Ablation Outcome In Patients Research Articles

Abstract 9548: De Novo Atypical Atrial Flutters: Locations, Mechanisms, and Long Term Outcomes Post Ablation

Introduction: Atypical atrial flutter (aAFL) has been described in the absence of prior atrial interventions, but prognosis for these patients after catheter ablation is poorly defined. This study was designed to define characteristics and ablation outcomes in patients with de novo aAFL. Methods: Patients with non-CTI flutter, without prior ablation or cardiac surgery, were identified from an institutional database. Clinical, mapping, ablation, and follow up data were compared to an equally sized group of randomly selected patients with typical flutter (tAFL). Results: The 35 patients with aAFL had 45 mapped non-CTI flutters. aAFL patients had similar age, gender, cardiovascular comorbidities, and LA size compared to tAFL, except aAFL patients had higher LVEF (54 ± 12 vs 46 ± 19%, p=0.04). Cycle length of aAFL was longer (268 [IQR 231, 310] vs 230 [220, 250] msec, p=0.0006). aAFL localized to the RA in 16, LA in 28, and biatrial in 1. Mechanisms were macroreentry in 23 (8 RA, 15 LA) and localized reentry in 22 (8 RA, 14 LA). Areas of scar predominated in the lateral/posterior RA (N=9), anterior LA (N=14), and posterior LA (N=6). Most common LA circuits were perimitral reentry (N=8) and roof dependent (N=8), including dual loop reentry. Localized reentry occurred most commonly in the anterior LA (N=7) or involved the pulmonary veins (N=4). Ablation was acutely successful for 41/45 aAFLs (91%) and for all tAFL. After median follow-up of 33 [6.6, 55] mo, atrial arrhythmias recurred in 23/34 aAFL patients (68%) and 24/35 tAFL patients (69%); those with aAFL had earlier recurrences (1.9 [0.43, 11] vs 19 [2.3, 36] mo, p=0.01). First recurrences after aAFL ablation were more likely to be AFL rather than AF (83% vs 17%) whereas tAFL patients were more likely to recur with AF (24% AFL vs 76% AF, p<0.0001). Conclusions: Patients with de novo aAFL tend to have spontaneous scar, commonly in the lateral/posterior RA and anterior LA, consistent with an atrial myopathy. Ablation can be accomplished with high acute success, but recurrent atrial arrhythmias are common, most re-presenting with atrial tachycardias. Future studies should clarify if a substrate-based approach or adjunctive antiarrhythmic drugs would result in better long term outcomes.

Catheter ablation of ganglionated plexi in patients with adenosine triphosphate-induced atrial fibrillation after pulmonary vein isolation.

Intravenous ATP may induce atrial fibrillation (AF). ATP shares similar receptor-effector coupling systems with acetylcholine. However, the association between an ATP injection and the hyperactivity of the intrinsic cardiac autonomic nervous system, known as ganglionated plexi (GPs), is not well understood. We describe a series of patients with non-pulmonary vein (PV) trigger sites provoked by an ATP injection, and assess the feasibility of a ganglionated plexus (GP) ablation. We retrospectively analyzed 547 patients (69% male; mean age 67.4 ± 10.4years; 38.5% non-paroxysmal AF) who underwent a total of 604 ablation procedures. Intravenous ATP was administered with an isoproterenol infusion during sinus rhythm after a pulmonary vein isolation in 21.3%, Box isolation in 78.6%, and SVC isolation in 52.0% of the procedures, respectively. We reviewed the incidence, the distribution of the foci, and the ablation outcomes in patients with ATP-induced AF. A total of seven patients (1.3%) had ATP-induced AF. Foci were identified in the coronary sinus (CS) in six patients, right atrial posterior wall (RAPW) adjacent to the interatrial groove in two, mitral annulus in two, ligament of Marshall in one, right septum below the foramen ovale in one and left atrial posterior wall in one, respectively. Among these trigger foci, we confirmed the vagal response by high-frequency stimulation in the CS and RAPW in six and two patients, respectively. After a median RF time of 2.9min (range 2.5-11.3) targeting these foci, in five of six patients who received a repeat ATP injection, the AF became non-inducible. ATP-provoked trigger foci were distributed among certain sites that overlapped with the distribution of the GPs. The GP ablation was effective for this rare, but challenging situation.

