Predictor Of Arrhythmia Recurrence Research Articles

Effect of hyperuricemia on paroxysmal atrial fibrillation after catheter ablation and influence of alcohol consumption.

Evidence regarding the association between hyperuricemia and arrhythmia recurrence after catheter ablation for paroxysmal atrial fibrillation (AF) is scarce. We investigated whether hyperuricemia predicts arrhythmia recurrence after catheter ablation for paroxysmal AF and the relationship between hyperuricemia and alcohol consumption in AF recurrence. Patients who underwent catheter ablation for paroxysmal AF were divided into the hyperuricemia (index serum uric acid [UA] >7.0 mg/dL; n = 114) and control (UA ≤7.0 mg/dL; n = 609) groups and were followed for a median of 24 (12-48) months after ablation. The hyperuricemia group had more patients with an alcohol intake of ≥20 g/day (33.3% vs. 22.7%, p = .017) and a lower incidence of AF-free survival (p = .019). Similarly, those with an alcohol intake of ≥20 g/day had a lower incidence of AF-free survival than other patients. Multivariate Cox regression analysis revealed the following independent predictors of AF recurrence (adjusted hazard ratio, 95% confidence interval): hyperuricemia (1.64, 1.12-2.40), female gender (1.91, 1.36-2.67), brain natriuretic peptide level >100 pg/mL (1.59, 1.14-2.22), and alcohol consumption ≥20 g/day (1.49, 1.03-2.15) (all p < .05). In addition, causal mediation analysis revealed that alcohol consumption of ≥20 g/day directly affected AF recurrence, independent of hyperuricemia. Patients with hyperuricemia may be at a high risk of arrhythmia recurrence after catheter ablation for paroxysmal AF. Although high alcohol consumption may contribute to increased UA levels, the presence of hyperuricemia may independently predict AF recurrence.

Outcome after cryoballoon ablation of persistent atrial fibrillation in patients with heart failure with preserved ejection fraction versus tachycardiomyopathy: a propensity score-matched analysis

Abstract Introduction Atrial fibrillation (AF) often coexists with heart failure (HF). The aim of the study was to detect differences in outcome between patients with arrhythmia induced cardiomyopathy (AIC)/tachycardiomyopathy and HFpEF undergoing cryoballoon pulmonary vein isolation (cryo-PVI) using a propensity score-based model. Methods In this retrospective observational study, we analysed persistent AF patients with HFpEF and AIC undergoing cryoballoon ablation between 2014 and 2020. AIC was diagnosed ex juvantibus during the first year after ablation at the 3- and 12-month follow-up when LVEF recovered to &amp;gt; 50% and by more than 10% after ablation and a different aetiology for reduced LVEF was excluded. Propensity score matching was used to pair patients based on their age, sex, CHA2DS2-VASc score and left atrial (LA) area. The primary endpoint was the first documented &amp;gt; 30-s recurrence of atrial arrhythmia after a 3-month blanking period during the one-year follow-up. The secondary endpoints were improvements in NYHA class and reduction of LA area. For identification of independent predictors of atrial arrhythmia recurrence after ablation, univariate and multivariate Cox regression analyses were performed. Results Out of 1293 consecutive patients who underwent cryo-PVI, 148 persistent AF patients with HFpEF and 66 patients with AIC were identified. Propensity score matching yielded 46 patients in each group. HFpEF patients were more symptomatic than AIC patients (NYHA: 2.4 +/- 0.5 vs. 2.0 +/- 0,8; p = 0.002). Other baseline characteristics did not differ between the two groups, except LVEF (57 % [IQR: 52-62%] vs. 41% [QR: 35%-45%]; p= 0.002). Kaplan-Meier curves (Figure 1) demonstrated no difference in recurrence-free survival rate between the groups during the 12-month follow-up (71.7 % vs. 56.5%, log-rank P = 0.16). After the 12-month follow-up, the median LA area decreased significantly in the HFpEF group from 25.8 cm2 (IQR: 23.4-29.5 cm2) to 24.6cm2 (IQR: 22.0-29.6 cm2; p = 0.045) and in the AIC group from 26.6 cm2 (IQR: 22.9-31.1 cm2) to 23.0 cm2 (IQR: 18.3-25.2 cm2; p=0.024). At the 12-month follow-up the median LA-area was significantly higher in the HFpEF than in the AIC cohort (p= 0.007). NYHA class improved significantly in both groups from baseline. At the 1-year follow-up NYHA class was similar between both groups (1.6 +/- 0.8 vs. 1.4 +/- 0,6; p = 0.206). After univariate and multivariate analysis, the following predictors of atrial arrhythmia recurrence were identified: body-mass-index (BMI; HR = 1.082, p = 0.015) and LA area (HR = 1.079, p = 0.003). Conclusions Cryoballoon catheter ablation of persistent AF seems to have similar effectiveness on arrhythmia free survival in patients with HFpEF and AIC. NYHA class and LA enlargement improved after ablation in both groups although LA area in HFpEF was higher than in AIC patients at follow-up. BMI and LA area were identified as predictors of arrhythmia recurrence.

