Complex Fractionated Atrial Electrograms Ablation Research Articles

Radiofrequency ablation of atrial fibrillation: A 14 years' experience at a tertiary care center in Thailand.

The result of atrial fibrillation (AF) ablation varies across centers. Most data are derived from the Western world, while data from Southeast Asian countries are lacking. We aimed to investigate the outcomes of AF ablation in Thailand. We performed a retrospective analysis of patients who underwent AF ablation in a tertiary care center, between the years 2006-2020. Details of AF ablation, including pulmonary vein isolation (PVI), and complex fractionated atrial electrogram (CFAE) ablation, were classified. The success rate of AF ablation is determined by freedom from AF beyond 3 months blanking period. Combined success rate of AF ablation was reported along with the success rate of each technique (PVI, CFAE, and combine PVI plus CFAE). We identified a total of 171 patients who underwent the first AF ablation. Ninety-four (55%) patients went through PVI, 55 (32%) patients for CFAE ablation, and 22 (13%) patients for PVI plus CFAE ablation. Overall freedom from AF was 73% at 12 months, 66% at 24 months, and 55% at 36 months. The success rate of PVI was 79% at 12 months, 74% at 24 months, and 59% at 36 months. The success rate of CFAE ablation was 63% at 12 months, 51% at 24 months, and 47% at 36 months. Catheter ablation of AF is proven safe and effective in Thai population.

10-Year Outcomes of Patients With Non-Paroxysmal Atrial Fibrillation Undergoing Catheter Ablation.

Radiofrequency catheter ablation (RFCA) is commonly performed in patients with non-paroxysmal atrial fibrillation (AF), but because very long-term follow-up results of RFCA are limited, we investigated the 10-year RFCA outcomes of non-paroxysmal AF.Methods and Results: We retrospectively enrolled 100 patients (89 men, mean age 53.5±8.4years) with drug-refractory symptomatic non-paroxysmal AF who underwent 3D electroanatomic-guided RFCA. Procedural characteristics at index procedures and clinical outcomes were investigated. In the index procedures, all patients had pulmonary vein isolation, 56 (56.0%), 48 (48.0%), and 32 (32.0%) underwent additional linear, complex fractionated atrial electrogram (CFAE) and non-pulmonary vein (NPV) foci ablations, respectively. After 124.1±31.7 months, 16 (16%) patients remained in sinus rhythm after just 1 procedure (3 with antiarrhythmic drugs [AAD]) and after multiple (2.1±1.3) procedures in 53 (53.0%) patients (22 with AAD). Left atrial (LA) diameter (hazard ratio HR 1.061; 95% confidence interval (CI) 1.020 to 1.103; P=0.003), presence of NPV triggers (HR 1.634; 95% CI 1.019 to 2.623; P=0.042) and undergoing CFAE ablation (HR 2.003; 95% CI 1.262 to 3.180; P=0.003) in the index procedure were independent predictors for recurrent atrial tachyarrhythmia. The 10-year outcomes of single RFCA in non-paroxysmal AF were unsatisfactory. Enlarged LA, presence of NPV triggers, and undergoing CFAE ablation in the index procedure independently predicted single-procedure recurrence. Multiple procedures are required to achieve adequate rhythm control.

Safety and efficacy of catheter ablation for atrial fibrillation in the very elderly