Mutation in a non-desmosomal gene is associated with poor outcome of endo-epicardial ventricular tachycardia ablation in patients with nonischaemic cardiomyopathy

Abstract Background Nonischaemic cardiomyopathy (NICM) represents a heterogenic disorder with a variable arrhythmogenic substrate. Its location is often epicardial and catheter ablation in this location proved to be an effective therapeutic modality in NICM patients with recurrent ventricular tachycardias (VTs). Purpose To determine the impact of the type of genetic mutation on the long-term outcome of endo-epicardial ablation in patients with NICM. Methods We investigated 82 patients (age 47±15 years, 10 women) with NICM who underwent endo-epicardial ablation for frequent VTs. Of them, 59% had a history of failed endocardial ablation. Patients had a left ventricular ejection fraction of 44±14% and all were implanted with cardioverter-defibrillator. One hundred candidate genes were examined using the new generation sequencing technique. Results Mutation in genes coding desmosomal complex (genes: PKP2, DSC, DSP, and DSG) was found in 30% of patients (“desmosomal” group). In 23% of patients, other gene mutations (genes: LMNA/C, MYH7, DES, TTN, RYR2, TPM1, MYPN, FLNC, and SCN5A) were detected (“non-desmosomal” group). In 46% of subjects no pathogenic mutation could be identified (“none” group). During a mean follow up of 34±33 months, patients in the “non-desmosomal” group were at significantly higher risk of VT recurrence and death/heart transplant compared to patients in the “desmosomal” group (Figure 1). Conclusion Potentially pathogenic mutation can be detected in about half of patients with NICM undergoing endo-epicardial VT ablation. Most commonly, mutations can be found in genes coding desmosomal complex and the endo-epicardial ablation is then associated with a satisfactory low VT recurrence rate and excellent survival in the long-term. On the other hand, patients with a mutation in non-desmosomal genes have poor outcomes despite endo-epicardial ablation. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Supported by Ministry of Health of the Czech Republic, grant nr. NV18-02-00237 Figure 1

Detection of left atrial fibrosis in LGE-MRI and high-density electroanatomical mapping: finding a threshold for the best match

Abstract Background Fibrotic atrial cardiomyopathy plays an important role in determining the outcome of ablation in patients with atrial fibrillation (AF). Two main methods are being used for the evaluation of fibrosis: voltage based high-density (HD) electroanatomical mapping (EAM) and late gadolinium enhancement MRI (LGE-MRI). The comparability between both methods in detecting fibrosis has not been systematically investigated. Method LGE-MRIs of the left atrium (LA) were performed in 21 patients (pts). The extent and distribution of fibrosis were evaluated using a custom-designed software generating a 3D model of the LA. HD-electroanatomical maps were recorded in each patient using a 3D mapping software (CARTO3, Biosense Webster). The MRI-3D-model of the LA was then integrated in the 3D mapping system. After processing the HD maps and the MRI models by excluding the mitral valve, pulmonary veins and the left atrial appendage, the atrium was then divided into three independent areas: anterior and posterior wall, and intra-atrial-septum. The LGE areas were then measured using the 3D surface measurement tool. These were then compared to the low voltage areas (LVA) measured in the HD maps using three different cut-off values of 0.5 mV, 0.7 mV, and 1.0 mV. Results In MRI 5 pts had no significant fibrosis (fibrotic area ≤1 cm2). 16 pts showed fibrosis on the anterior wall (7.3 cm2±6.2 cm2). 15 pts showed fibrosis at the septum (5 cm2±2.9 cm2) and 9 pts showed fibrosis on the posterior wall (3.9 cm2±2.5 cm2). Using EAM with a cut-off voltage value of 0.7 mV, 3 pts had no fibrosis. 15 pts showed fibrosis on the anterior wall (7.7 cm2±6.8 cm2). 16 pts showed fibrosis at the septum (5.3 cm2±4.1 cm2) and 8 patient showed fibrosis on the posterior wall (3.5 cm2±1.8 cm2). Using a lower voltage cut-off value of 0.5 mV, fibrosis was evident in less patients with smaller fibrotic areas in LA. Whereas when using a cut-off value of 1.0 mV more patients showed a greater extent of the LA fibrosis. We found significant differences between the two methods (MRI vs. 3D-mapping) when using a cut-off value of 0.5 mV (Wilcoxon, p<0.001 for the anterior and posterior wall and the septum). A cut-off value of 1.0 mV also showed significant differences on the anterior and posterior walls (Wilcoxon, p<0.001). When using a cut-off value of 0.7 mV we did not find a significant difference between the two groups (Wilcoxon, p=0.365) with a correlation coefficient of 0.97 (Pearson; p<0.001) for the anterior wall, 0.69 (Pearson; p=0.007) for the posterior wall, and 0.81 (Pearson; p=0.002) for the septum. Conclusion A cut-off value of 0.7 mV in EAM correlated best with the findings in LGE-MRI. The currently used predefined cut-off value of 0.5 mV in EAM may lead to an underestimation of the actual extent of the fibrosis. Increasing the voltage cut-off value towards 0.7 mV may therefore lead to a better characterisation of fibrotic atrial cardiomyopathy. Funding Acknowledgement Type of funding sources: None.

Distribution of triggers foci and outcomes of catheter ablation in atrial fibrillation patients in different age groups.