Characterisation of ablation strategies at redo catheter ablation for atrial fibrillation and predictors of arrhythmia recurrence: results from the AFREDO registry

Abstract Background Patients who have undergone prior pulmonary vein isolation (PVI) for atrial fibrillation (AF) often require a repeat ablation for AF recurrence. The optimal ablative strategy for the redo procedure and predictors of AF recurrence thereafter remain largely unknown. Purpose We aimed to characterise the ablation strategies applied at re-PVI and identify possible predictors of AF recurrence. Methods Our single-centre, retrospective study included all consecutive patients who underwent first redo PVI at our centre from 2017 to 2022. Inclusion criteria required at least one available follow-up visit within the first 12 months after the redo procedure. Ablation strategies of the initial and redo procedure were captured. Kaplan-Meier curves were used to illustrate time of AF recurrence, as classified by predictors of outcome determined by multivariable regression analyses. Results We included 215 patients (39.1% female) with a median age of 66.6 years (IQR 58.6-73.2) at the time of redo procedure. The initial PVI was cryoablation in 39.9%, RFA in 57.7% and surgical ablation in 2.4%. After the initial procedure, 55.8% had paroxysmal AF and 44.2% had persistent AF. At the redo procedure, 25.1% of patients were found to have no PV reconnection, whereas 20.5% had a single reconnected PV, and 54.4% had two or more reconnected PVs. A left-sided flutter ablation was performed in 18.8%, a left atrial (LA) roof line in 16.9%, a posterior mitral isthmus line in 5.2%, an anterior mitral isthmus line in 27.9%, and a posterior box lesion in 8.4%. Overall, 34.4% of patients showed areas of low-voltages in the redo procedure. Patients with areas of low voltages were less likely to have any reconnected PVs in the redo-procedure (p&amp;lt;0.001). After the second ablation procedure, 54.0% experienced AF recurrence. Univariable regression analysis revealed moderate (p=0.006) or severe (p= 0.015) LA dilatation, persistent AF (p=0.005), and posterior LA low voltage areas (p=0.011) as significant predictors of AF recurrence after the redo procedure. The number of reconnected PVs at the re-PVI did not predict AF recurrence (p=0.1090). As illustrated in Fig. 1 and 2, patients with paroxysmal AF experienced less AF recurrence compared to those with persistent AF (log-rank p=0.0025). Moreover, moderate or severe LA dilatation at baseline was associated with more frequent AF recurrences (log-rank p=0.0279). Conclusion A significant proportion of patients undergoing re-PVI experienced AF recurrence. We found that persistent AF and moderate or severe LA enlargement emerged as significant predictors of AF recurrence after the redo procedure. Although PV reconnection was observed in more than two thirds of patients at the re-PVI, it did not predict AF recurrence thereafter. However, patients without PV reconnection had significantly more low-voltage areas, which may be indicative of a different AF recurrence mechanism in this subgroup.Figure 1:Type of AFFigure 2:LA dilatation

Integrating clinical variables with magnetic resonance imaging and electroanatomic mapping parameters to predict response to first-time and repeat atrial fibrillation ablation procedures

Abstract Background The heterogeneity in patient response to atrial fibrillation ablation mandates the development of methods to predict clinical outcomes. Several clinical risk scores exist to prognosticate patients post ablation. Magnetic resonance imaging can quantify anatomical and functional atrial properties, whilst electroanatomic mapping data provides unparalleled atrial substrate characterisation. These data could be leveraged to predict ablation outcomes more accurately. Purpose To incorporate magnetic resonance imaging and electroanatomic mapping parameters with clinical variables to predict response to 1) first-time and 2) repeat atrial fibrillation ablation. Methods A retrospective analysis of 123 consecutive patients undergoing first-time atrial fibrillation ablation including pre-procedural atrial magnetic resonance imaging was performed. Data were split into training (n=68) and test (n=55) cohorts depending on data availability for clinical risk score calculation. The APPLE, DR-FLASH, FLAME, HATCH, HATCH+OSA, CHA2Ds2VASc and CAAP-AF scores were calculated for patients in the training cohort. Univariate logistic regression was used to identify variables associated with arrhythmia recurrence which were then combined into a multivariate logistic regression model. Area under the curve receiver operating characteristic (AUC-ROC) analysis was used to compare the ability of clinical risk scores and the combined model to predict arrhythmia recurrence risk after one procedure. The model's ability to predict repeat ablation response was tested in 38 patients who underwent redo procedures. The ROC optimal cut-off score was used to divide patients into two groups (high and low arrhythmia recurrence risk) for time-to-event analysis. Results In univariate analysis, weight, age, hypertension, left atrial ejection fraction and mean left atrial bipolar voltage were associated with arrhythmia recurrence after one procedure. The multivariate logistic regression model achieved an AUC of 0.7491 (95% confidence interval (CI) 0.6269-0.8712) in the training cohort and 0.7457 (95% CI 0.6137-0.8778) in the test cohort for predicting arrhythmia recurrence at 12 months (Figure 1A). Amongst clinical risk prediction tools, CAAP-AF had the highest predictive value (AUC 0.6529, 95% CI 0.5265-0.7793) (Figure 1B). In patients undergoing repeat ablations, the combined model had an AUC of 0.7585 (95% CI 0.5989-0.9182) for predicting arrhythmia recurrence (Figure 2A). The Kaplan-Meier curves showed a higher risk of arrhythmia recurrence in the ‘high recurrence risk’ group at 12 months (log-rank p=0.029) (Figure 2B). Conclusion A logistic regression model integrating clinical, anatomical, functional, and electrophysiological parameters improved the accuracy of atrial fibrillation ablation outcome prediction compared to existing clinical risk scores. The model may be used to predict response to repeat procedures offering the potential to improve the patient selection process.

