non-PV Triggers Research Articles

Catheter ablation approach and outcome in HIV+ patients with recurrent atrial fibrillation.

Earlier studies have shown a clear association between severity of human immunodeficiency virus (HIV) infection and incident atrial fibrillation (AF). We present the long-term outcome of catheter ablation (CA) and electrophysiological characteristics in HIV+ AF patients. This study evaluated 1438 consecutive AF patients [31 (2.15%) with HIV and 1407 (97.8%) without HIV diagnosis] undergoing their first CA at our center. A total of 31 HIV patients and 31 controls were generated by propensity matching, based on calculated risk factor scores, using a logistic model. During first procedure, all received isolation of pulmonary vein (PV) + posterior wall and superior vena cava. Non-PV triggers, defined as ectopic triggers originating from sites other than PVs, were identified at the redo ablation with high-dose isoproterenol challenge. Clinical characteristics were not different between the groups. When compared to the control, by the end of 5 years after the first procedure, recurrence was significantly greater in HIV group [100% vs. 54%, p < .001]. Among patients that underwent redo ablation non-PV triggers were higher in HIV group [93.5% vs. 54%, p < .001], and most frequently originated from the coronary sinus [67.7% vs. 45.2%, p < .001] and left atrial appendage [41.9% vs. 25.8%, p < .001]. After focal ablation of non-PV trigger, no difference in arrhythmia recurrence between two groups [80.6% vs. 87.1%, p = .753] at 1-year follow up was found. Our findings suggest that non-PV triggers are highly prevalent in HIV+ AF patients resulting in higher rate of the mid- and long-term arrhythmia recurrence.

Usefulness of simultaneous isolation of the coronary sinus and the left atrial inferior wall for persistent atrial fibrillation refractory to box isolation

Abstract Funding Acknowledgements Type of funding sources: None. Background In patients who are refractory to box isolation (BoxI) and have atrial fibrillation (AF) substrate in left atrial inferior wall (LAIW), LAIW isolation is effective, but the procedure is highly difficult because the connection between LAIW and coronary sinus (CS) is dense. In this study, we report four cases of persistent AF in which simultaneous isolation of LAIW and CS was so effective. Methods and Results Case 1 is a 76-year-old female with persistent AF who had undergone BoxI and failed mitral isthmus block (MIB) creation. However, AF and atrial tachycardia (AT) persisted. In the 4th session, chemical ablation of Marshall vein was performed, and AF/AT was terminated, and MIB was created. Thereafter, multiple ATs were still inducible by rapid atrial pacing. Because AT substrate seemed to be confined to LAIW, we attempted to isolate LAIW by performing linear ablation between the right inferior pulmonary vein (RIPV) and posteroseptal mitral annulus (MA) near CS ostium, and linear ablation parallel to CS along posterior MA. However, LAIW isolation could not be achieved. Finally, CS ostial ablation from right atrium (RA) succeeded in simultaneous isolation of LAIW and CS. CS burst pacing could induce AT confined to LAIW and CS although RA maintained sinus rhythm (SR). Rapid RA pacing could not induce AT/AF. Case 2 is a 78-year-old female with persistent AF who completed BoxI and MIB creation. Raid RA pacing induced AF. Because cycle length of LAIW was apparently shorter than RA, we attempted to isolate LAIW. Firstly, we performed linear ablation from RIPV ostium to posterior MA. During linear ablation, AF converted to AT, and finally RA returned to SR while AT was still sustained within LAIW and CS. This tachycardia was a reentrant tachycardia circling LAIW and CS. After this AT returned to SR by linear ablation within LAIW, LAIW and CS were not isolated during SR. CS ostial ablation from RA succeeded in simultaneous LAIW and CS isolation. Case 3 is a 74-year-old female with persistent AF refractory to BoxI. Although non-pulmonary vein (non-PV) trigger was documented in LAIW, the precise origin of non-PV trigger could not be identified due to infrequency. Case 4 is a 64-year-old male with persistent AF refractory to BoxI. He had undergone catheter ablation three times. Fractionation map showed that AF substrate was likely located in LAIW. Therefore, we attempted to isolate LAIW in Case 3 and 4. We performed MI ablation, linear ablation between RIPV ostium and posteroseptal MA, and CS ostial ablation from RA, which succeeded in simultaneous isolation of LAIW and CS in both cases. AF has never recurred in Case 1 and 2. SR could be maintained with antiarrhythmics in Case 3 and 4. Conclusions In patients with persistent AF refractory to BoxI, if LAIW has AF/AT substrate or non-PV triggers, simultaneous isolation of LAIW and CS may be a new therapeutic strategy. Simultaneous isolation of LAIW and CS requires ablation at CSos from RA.