Atrial fibrillation (AF) prevalence increases with age. Aging affects the substrate properties of the left atrium (LA) and the outcomes of catheter ablation for treating AF. We investigated the AF trigger distribution and catheter ablation outcomes in patients of different ages with AF. 1585 patients with AF (1181 paroxysmal and 404 non- paroxysmal AF) who had undergone catheter ablation were enrolled. The patients were divided into young (20-40 year-old, n=175), middle-aged (41-64 year-old, n=1134), and old (≥ 65 year-old, n=276) groups. Electrophysiological characteristics and AF trigger sites were recorded. The incidence of AF with only non-pulmonary vein (non-PV) foci was higher in the young group than in the other groups (8.6%vs. 3.6%vs. 3.3%, p<0.01). Non-PV foci were more commonly located in the superior vena cava (SVC) in the young group than in the other groups (13.1%vs. 7.8%vs. 6.5%, p=0.03). The left atrium (LA) mean voltage was higher and the incidence of very late recurrence after AF ablation was lower in the young group than in the other groups. However, the final AF recurrence rate after multiple procedures and complication rates were similar among all the groups at a mean follow-up of 5.6 years. The young patients with AF had a higher incidence of only non-PV foci, mostly located in SVC, than the middle-aged and old patients. Our study highlights the importance of identifying the non-PV foci in catheter ablation of young patients with AF.

The impact of height on recurrence after index catheter ablation of paroxysmal atrial fibrillation.

The relationship between height and incident atrial fibrillation (AF) has recently been demonstrated. We aimed to evaluate the impact of height on outcomes of ablation in patients with drug-refractory symptomatic paroxysmal AF (PAF). A total of 689 patients (470 males; age, 53.0 ± 11.7years) with symptomatic paroxysmal AF receiving index catheter ablation (CA) between 2003 and 2013 were enrolled in this study. The baseline characteristics, ablation, and follow-up results were evaluated. The patients were categorized according to the quartiles of height for each sex. Patients in the lower quartiles of height had a lower incidence of AF recurrence (log-rank p = 0.022). Height in female patients was strongly associated with AF recurrence (p = 0.027) after an index ablation in the 6.33 ± 4.32years of follow-up. Female patients > 159cm in height had a higher likelihood of AF recurrence after index CA (HR = 2.01, 95% CI: 1.24-3.25, p = 0.005) than that in those below this height. In computed tomography (CT) scan, the superoinferior diameter of the left atrium (LA) correlated with body height in females, but not in male patients. Height is associated with AF recurrence after the index CA of PAF in female patients. In Asian populations, women above height 159cm are twice as likely to have AF recurrence post-ablation as shorter women.

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.

B-PO02-122 LONG-TERM MORTALITY AND VENTRICULAR ARRHYTHMIA OUTCOMES IN ELECTRICAL STORM PATIENTS WHO UNDERGO ABLATION

Data regarding long-term ablation outcomes in patients with electrical storm (ES) is limited. ES treated with ablation were compared to those who did not undergo ablation to determine differences in a composite of 1-year all-cause mortality and ventricular arrhythmia (VA) rehospitalization. Secondary outcomes include in-hospital all-cause and VA-induced mortality. Single center, retrospective study including consecutive patients admitted to the coronary ICU with ES between April 2014 - 2020. ES was defined as ≥ 3 isolated sustained VA or ICD therapies within 24 hours. Of 214 patients admitted with ES, 79 underwent ablation. Overall demographics include mean age 64.2 +/- 13.2 years, 83.2% male, mean EF 30 +/- 13%, mean PAINESD score 17.5 +/- 6.2, and 82.7% had an ICD. 45 patients had a prior ablation. 20 (26.7%) ablations required mechanical circulatory support. The clinical VA was inducible in 84.8% of ablations and was successful in 73.4%, partially successful in 15.2%, and unsuccessful in 11.3%. ES treated with ablation had a lower composite 1-year all-cause mortality and VA readmission (39.24% vs. 64.44%; HR 0.50 [95% CI 0.33 - 0.76]; p 0.001; Figure 1) and 1-year all-cause mortality (29.11% vs. 48.89%; HR 0.51 [95% CI 0.32 - 0.82], p 0.005; Figure 2) compared to those who did not. 1-year VA recurrence (24.1% vs. 40.0%; p 0.059), in-hospital all-cause mortality (11.3% vs. 18.0%; p 0.18), and in-hospital VA-induced mortality (8.9% vs. 16.5%; p 0.11) were not statistically significant. ES patients treated with ablation had a 50% decreased risk of 1-year all-cause mortality and VA rehospitalization compared to those who were not ablated.