Scar tissue characterization to predict arrhythmia recurrence in patients undergoing ventricular tachycardia ablation: cardiac computed tomography compared with cardiac magnetic resonance

Abstract Background The role of imaging in evaluating patients undergoing ventricular tachycardia (VT) ablation is crucial for planning, procedural success, and clinical outcomes. In daily practice, cardiac computed tomography (CCT) assessing wall thinning and late iodine uptake (LI) and cardiac magnetic resonance (CMR) assessing late-gadolinium enhancement (LGE) are most commonly implemented. However, data comparing the two imaging modalities for scar tissue characterization is scarce. Aims To compare the performance of both imaging modalities for scar tissue characterization in ischemic (ICM) and non-ischemic (NICM) patients undergoing VT ablation and predict procedural outcomes. Methods In a retrospective analysis, consecutive patients undergoing both CCT and LGE-CMR before scheduled VT ablation were included. The presence and extent of scar was assessed by means of each imaging modality using dedicated softwares (MUSIC and ADAS). To compare scar distribution and agreement between the two modalities, a scar classification scheme was used for all 17 AHA segments: 0 points (no scar present), 1 point (scar &amp;lt;50% of total segment area), 2 points (scar representing 50-99% of total segment area) or 3 points (scar present in 100% of the segment area).&amp;lt;scar&amp;lt;100%)&amp;gt;&amp;lt;scar&amp;lt;100%&amp;gt; Results 36 patients (67±10 years; 97% male; LVEF 39±10%; 72% ischemic) undergoing CCT and LGE-CMR before scheduled VT ablation were included. In the ICM group, mean detected scar burden was higher than in the NICM group on LGE-CMR (total volume: 62.3±32.9g vs. 32.8±9.5g, p&amp;lt;0.001), using wall thinning model (WT)(mean scar area 69.0±45.6 cm2 vs. 23.4±23.6cm2, p=0.005) as well as LI (dense scar area: 39.2±28.1 cm2 vs. 11.0±6.3 cm2 , p=0.005). The absolute score difference per segment and patient between CCT and LGE-CMR was calculated and summed for all patients divided by the number of patients. Differences were more pronounced for NICM compared to ICM and LGE-CMR showed better concordance to LI than WT in both NICMP and ICM (Figure). Total procedure time was 205±68 min (ablation time 28±16 min; fluoroscopy time 15 ± 12 min). During a follow-up period of 19±7 months, 87 sustained VT episodes in 12 patients (33%) were documented. Three patients (8%) underwent a second VT ablation and one patient (3%) died during follow-up. In ICM, total scar volume on LGE-CMR and scar area on LI showed numerically higher predictive value for VT recurrence than total scar area by means of WT (AUC: LGE 0.76, LI 0.78 and WT 0.65 respectively), while in NICM scar characterization by means of WT yielded higher performance to predict VT recurrence than LI or LGE-CMR (AUC: LGE 0.67, LI 0.58, WT 0.83 respectively). Conclusions In patients undergoing VT ablation, both LGE-CMR and CCT are valuable for scar tissue characterization. Late iodine uptake on CCT showed a high concordance with LGE-CMR in both NICM and ICM.&amp;lt;/scar&amp;lt;100%&amp;gt;&amp;lt;/scar&amp;lt;100%)&amp;gt;

Atypical atrial flutter ablation: follow-up and predictors of arrhythmia recurrence.

Ablation techniques have evolved greatly with advances in high-density 3D mapping systems over the last few years. Some patients develop atypical atrial flutter (AAFL) after pulmonary vein isolation (PVI). The data regarding follow-up after AAFL ablation as well as predictors of arrhythmia recurrence are lacking. This analysis aims to report procedure success rates and establish predictors of long-term success. This retrospective cohort study included 45 patients (median age: 69years; 40% female) who qualified for their first AAFL after PVI. The procedures were performed with the use of conventional ablation-index-guided ThermoCool Smarttouch SF and QDOT MICRO catheters. Freedom from arrhythmia recurrence was used as a primary end point. After 52weeks of follow-up, 60% of patients suffered from arrhythmia recurrence, but over 70% of the studied cohort reported symptom improvement. In multivariate analysis, class I antiarrhythmics prescription (HR = 0.24 [95% CI 0.06-0.94], p = 0.04) was associated with the lack of arrhythmia recurrence during the follow-up, while cardioversion during procedure was associated with increased risk of arrhythmia recurrence (HR = 7.05 [95% CI 2.09-23.72], p = 0.002). Long-term success of AAFL ablation procedures is not satisfactory despite improvement in symptoms. Class I antiarrhythmics prescription at the discharge contributes to higher chances of sinus rhythm maintenance, whereas cardioversion during the procedure is related to increased risk of arrhythmia recurrence.

Can Pre-Ablation Biomarkers Be Used to Predict Arrhythmia Recurrence after Ablation Index-Guided Atrial Fibrillation Ablation?