Evaluation of redo procedures in blanking period following atrial fibrillation catheter ablation

Abstract Funding Acknowledgements Type of funding sources: None. Background and Objective Although early recurrence after atrial fibrillation catheter ablation (AFCA) is a risk factor for late recurrence, 3 months blanking period (BP) is generally an accepted period to wait for re-do intervention. In this study, we aimed to evaluate the cases of early recurrences in BP after AFCA using either radiofrequency (RF) or cryo-balloon (CB). Method One thousand fifty patients who had undergone AFCA between January 2017 and January 2022 were evaluated retrospectively. Seventy-five patients had documented tachyarrhythmia episodes in the BP. Among these, 33 patients underwent electrophysiologic study (EPS) and re-do catheter ablation for atrial tachyarrhythmia. Results The index procedure was performed with CB in 15 (45.5%) patients and RF in 18 (54.5%). 20 (60.1%) patients had paroxysmal atrial fibrillation before the index procedure. EPS was done routinely in all patients after the recurrence. In 3 patients, typical AVNRT was induced in EPS, the slow pathway was ablated, and substrate mapping (SM) was not performed. In 19 patients, atrial tachycardia, whose 3 were typical atrial flutter, was induced. Pulmonary vein (PV) reconnection was detected in 7 patients whose three also had non-PV triggers. Conclusion PV reconnection is responsible for the recurrence during the period of BP in a small percentage of patients. However, additional triggers are present in most. The optimal approach for the recurrence occurring in BP is still controversial. Performing EPS and SM may reduce the recurrence rate in this patient group.

PO-03-100 A VALIDATION STUDY OF THE ACCURACY OF THE ATRIAL PACE MAP ASSESSED WITH INTRACARDIAC PATTERN MATCHING: POTENTIAL UTILITY OF NON-PULMONARY VEIN MAPPING

The elimination of all non-PV triggers is known to be an additional strategy for the PVI of AF. However, activation mapping of infrequent non-PV triggers is challenging. We hypothesized that pace mapping assessed by intracardiac pattern matching (ICPM) with the CARTO3 mapping system yields a good diagnostic performance to locate atrial premature complexes (APCs). Furthermore, we assessed whether the combined use of both atrial electrograms for the ICPM improved the accuracy as compared to using electrograms only in the LA. In 16 patients, atrial pacing at 21 sites (LA anterior: 5, LA posterior: 8, LA septum: 3, and RA lateral: 5) was arbitrarily determined as APC foci, and the intracardiac atrial sequence of the obtained APC was set as a reference. The matching ICPM score was assessed during pace mapping around the APC focus. ICPM was determined by CS electrograms (CS group) or those from both the CS and RA (CS-RA group). The surface area was measured for each matching score. The mean pace mapping number was 213±113 points and was similar between the CS and CS-RA groups (181±81 vs. 237±114 points, P=0.09). By pace mapping with ICPM, maximum matching scores of ≥90% were obtained at all pacing origins in both the CS and CS-RA groups. At least 1 site with a matching score ≥98% was more often obtained in the CS group than CS-RA group (14/21 APCs [67%] vs. 7/21 APCs [33%], P=0.03), but sites with matching scores ≥95% were similarly obtained between the CS and CS-RA groups (17/21 APCs [81%] vs. 19/21 APCs [90%], P=0.66). The sites with matching scores ≥90% were all APCs in both groups. The surface area of matching scores ≥98% was similar between the CS and CS-RA groups (0.2 [0.1, 1.3] vs. 0.35 [0.1, 5.5] cm2, P=0.23), but that ≥95% was smaller in the CS-RA group than CS group (0.2 [0.1, 0.4] vs. 0.6 [0.15, 4.8] cm2, P=0.03). Of LA origins, the surface area for matching scores ≥95% was equal between the CS and CS-RA groups (0.2 [0.1, 0.5] vs. 0.5 [0.1, 1.3] cm2, P=0.19), but for RA origins, it was smaller in the CS-RA group than CS group (0.2 [0.1, 2.3] vs. 8 [0.3, 13.0] cm2, P=0.05) (Figure). ICPM-guided pace mapping may be useful to locate infrequent non-PV APCs. A combined use of RA and CS electrograms may improve the mapping quality and may be essential for identifying origins of RA non-PV APCs. RF applications targeting the area with a matching score ≥95% may be reasonable for a non-PV trigger ablation.