Value of cardiac 123I-mIBG scintigraphy in prognosis of catheter ablation outcome in patients with atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Russian Science Foundation Background. Previous studies show inconsistent results on the role of innervation imaging (with 123I-mIBG) in predicting late atrial fibrillation (AF) recurrence after catheter ablation (CA). These studies included patients with paroxysmal AF and studied prognostic value of post CA I-123-mIBG parameters. Current study investigated the ability of pre CA 123-I-mIBG imaging to predict late AF recurrence in patients with persistent AF. Thus, the goal of the present study was to estimate the utility of pre-procedural cardiac 123I-mIBG scintigraphy to identify patients at risk for AF recurrence after CA. Methods. 123I-mIBG cardiac imaging was performed before CA in 82 patients with persistent AF. Patients were followed for 12 months. A blanking period of 3 months was applied. The primary endpoint of the study was AF recurrence between 3 and 12 months after ablation. Results. Multivariable analysis demonstrated that late heart-to-mediastinum ratio (H/Mlate) and washout rate (WR) were independent predictors of AF recurrence. ROC-curve analysis data showed that H/Mlate &amp;lt;1.6 (sensitivity 73.53 %, specificity 81.3%, AUC 0,792 , p &amp;lt; 0.001) and WR &amp;gt; 25,11 (sensitivity 70.6%, specificity 70.8.3%, AUC 0,712 , p &amp;lt; 0.001) indicate high probability of AF relapses during 12 months after CA. Kaplan-Meier analysis showed that the H/Mlate &amp;lt; 1.6, WR &amp;gt; 25,11 and LAD &amp;gt; 45 mm significantly increase the risk of AF recurrence after CA (p &amp;lt; 0.001, p &amp;lt; 0.001, p &amp;lt; 0.025 respectively). Conclusion. Pre CA parameters of global cardiac sympathetic activity estimated by 123I-mIBG scintigraphy are associated with late AF relapses in persistent AF patients.

Atrial substrate characterization in patients with atrial fibrillation and hypertrophic cardiomyopathy: Evidence for an extensive fibrotic disease

IntroductionData regarding the left atrial (LA) electroanatomical substrate in patients with hypertrophic cardiomyopathy (HCM) and atrial fibrillation (AF) are missing. In this electroanatomical mapping (EAM) study, we evaluated the extent of LA fibrosis and its impact on catheter ablation outcomes in patients with HCM and AF. Materials and methodsHigh-density LA EAM was performed during AF in 28 consecutive patients with obstructive HCM and AF (42.9% displayed paroxysmal AF and 57.1% persistent AF). Propensity score (PS) matching analysis was performed to reduce the impact of potential confounding factors. PS were derived to match patients at a 1:1 ratio. Patients were matched according to age, sex and LA diameter. After PS, 28 non-HCM patients with AF were selected, and served as controls. Two different cut-off values of bipolar signal amplitude were investigated for fibrosis characterization (≤0.25 mV and ≤ 0.4 mV). HCM patients underwent pulmonary vein antral isolation (PVAI) and roof line, while non-HCM patients PVAI only. ResultsAfter the 3-month blanking period, 10 HCM patients (35.7%) displayed atrial arrhythmia recurrence. HCM patients with arrhythmia recurrence showed significantly greater low voltage areas defined as either bipolar voltage ≤0.25 mV (22.5 ± 10% vs. 5.5 ± 6.4%, p = 0.001) or ≤ 0.4 mV (32 ± 13.9% vs. 5.9 ± 5.1%, p < 0.001). The presence of low voltage areas ≤0.4 mV greater than 14.1% of the total LA area also predicted arrhythmia recurrence with excellent sensitivity (100%) and specificity (100%). Univariate analysis revealed that the extent of LA fibrosis was the only predictor of AF recurrence. After PS matching with non-HCM patients, patients with HCM exhibited wider fibrotic regions ≤0.25 mV compared to non-HCM patients (p = 0.016). ConclusionsHigh-density EAM reveals extensive LA fibrotic disease in patients with HCM, an event with certain implications in catheter ablation outcomes.

Catheter ablation of idiopathic outflow tract ventricular arrhythmias with low intraprocedural burden guided by pace mapping.

BackgroundThere are limited data comparing ablation outcomes in patients with low intraprocedural burden of ventricular arrhythmias (VA) undergoing a pace mapping (PM)–guided strategy vs those with high burden guided by standard activation mapping strategy (non-PM).ObjectiveWe sought to determine if catheter ablation–guided by PM of low-intraprocedural-burden idiopathic outflow tract VA would be noninferior compared to non-PM-guided ablation.MethodsOutcomes of catheter ablation of idiopathic outflow tract VA in 22 patients with a low burden of intraprocedural VA using PM-guided ablation were compared to 44 patients with a high burden of intraprocedural VA undergoing ablation using standard techniques.ResultsSixty-six patients were included (age 46.5 ± 14.8 years; 68% female, left ventricular ejection fraction 59% ± 5%). Within the PM group, 24-hour preprocedure premature ventricular complex (PVC) burden was 9.5% (interquartile range [IQR] 4%–13.8%), number of pace maps 33.6 ± 18.5, surface area of ≥95% pace map correlation 1.9 ± 1.2 cm2, with best pace map correlation 96% (IQR 92%–97%). Within the non-PM group, 24-hour preprocedure PVC burden was 13.5% (IQR 6.6%–30%), earliest activation time -33.7 ± 9.9 ms. Procedural duration, general anesthesia administration, fluoroscopy dose, and complications were all comparable. Following final procedure, 24-hour VA burden (PM 0% [IQR 0–2.4%] vs non-PM 0% [IQR 0–4.2%], P = .98), along with VA-free survival at 6-month follow-up (PM 77% vs non-PM 71%, P = .77), were both comparable.ConclusionIn patients with low intraprocedural burden of outflow tract VA, PM-guided catheter ablation can accurately identify the VA site of origin, leading to outcomes comparable to those achieved with standard ablation techniques.

