence versus 82 (93 %) patients in group B (p=ns). With regard to the procedural data, the procedure time was significantly shorter in group B (115.35 ± 15.38 versus 96.45 ± 17.19; p&amp;lt;0.01), the flouroscopy time and dose area were also significantly lower in Group B (9.66 ± 3.86 vs 5.45 ± 2.35; 330.84 ± 150.36 vs 202.51 ± 135.23) and total ablation times were significantly shorter in group B ((Table 1). Both procedures were performed with a low number of complications, no pericardial effusion was seen in either group, in both groups two patients had a significant hematoma of the groin with the need of surgical repair. Conclusions RF-ablation with high power (45 Watts) in combination with ablation index and following the CLOSE protocol leads to shorter procedure times, a lower total ablation time and a good safety profile.

Conduction velocity mapping in Bachmann Bundle using Omnipolar Technology

Abstract Funding Acknowledgements Type of funding sources: None. Background Bachmann’s bundle is emerging as a critical component of atrial fibrillation (AF) catheter ablation (CA). The introduction of Omnipolar Technology (OT) in the new Ensite X Cardiac Mapping system, provides three-dimensional information on conduction velocity, activation direction and voltage of endocardial potentials, independently of catheter orientation. OT can create a wave speed map: a color map type coded by numeric value of conduction velocity. Objective To assess the feasibility and reliability of left atrium wave speed maps in Bachmann’s bundle identification and conduction velocity characterization. Methods We included 10 patients, (60% male, 40% female, mean age 56±8.7 years) undergoing CA for paroxysmal AF at our institution with new Ensite X Cardiac Mapping System; the left atrium (LA) was mapped with the Advisor HD Grid catheter. A sinus rhythm voltage map and wave speed map were obtained and analyzed to identify high conduction velocity areas throughout the Bachmann’s bundle location (septum, roof and left atrium appendage (LAA)). Results Wave speed mapping allowed the identification, at the septum, roof and LAA, of a myocardial bundle with greater speed values (2.5±0.3 m/s) with respect to mean atrial value (1±0.1). Pulmonary vein antra conduction velocity mean value was 1.2±0.4 m/s. Standard voltage map (low-voltage areas defined as any LA region with voltage values &amp;lt; 0.5 mV) was compared with wave speed map. Standard voltage map (Figure 1) did not discriminate Bachmann’s bundle, while wave speed map did (Figure 2). Conclusion Wave speed mapping introduced by OT is a promising new map type, allowing characterization and identification of Bachmann’s bundle. Further studies are needed to assess the impact of this new technology on procedural workflow and clinical outcome.

Improved procedural workflow for catheter ablation of paroxysmal AF with high-density mapping system and advanced technology: Rationale and study design of a multicenter international study.

BackgroundThe antral region of pulmonary veins (PV)s seems to play a key role in a strategy aimed at preventing atrial fibrillation (AF) recurrence. Particularly, low‐voltage activity in tissue such as the PV antra and residual potential within the antral scar likely represent vulnerabilities in antral lesion sets, and ablation of these targets seems to improve freedom from AF. The aim of this study is to validate a structured application of an approach that includes the complete abolition of any antral potential achieving electrical quiescence in antral regions.MethodsThe improveD procEdural workfLow for cathETEr ablation of paroxysmal AF with high density mapping system and advanced technology (DELETE AF) study is a prospective, single‐arm, international post‐market cohort study designed to demonstrate a low rate of clinical atrial arrhythmias recurrence with an improved procedural workflow for catheter ablation of paroxysmal AF, using the most advanced point‐by‐point RF ablation technology in a multicenter setting. About 300 consecutive patients with standard indications for AF ablation will be enrolled in this study. Post‐ablation, all patients will be monitored with ambulatory event monitoring, starting within 30 days post‐ablation to proactively detect and manage any recurrences within the 90‐day blanking period, as well as Holter monitoring at 3, 6, 9, and 12 months post‐ablation. Healthcare resource utilization, clinical data, complications, patients' medical complaints related to the ablation procedure and patient's reported outcome measures will be prospectively traced and evaluated.DiscussionThe DELETE AF trial will provide additional knowledge on long‐term outcome following a structured ablation workflow, with high density mapping, advanced algorithms and local impedance technology, in an international multicentric fashion. DELETE AF is registered at ClinicalTrials.gov (NCT05005143).

The Dissimilar Impact in Atrial Substrate Modificationof Left and Right Pulmonary Veins Isolation after Catheter Ablation of Paroxysmal Atrial Fibrillation.