AB-452666-3 CATHETER ABLATION IN ASIAN PATIENTS WITH ATRIAL FIBRILLATION AND HYPERTROPHIC CARDIOMYOPATHY: ELECTROPHYSIOLOGICAL CHARACTERISTICS OF RECURRENCE AND LONG-TERM CLINICAL OUTCOMES

Catheter ablation (CA) is an effective and safe strategy for treating atrial fibrillation (AF) in patients with hypertrophic cardiomyopathy (HCM). We investigated the electrophysiological characteristics of recurrence at a tertiary referral center and compared the long-term clinical outcomes after CA therapy with patients who did not receive CA. Patients with HCM and AF who underwent CA (group 1, n=60) or pharmacological treatment (group 2, n=298) from 2006 to 2021 were enrolled. The patients’ baseline characteristics and electrophysiological features were examined to elucidate the reason for AF recurrence after CA in part I of the study (group 1). The clinical outcomes of group 1 and group 2 patients were compared using a propensity score (PS)-matched method in part II. In part I, the most common cause of recurrence was pulmonary vein (PV) reconnection (86.5%), followed by non-PV triggers (40.5%), cavotricuspid isthmus flutter (29.7%), and atypical flutter (24.3%). Thyroid disease (HR: 14.713, p<0.001), diabetes (HR: 3.074, p=0.034), and non-paroxysmal AF (HR: 4.012, p=0.007) independently predicted recurrence. After the first recurrence, the patients who underwent repeat CA demonstrated better arrhythmia-free status (74.1%) compared to those who underwent drug-escalation therapy (29.4%, p=0.004). In part II, after matching, PS-group 1 patients had significantly better outcomes in all-cause mortality, heart failure hospitalization, and left atrium reverse remodeling than PS-group 2 patients. Patients who underwent CA had better clinical outcomes than those who did not receive CA. The main recurrence predictors were thyroid disease, diabetes, and non-paroxysmal AF.

AB-452663-3 DISTRIBUTION OF TRIGGERS IN THE LEFT ATRIAL POSTERIOR WALL IN AF PATIENTS UNDERGOING CATHETER ABLATION

Having a common embryologic origin with the pulmonary veins (PVs), left atrial posterior wall (LAPW) is considered to be a source of non-PV triggers that facilitate maintenance of atrial fibrillation (AF). However, the benefits of electrical isolation of the posterior wall (PWI) is still debated with contradictory data originating from different ablation approaches. . We report the distribution of triggers in the LAPW area in AF patients undergoing repeat ablation. Consecutive AF patients undergoing catheter ablation between 2015 and 2022 were included in this analysis. PVs were isolated first. Next, high-dose isoproterenol challenge (up to 30μg/min) was used to disclose triggers in the PW by moving the circular mapping catheter along the PW down to the level of coronary sinus, which were targeted using additional RF energy. We defined lower part of LAPW as the area between the line joining the inferior borders of the inferior PV-encircling lesions and the coronary sinus. The endpoint was to achieve electrical isolation, as documented by absence of any electrical activity in the PW. Of the 10,390 AF ablations performed during the specified time period, 5843 (56.2%) had triggers mapped and ablated in the LAPW area. Triggers were seen to be originating from the part of the PW between the PVs in 3809 (65.2%), from the lower part of the PW in 2028 (34.7%) and focal triggers from all over the PW including the lower part in 1519 (26%) cases. All triggers were targeted for ablation. Figure 1 demonstrates the triggers arising from lower PW. Ectopic triggers in the LAPW were documented to be arising from the lower part of the PW in a large number of cases. Thus, operators should consider extending the ablation to include the lower LAPW area to maximize the benefits of PWI.

Comparison of advanced generation cryoballoon ablation and ablation index-guided pulmonary vein isolation with non-pulmonary vein trigger induction test and additional ablation in paroxysmal atrial fibrillation.

An ablation index (AI)-guided pulmonary vein isolation (PVI) or 2nd generation cryoballoon (CB)-PVI has been shown to reduce the atrial fibrillation (AF) burden by 99% despite the absence of ablation of non-pulmonary vein (PV) triggers in patients with paroxysmal AF. The purpose of this study was to investigate the effects of PVI alone strategy using 2nd generation CB compared with AI-guided PVI with an additional induction test and subsequent AF trigger ablation. We investigated 223 patients with symptomatic paroxysmal AF who underwent an initial PVI between August 2018 and August 2020. The study patients were divided into 2 groups: CB-PVI without an induction test (CB-PVI alone group, n = 82) and AI-guided PVI with an induction test and subsequent additional ablation of non-PV triggers (AI-PVI plus group, n = 141). In the AI-PVI plus group, a total of 62 non-PV triggers were induced in 38 patients, and non-PV triggers in 22 patients were completely ablated. The procedure time and left atrium dwell time were significantly shorter in the CB-PVI alone group than AI-PVI plus group. There were no significant differences in the incidence of procedural complications between the 2 groups (P = 0.650). The AF free survival rate in the CB-PVI alone group and AI-PVI plus group was 80% vs. 80% at 24months (P = 0.969). An PVI alone strategy using advanced generation CB did not differ in the clinical outcomes compared with an AI-guided PVI strategy with an induction test and subsequent ablation of non-PV triggers in the patients with paroxysmal AF.