Treatment of symptomatic atrial tachycardia in complex anatomic conditions: use and outcome of ablation in patients after damus-kaye-stansel surgery

Abstract Funding Acknowledgements Type of funding sources: None. Background Atrial tachycardias (AT) are amongst the most frequent complications in adult patients with congenital heart disease (ACHD). Their incidence mainly depends on age and complexity of underlying defect. AT has a marked impact on morbidity and mortality and is associated with sudden cardiac death particularly in complex ACHD patients. The arrhythmic substrate can be variable from re-entry to multifocal resulting in demanding requirements for electrophysiologic ablation procedures (EP) and thus, relatively high rates of recurrence. Methods and results Retrospective analysis of ACHD patients with prior Damus-Kaye-Stansel (DKS) surgery treated at one of the largest specialized tertiary centers for ACHD patients worldwide. Analysis focussed on occurrence of AT, respective treatment and outcome of EP. Over a median observation time of 15 years, 13 patients with prior DKS surgery and complex congenital heart defects of different types but uniformly Fontan circulation, were identified (median age 22.0 years (IQR 20.5 – 25.5), 76.9% male, 92.3% NYHA Class I, median systemic ventricular ejection fraction 58.5%, 69.2% extracardiac tunnel). Seven patients (53.8%) presented with symptomatic AT (median cyclic length 440 ms (IQR 360.0 – 517.5)). Of these, six patients underwent EP. Median procedure time was 180.5 min (IQR 160.8 – 274.5), median fluoroscopy time 1.56 min (IQR 0.51 – 4.73) and radiofrequency time 851 sec (265.0 -2005.0). Remote magnetic navigation was used to access ablation site through a retrograde access via the aortic as well as the neo-aortic valve. Three-dimensional image integration aided in mapping and ablation. Throughout the procedure as well as in follow-up visits, no reportable complications were observed. After a mean of 1.5 procedures, all analysed patients stayed complaint-free throughout a median time-interval of 13 months. Conclusion AT are frequent in complex univentricular situations after Damus-Kaye-Stansel surgery (53.8%). Although more than one procedure (mean 1.5) was necessary to achieve satisfactory results even in experienced hands, EP appears to be an appropriate treatment strategy in this young and otherwise healthy patient cohort. According to our analysis, EP is feasible and safe in centers with knowledge of specific anatomic characteristics of congenital heart disease and when the appropriate technical infrastructure is present. Access to ablation site was performed by remote magnetic navigation in the majority of procedures. The floppy catheter was navigated through the neo-aortic as well as through the aortic valve without observable peri- or postinterventional complications. Mapping with three-dimensional image integration facilitated EP and led to a relatively low radiation exposure with the known benefits for the patient as well as for the healthcare professionals involved in the procedure. Abstract Figure.

Pleomorphic ventricular tachycardia in dilated cardiomyopathy is a strong predictor of VT recurrence after ablation independent of cardiac function: Comparison with ischemic cardiomyopathy

Abstract Funding Acknowledgements Type of funding sources: None. Background Compared to ICM patients, subgroups of DCM patients show higher VT recurrence rates after catheter ablation (CA), despite similar percentages of acute non-inducibility. Pleomorphic VTs (PL-VT) have been reported in ICM patients with fibrotic remodeling and progressive heart failure. Diffuse fibrosis is the dominant scar pattern in DCM. In these patients PL-VT may occur independent of cardiac function. Aim To investigate the prevalence, relation with cardiac function, and impact of PL-VT on long-term ablation outcome in patients with ICM and DCM. Methods Consecutive patients with ICM or DCM undergoing VT ablation (ICM 2009-2016; DCM 2008-2018) were included. PL-VT was defined as ≥1 spontaneous change of the 12-lead VT morphology lasting for ≥6 consecutive beats during the same induced VT episode. Complete procedural success was defined as non-inducibility of any VT at the end of the procedure. Patients were followed for VT recurrence and mortality. Results A total of 247 patients (86% men, age 63 ± 13 years) underwent CA for monomorphic VT, 152 with ICM (62%), and 95 with DCM (38%). Complete procedural success was achieved in 39% in ICM vs. 37% in DCM, respectively. PL-VT was observed in 22 and 29 patients with ICM and DCM, respectively (14% vs. 31%, P = 0.003). Among ICM patients, PL-VT was associated with a lower LVEF (PL-VT+ 28 ± 9% vs. PL-VT- 34 ± 12%, P = 0.02) and only occurred if LVEF was &amp;lt;40%. In contrast, in DCM patients, PL-VT was not related to cardiac function and occurred in 27% of patients with an EF &amp;gt;40%. After propensity score matching to account for baseline differences (age, gender, LVEF, prior VT ablation, VT storm, and amiodarone use), between ICM vs. DCM patients, the PLVT incidence was 4 times higher in DCM patients (7% [4/60] vs. 28% [17/60], P = 0.003). During a median follow-up of 30 months, 79 (32%) patients died (ICM 48 [32%), DCM 31 [33%], P = 0.88) and 120 (49%) patients had VT recurrence (ICM 59 [39%], DCM 61 [64%], P &amp;lt; 0.001). In Kaplan-Meier analyses, inducibility of PL-VT was associated with mortality only in ICM but not in DCM patients. In contrast, PL-VT was associated with poorer VT-free survival in both ICM and DCM patients (figure). In multivariate analyses, PL-VT remained a significant predictor of VT recurrence in DCM (HR 3.00, 95% CI 1.75-5.11, P &amp;lt; 0.001), independent of LVEF, (likely) pathogenic genetic mutation, amiodarone, endocardial low bipolar/unipolar voltage areas, dominant anteroseptal substrate, and non-complete acute procedural success, but not in ICM. Conclusions PL-VT was associated with poor systolic function and mortality in ICM, whereas it was independent of LVEF and the most decisive parameter for VT recurrence in DCM. This data suggests that PL-VT in DCM is a marker of a complex arrhythmic substrate challenging to control by CA. Abstract Figure. Kaplan-Meier analyses