Abstract Background The incidence and prevalence of atrial fibrillation (AF) increases with age. With an ageing general population, a 2.3-fold rise in AF prevalence is expected. Catheter ablation has emerged as an effective treatment option for rhythm control therapy. However, very elderly patients (≥80 years old) have been excluded in landmark clinical trials. Current data regarding the safety and efficacy of catheter ablation in the very elderly is therefore sparse. Purpose Due to the growing demand to manage AF in an increasingly ageing population, we investigated the safety and efficacy of catheter ablation in this particular patient population. Methods Patients with symptomatic paroxysmal, persistent and long-standing persistent AF aged ≥80 years undergoing catheter ablation, including first and re-ablation procedures in a single centre, were analysed retrospectively. Catheter ablation involved pulmonary vein isolation (PVI) using radiofrequency, cryoballoon and pulsed field ablation as energy sources. Re-ablation procedures included re-PVI and consecutive atrial tachycardia ablation including atrial lines and/or ablation of complex fractionated atrial electrograms (CFAE) in persistent AF. Endpoints included acute procedural success (complete isolation of pulmonary veins and/or non-inducibility in the case of atrial tachycardia), major complications and early arrhythmia-recurrence. Results A total of eighty-eight patients (mean age 83.1±1.9 years, mean CHA2DS2-VASc-Score 4.4±1, mean left ventricular ejection fraction 56.7±7%, direct oral anticoagulation 92.1%, vitamin-K antagonists 7.9%) were included from January 2021 to October 2021. Fifty cases (56.8%) involved PVI as an index procedure (radiofrequency 58%, n=29/50, cryoballoon 36%, n=18/50, pulsed field ablation 6%, n=3/50). Thirty-eight procedures (43.2%) involved re-ablation procedures (Re-PVI 60.5%, n=23/38, linear lesions 65.8%, n=25/38, atrial tachycardia ablation 26.3%, n=10/38 and ablation of CFAE 15.8%, n=6/38). Acute procedural success was achieved in 87/88 patients (98.9%). Major complications included stroke (n=1/88, 1.1%), pericardial tamponade (n=1/88, 1.1%) and bradycardia with subsequent pacemaker implantation (n=3/88, 3.4%). No further major complications were documented. In 13/88 patients (14.8%) early arrhythmia-recurrence occurred (38.5%, n=5/13 after the index procedure and 61.5%, n=8/13 after re-ablation) during the 90-day blanking period. Conclusions Catheter ablation for atrial fibrillation in the very elderly shows favourable acute success and low complication rates. Long term success of catheter ablation and superiority to rate control in this patient population is unknown and requires investigation in the future. Funding Acknowledgement Type of funding sources: None.

Outcomes of radiofrequency catheter ablation for persistent and long-standing persistent atrial fibrillation

ObjectiveTo assess one-year outcomes in patients with persistent and long-standing persistent atrial fibrillation (AF) treated by catheter ablation. MethodsA retrospective observational study was conducted of consecutive patients referred for catheter ablation of persistent or long-standing persistent AF between May 2016 and October 2018. Patients underwent two different ablation strategies: pulmonary vein isolation (PVI) plus complex fractionated atrial electrograms (CFAE) (from May 2016 to June 2017) or a tailored approach (from July 2017 to October 2018). The overall recurrence rate at one year was analyzed. The secondary endpoint was arrhythmia recurrence according to the type of AF (persistent vs. long-standing persistent AF) and according to the ablation strategy employed. ResultsDuring the study period, 67 patients were included (40% with long-standing persistent AF). During a mean follow-up of 16±6 months, 27% of the patients had arrhythmia recurrence. Patients with long-standing persistent AF had a higher recurrence rate than those with persistent AF (44.4% vs. 15%, p=0.006), while patients who underwent a tailored approach presented better outcomes than those undergoing PVI plus CFAE ablation (17.5% vs. 40.7%, p=0.024). Ablation strategy (HR 6.457 [1.399-29.811], p=0.017), time in continuous AF (HR 1.191 [1.043-1.259], p=0.010) and left atrial volume index (HR 1.160 [1.054-1.276], p=0.002) were independent predictors of arrhythmia recurrence. ConclusionCatheter ablation is an effective treatment for patients with persistent and long-standing persistent AF. Patients with persistent AF and those undergoing a tailored approach presented lower arrhythmia recurrence.

PO-622-02 PREDICTOR OF ATRIAL TACHYARRHYTHMIA RECURRENCE AMONG ABLATION STRATEGIES AFTER ABLATION INDEX-GUIDED ATRIAL FIBRILLATION ABLATION

Ablation index (AI)-guided atrial fibrillation (AF) ablation improved the procedural success and long-term outcome, but it remained unsatisfactory, especially in non-paroxysmal AF (non-PAF). Various ablation strategies were performed to improve the outcome. However, the strategies vary with the institutions and operators, and predictors of recurrence of atrial tachyarrhythmia (AT) among the strategies remain to be elucidated. We analyzed the predictors of AT recurrence, focusing on high-power radiofrequency application (50W, HP), first-pass pulmonary vein (PV) isolation (FPI), and extra-PV ablation strategies such as left atrium roof linear ablation (LARLA), superior vena cava (SVC) isolation, left atrium posterior wall box isolation (POBI) and complex fractionated atrial electrogram (CFAE) ablation. We retrospectively investigated 1384 patients undergoing the first AI-guided AF ablation from January 2018 to October 2020 (mean age, 67±10 years; female, 422 [31%]; non-PAF, 598 [43%]). HP was performed for 1074 patients (78%) undergoing ablation procedures since November 2018. SVC isolation was performed in all patients with SVC sleeve ≥ 20mm and the other extra-PV ablation strategies at the operator’s discretion. We performed univariate and multivariate analyses by cox proportional hazard model to define the predictors of AT recurrence. During follow-up (mean, 371±160 days), any ATs recurred in 317 patients (24%). Univariate analysis revealed that HP (Hazard ratio [HR], 1.08 [95% confidence interval, 0.83-1.40], p=0.57), FPI in both PV sides (HR, 1.08 [0.87-1.36], p=0.49), and FPI in at least one side (HR, 0.85 [0.61-1.19], p=0.36) had no effect on AT recurrence. Multivariate analysis revealed that LARLA had a negative effect (HR, 1.86 [1.21-2.86], p=0.005) and SVC isolation had a positive effect (HR, 0.71 [0.56-0.89], p=0.003); however, POBI (HR, 1.03 [0.77-1.38], p=0.84) and CFAE ablation (HR, 1.10 [0.78-1.56], p=0.59) had no effect on AT recurrence. The present analysis of a large number of AI-guided AF ablation revealed that HP, FPI, POBI, and CFAE ablation showed no effect, LARLA showed a worsening effect, and SVC isolation showed a protective effect on AT recurrence.

