Catheter ablation for persistent atrial fibrillation: patterns of recurrence and impact on quality of life and health care utilisation.

BACKGROUND AND AIMS: Patterns of atrial fibrillation (AF) recurrence post catheter ablation for persistent AF are not well described. This study aimed to describe the pattern of AF recurrence seen following catheter ablation for persistent AF (PsAF) and the implications for healthcare utilisation and quality of life. METHODS: This was a post-hoc analysis of the CAPLA study, an international, multi-centre study that randomised patients with symptomatic PsAF to pulmonary vein isolation plus posterior wall isolation or pulmonary vein isolation alone. Patients underwent twice daily single lead ECG, implantable device monitoring or three monthly Holter monitoring. RESULTS: 154 of 333 (46.2%) patients (median age 67.3 years, 28% female) experienced AF recurrence at 12-month follow-up. Recurrence was paroxysmal in 97 (63%) patients and persistent in 57 (37%). Recurrence type did not differ between randomisation groups (p=0.508). Median AF burden was 27.4% in PsAF recurrence and 0.9% in paroxysmal AF (PAF) recurrence (p<0.001). Patients with PsAF recurrence had lower baseline left ventricular ejection fraction (PsAF 50% vs PAF 60%, p<0.001) and larger left atrial volume (PsAF 54.2±19.3 ml/m² vs PAF 44.8±11.6 ml/m², p=0.008). Healthcare utilisation was significantly higher in PsAF (45 patients [78.9%]) vs PAF recurrence (45 patients [46.4%], p<0.001) and lowest in those without recurrence (17 patients [9.5%], p<0.001). Patients without AF recurrence had greater improvements in quality of life as assessed by the Atrial Fibrillation Effect on Quality-of-Life (AFEQT) questionnaire (Δ33.3±25.2 points) compared to those with PAF (Δ24.0±25.0 points, p=0.012) or PsAF (Δ13.4±22.9 points, p<0.001) recurrence. CONCLUSIONS: AF recurrence is more often paroxysmal after catheter ablation for PsAF irrespective of ablation strategy. Recurrent PsAF was associated with higher AF burden, increased healthcare utilisation and antiarrhythmic drug use. The type of AF recurrence and AF burden may be considered important endpoints in clinical trials investigating ablation of PsAF.

Impact of Posterior Wall Isolation During AF Ablation on the Incidence of Left Atrial Flutter.

BACKGROUND: Linear and complex electrogram ablation (LCEA) beyond pulmonary vein isolation (PVI) is associated with an increase in left atrial macro-re-entrant tachycardias (LAMTs). Posterior wall isolation (PWI) is increasingly performed to improve AF ablation outcomes. However, the impact of PWI on the incidence of LAMT is unknown. OBJECTIVES: The purpose of this study was to establish the incidence of LAMT following PVI alone vs PVI + PWI vs PVI + PWI + LCEA. METHODS: Consecutive patients undergoing catheter ablation for AF or LAMT post-AF ablation between 2008 and 2022 from 4 electrophysiology centers were reviewed with a minimum follow-up of 12 months. RESULTS: In total, 5,619 (4,419 index, 1,100 redo) AF ablation procedures were performed in 4,783 patients (mean age 60.9 ± 10.6 years, 70.7% men). Over a mean follow-up of 6.4 ± 3.8 years, 246 procedures for LAMT were performed in 214 patients at a mean of 2.6 ± 0.6 years post-AF ablation. Perimitral (52.8% of patients), roof-dependent (27.1%), PV gap-related (17.3%), and anterior circuits (8.9%) were most common, with 16.4% demonstrating multiple circuits. The incidence of LAMT was significantly higher following PVI + PWI (6.2%) vs PVI alone (3.0%; P < 0.0001) and following PVI + PWI + LCEA vs PVI + PWI (12.5%; P = 0.019). Conduction gaps in previous ablation lines were responsible for LAMT in 28.4% post-PVI alone, 35.3% post-PVI + PWI (P = 0.386), and 81.8% post-PVI + PWI + LCEA (P < 0.005). CONCLUSIONS: The incidence of LAMT following PVI + PWI is higher than with PVI alone but significantly lower than with more extensive atrial substrate modification. Given a low frequency of LAMT following PWI, empiric mitral isthmus ablation is not justified and may be proarrhythmic.

Sex-specific outcomes after catheter ablation for persistent AF.