Long-term outcomes of empirical extra-pulmonary vein linear ablation in patients with persistent atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by grants [HI18C0070] and [HI19C0114] from the Korea Health 21 R&amp;D Project, Ministry of Health and Welfare, and a grant [NRF-2020R1A2B01001695] from the Basic Science Research Program run by the National Research Foundation of Korea (NRF). Background Although extra-pulmonary vein (PV) left atrial (LA) linear ablation has been performed during catheter ablation (CA) of persistent atrial fibrillation (PeAF), the long-term efficacy and safety of this procedure have not yet been verified. Purpose We investigated whether an anterior line (AL) and posterior box ablation (POBA) in addition to circumferential PV isolation (CPVI) improves the rhythm without worsening the LA function in PeAF patients. Methods We retrospectively compared the additional AL + POBA and CPVI alone groups in 604 patients with PeAF who underwent regular rhythm follow-ups (16.9%; males 79.3%, 58.5 ± 10.7 years of age) after propensity score matching. The primary endpoint was AF recurrence after single procedures and secondary endpoints were the cardioversion rate, response to anti arrhythmic drugs, LA changes, and re-conduction rates of the de-novo ablation lesion set. Results After a mean follow-up of 45.2 ± 33.6 months, the clinical recurrence rate did not significantly differ between the two groups (log-rank p = 0.554) despite longer procedure times in the AL + POBA group (p &amp;lt; 0.001). Atrial tachycardia recurrences (p = 0.001) and the cardioversion rates after ablation (p &amp;lt; 0.001) were higher in the AL + POBA group than CPVI group. AL + POBA was associated with better rhythm outcomes in patients with large anterior LA volume indices (p for interaction 0.037) and low mean LAA(left atrial appendage) voltages (p for interaction 0.019). In repeat procedures, the LA pulse pressure elevation was significant after the AL + POBA. Conclusion In patients with PeAF, an AL + POBA in addition to the CPVI did not improve the rhythm outcomes nor influence the long-term safety, and lead to more extended procedures. Procedure outcomes OverallAL + POBACPVIp-value(n = 604)(n = 302)(n = 302)Procedure time, min190.8 ± 62.6226.9 ± 49.4154.6 ± 52.8&amp;lt;0.001Ablation time, sec5079 ± 19566420 ± 13723738± 1475&amp;lt;0.001Overall complications24 (4.0)13 (4.3)11 (3.6)0.835Early recurrence, n (%)277 (45.9)129 (42.7)148 (49.0)0.142Recurrence type AT, n (% in early recur)77 (27.8)51 (39.5)26 (17.6)&amp;lt;0.001Clinical recurrence within 1-year, n(%)116 (19.2)52 (17.2)65 (21.5)0.256Recurrence type AT, n (% in clinical recur)60 (23.1)46 (30.7)14 (12.7)0.001Cardioversion, n (% in total recur/ % overall)105 (40.4/17.4)74 (49.3/24.5)31 (28.1/10.3)&amp;lt;0.001POBA, posterior box ablation; AL, anterior line; CPVI, circumferential pulmonary vein isolation; AT, atrial tachycardia;Abstract Figure. Long term ablation outcome

Influence of baseline inducibility and activation mapping on ablation outcomes in patients with structural heart disease and ventricular tachycardia.