B-PO05-097 TEN-YEAR OUTCOMES OF THE PATIENTS WITH NON-PAROXYSMAL ATRIAL FIBRILLATION UNDERGOING CATHETER ABLATION

Catheter ablation in patients with non-paroxysmal atrial fibrillation (AF) has become common practice. However, very long-term follow-up result is limited. We aimed to investigate the 10-year catheter ablation outcomes in patients with non-paroxysmal AF. We retrospectively enrolled 100 patients (89 men, mean age 53.5±8.4years) with drug-refractory symptomatic persistent and long-lasting persistent AF who underwent 3D electroanatomic-guided catheter ablation. Procedural characteristics and very long-term outcomes were investigated. In the index procedures, all patients received pulmonary vein isolation, 56, 48, and 32 patients received additional linear, complex fractionated atrial electrogram (CFAE) and non-pulmonary vein (NPV) foci ablations, respectively. After a mean follow-up period of 124.1± 31.7months, single procedure AF free outcome was achieved in 16(16%) patients (3 with antiarrhythmic medications, AAD) and multiple (2.1±1.3) procedures in 53(53.0%) patients. Left atrial (LA) diameter (OR 1.061; 95% CI 1.020 to 1.103; P =0.003), presence of NPV trigger (OR 1.634; 95% CI 1.019 to 2.623; P =0.042) and receiving CFAE ablation (OR 2.003; 95% CI 1.262 to 3.180 ; P =0.003) in the index procedure are independent predictors for recurrent atrial tachyarrhythmia. The very long-term single ablation outcome of non-paroxysmal AF is unsatisfactory, with freedom from recurrence at 10 years of 16%. Enlarged LA, presence of NPV triggers, and receiving CFAE ablation in the index procedure independently predict recurrence. Multiple (at least 2) procedures are required to achieve adequate, very long-term rhythm control.

Pulmonary vein isolation alone vs. more extensive ablation with defragmentation and linear ablation of persistent atrial fibrillation: the EARNEST-PVI trial.

Previous studies could not demonstrate any benefit of more intensive ablation in addition to pulmonary vein isolation (PVI) including complex fractionated atrial electrogram (CFAE) and linear ablation for recurrence in the initial catheter ablation of persistent atrial fibrillation (AF). This study aimed to establish the non-inferiority of PVI alone to PVI plus these additional ablation strategies. Patients with persistent AF who underwent an initial catheter ablation (n = 512, long-standing persistent AF; 128 cases) were randomly assigned in a 1:1 ratio to either PVI alone (PVI-alone group) or PVI plus CFAE and/or linear ablation (PVI-plus group). After excluding 15 cases who did not receive procedures, we analysed 249 and 248 patients, respectively. The primary endpoint was recurrence of AF, atrial flutter, and/or atrial tachycardia, and the non-inferior margin was set at a hazard ratio of 1.43. In the PVI-plus group, 85.1% of patients had linear ablation and 15.3% CFAE ablation. After 12 months, freedom from the primary endpoint occurred in 71.3% of patients in the PVI-alone group and in 78.3% in the PVI-plus group [hazard ratio = 1.56 (95% confidence interval: 1.10-2.24), non-inferior P = 0.3062]. The procedure-related complication rates were 2.0% in the PVI-alone group and 3.6% in the PVI-plus group (P = 0.199). This randomized trial did not establish the non-inferiority of PVI alone to PVI plus linear ablation or CFAE ablation in patients with persistent AF, but implied that the PVI plus strategy was promising to improve the clinical efficacy (NCT03514693).

