Conventional Pulmonary Vein Isolation Research Articles

Voltage-guided Pulmonary Vein Isolation for Atrial Fibrillation

BackgroundBipolar voltage amplitude is capable of helping determine the ideal lesion size index (LSI) setting during radiofrequency (RF) ablation for atrial fibrillation (AF). ObjectiveTo determine whether voltage-guided pulmonary vein isolation (PVI) is noninferior to conventional LSI-guided PVI in patients with nonvalvular AF. MethodsThis was a multicenter randomized trial conducted over a period of 12 months. The primary efficacy endpoints of the study were AF recurrence, atrial flutter, and/or atrial tachycardia, and the noninferiority margin was set at a hazard ratio of 1.4. The primary safety end point was a composite of procedure-related complications. ResultsA total of 370 patients underwent randomization; 189 and 181 were assigned to the voltage (underwent voltage-guided PVI) and control (underwent conventional LSI-guided PVI) groups, respectively. The primary efficacy endpoint occurred in 22 patients (12.0%) in the voltage group and 23 (12.9%) in the control group (1-year Kaplan–Meier event-free rate estimates, 88.0% and 87.1%, respectively; hazard ratio, 1.00; 95% confidence interval [CI], 0.80 1.25). The primary safety endpoints were 4.8% in the voltage group and 6.6% in the control group (p = 0.2791). PVI time was significantly shorter in the voltage group (35.7 ± 14.5 min vs. 39.7 ± 14.7 min, p < 0.001). ConclusionVoltage-guided PVI was noninferior to conventional LSI-guided PVI with respect to efficacy in the treatment of patients with AF and its use significantly reduced procedure time.

Superior vena cava isolation in paroxysmal atrial fibrillation - mind the phrenic

Abstract Background Pulmonary vein isolation (PVI) is the standard of care for patients with atrial fibrillation (AF), but medium-term success rates are far from ideal. Therefore, new methods are being developed, with emphasis on ectopic foci outside the pulmonary veins. Superior vena cava (SVC) is one of the most important non-pulmonary origins of AF and some studies suggested that empiric SVC isolation could improve outcomes in ablation of paroxysmal atrial fibrillation (PAF). Although complications have been reported in SVC ablation, most studies found complication rates of SVC ablation similar to conventional cryoballoon PVI. Aim This prospective, single-center study aimed to assess the complication rate and success rate of PVI followed by SVC isolation by cryoballoon application in comparison with conventional cryoballoon PVI. Methods We designed an unblinded, randomized clinical trial and recruited consecutive patients with PAF who were randomized to a conventional cryoballoon PVI or PVI and additional SVC cryoballoon isolation using single 180 s freeze. Results A total of 140 patients (61.4% male, mean age 62.1 years) with PAF were included and 67 (47.9%) were randomized to SVC isolation in addition to conventional ablation. Planned 180-s freeze in the SVC could be completed in 15 (22.4%) patients, while 27 (40.3%) patients received at least 120-s freeze. The mean time to SVC isolation was 40.2 ± 37.9 s. Real-time recording of SVC isolation was observed in 39 (58.2%) patients. Right phrenic nerve palsy (PNP), impending or transient, occurred in 6 (8.2%) patients in the PVI-only group and in 25 (37.3%) patients in the SVC-group (Chi-square test p &amp;lt; 0.001). There were no persistent PNP cases. Bradycardia or junctional rhythm was observed during a procedure in 15 (22.4%) patients who received SVC isolation. One patient eventually received a permanent AAI pacemaker due to a sinus node injury. Conclusion Our data suggest that SVC isolation can be successfully achieved in the majority of PAF patients using conventional cryoballoon. However, this significantly increases the rate of transient or impending PNP and sinus node injury in comparison to conventional cryoballoon PVI. Therefore, careful phrenic nerve function monitoring and attention to sinus bradycardia or junctional rhythm are important to mitigate this risk. Follow-up data are being collected to determine whether this risk could be outweighed by a lower rate of PAF recurrence.

Incidence and impact on arrhythmia recurreces of atrial fibrillation termination during linear radiofrequency ablation in the left atrium