Empirical superior vena cava isolation improves outcomes of radiofrequency re-ablation in pulmonary vein isolation non-responders: A 2-center retrospective study in China.

Pulmonary vein isolation (PVI) is the standard ablation strategy for treating atrial fibrillation (AF). However, the optimal strategy of a repeat procedure for PVI non-responders remains unclear. This study aims to investigate the incidence of PVI non-responders in patients undergoing a repeat procedure, as well as the predictors for the recurrence of repeat ablation. A total of 276 consecutive patients who underwent repeat ablation from August 2016 to July 2019 in two centers were screened. A total of 64 (22%) patients with durable PVI were enrolled. Techniques such as low voltage zone modification, linear ablation, non-PV trigger ablation, and empirical superior vena cava (SVC) isolation were conducted. After the 20.0 ± 9.9 month follow-up, 42 (65.6%) patients were free from atrial arrhythmias. A significant difference was reported between the recurrent and non-recurrent groups in non-paroxysmal AF (50 vs. 23.8%, p = 0.038), diabetes mellitus (27.3 vs. 4.8%, p = 0.02), and empirical superior vena cava (SVC) isolation (28.6 vs. 60.5%, p = 0.019). Multivariate regression analysis demonstrated that empirical SVC isolation was an independent predictor of freedom from recurrence (95% CI: 1.64-32.8, p = 0.009). Kaplan-Meier curve demonstrates significant difference in recurrence between empirical and non-empirical SVC isolation groups (HR: 0.338; 95% CI: 0.131-0.873; p = 0.025). About 22% of patients in repeat procedures were PVI non-responders. Non-paroxysmal AF and diabetes mellitus were associated with recurrence post-re-ablation. Empirical SVC isolation could potentially improve the outcome of repeat procedures in PVI non-responders.

Abstract 11177: Pulmonary Vein Reconnections Predict Good Clinical Outcomes After a Second Catheter Ablation of Persistent Atrial Fibrillation: Insight From the EARNEST-PVI Trial

Introduction: The effect of an extensive ablation strategy in addition to pulmonary vein (PV) isolation is still controversial in persistent atrial fibrillation (AF) ablation. Electrical PV reconnection is an important confounder affecting the trial results. Objectives: To evaluate the PV reconnection rate and association between the reconnection and AF recurrence after a re-do AF ablation in the EARNEST-PVI trial (NCT03514693). Methods: The analysis was performed using the extended data of the EARNEST-PVI trial (N=512), a randomized controlled trial to evaluate ablation strategies for persistent AF, which was conducted in the Osaka region of Japan. During a median follow-up of 47 months, a total of 126 (25%) patients underwent a re-do AF ablation. Among them, 120 (median age, 68 years; 36% female; 31% long-standing persistent AF, 95% contact force-sensing catheter use) whose follow-up data were available after the 2 nd AF ablation were enrolled in this study. Results: PV reconnections were observed in 75 (63%) patients. Although there was no difference in age, gender, long-standing persistent AF, and CA strategy during the index procedure, AF recurrence within 1 year was more frequent in patients with PV reconnections (81.3% vs. 64.4%, p = 0.039). During a median follow-up of 31 months after the re-do AF ablation, patients with PV reconnections had a lower clinical recurrence rate than those without (38.7 vs. 44.4%, log-rank p = 0.047). However, additional linear ablation did not affect the recurrence rate. Even after adjustment for age, gender, long-standing persistent AF, and presence of non-PV triggers, Cox regression analysis revealed that a number of reconnected PVs of ≥2 was independently associated with a lower recurrence of AF after the 2 nd AF ablation (hazard ratio, 0.36; 95% confidence interval, 0.19-0.67; p = 0.001). Conclusions: Among patients who underwent a redo-AF ablation in the EARNEST-PVI trial, about two-thirds exhibited PV reconnections. Patients with ≥2 PV reconnections had better clinical outcomes than those with ≤1 PV reconnections. A durable PV isolation is an important pre-requisite before exploring any additional ablation strategies for persistent AF.

Prevalence and distribution of non-pulmonary vein atrial fibrillation triggers in real-world clinical settings

