Treatment Of Persistent Atrial Fibrillation Research Articles

Posterior left atrial wall isolation for treatment of persistent atrial fibrillation during first-time catheter ablation: An updated systematic review and meta-analysis.

Although catheter ablation (CA) by mean of pulmonary vein isolation (PVI) is nowadays the mainstay treatment for atrial fibrillation (AF), its success-rate in persistent AF remains suboptimal. Results from studies evaluating whether adding posterior wall isolation (PWI) to PVI can increase the success-rate of CA in persistent AF have yielded conflicting data. The aim of this meta-analysis was to assess whether PWI plus PVI might be beneficial in patients with persistent AF. Electronic databases were searched for randomized control trials (RCTs) and observational studies that compared clinical outcomes between patients with persistent AF who underwent PVI with or without PWI. Fifteen studies, including a total of 3072 patients, were considered (1533 treated with PVI and 1539 with PWI + PVI). Comparing patients treated with or without PWI, no statistically significant difference was found in the risk of any atrial tachyarrhythmias recurrence after CA (RR 0.83; 95 % CI 0.66-1.03). The analyses detected a statistically significant reduction in the risk of AF in patients treated with PWI (RR 0.63; 95 % CI 0.48-0.84) balanced by a trend towards an increased risk of atrial flutter/atrial tachycardia (RR 1.51; 95 % CI 0.92-2.49). No statistically significant differences were identified in the risk of major procedural complications (RR 0.94; 95 % CI 0.50-1.78). According to our updated meta-analysis, the addition of PWI to PVI was not associated with a reduction of atrial arrhythmia recurrences. A reduction of the risk of AF recurrence and a trend towards an increased risk of atrial flutter/atrial tachycardia were identified.

Effect of Pulmonary Vein Isolation with Left Atrial Wall Isolation Plus Selective CFAE Ablation in Patients with Persistent Atrial Fibrillation.

Pulmonary vein isolation (PVI) is a foundational treatment for persistent atrial fibrillation (PeAF), but the effectiveness of adding posterior wall isolation (PWI) and selective complex fractionated atrial electrogram (CFAE) ablation in the roof and anterior wall remains debated. The potential of these additional ablation techniques to improve long-term outcomes for PeAF patients is still uncertain. This retrospective study included 151 PeAF patients who underwent first-time catheter ablation at our center. The choice of ablation strategy was based on the operator's clinical judgment, taking into account the patient's specific condition and anatomical features. Patients were divided into two groups: the PVI group, which received PVI alone, and the modified PWI (MPWI) group, which received PVI along with additional PWI and selective CFAEs ablation in the roof and anterior wall. The primary endpoint was the absence of atrial arrhythmia lasting more than 30 s, without antiarrhythmic drugs, at 12 months. At the 12-month follow-up, 77.3% of the patients in the MPWI group and 52.1% of the patients in the PVI group remained in sinus rhythm without an atrial arrhythmia recurrence (p = 0.001). The BIC-based Cox regression analysis identified the ablation strategy and atrial fibrillation (AF) duration as independent predictors of recurrence across the cohort. It was found that MPWI significantly reduced the risk of recurrence, while a longer AF duration increased it. In the MPWI group, AF duration, left ventricular internal diameter in systole (LVIDs), and moderate or greater tricuspid regurgitation were independent predictors of recurrence. In the PVI group, only the left atrial low voltage area (LVA) index was a significant predictor. The addition of PWI and selective CFAE ablation to PVI significantly improves 12-month arrhythmia-free survival compared to PVI alone, demonstrating the superiority of this combined approach in improving long-term outcomes for patients with persistent AF.

Electrographic flow mapping of atrial fibrillation.

A low ceiling of efficacy exists for the treatment of persistent atrial fibrillation via pulmonary vein isolation without adjunctive ablations, which is likely because they do not target an individual patient's specific underlying disease mechanisms. Electrographic flow (EGF) mapping is the first system that reliably displays wavefront propagation through the atria. It is a promising tool for localizing sources of atrial fibrillation, guiding targeted ablation, and visualizing conduction through the atrial substrate. We describe EGF mapping with emphasis on contemporary studies examining map reproducibility and use cases in the preclinical and clinical environment. Animal experiments demonstrated that maps were interpretable across increasingly complex rhythms with pacing during spontaneously persistent atrial fibrillation reliably simulating EGF sources. The FLOW-AF randomized controlled trial showed that source ablation improved outcomes and that EGF map properties may be used to phenotype patients based on their atrial fibrillation mechanisms and recurrence likelihoods. Targeted ablation strategies balance the risks of insufficiently ablating atrial fibrillation triggers with exacerbating disease through additional scar formation. EGF mapping leverages spatiotemporal relationships in voltage to localize sources and quantify substrate health. Further research is needed to optimize phenotyping and treatment efforts.