Abstract Atrial Fibrillation Termination During Linear Radiofrequency Ablation in the Left Atrium: Incidence and Impact on Arrhythmia Recurrences Background Termination of atrial fibrillation (AF) during persistent atrial fibrillation (peAF) ablation is infrequent and has shown no clear association with reduced recurrences during follow-up. Linear ablation, often considered to have minimal impact on efficacy, has been primarily explored through creating ablation lines from the mitral annulus to the inferior pulmonary vein or by isolating the posterior wall. Purpose This study aims to assess the incidence of AF termination using an alternative linear ablation approach and its correlation with arrhythmia recurrence during follow-up. Methods Patients enrolled in the PowerFast III trial (a multicenter randomized trial comparing high- power short-duration radiofrequency (RF) application to conventional RF application) with peAF and undergoing linear ablation were included in this sub-study. Conventional pulmonary vein isolation (PVI) was performed using two different RF settings along with a set of RF lines, including anteroseptal (AS), anterolateral (AL), posterior wall isolation between the pulmonary veins, and between the two anterior lines. Patients were categorized into two groups based on AF termination or flutter organization (Group 1) or no AF termination (Group 2) during RF application. All patients were monitored with EKG transmission for one year. Results Fifty-one consecutive patients (mean age 61 years, male 39) were included. AF terminated in 21 patients (41%) during RF application (9 converting to AF and 12 to atrial flutter). AF did not terminate during RF application for PVI, except for one patient during right PV ablation following left PVI. AF termination occurred by posterior wall lines in three patients, roof line in three, and anterior line in two. AF converted into atrial flutter during ablation by a roof line in 5 patients and by an anterior line in 7. No significant differences in atrial arrhythmia recurrence were observed between the two groups (three patients in Group 1 vs. eleven in Group 2, P = 0.11). However, Group 1 exhibited fewer AF recurrences (zero patients) than Group 2 (eight patients, P = 0.015). Conclusions Extensive linear RF ablation resulted in a substantial proportion of patients experiencing AF termination or conversion into atrial flutter. AF termination or conversion did not appear to be correlated with atrial arrhythmia freedom during follow-up but was associated with fewer AF recurrences.Any arrhythmia recurrenceAF recurrence

One-year outcomes of wide antral cryoballoon ablation guided by high-density mapping vs. conventional cryoballoon ablation for atrial fibrillation: a propensity score-matched study.

Pulmonary vein isolation with wide antral ablation leads to better clinical outcomes for the treatment of atrial fibrillation, but the isolation lesion is invisible in conventional cryoballoon ablation. In this study, we aim to investigate the efficacy of the wide pulmonary vein isolation technique that includes the intervenous carina region, guided by high-density mapping, compared with pulmonary vein isolation alone without the mapping system. We conducted a propensity score-matched comparison of 74 patients who underwent a wide cryoballoon ablation guided by high-density mapping (mapping group) and 74 controls who underwent conventional cryoballoon ablation in the same period (no-mapping group). The primary outcome was a clinical recurrence of documented atrial arrhythmias for >30 s during the 1-year follow-up. Of 74 patients in the mapping group, residual local potential in the pulmonary vein antrum was found in 30 (40.5%) patients, and additional cryothermal applications were performed to achieve a wide pulmonary vein isolation. Compared with the no-mapping group, the use of the mapping system in the mapping group was associated with a longer fluoroscopic time (26.97 ± 8.07 min vs. 23.76 ± 8.36 min, P = 0.023) and greater fluoroscopic exposure [339 (IQR181-586) mGy vs. 224 (IQR133-409) mGy, P = 0.012]. However, no significant differences between the two groups were found in terms of procedural duration and left atrial dwell time (104.10 ± 18.76 min vs. 102.45 ± 21.01 min, P = 0.619; 83.52 ± 17.01 min vs. 79.59 ± 17.96 min, P = 0.177). The rate of 12-month freedom from clinical atrial arrhythmia recurrence was 85.1% in the mapping group and 70.3% in the no-mapping group (log-rank P = 0.029). Voltage and pulmonary vein potential mapping after cryoballoon pulmonary vein isolation can identify residual potential in the pulmonary vein antrum, and additional cryoablation guided by mapping leads to improved freedom from atrial arrhythmias compared with conventional pulmonary vein isolation without the mapping system. ChiCTR2200064383.

Left atrial fibrosis-guided ablation in patients with atrial fibrillation: a systematic review and meta-analysis of randomized trials