Optimum lesion set and predictors of outcome in persistent atrial fibrillation ablation: a meta-regression analysis.

Ablation of persistent atrial fibrillation (PsAF) has been performed by many techniques with varying success rates. This may be due to ablation techniques, patient demographics, comorbidities, and trial design. We conducted a meta-regression of studies of PsAF ablation to elucidate the factors affecting atrial fibrillation (AF) recurrence. Databases were searched for prospective studies of PsAF ablation. A meta-regression was performed. Fifty-eight studies (6767 patients) were included. Complex fractionated atrial electrogram (CFAE) ablation reduced freedom from AF by 8.9% [95% confidence interval (CI) -15 to -2.3, P = 0.009). Left atrial appendage [LAA isolation (three study arms)] increased freedom from AF by 39.5% (95% CI 9.1-78.4, P = 0.008). Posterior wall isolation (PWI) (eight study arms) increased freedom from AF by 19.4% (95% CI 3.3-38.1, P = 0.017). Linear ablation or ganglionated plexi ablation resulted in no significant effect on freedom from AF. More extensive ablation increased intraprocedural AF termination; however, intraprocedural AF termination was not associated with improved outcomes. Increased left atrial diameter was associated with a reduction in freedom from AF by 4% (95% CI -6.8% to -1.1%, P = 0.007) for every 1 mm increase in diameter. Linear ablation, PWI, and CFAE ablation improves intraprocedural AF termination, but such termination does not predict better long-term outcomes. Study arms including PWI or LAA isolation in the lesion set were associated with improved outcomes in terms of freedom from AF; however, further randomized trials are required before these can be routinely recommended. Left atrial size is the most important marker of AF chronicity influencing outcomes.

Influence of substrate modification in catheter ablation of atrial fibrillation on the incidence of acute complications: Analysis of 10795 procedures in J-CARAF Study 2011-2016.

Background and purposeIn expectation of better outcome of catheter ablation of atrial fibrillation (AF), several strategies of extra‐PV (pulmonary vein) substrate modification have been utilized. We assessed whether substrate modification or ablation of extra‐PV source is a predictor of complications.MethodsJapanese Heart Rhythm Society requested electrophysiology centers to register the data of patients who underwent AF ablation.ResultsThe data of 10 795 AF ablation cases (age; 63.8 ± 10.6 years) treated during 2011‐2016 were registered. Pericardial effusion (n = 105), massive bleeding (n = 108), stroke (n = 6), atrial‐esophageal fistula (n = 2), and other 114 complications occurred in 323 patients (3.0%). Univariate analysis revealed that age ≧ 65 years, female gender, heart failure, CHA2DS2‐VASc≧3, hemodialysis, deep sedation, and complex fractionated atrial electrogram (CFAE)‐guided ablation ([+] vs [−] = 4.3% vs 2.8%, P = .005) were related with the higher incidence of complications. Redo session, 3‐D imaging system ([+] vs [−]: 4.4% vs 2.9%, P = .017), and periprocedural dabigatran were related with the lower incidence of complications. None of the linear ablation of the left atrium, ganglionated plexi ablation, and superior vena cava ablation affected the incidence of complications. Multiple logistic regression analysis showed that in addition to 3‐D imaging system, age ≧ 65 years, redo session, and deep sedation, CFAE ablation was an independent predictor of the risk of complications (OR 1.78, P = .001). Specifically, implantation of a permanent pacemaker due to emerging sinus node dysfunction was frequent after CFAE ablation (CFAE [+] vs [−] = 4/1047 vs 2/9748, P < .001).ConclusionsAmong extra‐PV ablation strategies, CFAE‐guided ablation is a predictor of ablation‐related complications.

Beyond Pulmonary Vein Isolation: the Role of Additional Sites in Catheter Ablation of Atrial Fibrillation.

Pulmonary vein (PV) isolation is the cornerstone of atrial fibrillation (AF) ablation. However, the long-term procedural outcome remains suboptimal and there is a frequent need for repeat ablation procedure, especially in patients with non-paroxysmal AF. The review article summarizes the rationales, recent evidences, and strategies of ablation of extra-PV sites and its clinical outcomes. It is a consensus that durable PV isolations are a definite therapy in patients with paroxysmal AF. In non-paroxysmal AF, many laboratories still believe that adequate substrate ablation outside PVs is definitely required. Empirical linear ablation is not recommended because of difficulty in achieving complete linear block, unless macro-reentry atrial tachycardia developed during procedure. Most of laboratories applied complex fractionated atrial electrogram (CFAE) ablation after PV isolation in non-paroxysmal AF, but the efficacy is limited in the long-term follow-up studies. A combined approach using CFAE, non-linear similarity, and phase mapping strategy to identify rotors or focal sources for substrate modification increases the ablation outcome, when compared to CFAE ablation alone. Provocative test with mapping of non-PV triggers is also recommended in all patients to improve long-term ablation success. Ablation beyond PV isolation is important, especially in non-paroxysmal AF patients, to modify the diseased atrial substrate and eliminate the non-PV triggers, which in turn improve the ablation outcome.