Stand-alone substrate ablation has become a standard ventricular tachycardia (VT) ablation strategy. We sought to evaluate the influence of baseline VT inducibility and activation mapping on ablation outcomes in patients with structural heart disease (SHD) undergoing VT ablation. Single center, observational and retrospective study including consecutive patients with SHD and documented VT undergoing ablation. Baseline VT induction was attempted before ablation in all patients and VT activation mapping performed when possible. Ablation was guided by activation mapping for mappable VTs plus substrate ablation for all patients. Ablation outcomes and complications were evaluated. One hundred and sixty patients were included and were classified in three groups according to baseline VT inducibility:group 1 (non inducible, n = 18), group 2 (1 VT morphology induced, n = 53), and group 3 (>1 VT morphology induced, n = 89). VT activation mapping was possible in 35%. After a median follow-up of 38.5 months, baseline inducibility of greater than 1 VT morphology was associated with a significant incidence of VT recurrence (42% for group 3 vs. 15.1% for group 2% and 5.6% for group 1, Log-rank p < .0001) and activation mapping with a lower rate of VT recurrence (24% vs. 36.3%, Log-rank p = .035). Baseline inducibility of greater than 1 VT morphology (hazards ratio [HR]: 12.05, 95% confidence interval [CI]: 1.60-90.79, p = .016) was an independent predictor of VT recurrence while left ventricular ejection fraction less than 30% (HR: 1.93, 95% CI: 1.13-3.25, p = .014) and advanced heart failure (HR: 4.69, 95% CI: 2.75-8.01, p < .0001) were predictors of mortality or heart transplantation. Complications occurred in 11.2% (5.6% hemodynamic decompensation). Baseline VT inducibility and activation mapping may add significant prognostic information during VT ablation procedures.

Clinical significance of J waves with respect to substrate characteristics and ablation outcomes in patients with arrhythmogenic right ventricular cardiomyopathy

Abstract Aims J-wave syndrome in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) has been linked to an increased risk of ventricular arrhythmia. We investigated the significance of J waves with respect to substrate manifestations and ablation outcomes in patients with ARVC. Methods and results Forty-five patients with ARVC undergoing endocardial/epicardial mapping/ablation were studied. Patients were classified into two groups: 13 (28.9%) and 32 (71.1%) patients with and without J waves, respectively. The baseline characteristics, electrophysiological features, ventricular substrate, and recurrent ventricular tachycardia/fibrillation (VT/VF) were compared. Among the 13 patients with J waves, only the inferior J wave was observed. More ARVC patients with J waves fulfilled the major criteria of ventricular arrhythmias (76.9% vs. 21.9%, P = 0.003). Similar endocardial and epicardial substrate characteristics were observed between the two groups. However, patients with J waves had longer epicardial total activation time than those without (224.7 ± 29.9 vs. 200.8 ± 21.9 ms, P = 0.005). Concordance of latest endo/epicardial activation sites was observed in 29 (90.6%) patients without J waves and in none among those with J waves (P &amp;lt; 0.001). Complete elimination of endocardial/epicardial abnormal potentials resulted in the disappearance of the J wave in 8 of 13 (61.5%) patients. The VT/VF recurrences were not different between ARVC patients with and without J waves. Conclusion The presence of J waves was associated with the discordance of endocardial/epicardial activation pattern in terms of transmural depolarization discrepancy in patients with ARVC.

Comparison of the catheter ablation outcome in patients between targeting the entrance and exit of the reentry circuit in verapamil-sensitive atrial tachycardia originating from the atrioventricular-node vicinity

Verapamil-sensitive atrial tachycardia originating from the atrioventricular node vicinity (AVN-AT) can be eliminated with radiofrequency energy (RF) deliveries targeting either the entrance or exit of its reentry circuit. However, the outcome of these different approaches has not been clarified well. Thus, we compared the catheter ablation outcome targeting the entrance of reentry circuit, identified by the entrainment method (Ent-Group; 21 patients) with that targeting the earliest atrial activation site (EAAS) during AT (Exit-Group; 16 patients). There was no significant difference in the tachycardia cycle length (441.4 ± 87.4 vs. 392.8 ± 64.8ms, p = 0.0704) or distance from the His bundle (HB) site to the EAAS (6.5 ± 2.0 vs. 7.6 ± 1.8mm, p = 0.0822) between the Ent- and Exit-Groups. However, distance from the successful ablation site to the HB site in the Ent-Group was significantly longer than that in the Exit-Group (13.4 ± 3.1 vs. 7.6 ± 1.8mm, p < 0.0001), resulting in more frequent transient atrioventricular block episodes in the Exit-Group than Ent-Group (31.3 vs. 0%, p < 0.01). Initial ATs (AT1s) were terminated in all patients in both Groups. However, ATs accompanied by shifting in the EAAS (AT2) were induced more frequently in the Exit-Group than Ent-Group (50.0 vs. 14.3%, p < 0.02) after eliminating AT1. RF deliveries to the EAAS eliminated all AT2s. The number of RF deliveries was greater in the Exit-Group than Ent-Group (6.9 ± 3.3 vs. 3.9 ± 1.6, p < 0.001). In conclusion, RF ablation targeting the entrance sites can avoid AVN injury and is superior in reducing the number of RF deliveries and occurrence of different ATs than targeting the exit sites in the AVN-AT.