A proposed index of myocardial staining for vein of marshall ethanol infusion

Abstract Background Mitral isthmus(MI) conduction block is a fundamental step in anatomical approach treatment for persistent atrial fibrillation(PeAF). However, MI block is hardly achievable with endocardial ablation only. Retrograde ethanol infusion(EI) into the vein of Marshall(VOM) facilitates MI block. Fluorographic myocardial staining(MS) during VOM-EI could be helpful in predicting procedural alcoholization outcome even if its role is qualitatively assessed in the routine. Purpose The aim was to quantitatively assess MS during VOM-EI and to evaluate its association with MI block achievement. Methods Consecutive patients undergoing catheter ablation for PeAF at our Institution from February 2022 to May 2023 were considered. Patients with identifiable VOM were included. A proposed index of MS(MSI) was retrospectively calculated in each included patient. Correlation of MSI with low voltage zones(LVZ) extension after VOM-EI and its association with MI block achievement were assessed. Results 42 patients out of 49 (85.8%) had an identifiable VOM. MI block was successfully achieved in 35 patients out of 42 (83.3%). MSI was significantly associated with the occurrence of MI block (OR 1.24 (1.03 – 1.48); p = 0.022). A higher MSI resulted in reduced ablation time (p = 0.014) and reduced radiofrequency applications (p = 0.002) to obtain MI block. MSI was also associated with MI block obtained by endocardial ablation only (OR 1.07 (1.02 – 1.13); p = 0.002). MSI was highly correlated with newly formed LVZ extension (r = 0.776; p = 0.001). Conclusion In our study cohort, optimal MSI predicts MI block and facilitates its achievement with endocardial ablation only.Myocardial stainingSpline plots

Cryoballoon versus radiofrequency catheter ablation: 3-year follow-up data from the prolonged Norwegian randomized study of persistent atrial fibrillation (NO-PERSAF study)

Abstract Background Pulmonary vein isolation (PVI) is still regarded as a cornerstone for treatment of persistent atrial fibrillation (AF). Both radiofrequency ablation (RFA) and cryoballoon ablation (CBA) are frequently employed to achieve PVI. Similar results of both techniques have been reported during short follow-up, but clinical outcomes for long-term follow-up from randomized trials are still missing. Purpose This study aimed to evaluate the effectiveness of PVI performed with CBA compared with RFA in patients with persistent AF over 3 years. Methods For the NO-PERSAF study, 101 patients (63.2±8.6 years old, 80 male, 21 female), with persistent AF (77 persistent AF, 24 long-standing persistent AF) referred to PVI were randomized (1:1) to CBA or RFA and followed for 12 months. All patients participating in the NO-PERSAF study were invited to an extended outpatient evaluation with 12-lead ECG and 7-day Holter. The primary endpoint was any documented recurrent atrial tachyarrhythmia (ATA) lasting longer than 30 s during 3 years after the index ablation procedure (following a 3-month blanking period). The ATA-free survival curves were estimated by Kaplan-Meier method and analyzed by log-rank test. Results One patient crossed over from CBA to RFA group because of equipment problem during index ablation procedure. 99 of the original 101 patients responded (1 died of non-cardiovascular diseases, 1 lost). Freedom from ATA was achieved in 51 (50.5%) of the 101 patients, 28 (54.9%) out of 51 patients in the CBA group and 23 (46.0%) out of 50 patients in the RFA group (Figure 1). No difference of ATA recurrence was found between the two groups (p=0.327). There was significantly (p=0.031) less atrial flutter in the CBA group (7.8%; 4 atypical) compared with the RFA group (22%; 10 atypical, 1 typical). 28 patients received repeat ablations with RFA during the follow-up period, 15 in the CBA group and 13 in the RFA group (1 twice). Freedom from ATA after multiple ablations was achieved in 74 (73.3%) of the 101 patients, 40 (78.4%) out of the 51 patients in the CBA group and 34 (68.0%) out of the 50 patients in the RFA group. No difference of ATA recurrence was found between the two groups (p=0.178, Figure 2) after multiple ablations with RFA for AF and atrial flutter. Noticeably, 2 patients in the CBA group and none in the RFA group received atrioventricular nodal ablation after permanent pacemaker implantation. Conclusions Compared to RFA, PVI performed with CBA showed similar outcome of freedom from ATA over a long-term follow-up of 3 years. However, the incidence of atrial flutter was significantly lower in the CBA group.Figure 1Figure 2