Abstract Background Left atrial fibrosis is related to atrial fibrillation (AF) recurrence after AF ablation. However, the benefit of patient-specific substrate modification guided by fibrosis delineated on voltage mapping or magnetic resonance imaging (MRI) is conflicting. Objective To compare the efficacy and safety of additional modification of left atrial fibrosis [identified by low-voltage area (LVA) or late gadolinium-enhancement on MRI] vs. circumferential pulmonary vein isolation (PVI) with or without stepwise ablation not targeting fibrosis in AF. Methods A systematic search of PubMed, EMBASE, and Cochrane Central Register of Controlled Trials was performed from inception to November 2022. Only randomized studies investigating the utility of fibrosis-guided substrate modification beyond conventional PVI were included. The primary outcome was a recurrence of any atrial arrhythmia. Major adverse events and procedural, fluoroscopic, and total ablation time were defined as secondary outcomes. We calculated pooled estimates of the outcomes by a random-effect model and reported them as risk ratio (RRs) and 95% confidence interval (CI). Results A total of 9 studies (8 randomized controlled clinical trials and 1 randomized design within a prospective study) and 2135 patients with AF were included. The atrial arrhythmia recurrence was lower in the additional fibrosis-guided ablation group (RR 0.82; 95% CI 0.71-0.94; p=0.006) (Figure 1A). No differences were found between fibrosis-guided substrate modification and conventional PVI group in major adverse events [RR 1.25 (0.55-2.81), p=0.598)] and mean differences of procedural time [-2.88 (-40.34 to 34.57) min], fluoroscopic time [1.82 (-1.86 to 5.49) min], and total ablation time [-14.28 (-48.70 to 20.14) min]. In the stratified analyses, there were no interactions of the lower atrial arrhythmia recurrences within the modality of fibrosis identification (LVA vs. delayed enhancement on MRI), type of AF (paroxysmal vs. persistent), the burden of LVA (no or low vs. high), and strategy of the control group (PVI only vs. PVI plus stepwise ablation) (Figure 1B). Conclusion By incorporating two modalities of left atrial substrate evaluation – voltage mapping and MRI – we conclude that the individually tailored fibrosis-guided ablation in AF is associated with a lower recurrence after catheter ablation.

Comparison of myocardial injury and inflammation between ablation index-guided and conventional contact force-guided ablation in atrial fibrillation patients

Abstract Background Ablation index (AI)-guided ablation improves the incidence of arrhythmia recurrence as compared to conventional contact force (CF)-guided ablation. Purpose The aim of this study was to elucidate the differences in the biomarkers associated with myocardial injury and inflammation between conventional CF-guided and AI-guided ablation. Methods Atrial fibrillation (AF) patients who underwent pulmonary vein isolation (PVI) from the Osaka Rosai Atrial Fibrillation ablation (ORAF) registry were enrolled. We divided the patients into two groups: conventional CF-guided PVI (CF group) and AI-guided PVI (AI group). The differences in biomarkers associated with myocardial injury and inflammation, and long-term durability of PVI between the two groups were evaluated. Results This study population included a total of 794 patients (CF-guided, 241 patients; AI-guided, 553 patients). Total application time was significantly shorter, and total application number was significantly smaller in AI than CF group. High-sensitive troponin I (hs-TnI) post-ablation was significantly higher in AI than CF group (p&amp;lt;0.001), even after taking the total application number and total application time into consideration. No significant differences in inflammatory markers changes from pre- to post-ablation were observed between the two groups. Multiple regression analysis showed that age, AF type, AI-guided ablation and creatinine were significantly associated with the acute myocardial injury (hs-TnI value) after catheter ablation (standardized beta-coefficient=-0.096, p=0.013, standardized beta-coefficient=0.159, p&amp;lt;0.001, standardized beta-coefficient=0.078, p=0.031 and standardized beta-coefficient=0.118, p=0.003, respectively). AI-guided ablation was significantly associated with the hs-TnI post-ablation by multiple regression analysis. The PV reconnection ratio was significantly smaller in AI than CF group (p=0.037). Conclusion According to the results of the biomarkers during AF ablation, AI-guided ablation had the ability to create larger lesions than CF-guided ablation, but had an equivalent inflammatory status to CF-guided ablation. The differences in myocardial injury and inflammation could be the mechanism of the better durability of PVI for AI-guided ablation.

Very high power- short duration radiofrequency ablation in patients with congenital heart disease and atrial fibrillation: safety and outcome

Abstract Funding Acknowledgements Type of funding sources: None. Background It has been shown recently that ablation of paroxysmal and persistent atrial fibrillation (AF) using very high-power-short duration (vHPSD) ablation protocol is safe and effective. Data for vHPSD ablation protocol in adult patients with congenital heart disease (ACHD) are lacking. We searched our database for ACHD patients undergoing AF ablation using vHPSD ablation regarding periprocedural safety and outcome. Methods The data of 62 consecutive ACHD patients with mild (n=43; 69.4%), moderate (n=15; 24.2%) or complex (n= 4; 6.4%) CHD were analysed (Table 1 ). Mean age was 60,43 ± 12,7 years ( 46% male) with a Cha2ds2-VASc2 Score median of 2. Patients were diagnosed with paroxysmal AF (n= 24; 38%) or persistent AF (n= 38; 61%). In 6 patients (9,6 %), a previous conventional pulmonary vein isolation (PVI) had been performed. Settings used for vHPSD ablation were 70 W/5-7 s or 60 W/7-10 s using irrigated-tip catheters. Circumferential PVI was performed in all 62 patients; in 30 patients (48%) additional substrate ablation was performed. The 30-day incidence of adverse events was analyzed and patients followed-up in regular visits at our outpatient clinic using repetitive 7 days Holter ECGs every 3 months. Results No adverse events such as cardiac tamponade, pericardial effusion &amp;gt;10mm, transient ischemic attack/stroke, atrio-esophageal fistula, cardiac arrest or death occurred. Vascular access complications were detected in 7/62 patients (11%), including 4 patients with a need of intervention (surgical n=2, thrombin injection n=2). Complete PVI was performed in all patients (mean procedure time 129 ± 42min, mean fluoroscopy time 9,09 ± 5.44 min. Radiofrequency (RF) time was 127.27 ± 7,25 min (111,43 ± 27,83 min PVI only, 148,76 ± 46,07 min PVI + substrate ablation). After a mean follow up of 249 days, freedom of any atrial arrhythmia off antiarrhythmic drugs (AAD) after a single ablation procedure was present in 26/47 patients (55.3%). Success rate was significantly higher in patients with paroxysmal AF (n=16/18; 88%) compared to patients with persistent AF (n=10/29; 34.5%; p&amp;lt; 0.001; Figure 1) Conclusion: In this first study using vHPSD in ACHD patients of variable complexity with paroxysmal or persistent AF, the technique was safe and effective. Major periprocedural complications were rare and limited to vascular access problems. No vHPSD ablation modality-related complications occurred. vHPSD was fast in all patintes regardless of CHD complexity. Results in the paroxysmal CHD group were excellent and encouraging for persistent AF.