BACKGROUND: Sex-specific outcomes after catheter ablation (CA) for atrial fibrillation (AF) have reported conflicting findings. OBJECTIVE: We examined the impact of female sex on outcomes in patients with persistent AF (PsAF) from the Catheter Ablation for Persistent Atrial Fibrillation: A Multicentre Randomized Trial of Pulmonary Vein Isolation vs PVI with Posterior Left Atrial Wall Isolation (CAPLA) randomized trial. METHODS: A total of 338 patients with PsAF were randomized to pulmonary vein isolation (PVI) or PVI with posterior wall isolation (PWI). The primary outcome was arrhythmia recurrence at 12 months. Clinical and electroanatomical characteristics, arrhythmia recurrence, and quality of life were compared between women and men. RESULTS: Seventy-nine women (23.4%; PVI 37; PVI + PWI 42) and 259 men (76.6%; PVI 131; PVI + PWI 128) underwent AF ablation. Women were older {median age 70.4 (interquartile range [IQR] 64.8-74.6) years vs 64.0 (IQR 56.7-69.7) years; P < .001} and had more advanced left atrial electroanatomical remodeling. At 12 months, arrhythmia-free survival was lower in women (44.3% vs 56.8% in men; hazard ratio 1.44; 95% confidence interval 1.02-2.04; log-rank, P = .036). PWI did not improve arrhythmia-free survival at 12 months (hazard ratio 1.02; 95% confidence interval 0.74-1.40; log-rank, P = .711). The median AF burden was 0% in both groups (women: IQR 0.0%-2.2% vs men: IQR 0.0%-2.8%; P = .804). Health care utilization was comparable between women (36.7%) and men (30.1%) (P = .241); however, women were more likely to undergo a repeat procedure (17.7% vs 6.9%; P = .007). Women reported more severe baseline anxiety (average Hospital Anxiety and Depression Scale [HADS] anxiety score 7.5 ± 4.9 vs 6.3 ± 4.3 in men; P = .035) and AF-related symptoms (baseline Atrial Fibrillation Effect on Quality-of-Life Questionnaire [AFEQT] score 46.7 ± 20.7 vs 55.9 ± 23.0 in men; P = .002), with comparable improvements in psychological symptoms (change in HADS anxiety score -3.8 ± 4.6 vs -3.0 ± 4.5; P = .152 (change in HADS depression score -2.9 ± 5.0 vs -2.6 ± 4.0; P = .542) and greater improvement in AFEQT score compared with men at 12 months (change in AFEQT score +45.9 ± 23.1 vs +39.2 ± 24.8; P = .048). CONCLUSION: Women undergoing CA for PsAF report more significant symptoms and poorer quality of life at baseline than men. Despite higher arrhythmia recurrence and repeat procedures in women, the AF burden was comparably low, resulting in significant improvements in quality of life and psychological well-being after CA in both sexes.

Sediment carbon storage differs in native and non-native Caribbean seagrass beds.

Non-native species are expanding globally and can alter ecosystem functions, including food web dynamics, community structure and carbon storage. Seagrass are foundation species that contribute a variety of ecosystem services in near-shore coastal ecosystems, including a significant sink of carbon. In the Caribbean, the rapidly expanding non-native Halophila stipulacea has unknown impacts on carbon storage. To investigate the impacts on carbon storage, we quantified organic carbon (Corg) content in sediment and seagrass tissues from monotypic H. stipulacea beds, mixed native seagrass beds dominated by Thalassia testudinum and Syringodium filiforme, and unvegetated substrate in St. John, USVI. We found native seagrass-vegetated sediment contained 1.3 times more Corg than sediment covered by H. stipulacea, and 1.6 times more Corg than unvegetated areas on average. Whereas, H. stipulacea-dominated substrate stored 1.2 times more Corg than unvegetated substrate. Likewise, native species contained 2.2 times more aboveground biomass and 6.0 times more belowground biomass than H. stipulacea. Since seagrasses are critical sources of carbon sequestration, our results suggest that invading H. stipulacea is associated with lower carbon stocks which has potential implications for conservation activities and climate change mitigation.

Optimal Annotation of Local Activation Time in Ventricular Tachycardia Substrate Mapping.