Since the discovery of pulmonary veins (PVs) as foci of atrial fibrillation (AF), the commonest cardiac arrhythmia, investigation revolves around PVs catheter ablation (CA) results. Notwithstanding, CA process itself is rather neglected. We aim to decompose crucial CA steps: coronary sinus (CS) catheterization and the impact of left and right PVs isolation (LPVI, RPVI), separately. We recruited 40 paroxysmal AF patients undergoing first-time CA and obtained five-minute lead II and bipolar CS recordings during sinus rhythm (SR) before CA (B), after LPVI (L) and after RPVI (R). Among others, duration, amplitude and atrial-rate variability (ARV) were calculated for P-waves and CS local activation waves (LAWs). LAWs features were compared among CS channels for reliability analysis. P-waves and LAWs features were compared after each ablation step (B, L, R). CS channels: amplitude and area were different between distal/medial () and distal/mid-proximal channels (). Medial and distal showed the most and least coherent values, respectively. Correlation was higher in proximal (≥93%) than distal (≤91%) areas. P-waves: duration was significantly shortened after LPVI (after L: ). LAWs: insignificant variations. ARV modification was more prominent in LAWs (L: >+73.12%, , R: <−33.94%, ). Medial/mid-proximal channels are recommended during SR. CS LAWs are not significantly affected by CA but they describe more precisely CA-induced ARV modifications. LPVI provokes the highest impact in paroxysmal AF CA, significantly modifying P-wave duration.

Pulmonary vein isolation using cryoballoon ablation versus RF ablation using ablation index following the CLOSE protocol: A prospective randomized trial.

The single procedure success rates of durable pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF) varybetween 80% and 90%. This prospective, randomized study investigated the efficacy of cryoballoon PVI (CBA) versus PVI with radio-frequency (RF)-energy following the CLOSE protocol (ablation index [AI], interlesion distance ≤6 mm, surround flow catheter) in terms of single-procedure arrhythmia-free outcome and safety. A total number of 150 patients undergoing de novo catheter ablation for paroxysmal AF were randomized to two different treatment arms. In group A patients, PVI was performed with the 23 or 28 mm cryoballoon (Artic Front™Balloon in conjunction with an Achieve Mapping Catheter, Medtronic Inc.). The ablation procedure in group B was performed with RF-energy, using AI and following the CLOSE protocol. PVI using AI incorporates stability, contact force (CF), time, and power. The CLOSE protocol combines AI and ≤6 mm interlesion distance using a surround flow catheter (Biosense Webster Thermocool STSF). A total of 75 patients were randomized into each group without significant differences in baseline characteristics. During a mean follow-up of 12 ± 4.5 months after a single procedure, 64 (85.33%) patients of group A were free of arrhythmia recurrence versus 65 (86.67%) patients in group B (p = ns). A total of 14 patients (group A: 7 [9.33%]; group B: 7 [9.33%]; p = ns) underwent a redo-procedure. No significant difference between both groups was observed in terms of PV recovery (group A: 4 [5.33%] vs. group B: 3 [4%]; p = ns). In two patients of group A and four patients of group B, the PVs were durably isolated, whereas the patients had AF recurrence caused by extra-PV AF sources. Two patients of each group had continued paroxysmal AF but did not undergo redo-procedure. Patients of group A showed significantly more AF recurrence during the blanking period of 3 months (group A: 14 [18.67%] vs. group B: 6 [8%]; p < .05). With regard to the procedural data, the procedure time was significantly shorter in group A (70.53 ± 16.13 vs. 115.35 ± 15.38; p < .01); the flouroscopy time and dose area product showed no significant differences (Table 2). Both procedures were performed with a low number of complications; no pericardial effusion was seen in either group; in group A two patients had a significant hematoma of the groin with the need for surgical repair. Cryoballoon PVI and PVI using ablation index following the CLOSE protocol are equally efficient in achieving durable PV isolation. In this study, cryoballoon ablation led to significantly more AF recurrence during the blanking period.

Increase in heart rate-dependent left atrial pressure is associated with symptoms in patients with paroxysmal atrial fibrillation.

It remains unclear why some patients with the same heart rate during an atrial fibrillation (AF) have subjective symptoms, whereas others do not. We assessed the hypothesis that different responses of arterial and left atrial blood pressures to rapid stimulation may be associated with the symptoms of AF. A total of 110 patients who underwent catheter ablation for paroxysmal AF were retrospectively studied. Asymptomatic AF was defined as a European Heart Rhythm Association score of Ⅰ for AF-related symptoms. The left atrial pressure (LAP) was measured during sinus rhythm (SR), in 10 pacing per minute (ppm) increments from 100 ppm to the Wenckebach block rate in high right atrial pacing. Asymptomatic AF was observed in 19/110 patients (17%). Patients with symptomatic AF showed higher E/e' ratio and gradual LAP increase that was dependent on the pacing rate. Patients with asymptomatic AF had decreased LAP at 100 ppm compared that at SR, and thereafter, LAP gradually increased depending on the pacing rate. The rate of LAP change compared to that at SR was significantly lower in patients with asymptomatic AF than that in patients with symptomatic AF. The rate of LAP change was independently associated with AF symptoms. Patients with asymptomatic AF showed lower E/e' ratio and decreased LAP at 100 ppm to rapid stimulation, followed by a steady increase in LAP afterwards. Factors other than left ventricular diastolic dysfunction may be involved in AF symptoms.