Ablation Index (AI) software has allowed better atrial fibrillation (AF) ablation results, but recurrence rates remain significant. Specific serum biomarkers have been associated with this recurrence. To evaluate whether certain biomarkers could be used (either individually or combined) to predict arrhythmia recurrence after AI-guided AF ablation. Prospective multicenter observational study of consecutive patients referred for AF ablation from January 2018 to March 2021. Hemoglobin, brain natriuretic peptide (BNP), C-reactive protein, high sensitivity cardiac troponin I, creatinine clearance, thyroid-stimulating hormone (TSH) and free thyroxine (FT4) were assessed for their ability to predict arrhythmia recurrence during follow-up. Statistical significance was accepted for p values of<0.05. A total of 593 patients were included - 412 patients with paroxysmal AF and 181 with persistent AF. After a mean follow-up of 24±6 months, overall single-procedure freedom from atrial arrhythmia was 76.4%. Individually, all biomarkers had no or only modest predictive power for recurrence. However, a TSH value >1.8 μUI/mL (HR=1.82 [95% CI, 1.89-2.80], p=0.006) was an independent predictor of arrhythmia recurrence. When assessing TSH, FT4 and BNP values in combination, each additional "abnormal" biomarker value was associated with a lower freedom from arrhythmia recurrence (87.1 % for no biomarker vs. 83.5% for one vs. 75.1% for two vs. 43.3% for three biomarkers, p<0.001). Patients with three "abnormal" biomarkers had a threefold higher risk of AF recurrence compared with no "abnormal" biomarker (HR=2.88 [95% CI, 1.39-5.17], p=0.003). When used in combination, abnormal TSH, FT4 and BNP values can be a useful tool for predicting arrhythmia recurrence after AI-guided AF ablation.

Os Biomarcadores podem ser Utilizados para Prever Recorrência de Arritmia após a Ablação de Fibrilação Atrial Guiada pelo Ablation-Index?

Abstract Background: Ablation Index (AI) software has allowed better atrial fibrillation (AF) ablation results, but recurrence rates remain significant. Specific serum biomarkers have been associated with this recurrence. Objectives: To evaluate whether certain biomarkers could be used (either individually or combined) to predict arrhythmia recurrence after AI-guided AF ablation. Methods: Prospective multicenter observational study of consecutive patients referred for AF ablation from January 2018 to March 2021. Hemoglobin, brain natriuretic peptide (BNP), C-reactive protein, high sensitivity cardiac troponin I, creatinine clearance, thyroid-stimulating hormone (TSH) and free thyroxine (FT4) were assessed for their ability to predict arrhythmia recurrence during follow-up. Statistical significance was accepted for p values of&lt;0.05. Results: A total of 593 patients were included - 412 patients with paroxysmal AF and 181 with persistent AF. After a mean follow-up of 24±6 months, overall single-procedure freedom from atrial arrhythmia was 76.4%. Individually, all biomarkers had no or only modest predictive power for recurrence. However, a TSH value &gt;1.8 μUI/mL (HR=1.82 [95% CI, 1.89-2.80], p=0.006) was an independent predictor of arrhythmia recurrence. When assessing TSH, FT4 and BNP values in combination, each additional “abnormal” biomarker value was associated with a lower freedom from arrhythmia recurrence (87.1 % for no biomarker vs. 83.5% for one vs. 75.1% for two vs. 43.3% for three biomarkers, p&lt;0.001). Patients with three “abnormal” biomarkers had a threefold higher risk of AF recurrence compared with no “abnormal” biomarker (HR=2.88 [95% CI, 1.39-5.17], p=0.003). Conclusions: When used in combination, abnormal TSH, FT4 and BNP values can be a useful tool for predicting arrhythmia recurrence after AI-guided AF ablation.

Can Pre-Ablation Serum Biomarkers be Used to Predict Arrhythmia Recurrence after Ablation Index-Guided Atrial Fibrillation Ablation?

Can Pre-Ablation Serum Biomarkers be Used to Predict Arrhythmia Recurrence after Ablation Index-Guided Atrial Fibrillation Ablation?

Right superior pulmonary vein parameter determined by three-dimensional transesophageal echocardiography is an independent predictor of the outcome after cryoballoon isolation of the pulmonary veins.

A direct comparison of three-dimensional transesophageal echocardiography (3DTEE) and cardiac computed tomography imaging has demonstrated good inter-technique agreement for the following pulmonary vein (PV) parameters: the ostium area of the right superior PV (RSPV) and its major (a) and minor axis (b) diameters, the left lateral ridge and the minor axis (b) diameter of the left superior PV. Herein, under investigation, was the predictive value of these parameters for arrhythmia recurrence (AR) after PV isolation with the 28 mm second generation cryoballoon (CBG2). One hundred eleven patients (67 men, mean age 58.06 ± 10.58 years) undergoing 3DTEE before PV isolation with the CBG2 for paroxysmal atrial fibrillation were followed. "Point by point" redo intervention was offered in case of AR and reconnected PVs were defined. During a mean follow-up of 617 ± 258.86 days, 65 (58.9%) patients remained free of AR. Longer RSPV b was found to be the only significant predictor for AR (hazard ratio [HR] 1.059; 95% confidence interval [CI] 1.000-1.121; p = 0.048). RSPV b ≥ 28 mm resulted in a threefold (HR 3.010; 95% CI 1.270-7.134, p = 0.012) increase in the risk of AR. The association of RSPV b with AR was independent of the biophysical parameters of cryoapplications. In 25 "redo" patients, reconnections were found 1.75 times more likely in the RSPV than in the other 3 PVs altogether. Right superior PV b measured with 3DTEE might be a significant predictor of AR after PV isolation with the CBG2. In case of RSPV b exceeding 28 mm, alternative PV isolation techniques or use of a larger balloon might be considered.