Type of atrial arrhythmias and substrates after convergent ablation procedures

Abstract Background Convergent epicardial and endocardial catheter ablation had been used for the treatment of persistent atrial fibrillation (PeAF). Aims The aims of this retrospective study are to describe the pattern of arrhythmias and substrate findings in patients previously submitted to convergent ablation and showing arrhythmic recurrences (AF/AT/AFL lasting at least 30 seconds) and documented with ILR during follow up. Methods From a cohort of 119 patient who underwent convergent ablation, we selected the 55 with arrhythmic recurrences and showing AT/AF/AFL stored in ILR memories to submit them to remap procedure. Results We excluded 1 patient who was submitted to ablate and pace without remapping and 1 patient whose data has been lost. Among 53 patients, 69.7% experienced AF (33.9% PAF and 35.8% PeAF), 5.6% typical AFL and 30.2% AT/atypical AFL. As for the substrates found, at detailed high-density mapping we had: 66.9% with veins reconnection (regardless the gaps localization), 37.7% with low-voltage area/abnormal signals on the posterior wall, 11.3% deserving CTI ablation for typical AFL and 28.3% with different LA substrates (septal, anterior, LAA, mitral annulus and 9.4% with gaps at superior surgical line). Notably, overlaps of arrhythmic patterns and substrate were also found in the same patients. Conclusion In our study a total of 79.1% patients had substrates related to previous convergent ablation due to gaps at pulmonary veins or superior line. The rest had an arrhythmic substrate in areas not previously ablated like posterior wall or CTI. These findings suggest that a large amount of patients submitted to convergent ablation (up to 80%) may have an arrhythmic substrate and thus potentially recurrences due to previous epi-endocardial ablation.

Posterior wall isolation in patients with persistent atrial fibrillation: a single center comparative study between ablation index and very high power short duration radiofrequency ablation protocol

Abstract Background Circumferential pulmonary veins ablation (CPVA) with posterior wall isolation (PWI) using radiofrequency catheter ablation (RFCA) is gaining increasing interest in terms of safety and efficacy. Purpose To compare procedural data and efficacy between two radiofrequency ablation protocols for the treatment of persistent atrial fibrillation (PersAF): very high power-short duration (vHPSD) ablation using a novel temperature-controlled ablation catheter and Ablation Index (AI) guided RFCA using traditional contact-force catheter. Methods This single center prospective study enrolled 75 consecutive patients (Group 1) with symptomatic PersAF undergoing RFCA using a novel contact-force catheter optimized for temperature-controlled ablation with microelectrodes and 6 thermocouples for real-time temperature monitoring during ablation. The vHPSD algorithm modulates power to maintain target temperature during these lesions (90 Watts, 4 s) in the posterior wall. RF delivery in anterior regions was performed in a temperature guided setting (1-45W, 45°C) to achieve a 500-550 AI. These patients were compared to 75 propensity matched patients (Group 2) undergoing PersAF ablation with traditional AI-guided ablation. Procedural data were compared between the two groups (Table 1). Procedural outcome was considered as loop recorder documented atrial arrhythmias recurrences and compared between the two groups. Results Seventy-five patients (69% male, 63.1±11.2 years old) underwent ablation with vHPSD protocol (Group 1). CPVA and PWI was achieved in all patients with total procedure and fluoroscopy times of 67.5±28.8 min and 4.5±2.8 min, respectively. After 12-month median follow-up, 57/75 patients (76%) were free from AF. Seventy-five propensity matched patients (69% male, 60.7±9.9 years old) have undergone ablation with standard contact-force catheter. CPVA and PWI was achieved in all patients with total procedure and fluoroscopy times of 81.99±20.5 min and 5.7±2.1 min, respectively. After 12-month median follow-up, 55/75 patients (73%) were free from AF. Procedural and fluoroscopy times were significantly lower in in Group 1 than in Group 2 (Table 1). AF recurrencies were comparable between the two groups as assessed with survival analysis (Figure 1, log-rank 0.509). There were no deaths or other severe periprocedural complications. Conclusions PWI on top of CPVA is effective in limiting arrhythmic recurrences following RFCA of PersAF. Compared to standard AI guided ablation, vHPSD protocol significantly reduces procedural time and fluoroscopy exposure. Clinical outcomes between the two protocols are similar.Figure 1

Presence and predictors of atrial low voltage zones in patients with non cardiovertable atrial fibrillation