Incremental value of low-voltage area ablation in persistent atrial fibrillation: a systematic review and meta-analysis

Abstract Funding Acknowledgements Type of funding sources: None. Background/Introduction The optimal ablation approach for patients with persistent atrial fibrillation (AF) is a topic of high controversy. The efficacy of adjunctive ablation strategy beyond conventional pulmonary vein isolation remains uncertain. Purpose We sought to investigate the effectiveness of individualized low-voltage area (LVA) substrate modification in patients with persistent AF receiving conventional catheter ablation. Methods We systematically searched PubMed, Cochrane Library, and grey literature sources including clinicaltrials.gov, from inception to 1st November 2022, to identify relevant randomized controlled trials (RCTs). Patients with persistent AF undergoing conventional catheter ablation vs. ablation with additional LVA substrate modification were compared. Freedom from arrhythmia was set as the primary efficacy outcome and total procedure time as the secondary efficacy outcome. A prespecified subgroup analysis was performed for patients with presence of LVAs. We did not impose any filter regarding the study setting, sample size, study duration, or publication language. All analyses were performed using R version 4.1.0 and a two-sided p-value&amp;lt;0.05 was considered statistically significant. Results We pooled data from 5 RCTs with a total of 989 participants (31% female) with persistent AF. Ablation with additional LVA substrate modification resulted in a significantly increased likelihood for freedom from arrhythmia by 60%, compared to conventional AF ablation (odds ratio 1.60; 95% confidence interval 1.13-2.28; I2=39%; p=0.009). No difference in the total procedure time was identified between the two approaches (mean difference -28.94 min; 95% confidence interval -69.39 to 11.51 min; I2 = 98%, p=0.16). In patients with LVAs (n=240), additional LVA substrate modification yielded a higher probability for freedom from arrhythmia than conventional AF ablation (odds ratio 1.73; 95% confidence interval 1.03-2.90; I2=0%; p=0.04). Conclusion This meta-analysis demonstrates that an individualized ablation approach with low-voltage area substrate modification is associated with improved outcomes in patients with persistent AF.

Impact of left atrial CT-angiography prior cryoballoon pulmonary vein isolation on procedural characteristics and outcomes

Abstract Funding Acknowledgements Type of funding sources: None. Background Cryoballoon (CB) ablation for pulmonary vein isolation (PVI) is a frequently performed procedure for rhythm control therapy in atrial fibrillation (AF). However, there is limited data on the impact of preprocedural computed tomography (CT) imaging on procedural characteristics and outcomes. Purpose We aimed to determine whether the use of left atrial CT-angiography to guide CB ablation makes a difference on procedural outcomes by revealing left atrial (LA) anatomy and pulmonary vein (PV) characteristics. Methods A total of 146 AF patiens (paroxismal: 58%, age: 62 ±11 years) undergoing CB ablation were randomized for conventional PVI (control group, n=74) and PVI following preoperative CT-angiography (CTA group, n=72). In the CTA group, LA and PV anatomical features were available during the procedure using 3-dimensional reconstruction images derived from an electroanatomical mapping system. A strategy of 240-second freeze time was used for each pulmonary vein with an option for extra freeze circles until PVI was achieved. Results Procedural time (51±13 min vs. 58±21 min, p&amp;lt;0.05), LA dwell time (41±11 min vs. 47±20 min, p&amp;lt;0.05) and fluoroscopy time (9±4 min vs. 11±5 min, p&amp;lt;0.05) were significantly shorter in the control group. Fluoroscopy dose (1892.4±1319.7 cGycm2 vs. 2216.6±2371.8 cGycm2, p=0.307) and 12-month success rates (control group: 61%; CTA group: 62%, p=0.835) were comparable. No major complications were observed. Conclusions The additional information on anatomy provided by left atrial CT angiography does not manifest in improved procedural characteristics or clinical outcome. Our findings do not support the routine use of preprocedural CTA for guidance of cryoballoon ablation.