Abstract Background Epidemiology of non-pulmonary vein (PV) triggers of atrial fibrillation (AF) is not fully known. Purpose This study aimed to clarify the prevalence and distribution of non-PV triggers in real-world clinical settings of AF catheter ablation. Methods One-thousand and twenty patients undergoing AF ablations were retrospectively analyzed (mean age 65 years old, 702 males (69%), 506 paroxysmal and 514 non-paroxysmal). Induction and observation of AF triggers were attempted using intravenous isoproterenol/adenosine triphosphate and repeated direct current cardioversion during AF in each session. Documentable non-PV AF triggers were characterized in the studied population. Premature atrial contractions that did not initiate AF were excluded. Results A hundred and twenty-six non-PV triggers were documented in 108 patients (10.6%). Non-PV trigger was documented in 6.3% of 1st session cases, whereas 30.9% of recurrent cases undergoing multiple sessions (p&amp;lt;0.0001). Left atrial (LA) posterior wall was the most prevalent site (N=34), followed by 30 intra-atrial septum (IAS), 29 superior vena cava (SVC), 13 crista terminalis, 7 right atrial (RA) free wall, 6 LA anterior wall, 3 coronary sinus (CS), 3 left atrial appendage, and 1 persistent left superior vena cava (LSVC). We classified those non-PV triggers into 4 groups; 43 LA, 33 thoracic veins (SVC, CS and LSVC), 30 IAS and 20 RA. Thoracic vein/RA origins were more prevalently detected in paroxysmal AF cases (57%) compared to non-paroxysmal AF (28%) (p&amp;lt;0.01). Conversely, LA origin was more prevalently detected in non-paroxysmal AF cases (48%) compared to paroxysmal AF (20%) (p&amp;lt;0.01). Conclusions Prevalence of non-PV trigger in cases undergoing multiple sessions is extremely high, suggesting a particular importance of non-PV trigger targeting in patients with recurrent AF undergoing 2nd or 3rd ablation sessions. Progressive nature of AF with newly generated AF triggers should be under consideration. Distributions of non-PV triggers are largely different between paroxysmal and non-paroxysmal AF. These findings may help ablation strategy regarding non-PV trigger targeting in practice. Funding Acknowledgement Type of funding sources: None.

Impact of very early recurrence of atrial fibrillation after cryoballoon ablation.

Although much has been discussed about the early recurrence of atrial fibrillation (ERAF) after cryoballoon ablation (CBA), the clinical impact of very early recurrence of atrial fibrillation (VERAF) after CBA remains unclear. This study aimed to investigate the impact of VERAF after CBA. We enrolled 236 consecutive patients who underwent an initial CBA for paroxysmal atrial fibrillation between February 2017 and December 2020 in our hospital. These patients were categorized into three groups: VERAF group who experienced an initial recurrence of atrial tachyarrhythmia within 48 h after CBA, late-ERAF (LERAF) group who experienced an initial recurrence of atrial tachyarrhythmia between 48 h and 3 months after CBA, and non-ERAF (NERAF) group who did not experience a recurrence of atrial tachyarrhythmia within 3 months after CBA. We investigated the late recurrence of AF (LRAF, defined as recurrence of atrial tachyarrhythmia more than 3 months after CBA), and the incidence of non-pulmonary vein (PV) triggers in the patients who experienced a repeat ablation procedure due to LRAF. VERAF group had a higher incidence of freedom from LRAF than LERAF group (p=0.032) and a lower incidence of freedom from LRAF than NERAF group (p =0.002). Moreover, VERAF group had the highest incidence of non-PV triggers at repeat ablation procedure among the three groups (p =0.003). While ERAF was a predictor of LRAF, VERAF was less related to LRAF among the patients with ERAF after CBA. Furthermore, VERAF might be associated with non-PV triggers.

Comparing the efficacy of catheter ablation strategies for persistent atrial fibrillation: a Bayesian analysis of randomized controlled trials.

Catheter ablation has been recommended as the first-line treatment option for selected patients with atrial fibrillation (AF). However, a widely accepted ablation strategy for persistent AF (perAF) has not yet been established. The benefits of ablation strategies are not conclusive for perAF. There is an urgent need to systematically analyze the results of previous studies and rank these treatment strategies to guide clinical practice. Randomized controlled trials (RCTs) on ablation for perAF were included. The primary outcome was recurrence of atrial tachyarrhythmia (AT) after a single ablation procedure. A Bayesian random-effects network meta-analysis model was fitted. Twenty-three studies were included in the analysis. A total of 3394 patients and 22 ablation strategies were found in the involved studies. The ablation strategy of pulmonary vein isolation (PVI) + electrical box isolation of the left atrial posterior wall (PBOX) + non-PV trigger ablation (NPV) showed the best treatment effect in terms of the primary outcome. The individualized ablation strategies of mapping and ablation combined with PVI, such as PVI + rotors, PVI + dispersion areas, and PVI + low voltage zone (LVZ) also showed a better ablation effect in perAF. PVI ablation is a widely used strategy in perAF and is recognized as a cornerstone procedure for perAF. The PVI + PBOX + NPV strategy showed the highest rank in our analysis. Mapping and ablation strategies that could provide individualized substrate modification also showed a better rank in our analysis and are believed to be a promising direction for the treatment of perAF.