Ablation of Complex Fractionated Electrograms With or Without ADditional LINEar Lesions for Persistent Atrial Fibrillation (The ADLINE Trial).

For persistent atrial fibrillation (AF) ablation, different strategies including complex fractionated atrial electrograms (CFAE) ablation and linear lesions (LL) have been used in addition to pulmonary vein isolation (PVI). However, it is still a matter of debate if extended substrate modification improves long-term outcome. The aim of this study was to determine the benefit of LL in addition to PVI and CFAE ablation regarding freedom from arrhythmia recurrence in patients with persistent AF. The study was a prospective randomized trial including 90 patients with persistent and longstanding persistent AF. All patients underwent PVI and CFAE ablation. If AF did not terminate to atrial tachycardia (AT) or sinus rhythm, patients were randomized to direct current cardioversion (Group 1; n = 45) or LL (Group 2; n = 45). Primary endpoint was freedom from any atrial arrhythmia off antiarrhythmic drugs at 12 months. (NCT02059369) RESULTS: Baseline characteristics were similar between the two groups with more than half of the patients having structural heart disease. The primary endpoint was reached in 37% in Group 1 (G1) and 16% in Group 2 (G2; P = 0.03). After a total number of 1.4 ± 0.5 (G1) versus 1.7 ± 0.4 (G2; P = 0.01) procedures, freedom from any arrhythmia was reached in 54% in G1 and 65% in G2 (P = 0.35). In persistent AF ablation, LL in addition to PVI and CFAE show a significantly lower success rate after a single procedure compared to PVI and CFAE. Following LL, significantly more patients needed a reablation to reach a similar success rate during a 12-month follow-up.

Does Additional Electrogram-Guided Ablation After Linear Ablation Reduce Recurrence After Catheter Ablation for Longstanding Persistent Atrial Fibrillation? A Prospective Randomized Study.

BackgroundAlthough circumferential pulmonary vein isolation (CPVI) catheter ablation may not be sufficient for long‐standing persistent atrial fibrillation (L‐PeAF), it is not clear which ablation strategy is beneficial in addition to CPVI. We sought to investigate whether additional complex fractionated atrial electrogram (CFAE)‐guided ablation improves clinical outcomes in L‐PeAF patients who exhibit continuous atrial fibrillation (AF) after CPVI and linear ablation (Line).Methods and ResultsThis study enrolled 137 L‐PeAF patients (71.4% male, 61.6±10.9 years old) who underwent radiofrequency catheter ablation. We conducted CPVI+Line based on the Dallas lesion set (posterior box+anterior line) after baseline CFAE mapping in all patients. If AF was defragmented (terminated or changed to atrial tachycardia), the procedure was stopped (AF‐Defrag group, n=29). If AF was maintained after CPVI+Line, we mapped the CFAE again and randomly assigned the patient to the CPVI+Line group (n=54) or the additional CFAE ablation group (CPVI+Line+CFAE group, n=54). L‐PeAF was defragmented during CPVI+Line in 21.2% of patients (29/137, AF‐Defrag group). The mean CFAE cycle length was prolonged (P<0.001), and CFAE area (CFAE cycle length <120 milliseconds) was reduced (P<0.001) after CPVI+Line in the remaining patients. Procedure time was longer in the CPVI+Line+CFAE group than the CPVI+Line group (P=0.023), but procedure‐related complication rates did not vary. During 22.3±13.2 months of follow‐up, the clinical recurrence rates were 17.2% in the AF‐Defrag group, 18.5% in the CPVI+Line group, and 32.1% in the CPVI+Line+CFAE group (log rank, P=0.166).ConclusionsAlthough CPVI+Line reduces and localizes CFAE area, additional CFAE ablation after CPVI+Line does not improve the clinical outcomes of catheter ablation in patients with L‐PeAF.