Comparison of myocardial injury and inflammation between ablation index-guided and conventional contact force-guided ablation in atrial fibrillation patients.

Ablation index (AI)-guided ablation improves the incidence of arrhythmia recurrence as compared to conventional contact force (CF)-guided ablation. The aim of this study was to elucidate the differences in the biomarkers associated with myocardial injury and inflammation between conventional CF-guided and AI-guided ablation. Atrial fibrillation (AF) patients who underwent pulmonary vein isolation (PVI) from the Osaka Rosai Atrial Fibrillation ablation (ORAF) registry were enrolled. We divided the patients into two groups: conventional CF-guided PVI (CF group) and AI-guided PVI (AI group). The differences in biomarkers associated with myocardial injury and inflammation, and long-term durability of PVI between the two groups were evaluated. This study population included a total of 794 patients (CF-guided, 241 patients; AI-guided, 553 patients). Total application time was significantly shorter, and total application number was significantly smaller in AI than CF group. High-sensitive troponin I (hs-TnI) post-ablation was significantly higher in AI than CF group (p < 0.001), even after taking the total application number and total application time into consideration. No significant differences in inflammatory markers changes from pre- to post-ablation were observed between the two groups. AI-guided ablation was significantly associated with the hs-TnI post-ablation by multiple regression analysis. The PV reconnection ratio was significantly smaller in AI than CF group (p = 0.037). AI-guided ablation had the ability to create larger lesions than CF-guided ablation despite no increase in inflammation and achieved the better PVI durability than that of CF-guided.

Impact of high frequency stimulation to confirm a complete box isolation in catheter ablation of non-paroxysmal atrial fibrillation.

Pulmonary vein (PV) isolation (PVI) including the left atrial posterior wall (LAPW) (Box-PVI) is proposed as an additional strategy for non-paroxysmal atrial fibrillation (NPAF), however, the efficacy remains controversial. The more reliable and durable the Box-PVI we can create, the better the rhythm outcomes might be than with a conventional PVI alone. This study focused on the potential exit conduction of the box lesion and investigated whether the conventional Box-PVI would be sufficient. We enrolled 350 consecutive patients with NPAF that underwent a conventional encircling Box-PVI and examined whether latent exit conduction and dormant "exit" conduction independently remained on the LAPW and in the PVs using high frequency stimulation (HFS) and an adenosine triphosphate (ATP) injection. All electrograms inside the box lesion were eliminated in all cases, however, HFS inside the box propagated outward in 23 cases (6.6%) without any exit conduction by conventional burst stimulation, and 24 cases (6.9%) exhibited only dormant "exit" conduction of the LAPW. Additional ablation where positive HFSs were observed created a complete bidirectional Box-PVI in 43 (41.3%) of the cases without a first pass Box-PVI. The recurrence rates depended on the groups classified according to the HFS response. HFS delivered with an ATP injection on the LAPW and in the PVs following a Box-PVI could not only elucidate true exit block but also identified possible incomplete lesions or connections outside the ablation line, whose elimination could achieve a complete Box-PVI leading to a better rhythm outcome.

Effectiveness and Safety of High-Power Radiofrequency Ablation Guided by Ablation Index for the Treatment of Atrial Fibrillation.

Background To investigate the efficacy and safety of ablation index- (AI-) guided high-power radiofrequency ablation in the treatment of atrial fibrillation (AF). Methods Outcomes of radiofrequency (RF) applications were compared in a swine ventricular endocardial model (n = 10 each for 50 W, 40 W, and 30 W; AI = 500). And a total of 100 consecutive patients with paroxysmal AF undergoing pulmonary vein isolation (PVI) were included. The patients were divided into two groups (n = 50 for each) as follows: control group, treated with conventional power (30 W) ablation mode; and study group, treated with high power (40 W) radiofrequency ablation mode. All groups were treated with the same AI value guided the ablation (target AI = 400/500 on posterior/anterior wall, respectively). Acute pulmonary vein (PV) reconnection was assessed post adenosine administration 20 minutes after ablation. Subsequently, pathological observation of porcine heart lesions and necrotic tissue was performed. Additionally, statistical analyses were carried out on patients' baseline clinical characteristics, surgical data, and total RF energy. Results In swine ventricular endocardial RF applications, compared with 40 W and 30 W, the use of 50 W was associated with shallower tissue lesion depth (p < 0.001) and greater lesion maximum diameter (p < 0.001). Compared with 40 W and 30 W, tissue necrosis caused by 50 W was the deepest and largest (p < 0.001). In pulmonary vein isolation (PVI), there was no significant difference in baseline data between the study group and control group (p > 0.05). In patients with paroxysmal atrial fibrillation, the procedure time in the high-power group was significantly shortened (p < 0.001). The ablation time was significantly shorter (p < 0.001). Compared with control group, RF energy per point and acute pulmonary vein (PV) reconnection were lower (p < 0.001), and first-pass PVI was higher (p < 0.01) in study group. There were no significant differences in complications and sinus rhythm maintenance at 12 months between the two groups (p > 0.05). Conclusions Compared with conventional (30 W) PVI, AI-guided high-power (40 W) was safe and associated with shorter procedure time and reduced acute PV reconnection.