A novel stepwise approach incorporating ethanol infusion in the vein of Marshall for the ablation of persistent atrial fibrillation.

Apart from pulmonary vein isolation (PVI), several step-by-step procedures that aim to modify left atrial substrate have been proposed for the ablation of persistent atrial fibrillation (AF), yet the optimal strategy remains elusive. There are cumulative data suggesting an incremental benefit of adding vein of Marshall (VOM) ethanol infusion to PVI in patients with persistent AF. We sought to evaluate the feasibility and efficacy of a novel stepwise ablation approach, incorporating a VOM alcoholization step, for persistent AF. In this single-center study, we prospectively enrolled 66 consecutive patients with symptomatic persistent AF and failure of at least one antiarrhythmic drug (ADD). The ablation procedure consisted of (i) PVI, (ii) left atrial segmentation with VOM ethanol infusion and the deployment of linear radiofrequency lesions across the roof and the mitral isthmus and (iii) electrogram-based ablation of dispersion zones. The first two steps were performed in all patients, whereas the third step was carried out only in those still in AF at the end of the second step. Atrial tachycardias during the procedure were mapped and ablated. At the end of the procedure, cavotricuspid isthmus ablation was additionally performed in all patients. The primary endpoint was 12-month freedom from AF and atrial tachycardia after a single procedure and an initial three-month blanking period. Total procedure time was 153 ± 38.5 min. Fluoroscopy time was 16 ± 6.5 min and the radiofrequency ablation time was 26.14 ± 0.26 min. The primary endpoint occurred in 54 patients (82%). At 12 months, 65% of patients were off any AAD. In the univariate Cox regression analysis, left ventricular ejection fraction < 40% was the only predictor of arrhythmia recurrence (HR 3.56; 95% CI, 1.04-12.19; p = 0.04). One patient developed a pericardial tamponade and another a minor groin hematoma. A novel stepwise approach, including a step of ethanol infusion in the VOM, is feasible, safe and provides a high rate of sinus rhythm maintenance at 12 months in patients with persistent AF.

PO-01-099 EARLY REMODELING OF THE LEFT ATRIUM FOLLOWING CATHETER ABLATION OF PERSISTENT ATRIAL FIBRILLATION: THE IMPACT OF SUBSTRATE MODIFICATION IN DECAAF II

Left Atrial (LA) enlargement is prevalent amongst atrial fibrillation (AF) patients and constitutes an important marker of underlying atrial myopathy. Several studies have described reduction in LA volume following catheter ablation (CA) of AF, however, none have investigated differences in remodeling related to additional ablation outside of the pulmonary veins. We sought to compare early remodeling of the LA between patients who received pulmonary vein isolation (PVI) only, and those who received additional fibrosis-guided extra-PV ablation. This study was a retrospective analysis of the DECAAF II randomized controlled trial. Patients with persistent AF (perAF) were randomized to receive PVI only or PVI + fibrosis-guided ablation. Late Gadolinium Enhancement Magnetic Resonance Imaging (LGE-MRI) was performed before and three months after CA to measure LA volume. Only patients in sinus rhythm at both MRIs are included. Patients were followed up with single-lead ECG devices for 12-18 months. Arrhythmic burden was calculated as the percentage of ECGs exhibiting AF. Univariate and multivariate regression were used to identify predictors of LA volume change. This analysis included 206 patients who met our inclusion criteria. The mean LA volume before ablation was 114.6 ± 36.9 mm3, and the mean volume post-ablation was 101.2 ± 32.3 mm3, with a mean reduction of 13.5 ± 22.3 mm3 (9.92% reduction, p <0.001). Patients randomized to receive MRI-guided fibrosis ablation had more LA volume reduction than patients who were randomized to PVI only (17.03 ± 25.04 mm3 vs 10.17 ± 18.89 mm3, p=0.03). This association persisted with multivariate analysis where pre-ablation left ventricular ejection fraction (LVEF) and randomization to receive substrate modification were the only predictors of LA volume reduction (table). LA volume reduction was associated with greater improvement in LVEF, regardless of treatment randomization (r = 0.242, p = 0.01). LA volume reduction did not predict arrhythmia recurrence when considered as a continuous variable. We noted more pronounced LA volume reductions in patients randomized to receive PVI + fibrosis-guided ablation when compared to those randomized to receive PVI only. We hypothesize worsened left atrial relaxation and diastolic dysfunction as an etiology for this difference, but further study is needed to better characterize the important structural impacts of extra-PV ablation.

PO-02-135 DOES LA SIZE PREDICT OUTCOMES IN AF AND SYSTOLIC HEART FAILURE?