BACKGROUND: Accurate annotation of electrogram local activation time (LAT) is critical to the functional assessment of ventricular tachycardia (VT) substrate. Contemporary methods of annotation include: 1) earliest bipolar electrogram (LATearliest); 2) peak bipolar electrogram (LATpeak); 3) latest bipolar electrogram (LATlatest); and 4) steepest unipolar -dV/dt (LAT-dV/dt). However, no direct comparison of these methods has been performed in a large dataset, and it is unclear which provides the optimal functional analysis of the VT substrate. OBJECTIVES: This study sought to investigate the optimal method of LAT annotation during VT substrate mapping. METHODS: Patients with high-density VT substrate maps and a defined critical site for VT re-entry were included. All electrograms were annotated using 5 different methods: LATearliest, LATpeak, LATlatest, LAT-dV/dt, and the novel steepest unipolar -dV/dt using a dynamic window of interest (LATDWOI). Electrograms were also tagged as either late potentials and/or fractionated signals. Maps, utilizing each annotation method, were then compared in their ability to identify critical sites using deceleration zones. RESULTS: Fifty cases were identified with 1,.813 ± 811 points per map. Using LATlatest, a deceleration zone was present at the critical site in 100% of cases. There was no significant difference with LATearliest (100%) or LATpeak (100%). However, this number decreased to 54% using LAT-dV/dt and 76% for LATDWOI. Using LAT-dV/dt, only 33% of late potentials were correctly annotated, with the larger far field signals often annotated preferentially. CONCLUSIONS: Annotation with LAT-dV/dt and LATDWOI are suboptimal in VT substrate mapping. We propose that LATlatest should be the gold standard annotation method, as this allows identification of critical sites and is most suited to automation.

The Role of Posterior Wall Isolation in Catheter Ablation for Persistent Atrial Fibrillation and Systolic Heart Failure: A Secondary Analysis of a Randomized Clinical Trial.

Importance: Catheter ablation for patients with atrial fibrillation (AF) and heart failure with reduced ejection fraction (HFrEF) is associated with improved left ventricular ejection fraction (LVEF) and survival compared with medical therapy. Nonrandomized studies have reported improved success with posterior wall isolation (PWI). Objective: To determine the impact of pulmonary vein isolation (PVI) with PWI vs PVI alone on outcomes in patients with HFrEF. Design, Setting, and Participants: This was an ad hoc secondary analysis of the CAPLA trial, a multicenter, prospective, randomized control trial that involved 11 centers in 3 countries (Australia, Canada, and UK). CAPLA featured 338 patients with persistent AF randomized to either PVI plusPWI or PVI alone. This substudy included patients in the original CAPLA study who had symptomatic HFrEF (LVEF <50% and New York Heart Association class ≥II). Interventions: Pulmonary vein isolation with PWI vs PVI alone. Main Outcomes and Measures: The primary end point was freedom from any documented atrial arrhythmia greater than 30 seconds, after a single ablation procedure, without the use of antiarrhythmic drug (AAD) therapy at 12 months. Results: A total of 98 patients with persistent AF and symptomatic HFrEF were identified (mean [SD] age, 62.1 [9.8] years; 79.5% men; and mean [SD] LVEF at baseline, 34.6% [7.9%]). After 12 months, 58.7% of patients with PVI plus PWI were free from recurrent atrial arrhythmia without the use of AAD therapy vs 61.5% with PVI alone (hazard ratio, 1.02; 95% CI, 0.54-1.91; P = .96). There were no significant differences in freedom from atrial arrhythmia with or without AAD therapy after multiple procedures (PVI plus PWI vs PVI alone, 60.9% vs 65.4%; P = .73) or AF burden (median, 0% in both groups; P = .78). Mean LVEF improved substantially in PVI plus PWI (∆ LVEF, 19.3% [13.0%; P < .01) and PVI alone (18.2% [14.1%; P < .01), with no difference between groups (P = .71). Normalization of LV function occurred in 65.2% of patients in the PVI plus PWI group and 50.0% of patients with PVI alone (P = .13). Conclusions and Relevance: The results of this study indicate that addition of PWI to PVI did not improve freedom from arrhythmia recurrence or recovery of LVEF in patients with persistent AF and symptomatic HFrEF. Catheter ablation was associated with significant improvements in systolic function, irrespective of ablation strategy used. These results caution against the routine inclusion of PWI in patients with HFrEF undergoing first-time catheter ablation for persistent AF. Trial Registration: http://anzctr.org.au Identifier: ACTRN12616001436460.

The impact of age on ablation outcomes in AF-mediated cardiomyopathy.