Beyond pulmonary vein isolation for persistent atrial fibrillation: sequential high-resolution mapping to guide ablation

PurposeWe aimed to evaluate whether outcomes with ablation in persistent (PsAF) and long-standing persistent (LsPsAF) AF can be improved beyond what can be achieved with pulmonary vein isolation (PVI) alone, using individualized mapping to guide ablation.MethodsWe studied 20 pts (15 M, 68 ± 11y) with PsAF (14) or LsPsAF (6) referred for first-time AF ablation. Following antral PVI, individualized mapping (IM) was performed using a high-density mapping catheter stably and fully deployed for 30 s at each of 23 ± 9 sites per patient. Activation data were reviewed, and an ablation strategy designed to intersect areas of focal and rotational activity. Mean follow-up was 429 ± 131 days. The study population was compared to a matched contemporary control cohort (CC) of 20 consecutive patients undergoing conventional ablation.ResultsDespite the IM group having a higher median comorbidities score, 3.5 vs. 2.5 in the CC group, indicating potentially more complex patients and more advanced substrate, cumulative freedom from AF after a single procedure was achieved in 94% of patients in the IM group vs. 75% in the CC group at 1 year and remained the same in both groups at the conclusion of the study (p = 0.02). There was a similar trend in atrial arrhythmia-free survival between both groups (84% vs. 67% at 1 year) that did not reach statistical significance. The procedure duration was longer in the IM group by a median of 31.5 min (p = 0.004).ConclusionsIndividualized mapping to guide AF ablation appears to achieve significantly greater AF-free survival compared to conventional PVI when applied as a primary ablation treatment. The results of this pilot study need to be confirmed in a larger, randomized trial.

Neuromodulatory Approaches for Atrial Fibrillation Ablation.

In this review, the authors describe evolving alternative strategies for the management of AF, focusing on non-invasive and percutaneous autonomic modulation. This modulation can be achieved – among other approaches – via tragus stimulation, renal denervation, cardiac afferent denervation, alcohol injection in the vein of Marshall, baroreceptor activation therapy and endocardial ganglionated plexi ablation. Although promising, these therapies are currently under investigation but could play a role in the treatment of AF in combination with conventional pulmonary vein isolation in the near future.

Ablation index-guided pulmonary vein isolation can reduce early recurrences of atrial tachyarrhythmias: a propensity score-matched analysis.

Early recurrence of atrial tachyarrhythmias (ERAT) cause various symptoms and predict worse outcomes after pulmonary vein isolation (PVI). This study aimed to clarify whether ablation index (AI)-guided PVI, which is a novel technology of radiofrequency ablation, could reduce ERAT as compared to conventional contact force (CF)-guided PVI. Consecutive atrial fibrillation (AF) patients who underwent initial PVI from September 2014 to August 2019 were enrolled. We divided the patients into two groups: patients who underwent AI-guided PVI (AI group) and those who underwent CF-guided PVI (CF group). Using propensity score matching (PSM), we adjusted for the patient backgrounds. We compared the incidence of ERAT and late reconnection rate of isolated pulmonary veins (PVs) during second session between the two groups. ERAT was defined as any atrial tachyarrhythmias ≥ 30s during a 90-day blanking period. A total of 697 AF patients (paroxysmal 51%) were enrolled. After the PSM, both groups included 229 patients. The incidence of ERAT was significantly lower in the AI group than that in the CF group (21.5% vs. 36.1%, P < 0.001). Total 118 patients (25.7%) experienced late recurrence of atrial tachyarrhythmias (LRAT) after blanking period. LRAT free survival rate was significantly higher in patients without ERAT than those with ERAT (88.1% vs. 42.0%, P < 0.001). The rate of PV reconnection was lower in the AI group than that in the CF group (45.8% vs. 71.4%, P = 0.028). Multivariate analysis demonstrated that AI-guided PVI was independently correlated with ERAT (OR = 0.415, 95%CI = 0.269-0.639, P < 0.001). AI-guided PVI can reduce ERAT as compared to conventional CF-guided PVI.