Significant left atrial (LA) enlargement often accompanies heart failure with reduced ejection fraction (HFrEF) and may determine the success of AF ablation. However, the impact of LA size on long-term outcomes remains unclear. We aim to determine the relationship between LA size and AF recurrence in patients with normal LV function (NLV) and HFrEF following AF ablation. Consecutive patients undergoing index AF ablation across 11 centres were stratified according to baseline LVEF (<50% or >50%). The impact of baseline LA size on 12-month AF recurrence was determined utilising continuous remote rhythm monitoring to detect arrhythmia recurrence and quantify AF burden. 360 patients were included (NLV=237, HFrEF=123). The HFrEF group (mean LVEF 34.9±8.3%) were younger (62±10 vs 65 ± 9 years, p=0.020), with larger LA size (LAVI 54.6±16.5ml/m2 vs 45.4±14.1ml/m2, p<0.001). Despite differences in LA size, freedom from AF was similar in those with and without HF (56% vs 54% respectively, Log Rank p=0.621, figure 1a). Similarly, AF burden did not differ between groups (median burden HFrEF 0% (0-1.1); NLV 0 (0-2.5), p=0.195). An age-matched 1:1 comparison of NLV and HFrEF (N=246) demonstrated no impact of baseline LA size on arrhythmia recurrence (p=0.579), despite larger LA in those with HFrEF (LAVI 54.6±16.5 vs NLV 45.0±15.0, p=0.0002). LA enlargement did not predict arrhythmia recurrence (HR 1.400, 95% CI 0.952-2.057, p=0.086) regardless of HF status (figure 1b). At 12 months, LV function normalised in 80% (LVEF>50%) of those with HFrEF (ΔLVEF: +19±13%, p<0.001) with a significant reduction in LA size (54.6±16.5 to 44.7±14.6ml/m2, p<0.001), comparable in those with and without AF recurrence (p=0.819). Baseline LA enlargement did not influence AF recurrence in those with or without LV recovery (HR 1.622 95% CI 0.702-3.748, p=0.258). LA enlargement did not determine the outcome of AF ablation in those with and without HFrEF. LA size is less useful in guiding patient selection for AF ablation in HFrEF

Amplified sinus-P-wave analysis predicts outcomes of cryoballoon ablation in patients with persistent and long-standing persistent atrial fibrillation: A multicentre study.

Outcomes of catheter ablation for non-paroxysmal atrial fibrillation (AF) remain suboptimal. Non-invasive stratification of patients based on the presence of atrial cardiomyopathy (ACM) could allow to identify the best responders to pulmonary vein isolation (PVI). Observational multicentre retrospective study in patients undergoing cryoballoon-PVI for non-paroxysmal AF. The duration of amplified P-wave (APW) was measured from a digitally recorded 12-lead electrocardiogram during the procedure. If patients were in AF, direct-current cardioversion was performed to allow APW measurement in sinus rhythm. An APW cut-off of 150 ms was used to identify patients with significant ACM. We assessed freedom from arrhythmia recurrence at long-term follow-up in patients with APW ≥ 150 ms vs. APW < 150 ms. We included 295 patients (mean age 62.3 ± 10.6), of whom 193 (65.4%) suffered from persistent AF and the remaining 102 (34.6%) from long-standing persistent AF. One-hundred-forty-two patients (50.2%) experienced arrhythmia recurrence during a mean follow-up of 793 ± 604 days. Patients with APW ≥ 150 ms had a significantly higher recurrence rate post ablation compared to those with APW < 150 ms (57.0% vs. 41.6%; log-rank p < 0.001). On a multivariable Cox-regression analysis, APW≥150 ms was the only independent predictor of arrhythmia recurrence post ablation (HR 2.03 CI95% 1.28-3.21; p = 0.002). APW duration predicts arrhythmia recurrence post cryoballoon-PVI in persistent and long-standing persistent AF. An APW cut-off of 150 ms allows to identify patients with significant ACM who have worse outcomes post PVI. Analysis of APW represents an easy, non-invasive and highly reproducible diagnostic tool which allows to identify patients who are the most likely to benefit from PVI-only approach.

Elevated fibrosis burden as assessed by MRI predicts cryoballoon ablation failure.

Late-gadolinium enhancement magnetic resonance (LGE-MRI) imaging is increasingly used in management of atrial fibrillation (AFib) patients. Here, we assess the usefulness of LGE-MRI-based fibrosis quantification to predict arrhythmia recurrence in patients undergoing cryoballoon ablation. Our secondary goal was to compare two widely used fibrosis quantification methods. In 102 AF patients undergoing LGE-MRI and cryoballoon ablation (mean age 62 years; 64% male; 59% paroxysmal AFib), atrial fibrosis was quantified using the pixel intensity histogram (PIH) and image intensity ratio (IIR) methods. PIH segmentations were completed by a third-party provider as part of the standard of care at our hospital; Image intensity ratio(IIR) segmentations of the same scans were carried out in our lab using a commercially available software package. Fibrosis burdens and spatial distributions for the two methods were compared. Patients were followed prospectively for recurrent arrhythmia following ablation. Average PIH fibrosis was 15.6 ± 5.8% of the left atrial (LA) volume. Depending on threshold (IIRthr ), the average IIR fibrosis (% of LA wall surface area) ranged from 5.0 ± 7.2% (IIRthr = 1.2) to 37.4 ± 10.9% (IIRthr = 0.97). An IIRthr of 1.03 demonstrated the greatest agreement between the methods, but spatial overlap of fibrotic areas delineated by the two methods was modest (Sorenson Dice coefficient: 0.49). Fourty-two patients (41.2%) had recurrent arrhythmia. PIH fibrosis successfully predicted recurrence (HR 1.07; p = .02) over a follow-up period of 362 ± 149 days; regardless of IIRthr , IIR fibrosis did not predict recurrence. PIH-based volumetric assessment of atrial fibrosis was modestly predictive of arrhythmia recurrence following cryoballoon ablation in this cohort. IIR-based fibrosis was not predictive of recurrence for any of the IIRthr values tested, and the overlap in designated areas of fibrosis between the PIH and IIR methods was modest. Caution must therefore be exercised when interpreting LA fibrosis from LGE-MRI, since the values and spatial pattern are methodology-dependent.