Abstract Background Interventional treatment of persistent atrial fibrillation (pAF) presents a challenge due to the lack of clear evidence on adjunctive strategies beyond pulmonary vein isolation (PVI). One promising approach is ablation of left atrial low voltage zones, which has been shown to improve outcomes in patients with pAF. However, reliable assessment of left atrial endocardial voltage requires sinus rhythm (SR). In a significant proportion of patients with persistent atrial fibrillation (pAF) however, restoration of sinus rhythm (SR) cannot be achieved. These may lead to extensive ablations such as defragmentation or empirical isolation of the posterior wall of the left atrium. This study aims to investigate the potential of unsuccessful cardioversion prior ablation as a predictor for the presence of low voltage zones (LVZ) in the left atrium. Methods This retrospective, single-centre study was conducted on 264 patients (31,8% female; age: 67±10 years; mean AF duration: 1-2 years) diagnosed with pAF who underwent catheter ablation for pAF between 01/2017 and 01/2020. All patients underwent electrical cardioversion (CV) before ablation. If restoration of SR was achieved, high-density contact mapping was performed in sinus rhythm before pulmonary vein isolation (PVI), in case of unsuccessful initial cardioversion, high-density contact mapping was performed after repeated CV followed the PVI, respectively. Results Initial cardioversion was unsuccessful in 53 out of 264 (19.7%) patients. Subsequent to pulmonary vein isolation, cardioversion was successful in 47 out of 53 (81%) patients initially considered non-cardiovertible. In 32 out of 53 (60.4%) patients who had an initial unsuccessful cardioversion, no left atrial low voltage was identified. Amongst patients who underwent a successful initial cardioversion, left atrial low voltage zones were apparent in 77 out of 211 patients (36.5%). There is no significant difference in the the presence of left atrial low voltage between patients who had initially successful and unsuccessful CV (χ²(1) = 0.178, p = 0.673, φ = 0.026). According to the ROC analysis, the success of CV does not have any predictive value for LVZ (AUC 0.511). Conclusion Cardioversion failure before pulmonary vein isolation does not predict left atrial low-voltage zones (LVZ). PVI alone may be adequate even in patient with clinically "end stage" non-cardiovertible atrial fibrillation. Ablation beyond pulmonary vein isolation have the potential to overtreat this specific patient group, resulting in an increase in secondary arrhythmias. These findings indicate that even single-shot devices such as balloon-based techniques may be a considerable ablation strategy in these patient cohort.

Four-year follow-up of outcomes of the hybrid epicardial-endocardial ablation: A single-center experience

BackgroundThe CONVERGE trial demonstrated that hybrid epicardial and endocardial ablation was more effective than catheter ablation for the treatment of persistent atrial fibrillation (AF) at 1 year. Long-term real-world outcome data are scarce. ObjectiveWe described a single-center experience by evaluating the long-term effectiveness and safety of hybrid epicardial-endocardial ablation. MethodsThis is a retrospective single-center study. Patients were followed up to 4 years. The primary end point was the rate of AF recurrence up to 4 years postablation. Secondary end points included reduction in antiarrhythmic therapy use, the effect of the ligament of Marshall removal, epicardial posterior wall, 3-dimensional mapping during epicardial ablation, and left atrial appendage exclusion as adjunct intraoperative interventions for AF recurrence. ResultsOf the 170 patients, 86.5% had persistent AF and 13.5% had long-standing persistent AF. AF-free survival was 87.6% at 1 year, 76.9% at 2 years, 70.4% at 3 years, and 59.3% at 4 years. Antiarrhythmic drug use was 87.6% at baseline and reduced to 21%, 20.6%, 18%, and 14.1% at year 1, 2, 3, and 4, respectively (P < .01 for all). Three-dimensional epicardial mapping showed a significant reduction in combined recurrence from 42% to 25% over 4 years of follow-up (P = .023). Ligament of Marshall and left atrial appendage exclusion showed numerical reduction in AF recurrence from 35% to 26% (P = .49) and from 44% to 30% (P = .07). ConclusionThe hybrid convergent procedure reduces AF recurrence and the need for antiarrhythmic drugs and, while maintaining a good safety profile, for the treatment of persistent and long-standing persistent AF.

Atrial fibrillation symptom reduction and improved quality of life following the hybrid convergent procedure: a CONVERGE trial subanalysis.

CONVERGE was a prospective, multicenter, randomized controlled trial that evaluated the safety of Hybrid Atrial Fibrillation Convergent (HC) and compared its effectiveness to endocardial catheter ablation (CA) for the treatment of persistent atrial fibrillation (PersAF) and longstanding PersAF (LSPAF). In 2020, we reported that CONVERGE met its primary safety and effectiveness endpoints. The primary objective of the present study is to report CONVERGE trial results for quality of life (QOL) and Class I/III anti-arrhythmic drug (AAD) utilization following HC. Eligible patients had drug-refractory symptomatic PersAF or LSPAF and a left atrium diameter ≤6.0 cm. Enrolled patients were randomized 2:1 to receive HC or CA. Atrial Fibrillation Severity Scale (AFSS) and the 36-Item Short Form Health Survey (SF-36) were assessed at baseline and 12 months; statistical comparison was performed using paired t-tests. AAD utilization at baseline through 12 and 18 months post-procedure was evaluated; statistical comparison was performed using McNemar's tests. A total of 153 patients were treated with either HC (n=102) or CA (n=51). Of the 102 HC patients, 38 had LSPAF. AFSS and SF-36 Mental and Physical Component scores were significantly improved at 12 months versus baseline with HC overall and for the subset of LSPAF patients treated with either HC or CA. The proportion of HC patients (n=102) who used Class I /III AADs at 12 and 18 months was significantly less (33.3% and 36.3%, respectively) than baseline (84.3%; P<0.001). In LSPAF patients who underwent HC (n=38), AADs use was 29.0% through 18 months follow-up versus 71.1% at baseline (P<0.001). HC reduced AF symptoms, significantly improved QOL, and reduced AAD use in patients with PersAF and LSPAF. NCT01984346.