Accuracy and acute efficacy of a novel occlusion tool to guide cryoballoon-based pulmonary vein isolation

Abstract Background Cryoballoon (CB)-based pulmonary vein isolation (PVI) currently requires to verify occlusion of each pulmonary vein (PV) using fluoroscopy and dye injection. Objective The current study evaluated whether the novel CB-occlusion tool integrated into the wide-band dielectric imaging system KODEX-EPD reliably verifies occlusion of PV according to a novel dye-injection based algorithm. Methods Consecutive patients suffering from symptomatic atrial fibrillation (AF) underwent CB-based PVI using the KODEX-EPD and the novel occlusion-tool (group I). To confirm accurate display of the PVs, selective PV-angiography was performed in the first half of the patients of group I (group Ia) in addition to a three-dimensional left atrial (LA) map using a spiral mapping catheter (Achieve, SMC1, Medtronic, MN, USA). PV-angiographies were waived for the following patients (group Ib). Procedural duration and radiation exposure were compared to a control group of patients undergoing conventional CB-based PVI. Results CB-based PVI was successful in 50/50 patients of group I (mean age 63±11 years, 18 paroxysmal (36%)) and 25/25 patients of group II (66±10 years, 9 paroxysmal (60%)). Concordance of PV-occlusion as assessed by either PV-occlusion-angiography or KODEX-EPD, was documented in 237/272 (87%) occlusion-analyses among 198 PVs (95% for left superior PV, 93% for left inferior PV, 86% for right inferior PV and 77% for right superior PV). In the final evaluation phase (group Ib) LA fluoroscopy times and dose area products were comparable to the conventional CB-ablation group (10.5±5 vs 8.8±4 minutes (p=0.23) and 403±425 vs 321±202 cGycm2 (p=0.44), whereas the amount of dye could be significantly reduced (group Ib: 31±10 ml vs group II: 70±20 ml, p&amp;lt;0.0001). Conclusion The novel KODEX-EPD PV-occlusion tool allows for accurate PV-occlusion assessment in the majority of PVs and a high acute success rate. The system has the potential to reduce dye and radiation exposure. This should be evaluated in controlled clinical trials. Funding Acknowledgement Type of funding sources: None.

Contrast-enhanced computed tomography for optimizing the outcomes of pulmonary vein isolation with cryoablation -the role of isolation of PVs including carina-

PurposeCompared with conventional pulmonary vein isolation (PVI) with radiofrequency ablation, PVI with cryoballoon is an easier and shorter procedure without reconnection, particularly in the superior pulmonary vein. However, the durability of the cryoballoon may be reduced due to anatomical factors and the position of the pulmonary vein (PV). Further, inadequate isolation of the carina leads to recurrence of atrial fibrillation (AF). We aimed to determine whether using contrast-enhanced computed tomography (CT) for patient selection improves the early success rate and prevents the recurrence of AF in PVI with cryoballoon.MethodsWe evaluated patients who underwent ablation for paroxysmal atrial fibrillation in our hospital between July 2019 and November 2020. After excluding patients with contraindications for cryoablation, 50 patients were selected through visual inspection of the results of preoperative contrast-enhanced CT. A treatment plan was established, and the clinical course and outcomes were followed up.ResultsOf the 200 PVs of the 50 patients, only 8 PVs (4%) were incompletely isolated with a single cryoablation. Six of the eight PVs were successfully isolated with additional cryoablation. Only 2 patients (4%) underwent additional PVI with radiofrequency ablation. Four patients had AF recurrence within a mean follow-up period of 14.3 ± 5.1 months. The rate of sinus rhythm maintenance was 92%. PV reconnection was observed in 2 patients. None of the patients had postoperative atrial flutter.ConclusionsSelecting patients for cryoablation according to contrast-enhanced CT findings made the procedure easier to perform, leading to improved early success rates and clinical course.

Fluoroless Catheter Ablation of Atrial Fibrillation: Integration of Intracardiac Echocardiography and Cartosound Module.

To evaluate the feasibility, safety, and clinical efficacy of non-fluoroscopic radiofrequency catheter ablation of atrial fibrillation (AF) in comparison to traditional fluoroscopy-guided ablation in a local Canadian community cohort. We retrospectively studied consecutive patients with paroxysmal and persistent AF undergoing pulmonary vein isolation (PVI) guided by intracardiac echocardiography (ICE) and Carto system (CartoSound module). ICE-guided PVI without fluoroscopy (Zero-fluoro group) was performed in 116 patients, and conventional fluoroscopy-guided PVI (Traditional group) was performed in 131 patients. Two hundred and forty-seven patients with AF (60.7% male; mean age: 62.2 ± 10.6 years; paroxysmal AF =63.1%) who underwent PVI were studied. Mean procedure times were similar between both groups (136.8±33.4 minutes in the zero-fluoro group vs. 144.3±44.9 minutes in the traditional group; p=0.2). Acute PVI was achieved in all patients. Survival from early AF recurrence was 85% and 81% in the zero-fluoro and traditional groups, respectively (p = 0.06). Survival from late AF recurrence (12-months) between the zero-fluoro and traditional groups was also similar (p=0.1). Moreover, there were no significant differences between complication rates, including hematoma (p = 0.2) and tamponade (p = 1),between both groups. Zero-fluoroscopy ICE and CartoSound-guided AF ablation may be safe and feasible in patients undergoing PVI compared to conventional fluoroscopy-guided ablation.