Safety and acute performance of paroxysmal and early persistent atrial fibrillation ablation using temperature-controlled, very high power, short duration catheter with a new radiofrequency generator

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Biosense Webster Inc. Background/Introduction The temperature-controlled contact force radiofrequency (RF) ablation catheter (QDM) has 6 thermocouples to maintain target catheter tip temperature and 3 tip microelectrodes for high local signal resolution. It has an enhanced irrigation profile to reduce char formation. Three prospective multicenter trials demonstrated safety and effectiveness of the QDM catheter using very high-power, short duration (vHPSD; 90W/4s), conventional power (CP; ≤50W) or combined modes. These studies were performed with an older RF generator. A new generator was developed to support the full suite of legacy, temperature controlled and multichannel ablation catheters, but has not yet been formally tested in a clinical setting. Purpose Evaluate safety and acute performance of the QDM catheter with the new 90W-enabled generator. Methods This prospective, multicenter study (4 Canadian sites) used vHPSD as primary mode for Pulmonary Vein (PV) isolation with overlapping 3mm lesion tags for anterior, inferior and roof of left atrium. Adjacent, non-overlapping lesions were used posteriorly to avoid esophageal heating. CP mode was used at operator discretion for thicker atrial tissue, touch ups, and non-PV triggers (Figure). Primary endpoint was confirmed entrance block in all PVs after adenosine and/or isoproterenol challenge. Acute procedural and safety data were assessed. Systematic char evaluation was performed. Results Effectiveness analysis included 38/40 subjects with mean 110-day follow up (mean age, 61.7 ± 9.5 years; 63.2% male). Hypertension (47.4%) and congestive heart failure (15.8%) were the most common comorbidities. Fourteen subjects were treated with version V0 of the generator, and 24 subjects were treated using version V1c which included further software adjustments to the power titration, and current response to optimize performance. Combination vHPSD/CP workflow was used for PV isolation in 28 (75.7%) subjects and vHPSD was used solely in 10. A non-study catheter was used in 1 subject during connectivity troubleshooting. Primary endpoint of entrance block confirmation was achieved in 37/38 subjects and in all 37 subjects treated with study catheter only. No incidences of char or device-related adverse events were reported. There were no noted differences in the endpoints evaluated between the V0 and V1c groups. Median (Q1/Q3) RF application times for ablating PVs was 13.0 min (9.0/16.0) for the entire cohort. Median (Q1/Q3) time to achieve PV isolation in vHPSD-only group was 9 (7/12) min, and 14 (11/18) min, respectively. Conclusion(s) Consistent with data from prior 3 clinical studies, QDM catheter with the new 90W-enabled generator demonstrated the acute safety and effectiveness of temperature-controlled AF ablation with short PV ablation time and no char observed.

PO-635-06 IMPACT OF PRIOR ABLATION STRATEGIES ON PROCEDURE EFFICIENCY AND ABLATION STRATEGY IN REPEAT PROCEDURES FOR ATRIAL FIBRILLATION

Many ablation strategies, such as box isolation and linear ablation, have been proposed to improve outcomes in atrial fibrillation (AF) ablation. While the ablation of non-pulmonary vein (PV) targets has gained considerable traction, whether these strategies should be incorporated at the index procedure remain to be addressed. To examine the correlation between ablation strategies at index procedure and the need for creation of non-PV lesion sets at repeat procedure. Data from patients who underwent a first repeat procedure for AF were prospectively collected between February to September of 2021. Where the history of index procedure was available, procedure characteristics and ablation strategies at repeat procedure were grouped and compared based on ablation strategies at index procedure A total of 343 patients [Paroxysmal (PAF): 209, Persistent(PersAF): 134] were included in this analysis. Patients were grouped into PV, PV+ linear (including posterior wall isolation), and PV+other (including focal, rotor, alcohol ablation, and hybrid procedure) based on ablation strategy at index procedure. Non-PV lesion sets were delivered in 52.6% (n=110) and 76.9% (n=103) of the PAF and PersAF cases at repeat procedure. For PAF, elimination of non-PV triggers at the redo procedure was documented in 47.6%, 94.4%, and 83.3% of the PV, PV+linear, and PV+other group, respectively (P<0.05). For PersAF, 73.1%, 83.3%, and 90.9% of the PV, PV+linear, and PV+other group received lesion sets beyond PV isolation at redo (Table 1). More non-PV lesions were delivered per patient at the repeat procedure in the index PV+linear group. At the end of the redo procedure, sinus rhythm was achieved in a similar (p>0.05) proportion of patients across groups in both PAF and PersAF (Table 1). Incorporation of non-PV lesions at index procedure was associated with a more extensive ablation strategy at subsequent repeat procedures. Although a higher percentage of the patients in the index PV+linear and PV+other groups achieved sinus rhythm at the end of the repeat procedure, it did not appear to correlate with the number of non-PV lesion sets created. A larger randomized study may be warranted to investigate long-term clinical outcomes following extensive ablation at index and repeat ablation.