First clinical data on artificial intelligence-guided catheter ablation in long-standing persistent atrial fibrillation.

Despite advanced ablation strategies and major technological improvements, treatment of persistent atrial fibrillation (AF) remains challenging and the underlying pathophysiology is not fully understood. This study analyzed the multiple procedure outcome and safety of catheter ablation of spatiotemporal dispersions (DISPERS) detected by artificial intelligence (AI)-guided software in patients with long-standing persistent AF. The Volta VX1 software was used for 50 consecutive patients undergoing catheter ablation for persistent AF. First, high-density mapping (78% biatrial) with a multipolar mapping catheter was performed. In addition to pulmonary vein isolation (PVI), ablation of DISPERS was performed aiming at homogenizing, dissecting, isolating, or connecting DISPERS areas to nonconducting anatomical structures. Follow-up contained regular visits at our outpatient clinic at 1, 3, 6, and 12 months including 7-day Holter electrocardiograms. Patients were mainly suffering from long-standing persistent AF (mean AF duration 50.30 ± 54.28 months). Following PVI, ablation of left atrial and right atrial DISPERS areas led to AF cycle length prolongation (mean of 162.0 ± 16.6to 202.2 ± 21.6 ms after) and AF termination to atrial tachycardia (AT) or sinus rhythm (SR) in 12 patients (24%). No stroke or pericardial effusion occurred; major groin complications (pseudoaneurysm n = 1, atrioventricularfistula n = 1) were detected in two patients. After a blanking period of 6 weeks, recurrence of any atrial arrhythmia was documented in 26 patients (52%). The majority of patients presented with organized AT (n = 15) while AF was present in n = 9 patients and AT/AF was observed in n = 2 patients. Twenty-twopatients underwent reablation. During a mean follow-up of 363.14 ± 187.42 days and after an average of 1.46 ± 0.68 procedures, 82% of patients remained in stable SR. DISPERS-guided ablation using machine learning software (the Volta VX1 software) in addition to PVI in long-standing persistent AF ablation resulted in high long-term success rates regarding AF and AT elimination. Most arrhythmia recurrences were reentrant AT. After a total of 1.46 ± 0.68 procedures, freedom from AF/AT was 82%. Despite prolonged procedure times complication rates were low. Randomized studies are necessary to evaluate long-term efficacy of dispersion-guided ablation using AI.

Efficacy and safety of the vein of Marshall ethanol infusion with radiofrequency catheter ablation for the treatment of persistent atrial fibrillation in elderly patients.

Increasing age is a significant risk factor for atrial fibrillation (AF) recurrence after catheter ablation (CA). We accomplished this study to evaluate the efficacy and safety of the vein of Marshall (VOM) ethanol infusion (VOM-EI) with CA in elderly patients with persistent AF (PsAF). This retrospective observational study included 360 consecutive adult patients with PsAF, of which 141 were in the Elder group (age ≥65 years) and 219 were in the Younger group (age <65 years), who underwent the VOM-EI and radiofrequency CA (RFCA) between May 2020 and April 2022. The efficacy endpoint was no recurrence of AF within one year after CA. The VOM-EI was successfully performed in 90.8% of patients from the Elder and 88.6% from the Younger group. All patients achieved PVI; 97.9% of patients from the Elder and 98.6% from the Younger group reached LA roof block, and 93.6% of patients from the Elder and 95.9% from the Younger group achieved MI block. There was no significant difference in 1-year survival without recurrence of AF between the two groups (83.0% and 84.5%, respectively). The incidence of complications within 30 days after the procedure from the two groups was low and did not differ significantly. The VOM-EI combined with RFCA proved to be an effective and safe strategy for treating PsAF in elderly and younger patients.