The role of ablation index-guided pulmonary vein isolation in high-sensitivity TrThe role of ablation index-guided pulmonary vein isolation in high-sensitivoponin I and atrial fibrillation recurrence

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Ablation Index (AI) software has been associated with better freedom from atrial arrhythmias after pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF). There is conflicting data regarding the relationship between high sensitivity cardiac Troponin I (Hs-cTnI) and arrhythmia recurrence. The objective was to evaluate the impact of AI on Hs-cTnI level and on ablation effectiveness quotient (AEQ) and to assess if these markers are predictors of arrhythmia recurrence. Methods Prospective observational study of consecutive patients referred for PVI for paroxysmal AF ablation from October 2017 to June 2018 according to a pre-specified AI protocol. Procedural endpoints and 2-year follow-up outcomes were assessed and compared to a retrospective cohort of conventional PVI contact-force-guided group . Results A total of 56 patients were included: 29 patients the AI group and 27 patients in the control group. The mean age was 60.5 ± 10.3 years, 48% males. Left ventricular ejection fraction (60 ± 6 % AI vs 61 ± 5 % control, P = 0.07) and left atrium diameter (43 ± 7 mm AI vs 44 ± 6 mm control, P = 0.58) were comparable between groups. First-pass isolation was shown to be higher in the AI group (79% AI vs 44%, p= 0.01). Mean number of radiofrequency applications was lower in the AI group (93 ± 24 vs 111 ± 30, P = 0.02). Average contact-force was similar between groups (17.6 ± 4.1 g vs 22.6 ± 10.7 g, P =0.166). Patients that performed PVI guided by the AI had lower Hs-cTnI (1815 ± 1146 ng/L vs 3274 ± 1696 ng/L, p &amp;lt; 0.001) and lower AEQ (1.01 ± 0.7 ng/L/s vs 1.51 ± 0.7 ng/L/s, P = 0.011) compared to patients in the control group. During a mean follow-up of 26 ± 11 months, AF recurrence was documented in 10.3% of patients in the AI group and 22.2% in the control group (P = 0.223). Neither Hs-cTnI nor AEQ levels were predictors of arrhythmia recurrence. Conclusions These data suggest that AI-guided catheter ablation is associated with reduced levels of of Hs-cTnI and AEQ. Neither Hs-cTnI and AEQ should be used to predict arrhythmia recurrence. Abstract Figure.

Efficacy of LGE-MRI-guided fibrosis ablation versus conventional catheter ablation of atrial fibrillation: The DECAAF II trial: Study design.

Success rates of catheter ablation in persistent atrial fibrillation (AF) remain suboptimal. A better and more targeted ablation strategy is urgently needed to optimize outcomes of AF treatment. We sought to assess the safety and efficacy of targeting atrial fibrosis during ablation of persistent AF patients in improving procedural outcomes. The DECAAF II trial (ClinicalTrials. gov identifier number NCT02529319) is a prospective, randomized, multicenter trial of patients with persistent AF. Patients with persistent AF undergoing a first-time ablation procedure were randomized in a 1:1 fashion to receive conventional pulmonary vein isolation (PVI) ablation (Group 1) or PVI + fibrosis-guided ablation (Group 2). Left atrial fibrosis and ablation induced scarring were defined by late gadolinium enhancement magnetic resonance imaging at baseline and at 3-12 months postablation, respectively. The primary endpoint is the recurrence of atrial arrhythmia postablation, including atrial fibrillation, atrial flutter, or atrial tachycardia after the 90-day postablation blanking period. Patients were followed for a period of 12-18 months with a smartphone ECG Device (ECG Check Device, Cardiac Designs Inc.). With an anticipated enrollment of 900 patients, this study has an 80% power to detect a 26% reduction in the hazard ratio of the primary endpoint. The DECAAF II trial is the first prospective, randomized, multicenter trial of patients with persistent AF using imaging defined atrial fibrosis as a treatment target. The trial will help define an optimal approach to catheter ablation of persistent AF, further our understanding of influencers of ablation lesion formation, and refine selection criteria for ablation based on atrial myopathy burden.