INTRODUCTION: The absence of ventricular scar in patients with atrial fibrillation (AF) and systolic heart failure (HF) predicts left ventricular (LV) recovery following AF ablation. It is unknown whether age impacts the degree of LV recovery, reverse remodeling, or AF recurrence following catheter ablation (CA) among this population. OBJECTIVES: To evaluate the impact of age on LV recovery and AF recurrence in a population with AF and systolic HF without fibrosis (termed AF-mediated cardiomyopathy) following CA. METHODS: Consecutive patients undergoing CA between 2013 and 2021 with LV ejection fraction (LVEF) < 45% and absence of cardiac magnetic resonance imaging (CMR) detected LV myocardial fibrosis were stratified by age (<65 vs. ≥65 years). Following CA, participants underwent remote rhythm monitoring for 12 months with repeat CMR for HF surveillance. RESULTS: The study population consisted of 70 patients (10% female, mean LVEF 33 ± 9%), stratified into younger (age < 65 years, 63%) and older (age ≥ 65 years, 37%) cohorts. Baseline comorbidities, LVEF (34 ± 9 vs. 33 ± 8 ≥65 years, p = .686), atrial and ventricular dimensions (left atrial volume index: 55 ± 21 vs. 56 ± 14 mL/m2 age ≥ 65, p = .834; indexed left ventricular end-diastolic volume: 108 ± 40 vs. 104 ± 28 mL/m2 age ≥ 65, p = .681), pharmacotherapy and ablation strategy (pulmonary vein isolation in all; posterior wall isolation in 27% vs. 19% age ≥ 65, p = .448; cavotricuspid isthmus in 9% vs. 11.5% age ≥ 65) were comparable (all p > .05) albeit a higher CHADS2 VASc score in the older cohort (2.7 ± 0.9 vs. 1.6 ± 0.6 age < 65, p < .001).   Freedom from AF was comparable (hazard ratio: 0.65, 95% confidence interval: 0.38-1.48, LogRank p = .283) as was AF burden [0% (interquartile range, IQR: 0.0-2.1) vs. age ≥ 65: [0% (IQR 0.0-1.7), p = .516], irrespective of age. There was a significant improvement in LV systolic function in both groups (ΔLVEF + 21 ± 14% vs. +21 ± 12% age ≥ 65, p = .913), with LV recovery in the vast majority (73% vs. 69%, respectively, p = .759) at 13 (IQR: 12-16) months. This was accompanied by comparable improvements in functional status (New York Heart Association class p = .851; 6-min walk distance 50 ± 61 vs. 93 ± 134 m in age ≥ 65, p = .066), biomarkers (ΔN-terminal-pro brain natriuretic peptide -139 ± 246 vs. -168 ± 181 age ≥ 65,p = .629) and HF symptoms (Short Form-36 survey Δphysical component summary p = .483/Δmental component summary, p = .841). CONCLUSION: In patients undergoing CA for AF with systolic HF in the absence of ventricular scar, comparable improvements in ventricular function, symptoms, and freedom from AF are achieved irrespective of age.

Impact of Posterior Left Atrial Voltage on Ablation Outcomes in Persistent Atrial Fibrillation: CAPLA Substudy.

BACKGROUND: Pulmonary vein isolation (PVI) is less effective in patients with persistent atrial fibrillation (PsAF). Adjunctive ablation targeting low voltage areas (LVAs) may improve arrhythmia outcomes. OBJECTIVES: This study aims to compare the outcomes of adding posterior wall isolation (PWI) to PVI, vs PVI alone in PsAF patients with posterior wall LVAs. METHODS: The CAPLA (Effect of Catheter Ablation Using Pulmonary Vein Isolation With vs Without Posterior Left Atrial Wall Isolation on Atrial Arrhythmia Recurrence in Patients With Persistent Atrial Fibrillation) study was a multicenter, randomized trial involving PsAF patients randomized 1:1 to either PVI alone or PVI with PWI. Voltage mapping performed during pacing pre-ablation was reviewed offline, with LVA defined as bipolar voltage of <0.5 mV. The primary endpoint was freedom from any documented atrial arrhythmia of >30 seconds off antiarrhythmic medication at 12 months after a single ablation procedure in patients with posterior LVA. RESULTS: A total of 210 patients (average 64.6 ± 9.2 years,73.3% males, median atrial fibrillation duration 4.5 months [IQR: 2 to 8 months]) underwent multipolar left atrial mapping during coronary sinus pacing with posterior LVA present in 69 (32.9%). Patients with posterior LVA were more likely to have LVA in other atrial regions (91.7% vs 57.1%; P < 0.01), larger left atrial diameter (4.8 cm vs 4.4 cm; P < 0.01), and significantly increased risk of atrial arrhythmia recurrence at 12 months (LVA: 56.5% vs no LVA: 41.4%; HR: 1.51; 95% CI: 1.01-2.27; P = 0.04) compared to no posterior LVA. However, the addition of PWI to PVI did not significantly improve freedom from atrial arrhythmia recurrence over PVI alone (PVI with PWI: 44.8% vs PVI: 41.9%; HR: 0.95; 95% CI: 0.51-1.79; P = 0.95). CONCLUSIONS: In patients with PsAF undergoing catheter ablation, posterior LVA was associated with a significant increase in atrial arrhythmia recurrence. However, the addition of PWI in those with posterior LVA did not reduce atrial arrhythmia recurrence over PVI alone.