Hybrid convergent ablation: an evaluation of left atrial electroanatomical voltage maps

Abstract Background Hybrid convergent ablation is an effective, emerging treatment for persistent atrial fibrillation (AF) (1). Minimally invasive surgical epicardial left atrial (LA) ablation is performed via a subxiphoid incision to ablate the posterior wall, within the limits of the pericardial reflections, before endocardial catheter ablation is performed primarily to complete pulmonary vein isolation. The overall aim is to create durable, transmural posterior wall ablation to target potential drivers that may sustain persistent AF. Purpose We evaluated electroanatomical maps obtained during endocardial ablation to determine the site and extent of LA posterior wall scar following epicardial ablation and whether this determines outcome in patients undergoing convergent ablation. Methods Patients who underwent Convergent ablation at a single UK cardiac centre (2012-2019) using CARTO-3 mapping system for endocardial ablation were included. Patients who had previous AF ablation were excluded. Low-voltage areas (LVAs) were manually measured using the CARTO-3 system and defined as areas &amp;lt;0.5mV on bipolar voltage maps (pulmonary veins were excluded). Scar location was classified by evaluating for presence and amount of LVA in each quadrant of the posterior LA wall. AF recurrence was evaluated at 12 months post-procedure. SPSS (v. 27) was used for statistical analysis. Results Of the 32 patients included, 7 patients experienced AF recurrence within 12 months post-procedure (21.9%). The average amount of posterior wall LVA following convergent ablation was 54.1% of posterior wall area and 5.8% of total left atrial area, neither of which were associated with 12-month AF recurrence (see Table 1). The presence and extent of LVAs in the upper quadrants were heterogeneous amongst patients and did not relate to AF recurrence. All patients displayed LVAs in the lower quadrants post-epicardial ablation, with the majority having LVAs occupying more than 50% of these quadrants. 96.8% had LVA on the inferior LA surface. In total, 75% of patients had a significant amount of LVA (defined as LVA occupying &amp;gt;50% of the quadrant area) in both lower posterior wall quadrants (see Figure 1) and this feature was associated with lower AF recurrence on multivariable Cox regression analysis (see Table 1). Conclusions Extensive scar was observed in the LA posterior wall in patients following epicardial convergent ablation. The presence of such scar, particularly in the lower regions of the posterior wall, may influence outcomes and be associated with reduced AF recurrence.Table 1Figure 1

Impact of Vein of Marshall Ethanol Infusion Combined with Anatomical Ablation for the Treatment of Persistent Atrial Fibrillation: A Long-Term Follow-Up Based on Implantable Loop Recorders.

The best ablation treatment for persistent atrial fibrillation (PeAF) patients is still debated. The vein of Marshall (VOM) seems to be a promising target for ablation and could be combined with a linear set of ablation lesions. The aim of our study is to evaluate the incidence of AF recurrences in a PeAF population treated with a comprehensive ablation approach consisting of VOM ethanol infusion (EI), pulmonary vein isolation (PVI), a left atrial (LA) roofline, a mitral line (guided by the newly formed lesion after alcohol infusion into the VOM and validated by pacing), and a cavotricuspid isthmus line. Consecutive patients undergoing the first ablation procedure of catheter ablation (CA) for PeAF were enrolled. All patients underwent VOM-EI, PVI, and ablation lines along the roof of the LA, mitral, and cavotricuspid isthmus. LA voltage mapping before and after VOM-EI was also performed. An implantable loop recorder (ILR) was implanted at the end of the ablation in each patient. Thirty-one consecutive patients (66 ± 8 years and 71% male) affected by PeAF were included in this study. The VOM-EI procedural phase lasted 21.4 ± 10.1 min. PV isolation and lines were validated in all subjects. The ML block was achieved within 10.8 ± 8.7 min. At a mean follow-up of 12 ± 7 months, 27 out of 31 (87%) patients remained free from AT/AF recurrences. Among the patients with recurrences, two (50%) had incomplete ablation lesions and three (75%) had "suboptimal" VOM-EI. In 23/31 patients (74%), antiarrhythmic drugs (AADs) were discontinued after 1 month of follow-up. No significant complications were reported during the follow-up. this single-center experience demonstrates that VOM-EI systematically combined with an anatomical ablation set in patients with PeAF resulted in feasible, safe, and effective freedom from AF/AT recurrences in 87% of the population after a 1-year follow-up period according to an ILR.

Box Lesion Isolation of the Left Atrial Posterior Wall with Radiofrequency Ablation Restricted in Predetermined Lines for the Treatment of Persistent Atrial Fibrillation: The Prognostic Role of Acute Interventional Outcome and Trigger Identification.

The left atrial posterior wall (PW) is known to be a critical substrate for the initiation and perpetuation of atrial fibrillation (AF) and has been explored as a target for catheter ablation, particularly in persistent AF (PerAF). In this retrospective study, we investigate the clinical outcome of patients with PerAF who underwent PW isolation (PWI) restricted in predetermined lines in addition to pulmonary vein isolation (PVI). One hundred consecutive patients (64 ± 9.1 years, 66% male, 20% with previous PVI ablation) underwent PWI in a box lesion setting for PerAF lasting >3 months (34% long-standing PerAF). PW triggers were defined as either foci from the PW that repeatedly induced AF or as isolated AF or atrial tachycardia (AT) within the PW. After a mean follow-up period of 25.6 ± 6.7 months, 61% of the patients remained in sinus rhythm after the last procedure. In 79 patients, the PW was successfully isolated, while, in 21 patients, complete isolation was not possible due to failure in completion of the roof line (n = 16), the floor line (n = 7), or both (n = 2). Patients with incomplete isolation had similar AF/AT recurrence rates compared to those with complete PWI. In 12 patients, PW triggers were identified, and PWI in these patients was shown to have a significantly better prognosis in terms of sinus rhythm maintenance (P = .031). Failure of complete PWI does not predispose a patient to an inferior outcome nor is it responsible for iatrogenic ATs. The presence of AF triggers within the PW leads to a particularly favorable result after box lesion isolation.