PO-710-05 MANAGEMENT OF A CORONARY SINUS PERFORATION WITH TEMPORARY BALLOON INFLATION DURING CATHETER ABLATION FOR ATRIAL FIBRILLATION

Empiric ethanol infusion into the Vein of Marshall (VoM) to ablate associated sympathetic fibers has been employed as a strategy to treat otherwise non-mappable non-PV triggers in patients with recurrent AF. An infrequent complication of this technique is perforation of the coronary sinus (CS) resulting in a pericardial effusion.

Intra-atrial activation pattern is useful to localize the areas of non-pulmonary vein triggers of atrial fibrillation

Pulmonary vein isolation (PVI) is an established ablation procedure for atrial fibrillation (AF), however, PVI alone is insufficient to suppress AF recurrence. Non-pulmonary vein (non-PV) trigger ablation is one of the promising strategies beyond PVI and has been shown to be effective in refractory/persistent AF cases. To make non-PV trigger ablation more standardized, it is essential to develop a simple method to localize the origin of non-PV triggers. We retrospectively analyzed 37 non-PV triggers in 751 ablation sessions for symptomatic AF from January 2017 to December 2020. Regarding non-PV triggers, intra-atrial activation interval from the earliest in right atrium (RA) to proximal coronary sinus (CS) (RA-CSp) and that from the earliest in RA to distal CS (RA-CSd) obtained by a basically-positioned duodecapolar RA-CS catheter were compared among 3 originating non-PV areas [RA, atrial septum (SEP) and left atrium (LA)]. RA-CSp of RA non-PV trigger (56.4 ± 23.4 ms) was significantly longer than that of SEP non-PV (14.8 ± 25.6 ms, p = 0.019) and LA non-PV (-24.9 ± 27.9 ms, p = 0.0004). RA-CSd of RA non-PV (75.9 ± 32.1 ms) was significantly longer than that of SEP non-PV (34.2 ± 32.6 ms, p = 0.040) and LA non-PV (-13.3 ± 41.2 ms, p = 0.0008). RA-CSp and RA-CSd of SEP non-PV were significantly longer than those of LA non-PV (p = 0.022 and p = 0.016, respectively). Sensitivity and specificity of an algorithm to differentiate the area of non-PV trigger using RA-CSp (cut-off value: 50 ms) and RA-CSd (cut-off value: 0 ms) were 88% and 97% for RA non-PV, 81% and 73% for SEP non-PV, 65% and 95% for LA non-PV, respectively. The analysis of intra-atrial activation sequences was useful to differentiate non-PV trigger areas. A simple algorithm to localize the area of non-PV trigger would be helpful to identify non-PV trigger sites in AF ablation.

Impact of baseline impedance of pulmonary vein antrum on success of catheter ablation for paroxysmal atrial fibrillation guided by ablation index

ObjectiveAblation index (AI) is an effective ablation quality marker. Impedance is also an important factor for lesion formation. The present study evaluated the influence of the baseline impedance in the effect of ablation for atrial fibrillation (AF) guided by AI.MethodsThis was a retrospective study. 101 patients with paroxysmal AF (PAF) were enrolled. All patients underwent radiofrequency ablation guided by the same AI strategy. The ablation strategy was pulmonary vein (PV) isolation with non-PV triggers ablation. The baseline impedance of the ablation points was recorded. The patients were followed up every 3 months or so.ResultsDuring a median follow-up of 12 (4–14) months, freedom from AF/atrial tachycardia recurrence were 82.2%. No difference existed in baseline characteristics between the success group and the recurrence group. The average baseline impedance was 124.3 ± 9.7 Ω. The baseline impedance of the ablation points in success group was lower compared to the recurrence group (122.9 ± 9.4 vs. 130.5 ± 8.8 Ω, P < 0.01). The ratio of impedance drop in the success group was higher than the recurrence group ([8.8 ± 1.4]% vs. [8.1 ± 1.2]%, P = 0.03). Multivariate analysis revealed that baseline impedance, PAF duration and AI were the independent predictors of AF recurrence. The cumulative free of recurrence rate of low-impedance group (≤ 124 Ω, n = 54) was higher than that of high-impedance group.ConclusionBaseline impedance correlates with clinical outcome of radiofrequency ablation for PAF guided by AI. Higher impedance in the same AI strategy may result in an ineffective lesion which probably causes recurrence.

Long-term outcome of patients with long-standing persistent atrial fibrillation undergoing ablation guided by a novel high-density panoramic mapping system: A propensity score matching study.