Posterior Wall Isolation Improves Outcomes for Persistent AF With Rapid Posterior Wall Activity: CAPLA Substudy.

BACKGROUND: Pulmonary vein isolation (PVI) is less effective in persistent atrial fibrillation (PerAF) than in paroxysmal atrial fibrillation (AF). However, the CAPLA (Effect of Catheter Ablation Using Pulmonary Vein Isolation With vs Without Posterior Left Atrial Wall Isolation on Atrial Arrhythmia Recurrence in Patients With Persistent Atrial Fibrillation: The CAPLA randomized clinical trial) of PVI vs posterior wall isolation (PWI) did not support empiric PWI in PerAF. We examined pulmonary vein (PV) and posterior wall (PW) electrical characteristics to determine if select patients may benefit from additional PWI. OBJECTIVES: This study sought to determine the impact of PV and PW electrical characteristics on AF ablation outcomes in the CAPLA randomized study. METHODS: Participants in spontaneous AF at the time of ablation were included from the CAPLA study. The mean, shortest, and longest PV, PW, and left atrial (LA) appendage cycle length measurements were annotated preablation using a multipolar catheter for 100 consecutive cycles. Next, cardioversion was performed with a high-density LA voltage map completed. Cox proportional hazards regression was utilized to determine clinical and electroanatomic predictors of AF recurrence overall and according to ablation strategy. Follow-up included twice daily single-lead electrocardiograms or continuous monitoring for 12 months. RESULTS: A total of 151 patients (27% female, age 65 ± 9 years, 18% long-standing PerAF, LA volume index 52 ± 16 mL/m2, median AF duration 5 months [IQR: 2-10 months]) were in AF on the day of procedure and were randomized to PVI alone (50%) or PVI+PWI (50%) according to the CAPLA randomized clinical trial protocol. Baseline clinical, echocardiographic, and electroanatomic parameters were comparable between groups (all P > 0.05) including PV and PW characteristics. After 12 months, freedom from AF off antiarrhythmic drug therapy was 51.7% in PVI and 49.7% in PVI+PWI (log-rank P = 0.564). Rapid PW activity was defined as less than the median of the shortest PW cycle length (140 ms) and rapid PV activity was defined as less than the median of the shortest PV cycle length (126 ms). In those with rapid PW activity, the addition of PWI was associated with greater arrhythmia-free survival (56.4%) vs PVI alone (38.6%) (HR: 0.78; 95% CI: 0.67-0.94; log-rank P = 0.030). Moreover, in those undergoing PVI only, the risk of AF recurrence was higher in those with rapid PW activity (55.3% vs 46.5% in slower PW activity; HR: 1.50, 95%CI 1.11-2.26; log-rank P = 0.036). Rapid PV activity and PV cycle length (individual PVs or average of all 4 PVs) were not associated with outcome (all P > 0.05) regardless of ablation strategy. There was no correlation between PW cycle length and posterior low voltage (r = -0.06, P = 0.496). The addition of PWI did not improve arrhythmia-free survival in subgroups with LA enlargement (LA volume index >34 mL/m2) (HR: 0.69; 95% CI: 0.39-1.25; P = 0.301), posterior low-voltage zone (HR: 1.06; 95% CI: 0.68-1.66; P = 0.807), or long-standing PerAF (HR: 1.10; 95% CI: 0.71-1.72; P = 0.669). CONCLUSIONS: Rapid PW activity is associated with an increased risk of AF recurrence post-catheter ablation. The addition of PWI in this subgroup was associated with a significant improvement in freedom from AF compared with PVI alone. The presence of rapid PW activity may identify patients with PerAF likely to benefit from PWI.