Durability of wide-area left atrial appendage isolation: Results from extensive catheter ablation for treatment of persistent atrial fibrillation

Extensive ablation strategies are currently performed in addition to pulmonary vein isolation (PVI) to improve the clinical outcome of patients with drug-refractory persistent atrial fibrillation (AF). Ablation of complex fractionated atrial electrograms (CFAEs), linear lesions, and/or isolation of the left atrial appendage (LAA) are thought to improve arrhythmia-free survival. The purpose of this study was to assess the durability of wide-area left atrial appendage isolation (LAAI) achieved by PVI, an anterior line, and a mitral isthmus line. Seventy-one patients with intentional or incidental LAAI during repeat catheter ablation for treatment of persistent AF were included. The initial ablation strategy was PVI. Additional ablation strategies were performed only if PVI failed to maintain stable sinus rhythm. Durability of LAAI was assessed during a subsequent ablation procedure for arrhythmia recurrences (n = 23) or a subsequent percutaneous LAA closure (n = 48). LAAI was performed after a mean of 3 ± 1 procedures. Ablation strategies included circumferential PVI in 71 patients (100%), mitral isthmus line in 64 (90%), anterior line in 60 (85%), CFAE in 27 (38%), and roof line in 13 (18%). LAAI occurred after ablation and bidirectional block of LA linear lesions in 63 patients (89%) and during extensive CFAE ablation in 8 patients (11%). After a median of 105 [61;426] days, the LAA remained electrically isolated in 52 of 71 patients (73%). Wide-area LAAI after extensive catheter ablation for persistent AF is durable in the majority of patients. The potential clinical benefit of LAAI for maintaining stable sinus rhythm requires further investigation.

Unanswered Questions in Complex Fractionated Atrial Electrogram Ablation.

Pulmonary vein isolation has been accepted as potential target for ablation of paroxysmal atrial fibrillation (AF) given that the pulmonary veins are the main source of AF triggers. However, ablation strategies for persistent AF are less well defined. Mapping and ablation of complex fractionated atrial electrograms (CFAEs) is one strategy that has been proposed as a strategy for substrate modification although there is no consensus on their definition and procedural end points. Results of clinical studies have been conflicting. In this review, we aimed to discuss yesterday, today, and tomorrow of CFAEs ablation in persistent AF ablation.

Anatomical proximity between ganglionated plexi and epicardial adipose tissue in the left atrium: implication for 3D reconstructed epicardial adipose tissue-based ablation.

We sought to better understand the association between and clinical implications of ganglionated plexi (GPs), epicardial adipose tissue (EAT) in the left atrium (LA), and the initiation and maintenance of atrial fibrillation (AF). Three-dimensional (3D) computed tomography (CT) reconstruction images of the LA, PVs, and LA-EAT were merged with the LA geometry for 25 with paroxysmal AF (PAF) and 15 with persistent AF (PerAF) scheduled for ablation. High-frequency stimulation (20Hz, 25mA, 10ms) was performed at three sites within each of the five major anatomical LA GPs (superior left, inferior left, anterior right, inferior right, and Marshall tract GPs) to elicit vagal responses. Correspondence between the five GP areas and vagal response sites, LA-EAT, and complex fractionated atrial electrograms (CFAEs) was examined. The long-term outcomes of adjuvant LA-EAT-based ablation were assessed in 31 patients with PAF and 102 with PerAF. LA-EAT overlapped 93 ± 14% of five major anatomical GP areas, and the vagal response sites and CFAE sites corresponded to 77 ± 23 and 76 ± 25%, respectively (p < 0.05 for both vs. LA-EAT locations). The EAT-based ablation eliminated 97.6% of the vagal response sites and lengthened the AF cycle from 160 ± 26 to 193 ± 27ms (p < 0.001). The 2-year arrhythmia-free rate after EAT-based ablation was 72% in the PAF group and 73% in the PerAF group (p = 0.614). LA-EAT tends to overlie the major anatomical GP areas including most of the active GP response sites and CFAEs associated with AF. Ablation of GPs and CFAEs may explain the long-term efficacy of EAT-based ablation following extensive encircling pulmonary vein isolation (EEPVI) for AF.

Minimizing discordances in automated classification of fractionated electrograms in human persistent atrial fibrillation.