BackgroundCatheter ablation is a current therapeutic approach for atrial fibrillation (AF). However, its efficacy for long-standing persistent AF remains suboptimal.ObjectiveThe purpose of this study was to test the hypothesis that a panoramic mapping system (CARTOFINDER, Biosense Webster) can guide pulmonary vein (PV) isolation and additional potential AF drivers.MethodsA total of 76 patients with nonparoxysmal AF referred for ablation guided by a novel high-density panoramic mapping system with CARTOFINDER were prospectively enrolled. Of this cohort, 40 patients (52.6%) had long-standing persistent AF (CARTOFINDER group). We then retrospectively screened the patients with long-standing persistent AF undergoing conventional PV isolation and elimination of non-PV triggers during the contemporary period (conventional group). They were matched at a 1:2 ratio (40 patients in group 1 received ablation guided by CARTOFINDER; 80 patients in group 2 receiving conventional PV isolation and elimination of non-PV triggers).ResultsDuring follow-up, patients in group 1 had a lower recurrence AF rate than those in group 2 (P = .040). There was no difference in recurrence of atrial flutter (P = .996) and atrial tachycardia (P = .525). In Cox proportional hazards regression analysis, AF duration and PV isolation along with AF driver ablation using a panoramic mapping system with CARTOFINDER both were independent predictors of recurrent AF after catheter ablation of long-standing persistent AF.ConclusionIdentification of the potential drivers in long-standing AF is crucial. Compared with conventional PV isolation and elimination of non-PV triggers, ablation guided by a high-density panoramic mapping system (CARTOFINDER) might have a better outcome in patients with long-standing persistent AF.

Optimal single procedure strategy of pulmonary vein isolation with cryoballoon or radiofrequency and non-pulmonary vein triggers ablation for non-paroxysmal atrial fibrillation.

BackgroundLimited data exist on pulmonary vein isolation (PVI) using cryoballoon (CB) or radiofrequency (RF) ablation and additional non-pulmonary vein trigger ablation for non-paroxysmal atrial fibrillation (non-PAF). We aimed to assess the outcomes of first-stage catheter ablation for non-PAF patients.MethodsInitial PVI was performed on 734 non-PAF patients (age: 64 ± 10 years; male: 584 (80%)) between September 2014 and June 2018 [315 (43%), CB ablation; 419 (57%), RF catheter]. A logistic regression model was used to match 257 pairs (514 patients) according to the propensity scores (CB or RF group). After PVI, additional non-PV trigger ablation was performed if induced by isoproterenol. We analysed the clinical outcomes of both groups.ResultsThe mean procedural time was significantly shorter in the CB group (125 [range, 89–165] min) than in the RF group (190 [160–224] min; P < 0.001). The 1-year Kaplan-Meier event rate revealed similar atrial fibrillation-free survival rates between the two groups (CB: 77.9%, RF: 82.3%; log-rank P = 0.111). The additional ablation percentage for non-PV foci (CB: 39%, RF: 41%; P = 0.653) and complication incidence (CB: 5%, RF: 4%; P = 0.670) were also similar.ConclusionsIn non-PAF patients, the combination strategy of PVI using CB or RF ablation and non-PV trigger ablation achieved comparable outcomes.

Outcomes of a comprehensive strategy during repeat atrial fibrillation ablation.

Atrial fibrillation (AF) recurs post-ablation in 30-40% of patients. The approach to a repeat ablation, beyond isolation of reconnected pulmonary veins (PVs), is not well established. We sought to prospectively assess outcomes and predictors of recurrence among consecutive patients who underwent repeat AF ablation with a standardized approach. This was a single-center prospective study of consecutive patients who underwent repeat AF ablation. Our protocol consisted of six steps: PV re-isolation, ablation of left atrial low-voltage areas (LVAs), ablation of isoproterenol-induced non-PV triggers, electrophysiology study (EPS) and ablation of induced AVNRT/AVRT, ablation of induced clinical atrial flutters, and lastly empiric ablation as per operator discretion if no other ablation was performed. Among 725 AF ablations performed during the study period, 74 were repeat ablations. Of those undergoing repeat ablation, 53 (72%) had PV reconnection, 30 (41%) had LVAs, seven (10%) had non-PV triggers, five (7%) had AVNRT, and 15 (20%) had typical atrial flutter. Following repeat ablation, arrhythmia-free survival was 65% at 1year. The absence of PV reconnection was the only factor independently associated with recurrence after repeat ablation (recurrence rate 71%, adjusted OR 7.91, 95% CI 2.31-27.16, p = 0.001). A comprehensive approach to repeat AF ablation including PV re-isolation, LVA ablation, non-PV trigger ablation, EPS, and flutter ablation was associated with a 65% 1-year arrhythmia-free survival. The absence of PV reconnection was the only independent predictor of arrhythmia recurrence. Further research is needed to identify therapies beyond PV isolation for patients undergoing repeat ablation.