Atrial Fibrillation Catheter Ablation vs Medical Therapy and Psychological Distress: A Randomized Clinical Trial.

Importance: The impact of atrial fibrillation (AF) catheter ablation on mental health outcomes is not well understood. Objective: To determine whether AF catheter ablation is associated with greater improvements in markers of psychological distress compared with medical therapy alone. Design, Setting, and Participants: The Randomized Evaluation of the Impact of Catheter Ablation on Psychological Distress in Atrial Fibrillation (REMEDIAL) study was a randomized trial of symptomatic participants conducted in 2 AF centers in Australia between June 2018 and March 2021. Interventions: Participants were randomized to receive AF catheter ablation (n = 52) or medical therapy (n = 48). Main Outcomes and Measures: The primary outcome was Hospital Anxiety and Depression Scale (HADS) score at 12 months. Secondary outcomes included follow-up assessments of prevalence of severe psychological distress (HADS score >15), anxiety HADS score, depression HADS score, and Beck Depression Inventory-II (BDI-II) score. Arrhythmia recurrence and AF burden data were also analyzed. Results: A total of 100 participants were randomized (mean age, 59 [12] years; 31 [32%] women; 54% with paroxysmal AF). Successful pulmonary vein isolation was achieved in all participants in the ablation group. The combined HADS score was lower in the ablation group vs the medical group at 6 months (8.2 [5.4] vs 11.9 [7.2]; P = .006) and at 12 months (7.6 [5.3] vs 11.8 [8.6]; between-group difference, -4.17 [95% CI, -7.04 to -1.31]; P = .005). Similarly, the prevalence of severe psychological distress was lower in the ablation group vs the medical therapy group at 6 months (14.2% vs 34%; P = .02) and at 12 months (10.2% vs 31.9%; P = .01), as was the anxiety HADS score at 6 months (4.7 [3.2] vs 6.4 [3.9]; P = .02) and 12 months (4.5 [3.3] vs 6.6 [4.8]; P = .02); the depression HADS score at 3 months (3.7 [2.6] vs 5.2 [4.0]; P = .047), 6 months (3.4 [2.7] vs 5.5 [3.9]; P = .004), and 12 months (3.1 [2.6] vs 5.2 [3.9]; P = .004); and the BDI-II score at 6 months (7.2 [6.1] vs 11.5 [9.0]; P = .01) and 12 months (6.6 [7.2] vs 10.9 [8.2]; P = .01). The median (IQR) AF burden in the ablation group was lower than in the medical therapy group (0% [0%-3.22%] vs 15.5% [1.0%-45.9%]; P < .001). Conclusion and Relevance: In this trial of participants with symptomatic AF, improvement in psychological symptoms of anxiety and depression was observed with catheter ablation, but not medical therapy. Trial Registration: ANZCTR Identifier: ACTRN12618000062224.

New-onset atrial fibrillation prediction: the HARMS2-AF risk score.

AIMS: Lifestyle risk factors are a modifiable target in atrial fibrillation (AF) management. The relative contribution of individual lifestyle risk factors to AF development has not been described. Development and validation of an AF lifestyle risk score to identify individuals at risk of AF in the general population are the aims of the study. METHODS AND RESULTS: The UK Biobank (UKB) and Framingham Heart Study (FHS) are large prospective cohorts with outcomes measured >10 years. Incident AF was based on International Classification of Diseases version 10 coding. Prior AF was excluded. Cox proportional hazards regression identified independent AF predictors, which were evaluated in a multivariable model. A weighted score was developed in the UKB and externally validated in the FHS. Kaplan-Meier estimates ascertained the risk of AF development. Among 314 280 UKB participants, AF incidence was 5.7%, with median time to AF 7.6 years (interquartile range 4.5-10.2). Hypertension, age, body mass index, male sex, sleep apnoea, smoking, and alcohol were predictive variables (all P < 0.001); physical inactivity [hazard ratio (HR) 1.01, 95% confidence interval (CI) 0.96-1.05, P = 0.80] and diabetes (HR 1.03, 95% CI 0.97-1.09, P = 0·38) were not significant. The HARMS2-AF score had similar predictive performance [area under the curve (AUC) 0.782] to the unweighted model (AUC 0.802) in the UKB. External validation in the FHS (AF incidence 6.0% of 7171 participants) demonstrated an AUC of 0.757 (95% CI 0.735-0.779). A higher HARMS2-AF score (≥5 points) was associated with a heightened AF risk (score 5-9: HR 12.79; score 10-14: HR 38.70). The HARMS2-AF risk model outperformed the Framingham-AF (AUC 0.568) and ARIC (AUC 0.713) risk models (both P < 0.001) and was comparable to the CHARGE-AF risk score (AUC 0.754, P = 0.73). CONCLUSION: The HARMS2-AF score is a novel lifestyle risk score which may help identify individuals at risk of AF in the general community and assist population screening.