Prognostic value of cardiac magnetic resonance septal late gadolinium enhancement patterns for periaortic ventricular tachycardia ablation: Heterogeneity of the anteroseptal substrate in nonischemic cardiomyopathy

Ventricular tachycardia (VT) from the anteroseptal subtype of nonischemic cardiomyopathy has a high probability of recurrence after catheter ablation. The purpose of this study was to determine the predictive value of septal scar patterns by late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) on ablation outcomes in patients with VT arising from an anteroseptal substrate. Patients with periaortic VT arising from an anteroseptal substrate with preprocedural wideband LGE-CMR were divided into 2 groups by the degree of longitudinal septal LGE extension as full-length septal (≥80% anteroposterior length) or partial septal (<80% anteroposterior length). Septal LGE volumes were quantified in those with and without VT recurrence. Among 234 patients referred for scar-related VT ablation between 2017 and 2020, 25 patients (92% male; age 64 ± 8 years) and a total of 108 VTs were analyzed. A greater number of VT morphologies were induced in patients with full-length septal LGE compared to partial septal LGE (median [interquartile range]: 5 [3-9] vs 2 [1-4]; P = .005). Patients with VT recurrence had larger septal LGE volumes compared to those without recurrence (11.4 mL [8.8-13.9] vs 4.2 mL [0-9.5]; P = .012). At median follow-up of 16 months (5-22), overall freedom from VT recurrence was 52% and significantly higher in patients with partial septal LGE than in those with full-length septal LGE (80% vs 20%; P = .005). VT originating from an anteroseptal substrate is associated with heterogeneous patterns and extent of CMR septal scar. Preprocedural imaging may substratify this challenging patient population for the propensity for multiple induced VT morphologies and recurrence after catheter ablation.

Abstract 15077: Serum-transthyretin: Does it Predict Ablation Outcome in Patients With Atrial Fibrillation?

Background: Transthyretin (TTR), a transport protein produced by liver, is closely associated with amyloidosis. Tetramers of TTR circulating in blood can dissociate to monomers that misassemble into amyloid fibrils. Although amyloidosis is a frequent finding in aged atrial fibrillation (AF) patients, the relevance of serum-TTR in AF is unknown. Objective: We evaluated if post-ablation change in serum-TTR level has any prognostic association with long-term ablation outcome in AF patients. Methods: One-hundred-forty-five patients (age: 62.8 ± 6.2years, male 69%, non-paroxysmal AF 41%, BMI : 30.8 ± 6.3) were included in this prospective study. Patients with chronic inflammatory conditions or taking anti-inflammatory drugs were excluded. All patients received pulmonary vein isolation plus isolation of left atrial posterior wall and superior vena cava. In non-paroxysmal AF, non-PV triggers identified by isoproterenol challenge were ablated. Fasting blood samples were collected at baseline and 24-hours post-ablation. Samples were tested for TTR using an automated quantitative test. Results: Mean TTR concentration was 27.94±6.5 mg/dL at baseline and 26.33±9.2 mg/dL at 24-hour post ablation (p&lt;0.001). Of the 145 patients, post-ablation TTR remained unchanged or increased in 65 (44.8%) and decreased in 80 (55.2%) patients at 24-hour post-ablation. Mean decrease in the serum TTR in these 80 patients was 7.9± 4.38 mg/dL. At 3 years of follow-up, the recurrence rate was 28/80 (35%) in the group with decreased-serum TTR and 11/65 (17%) in the population with unchanged/increased TTR (p=0.01). Post-ablation decrease in TTR was found to be an independent predictor of recurrence (OR 2.64 (1.19-5.85), p=0.01). Conclusion: Our findings demonstrated significant association of higher recurrence rate with decreased serum-TTR tetramer level at 24-hour post-ablation.

Abstract 13646: Clinical Profile and Ablation Outcomes in Patients With Arrhythmogenic Right Ventricular Cardiomyopathy and Biventricular Involvement

Background: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a progressive disease which can involve both ventricles. This study aimed to elucidate the clinical profile and ablation efficacy in Chinese ARVC patients with biventricular (BiV) involvement. Methods and Results: Based on cardiovascular magnetic resonance findings, 255 ARVC patients were divided into two groups: the BiV involved group (n=137) and the isolated right ventricular (RV) involved group (n=118). Patients with BiV involvement were more likely to suffer from heart failure (28.5% vs. 8.5%; P &lt;0.001) and recurrent syncope (32.8% vs. 21.2%; P =0.038), and presented with lower heart transplantation-free survival and composed endpoint (death or heart transplantation)-free survival (all P &lt;0.05). Of the 255 subjects, 52 BiV involved patients and 77 isolated RV involved patients underwent catheter ablation for ventricular tachycardia (VT). After 5 years’ follow-up, the outcomes including VT recurrence and all-cause mortality in 2 groups showed no difference (all P &gt;0.05). The age, amount of induced VT during electrophysiology study and non-acute procedural success (partial success, defined as inducing the same VT with cycle length 30% longer after ablation; substrate modification only) were independent predictors of VT recurrence in BiV involved patients (all P &lt;0.05). Conclusion: BiV involvement in ARVC indicated worse symptoms and poor prognosis. Nonetheless, catheter ablation remained effective for VT control in this population. The younger age, more induced VTs and non-acute procedural success were associated with VT recurrence after ablation.