Efficacy of Vein of Marshall Ethanol Infusion Added to Left Atrial Anatomical Ablation for Treatment of Persistent Atrial Fibrillation in Patients with Hypertrophic Cardiomyopathy.

Radiofrequency catheter ablation (RFCA) has been shown to have low efficacy for the treatment of persistent atrial fibrillation (AF) in patients with hypertrophic cardiomyopathy (HCM). We conducted this study to evaluate the benefit of adjunctive vein of Marshall (VOM) ethanol infusion during RFCA for persistent AF (PsAF) in patients with non-obstructive HCM. This multicenter retrospective observational study included 102 consecutive non-obstructive HCM patients with PsAF who underwent RFCA plus VOM ethanol infusion (VOM-EI) (RFCA + VOM, n = 56) or RFCA alone (RFCA, n = 46) for the first time. The efficacy endpoint was survival without AF or atrial tachycardia (AT) after the blanking period. We completed the VOM-EI in 92.9% (52/56) patients. The left pulmonary vein antrum ablation time (RFCA + VOM: 19.9 6.1 min vs. RFCA: 27.2 9.3 min), mitral isthmus (MI) ablation time (RFCA + VOM: 16.9 3.7 min vs. RFCA: 28.4 7.8 min), and rate of coronary sinus (CS) vein ablation (RFCA + VOM: 57.69% vs. RFCA: 80.43%) were lower but the acute success rate of MI block (RFCA + VOM: 98.1% vs. RFCA: 84.8%) were higher in the RFCA + VOM group than those in the RFCA group (all p 0.05). After twelve months follow-up, 84.6% of patients (44/52) survived without AF/AT in the RFCA + VOM group, compared to 65.2% of patients (30/46) in the RFCA group (p = 0.03; odds ratio = 2.93, 95% CI: 1.18-7.79). VOM-EI combined with RFCA decreased the recurrence rate of AF/AT at 12 months in HCM patients with PsAF. VOM-EI simplified the ablation of the left pulmonary vein antrum and MI and increased the success rate of MI bidirectional block.

PO-01-136 SAFETY AND EFFICACY OF 375 MCG DOSE OF DOFETILIDE IN PATIENTS WITH ATRIAL FIBRILLATION

Dofetilide is a class 3 antiarrhythmic drug approved in the treatment of persistent Atrial Fibrillation (AF). Previous randomized and controlled studies have assessed the safety of this drug at dosages of 125 mcg, 250 mcg and 500 mcg. However, efficacy has been shown to be dose dependent. We evaluated the safety and efficacy of 375mcg bid dose in the treatment of AF. We have collected data on all patients admitted for dofetilide initiation at 2 institutions. We reviewed the medical records to collect information on baseline characteristics at the time of initiation. Dosage, cardioversion parameters and discharge modalities were all recorded. Follow-up events were recorded including recurrence of AF and mortality. Follow-up ended when dofetilide was discontinued. 100 pts were successfully discharged on a 375mcg bid dosage out of 700 pts admitted for dofetilide initiation. Mean GFR by Cockroft was 106,63 (43.6-154.9), mean Baseline QT corrected by Fridericia (QTcF) was 426.77 (368-525); mean Discharge QTcF was 472.43 (427-519). 70% of the pts had persistent AF and 50% of the pts who got 375 mcg dose were in sinus rhythm at 1 year. No case of ventricular tachycardia was reported. The dose of 375 mcg appears to be safe and as effective as the 500mcg dose as reported in SAFFIRE-D trial (46% AF free at 1 year and 37% pharmacological cardioversion). This should be considered in dosing algorithm for inpatient dofetilide initiation.