Ablation of persistent atrial fibrillation (persAF) targeting complex fractionated atrial electrograms (CFAEs) detected by automated algorithms has produced conflicting outcomes in previous electrophysiological studies. We hypothesize that the differences in these algorithms could lead to discordant CFAE classifications by the available mapping systems, giving rise to potential disparities in CFAE-guided ablation. This study reports the results of a head-to-head comparison of CFAE detection performed by NavX (St. Jude Medical) versus CARTO (Biosense Webster) on the same bipolar electrogram data (797 electrograms) from 18 persAF patients. We propose revised thresholds for both primary and complementary indices to minimize the differences in CFAE classification performed by either system. Using the default thresholds [NavX: CFE-Mean ≤ 120 ms; CARTO: ICL ≥ 7], NavX classified 70 % of the electrograms as CFAEs, while CARTO detected 36 % (Cohen’s kappa κ ≈ 0.3, P < 0.0001). Using revised thresholds found using receiver operating characteristic curves [NavX: CFE-Mean ≤ 84 ms, CFE-SD ≤ 47 ms; CARTO: ICL ≥ 4, ACI ≤ 82 ms, SCI ≤ 58 ms], NavX classified 45 %, while CARTO detected 42 % (κ ≈ 0.5, P < 0.0001). Our results show that CFAE target identification is dependent on the system and thresholds used by the electrophysiological study. The thresholds found in this work counterbalance the differences in automated CFAE classification performed by each system. This could facilitate comparisons of CFAE ablation outcomes guided by either NavX or CARTO in future works.Electronic supplementary materialThe online version of this article (doi:10.1007/s11517-016-1456-2) contains supplementary material, which is available to authorized users.

Difference in the maintenance mechanism of atrial fibrillation perpetuated after pulmonary vein isolation between paroxysmal and persistent atrial fibrillation: Effects of subsequent stepwise ablation

BackgroundNeither the atrial fibrillation (AF) maintenance mechanism after pulmonary vein isolation (PVI) nor the mechanism of AF termination via stepwise ablation is clearly understood. MethodsAmong 226 consecutive AF patients (154 paroxysmal (P-AF) and 72 persistent AF (Per-AF) patients), left atrial endocardial non-contact mapping was performed after PVI in the initial 10 P-AF and 16 Per-AF patients to define the AF maintenance mechanism. Subsequently, effect of stepwise catheter ablation (linear roof lesion and complex fractionated atrial electrogram (CFAE) following PVI) was evaluated in all patients. ResultsAfter PVI, AF was maintained by the activation around isolated PV/mitral annulus, focal discharge and disorganized activations mostly observed over residual CFAE region (pivoting activation, wave break and fusion). CFAE region in P-AF was smaller than Per-AF after PVI (1.6±2.1 vs. 7.7±2.5cm2, p<0.0001). The frequency of pivoting activation, wave break and fusion in P-AF were lower than those in Per-AF (1.9±2.0 vs. 11.8±5.0 times/s; p<0.0001, 0.1±0.3 vs. 3.6±2.5 times/s; p<0.001, 5.8±3.6 vs. 9.8±3.2 times/s; p<0.01). AF termination was more frequent in P-AF than Per-AF (94.8% vs 81.9%, p=0.0019). AF termination by PVI alone was more frequent in P-AF than Per-AF (85.6% vs. 18.6%, p<0.0001). However, AF termination via roof line and/or CFAE ablation was less frequent in P-AF than Per-AF (14.4 vs. 81.4%, p<0.0001). ConclusionsDisorganized activations after PVI, more prominent in Per-AF, were associated with residual CFAE region. Most P-AF was terminated by PVI alone, however additional roof line lesion and CFAE ablation were necessary to terminate Per-AF, consistent with mapping results.

The modified stepwise ablation guided by low-dose ibutilide in chronic atrial fibrillation trial (The MAGIC-AF Study).

Complex fractionated atrial electrograms (CFAE) are targeted during persistent atrial fibrillation (AF) ablation. However, many CFAE sites are non-specific resulting in extensive ablation. Ibutilide has been shown to reduce left atrial surface area exhibiting CFAE. We hypothesized that ibutilide administration prior to CFAE ablation would identify sites critical for persistent AF maintenance allowing for improved procedural efficacy and long-term freedom from atrial arrhythmias. Two hundred patients undergoing a first-ever persistent AF catheter ablation procedure were randomly assigned to receive either 0.25 mg of intravenous ibutilide or saline placebo upon completion of pulmonary vein isolation. Complex fractionated atrial electrogram sites were then targeted with ablation. The primary efficacy endpoint was the 1-year single procedure freedom from atrial arrhythmia off anti-arrhythmic drugs. Similar procedural characteristics (procedure, fluoroscopy, and ablation times) were observed with both strategies despite a greater reduction in left atrial surface area with CFAE sites (8 vs. 1%, P < 0.0001) and AF termination during CFAE ablation with ibutilide compared with placebo (75 vs. 57%, P = 0.007). The primary efficacy endpoint was achieved in 56% of patients receiving ibutilide and 49% receiving placebo (P = 0.35). No significant differences in peri-procedural complications were observed in both groups. Despite a reduction in CFAE area and greater AF termination during CFAE ablation, procedural characteristics and clinical outcomes were unchanged when CFAE ablation was guided by ibutilide administration. ClinicalTrials.gov number: NCT01014741.