Impact of early vs. delayed atrial fibrillation catheter ablation on atrial arrhythmia recurrences.

BACKGROUND: Catheter ablation is an effective strategy in atrial fibrillation (AF). However, its timing in the course of management remains unclear. The aim of this study was to determine if an early vs. delayed AF ablation strategy is associated with differences in arrhythmia outcomes during 12-month follow-up. METHODS AND RESULTS: One hundred patients with symptomatic AF referred to a tertiary centre for management were randomized in a 1:1 ratio to either an early ablation strategy (within 1 month of recruitment) or a delayed ablation strategy (optimized medical therapy followed by catheter ablation at 12 months post recruitment). The primary endpoint was atrial arrhythmia free survival at 12 months post-ablation. Secondary outcomes included: (i) AF burden, (ii) AF burden by AF phenotype, and (iii) antiarrhythmic drug (AAD) use at 12 months. Overall, 89 patients completed the study protocol (Early vs. Delayed: 48 vs. 41). Mean age was 59 ± 12.9 years (29% women). Pulmonary vein isolation was achieved in 100% of patients. At 12 months, 56.3% of patients in the early ablation group were free from recurrent arrhythmia, compared with 58.6% in the delayed ablation group (HR 1.12, 95% CI 0.59-2.13, P = 0.7). All secondary outcomes showed no significant difference including median AF burden (Early vs. Delayed: 0% [IQR 3.2] vs. 0% [5], P = 0.66), median AF burden amongst paroxysmal AF patients (0% [IQR 1.1] vs. 0% [4.5], P = 0.78), or persistent AF patients (0% [IQR 22.8] vs. 0% [5.6], P = 0.45) or AAD use (33% vs. 37%, P = 0.8). CONCLUSION: Compared with an early ablation strategy, delaying AF ablation by 12 months for AAD management did not result in reduced ablation efficacy.

Atrial Fibrillation Ablation for Heart Failure With Preserved Ejection Fraction: A Randomized Controlled Trial.

BACKGROUND: Patients with heart failure with preserved ejection fraction (HFpEF) frequently develop atrial fibrillation (AF). There are no randomized trials examining the effects of AF ablation on HFpEF outcomes. OBJECTIVES: The aim of this study is to compare the effects of AF ablation vs usual medical therapy on markers of HFpEF severity, including exercise hemodynamics, natriuretic peptide levels, and patient symptoms. METHODS: Patients with concomitant AF and HFpEF underwent exercise right heart catheterization and cardiopulmonary exercise testing. HFpEF was confirmed with pulmonary capillary wedge pressure (PCWP) of 15 mm Hg at rest or ≥25 mm Hg on exercise. Patients were randomized to AF ablation vs medical therapy, with investigations repeated at 6 months. The primary outcome was change in peak exercise PCWP on follow-up. RESULTS: A total of 31 patients (mean age: 66.1 years; 51.6% females, 80.6% persistent AF) were randomized to AF ablation (n = 16) vs medical therapy (n = 15). Baseline characteristics were comparable across both groups. At 6 months, ablation reduced the primary outcome of peak PCWP from baseline (30.4 ± 4.2 to 25.4 ± 4.5 mm Hg; P < 0.01). Improvements were also seen in peak relative VO2 (20.2 ± 5.9 to 23.1 ± 7.2 mL/kg/min; P < 0.01), N-terminal pro-B-type natriuretic peptide levels (794 ± 698 to 141 ± 60 ng/L; P = 0.04), and MLHF (Minnesota Living with Heart Failure) score (51 ± -21.9 to 16.6 ± 17.5; P < 0.01). No differences were detected in the medical arm. Following ablation, 50% no longer met exercise right heart catheterization-based criteria for HFpEF vs 7% in the medical arm (P = 0.02). CONCLUSIONS: AF ablation improves invasive exercise hemodynamic parameters, exercise capacity, and quality of life in patients with concomitant AF and HFpEF.

Aberrant Ventricular Conduction: Revisiting an Old Concept.