Abstract 15924: Intelligent Machine Learning Fusion Framework Predicts Atrial Fibrillation Ablation Outcomes With Demographic, Morphological, and Imaging Features

Background: Structural changes in the left atrium (LA) modestly predict outcomes in patients undergoing catheter ablation for atrial fibrillation (AF). Machine learning (ML) is a promising approach to improve risk prediction based on complex and variable data inputs.Hypothesis: We hypothesized that ML approaches based on a patient's specific atrial morphology from cardiac computed tomography (CT) and clinical data can predict response to AF ablation. Methods: Consecutive patients undergoing AF ablation from 2014-2017 with preprocedural CT scans and long-term clinical follow-up were included in the retrospective analysis. A fusion model incorporated demographic data with morphologic and 3D imaging classifiers based on an automatous segmentation of CT scans to predict arrhythmia recurrence after catheter ablation of AF. LA morphologic features were derived from left atrial segmentation. The LA image classifier was developed using a 3D image convolutional neural network. Multi-modal data sources were fused in a framework that determines individual importance and optimizes classification. Results: 321 patients (64.2 + 10.6 years, 69% male, 40% paroxysmal AF) were analyzed. Post 10-fold nested cross-validation, the model trained to intelligently fuse and learn appropriate weights for clinical, morphological, and imaging data (AUC 0.81±0.02) outperformed those trained solely on clinical data (AUC 0.61±0.04), morphological (AUC 0.68±0.10) or imaging data (AUC 0.75±0.02). Conclusion: In the context of clinical data, information from atrial geometry from CT imaging improved risk prediction of AF recurrence in patients undergoing catheter ablation using an ML based-fusion framework model. The fusion technique allowed improved patient-specific prediction of clinical models and may inform therapy selection with non-invasive tools

3D atrial strain for prediction of atrial fibrillation recurrence

Abstract Introduction Atrial fibrillation (AF) is one of the most common supraventricular arrhythmias. Treatment options apart from medication include interventional catheter-guided pulmonary vein isolation (PVI). However, there is limited knowledge about factors predicting arrhythmia recurrence after PVI. Aim To study the association of 3-dimensional (3D) left atrial (LA) strain (LAS) and 3D electro-anatomical voltage mapping (EAVM) with early recurrence of AF after PVI. Methods In this prospective single center study, 93 patients undergoing PVI were enrolled between December 2018 and October 2021. All patients underwent an echocardiographic examination within two weeks before PVI using the Canon Aplio i900 system to analyse LAS from 3D LA volume. A 3D EAVM was obtained using high-density mapping catheters during PVI. The CARTO 3 system (Version V6-V7) was used for determining LA scar area by low voltage mapping (local amplitude &amp;lt;0.5 mV) indicated as percentage (EAVM-%). Follow-up time points were set at 2, 3, 6 and 12 months to investigate recurrence of AF, with exclusion of events occurring during the first two months (blanking phase). Results During follow-up, 12 out of 93 patients experienced recurrence of AF (12.9%; AF-Group). Baseline characteristics did not differ between AF-Group and Non-AF-Group. In contrast, LAS was significantly impaired in the AF-Group (median −4.6, IQR [−5.6 to −3.6]) when compared to the Non-AF-Group (−6.2 [−8.3 to −4.5]; p=0.009). The EAVM-% did not differ between the groups (AF-Group: 5.0 [1.5 to 21.5]; Non-AF-Group: 4.4 [1.5 to 15.9]; p=0.710). No significant correlations were found between LAS and EAVM-% (r=0.03, p=0.812). A cut-off value of −5.89% for LAS had a sensitivity of 100% and a specificity of 57% for AF recurrence (AUC=70%; p&amp;lt;0.001). Kaplan Meier curves for event-free survival were generated based on the LAS cut-off demonstrating excellent differentiation of those with and without AF recurrence (p&amp;lt;0.001; see figure). Furthermore, LAS was associated with an increased risk of early AF recurrence (HR 1.40, IQR [1.02–1.92], p=0.040), while EAVM-% was not (HR 0.99 [0.95–1.04], p=0.787). Conclusion 3D LAS was associated with an increased risk of early AF recurrence after PVI, while EAVM-% was not. 3D LAS might be used for identifying patients who would benefit from PVI. Funding Acknowledgement Type of funding sources: None.