PO-02-036 THE POSTERIOR WALL ISOLATION FOR PERSISTENT ATRIAL FIBRILLATION HIGH POWER SHORT DURATION (PEF-HOT) TRIAL

Treatment of persistent atrial fibrillation (PeF) remains a procedural challenge with high recurrence rate after catheter ablation. Posterior wall isolation (PWI) has emerged as a potential concomitant treatment strategy for PAF with conflicting outcomes. PWI introduces a left atrial (LA) roof and low posterior line through a series of radiofrequency (RF) applications to achieve entrance and exit block of the LA posterior wall. It remains unclear whether PWI with pulmonary vein isolation (PVI) during initial catheter ablation improves success rate over PVI alone. This study investigated whether PWI with PVI reduced recurrence rates compared to PVI alone in patients with PeF undergoing first-time radiofrequency ablation utilizing high-power-short-duration (HPSD) ablation. In this prospective, multicenter, randomized controlled trial, we randomized 67 patients with symptomatic PeF undergoing initial ablation to either PVI+PWI (n = 39) or PVI (n = 28) alone. The primary endpoint was freedom from atrial arrhythmias after a single procedure. Of the 67 study participants, the median duration of PeF was 0.67 (interquartile range, 0.25 - 2) years. The mean CHADS-VASc score was 2.7±1.6. No significant difference was found in the baseline characteristics between the two groups (Table 1). PWI was successfully achieved in all 39 patients in PVI+PWI group. Mean procedural times were 83.4±23.4 minutes for the PVI group, and 111.7±41.0 minutes for the PVI+PWI group. There was one complication of tamponade in the PVI+PWI group. At a median follow up of 12.4±3.0 months, the atrial arrhythmia recurrence rate did not significantly differ (P=0.9275) between PVI+PWI (20.5%) and PVI alone (21.4%). Kaplan-Meier analysis showed no significant difference in the overall AF recurrence (log-rank, P=0.9485). Additionally, the Cox univariate regression and multivariate Cox regression for all notable comorbidities revealed no significant association with procedural outcomes. In patients with PeF undergoing initial RF ablation, adjunctive PWI with PVI using HPSD did not significantly reduce recurrence rate of atrial arrhythmias.Tabled 1Table 1: Baseline Clinical CharacteristicsOverall (N = 67)Arm 1(N=28)Arm 2 (N=39)P-valueAge, mean (±SD)68.4 (±7.9)68.5 (±8.4)68.4 (±7.7)0.968Men, n (%)51 (76.1)20 (29.9)31 (46.3)0.445AF Duration, median (IQR)0.67 (0.25-2)1 (0.29-2)0.5 (0.25-2)0.440Comorbidities, n (%)Heart failure21 (31.3)10 (35.71)11 (28.21)0.513Hypertension49 (73.1)22 (78.6)27 (69.2)0.395Diabetes mellitus14 (20.9)8 (28.6)6 (15.4)0.190Stroke6 (9.0)3 (10.7)3 (7.7)0.669Vascular disease6 (9.0)2 (7.1)4 (10.3)0.660CHA2DS2-VASc score, mean (±SD)2.7 (±1.6)2.9 (±1.7)2.5 (±1.4)0.230Echocardiographic parameters, mean (±SD)LA dimension, cm4.7 (±0.6)4.6 (±0.6)4.8 (±0.6)0.206LA volume index, mL/m252.5 (±35.4)54.1 (±33.5)51.4 (±38.1)0.975LV ejection fraction, %52.1 (11.2)53.5 (±10.3)51.0 (±11.9)0.385 Open table in a new tab

How an innovative catheter with temperature control and very high-power, short-duration ablation changed our approach to the treatment of persistent atrial fibrillation.

Ablation targets of persistent atrial fibrillation remain poorly understood nowadays: due to structural alterations of the left atrium, isolation of the pulmonary veins alone has proved ineffective. New ablation targets such as the posterior wall, coronary sinus, and left atrial appendage were then sought. A new catheter (QDOT Micro™) has recently been released, which has the potential to increase the safety and efficacy of the procedure: it is connected to a new radiofrequency generator that allows for temperature-controlled ablation by reducing power and increasing irrigation with the increase in tissue temperature and allows to deliver power up to 90 W for few seconds (very high-power short-duration).

Preoperative Prediction of Catheter Ablation Outcome in Persistent Atrial Fibrillation Patients through Spectral Organization Analysis of the Surface Fibrillatory Waves.

Catheter ablation (CA) is a commonly used treatment for persistent atrial fibrillation (AF). Since its medium/long-term success rate remains limited, preoperative prediction of its outcome is gaining clinical interest to optimally select candidates for the procedure. Among predictors based on the surface electrocardiogram, the dominant frequency (DF) and harmonic exponential decay () of the fibrillatory waves (f-waves) have reported promising but clinically insufficient results. Hence, the main goal of this work was to conduct a broader analysis of the f-wave harmonic spectral structure to improve CA outcome prediction through several entropy-based measures computed on different frequency bands. On a database of 151 persistent AF patients under radio-frequency CA and a follow-up of 9 months, the newly introduced parameters discriminated between patients who relapsed to AF and those who maintained SR at about 70%, which was statistically superior to the DF and approximately similar to . They also provided complementary information to through different combinations in multivariate models based on lineal discriminant analysis and report classification performance improvement of about 5%. These results suggest that the presence of larger harmonics and a proportionally smaller DF peak is associated with a decreased probability of AF recurrence after CA.