The impact of adjunctive complex fractionated atrial electrogram ablation and linear lesions on outcomes in persistent atrial fibrillation: a meta-analysis.

In persistent atrial fibrillation (PsAF), success rates for pulmonary vein isolation (PVI) alone are limited and additional substrate modification is often performed. The two most widely used substrate-based strategies are the ablation of complex fractionated atrial electrograms (CFAE) and left atrial linear ablation (LALA) at the roof and mitral isthmus. However, it is unclear whether adjunctive CFAE ablation or LALA add significant benefit to PVI alone. We performed a meta-analysis to better gauge the benefit of adjunctive CFAE ablation and LALA in PsAF. Electronic databases were systematically searched. We included studies that examined the impact of CFAE ablation or LALA in addition to a PVI-based strategy on clinical outcomes in PsAF. We included both randomized and non-randomized studies. Totally 10 studies (n = 1821) were included: 6 evaluating CFAE ablation, 3 LALA, and 1 both approaches. In comparison with PVI alone, the addition of CFAE ablation [RR 0.86; 95% confidence intervals (CI) 0.64, 1.16; P = 0.32] or LALA (RR 0.64; 95% CI 0.37, 1.09; P = 0.10) offered no significant improvement in arrhythmia-free survival. However, adjunctive CFAE ablation was associated with significant increases (P < 0.05) and LALA non-significant increases in procedure and fluoroscopy times. In PsAF, the addition of CFAE ablation or LALA, in comparison with PVI alone, offers no significant improvement in arrhythmia-free survival. Furthermore, they are associated with increases in both procedural and fluoroscopy times. The optimal ablation strategy for PsAF is currently unclear and needs further refinement.

Abstract 17457: Does Additional Complex Fractionated Atrial Elecrogram Guided Ablation After Linear Ablation Improve Clinical Outcome of Catheter Ablation for Longstanding Persistent Atrial Fibrillation? A Prospective Randomized Study

Introduction: Although long-lasting circumferential pulmonary vein isolation (CPVI) is a corner stone of catheter ablation for atrial fibrillation (AF), it is not clear whether additional linear or complex fractionated atrial electrogram (CFAE)-guided ablations improve clinical outcome in patients with long-standing persistent AF (L-PeAF). Hypothesis: The purposes of this study were to compare CFAE maps before and after linear ablation, and to test whether additional CFAE ablation after linear ablation improves clinical outcome of L-PeAF. Methods: This study enrolled 119 consecutive L-PeAF patients (male 72.8%, 61.7±10.6 years old) who underwent RFCA. After baseline CFAE mapping, we conducted CPVI and linear ablations (posterior box lesion and anterior line). If AF maintained after linear ablation, we mapped CFAE again, and randomly assigned the patients to linear ablation group (Line, n=45) and additional CFAE ablation group (CFAE+Line, n=48). The patients whose AF terminated or changed to AT were excluded from randomization and classified as AF-Stop group (n=26). We compared pre- and post-linear ablation CFAE maps and clinical outcomes of CFAE+Line, Line, and AF-Stop groups. Results: 1. Mean CFAE-cycle length (CL) was significantly prolonged (203.65±40.35 ms to 264.17±39.03 ms, p&lt;0.001) and CFAE area was reduced (15.49±14.95% to 7.95±9.36%, p&lt;0.001) after linear ablation. Post-linear ablation CFAE was mainly located at left atrial (LA) appendage, septum, and posterior inferior LA. 2. There were no differences in total procedure time (p=0.441), ablation time (p=0.144), and procedure-related complication rate (p=0.955) among three groups. 3. During 17.4±10.5 month follow-up period, clinical recurrence rates were 30.4% in CFAE+Line group, 12.8% in Line group, and 16.7% in AF-Stop groups, respectively (Log rank, p=0.138). 4. Additional CFAE ablation after linear ablation did not improve clinical outcome of catheter ablation at all in patients with L-PeAF (HR 2.11, 95% CI 0.91 - 4.89, p=0.082). Conclusions: Linear ablation prolonged CFAE-CL and localized CFAE area in patients with L-PeAF. However, CFAE guided ablation in addition to linear ablation and CPVI did not improve clinical outcome of catheter ablation.