Artificial intelligence analysis of ECG signals to predict arrhythmia recurrence after cryoballoon ablation of atrial fibrillation

Abstract Introduction Cryoballoon-based pulmonary vein isolation (CB) is an effective option for rhythm control in atrial fibrillation (AF). There have been multiple attempts to predict arrhythmia recurrence, but with moderate success. Purpose To use artificial intelligence (AI) deep electrocardiogram (ECG) analysis to predict arrythmia recurrence after CB. Methods In a single-center study of 250 consecutive pts (58.2±12.6 years, 30% female) treated with CB for AF (05.2017–04.2019), 60% had paroxysmal AF (PAF), 66.5% had hypertension, and 27.2% had a redo CB. Analyses included left atrial volume (LA vol: indexed for BSA and assed by angio-MSCT in 76% and the rest with echo), left ventricle ejection fraction (LVEF) and hypertrophy (LVH: septal/posterior wall thickness ≥11mm in ♂ and ≥10mm in ♀) along with 30s arrhythmia recurrence at 2-yr follow-up. Baseline 500Hz raw 12-lead digital ECG signals were analyzed by means of convolutional neural network (CNN) architecture that was taught to process the 12-channel ECG signal (XML). The transfer learning method of CNN parameters learned on a very large number of coded consecutive training ECG samples (n=1,000) was adopted to analyze current sample of ECG signals. Results Arrhythmia recurrence at 2-yrs was 46.0% (n=115). There was gradual increase in predictive performance being the lowest if only baseline clinical data were analyzed and the highest combing all baseline clinical data plus anatomical and functional parameters (Table 1: #1–#3). AI baseline ECG analysis alone offered predictive performance similar to that made upon analysis of all baseline clinical data or joint analysis of LA vol, LVH, and LVEF (Table 1: #4). AI results added substantially to predictive performance of models using baseline clinical data alone (#1 vs #5, p&amp;lt;0.001) and joint analysis of baseline clinical plus LA vol, LVH and LVEF (#3 vs #6, p=0.0130) (Fig. 1). Conclusions Prediction of recurrence after CB using raw ECG data with deep AI analysis is feasible. Joint analysis of results of AI of baseline ECG and basic clinical data offers predictive performance similar to that made upon analysis of clinical data including advanced information on LA volume and LVH and function. AI analysis of baseline ECG adds significantly to models aimed at recurrent AF prediction. Funding Acknowledgement Type of funding sources: Public hospital(s). Main funding source(s): National Institute of Cardiology, Warsaw, Poland

Predicting arrhythmia recurrence following catheter ablation for ventricular tachycardia using late gadolinium enhancement magnetic resonance imaging: Implications of varying scar ranges.

Thresholding-based analysis of late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) can create scar maps and identify corridors that might provide a reentrant substrate for ventricular tachycardia (VT). Current recommendations use a full-width-at-half-maximum approach, effectively classifying areas with a pixel signal intensity (PSI) >40% as border zone (BZ) and >60% as core. The purpose of this study was to investigate the impact of 4 different threshold settings on scar and corridor quantification and to correlate this with postablation VT recurrence. Twenty-seven patients with ischemic cardiomyopathy who had undergone catheter ablation for VT were included for retrospective analysis. LGE-CMR images were analyzed using ADAS3D LV. Scar maps were created for 4 PSI thresholds (40-60, 35-65, 30-70, and 45-55), and the extent of variation in BZ and core, as well as the number and weight of conduction corridors, were quantified. Three-dimensional representations were reconstructed from exported segmentations and used to quantify the surface area between healthy myocardium and scar (BZ + core), and between BZ and core. A wider PSI threshold was associated with an increase in BZ mass and decrease in scar (P <.001). No significant differences were observed for the total number of corridors and their mass with increasing PSI threshold. The best correlation in predicting arrhythmia recurrence was observed for PSI 45-55 (area under the curve 0.807; P = .001). Varying PSI has a significant impact on quantification of LGE-CMR parameters and may have incremental clinical value in predicting arrhythmia recurrence. Further prospective investigation is warranted to clarify the functional implications of these findings for LGE-CMR-guided ventricular ablation.

ECG-I phenotyping of persistent AF based on driver burden and distribution to predict response to pulmonary vein isolation (PHENOTYPE-AF).

This prospective trial sought to phenotype persistent atrial fibrillation (AF) based on AF mechanisms using electrocardiographic imaging(ECGI) mapping to determine whether this would predict long-term freedom from arrhythmia after pulmonary vein isolation (PVI). Patients with persistent AF of <2 years duration underwent cryoballoon PVI. ECGI mapping was performed before PVIto determine potential drivers (PDs) defined as rotational activations completing ≥1.5 revolutions or focal activations. The coprimary endpoint was the association between (1) PD burden (defined as the number of PD occurrences) and (2) PD distribution (defined as the number of segments on an 18-segment model of the atria harboring PDs) with freedom from arrhythmia at 1-year follow up. Of 100 patients, 97 completed follow up and 52 (53.6%) remained in sinus rhythm off antiarrhythmic drugs. Neither PD burden nor PD distribution predicted freedom from arrhythmia (hazard ratio [HR]: 1.01, 95% confidence interval [CI]: 0.99-1.03, p = .164; and HR: 1.04, 95% CI: 0.91-1.17, p = .591, respectively). Otherwise, the burden of rotational PDs, rotational stability, and the burden of PDs occurring at the pulmonary veins and posterior wall all failed to predict arrhythmia recurrence (all p > .10). AF mechanisms as determined using ECGI mapping do not predict outcomes after PVI for persistent AF. Further studies using different methodologies to characterize AF mechanisms are warranted(NCT03394404).