The well-defined concept of aberrant ventricular conduction was introduced over 100 years ago and, despite advances in cardiac physiology and electrophysiologic testing, it is still widely misunderstood. Aberrant ventricular conduction is due to physiologic refractoriness of the His-Purkinje system and in most cases does not reflect underlying conduction system disease. Electrophysiologically, aberrant ventricular conduction can manifest with premature atrial ectopics, the Ashman phenomenon with atrial tachyarrhythmias, concealed conduction, echo beats and with the sinus mechanism including rate dependent bundle branch block, bradycardia dependent bundle branch block and early sinus beats. It is important to recognise aberrant ventricular conduction in the context of a broad complex tachycardia, as the differentiation between supraventricular tachyarrhythmias with aberrant ventricular conduction and ventricular tachyarrhythmias carry different therapeutic and prognostic implications. This review will define the ECG footprints of aberrant ventricular conduction to allow accurate ECG interpretation.

Utility of cardiac imaging in patients with ventricular tachycardia.

Ventricular tachycardia (VT) is a life-threatening arrhythmia that may be idiopathic or result from structural heart disease. Cardiac imaging is critical in the diagnostic workup and risk stratification of patients with VT. Data gained from cardiac imaging provides information on likely mechanisms and sites of origin, as well as risk of intervention. Pre-procedural imaging can be used to plan access route(s) and identify patients where post-procedural intensive care may be required. Integration of cardiac imaging into electroanatomical mapping systems during catheter ablation procedures can facilitate the optimal approach, reduce radiation dose, and may improve clinical outcomes. Intraprocedural imaging helps guide catheter position, target substrate, and identify complications early. This review summarises the contemporary imaging modalities used in patients with VT, and their uses both pre-procedurally and intra-procedurally.

Directed Graph Mapping for Ventricular Tachycardia: A Comparison to Established Mapping Techniques.

BACKGROUND: Understanding underlying mechanism(s) and identifying critical circuit components are fundamental to successful ventricular tachycardia (VT) ablation. Directed graph mapping (DGM) offers a novel technique to identify the mechanism and critical components of a VT circuit. OBJECTIVES: This study sought to evaluate the accuracy of DGM in VT ablation compared with traditional mapping techniques and a commercially available automated conduction velocity mapping (ACVM) tool. METHODS: Patients with structural heart disease who had undergone a VT ablation with entrainment-proven critical isthmus and a high-density electroanatomical activation map were included. Traditional mapping (TM) consisted of a combination of local activation time and entrainment mapping and was considered the gold standard for determining the VT mechanism, circuit, and isthmus location. The same local activation time values were then processed using DGM and a commercially available ACVM (Coherent Mapping, Biosense Webster) tool. The aim of this study was to compare TM vs DGM and ACVM in their ability to identify the VT mechanism, characterize the VT circuit, and locate the critical isthmus. RESULTS: Thirty-five cases were identified. TM classified the VT mechanism as focal in 7 patients and re-entrant in 28 patients. TM classified 11 VTs as single-loop re-entry, 15 as dual-loop re-entry, 1 as complex, and 1 case was indeterminant. The overall agreement between DGM and TM for determining VT mechanism and circuit type was strong (kappa value = 0.79; P < 0.01), as was the agreement between ACVM and TM (kappa value = 0.66; P < 0.01). Both DGM and ACVM identified the putative VT isthmus in 25 (89%) of the re-entrant cases. Focal activation was correctly identified by both techniques in all cases. CONCLUSIONS: DGM is a rapid automated algorithm that has a strong level of agreement with TM for manually re-annotated VT maps.

Effect of Catheter Ablation Using Pulmonary Vein Isolation With vs Without Posterior Left Atrial Wall Isolation on Atrial Arrhythmia Recurrence in Patients With Persistent Atrial Fibrillation: The CAPLA Randomized Clinical Trial.

Importance: Pulmonary vein isolation (PVI) alone is less effective in patients with persistent atrial fibrillation (AF) compared with paroxysmal AF. The left atrial posterior wall may contribute to maintenance of persistent AF, and posterior wall isolation (PWI) is a common PVI adjunct. However, PWI has not been subjected to randomized comparison. Objective: To compare PVI with PWI vs PVI alone in patients with persistent AF undergoing first-time catheter ablation. Design, Setting, and Participants: Investigator initiated, multicenter, randomized clinical trial involving 11 centers in 3 countries (Australia, Canada, UK). Symptomatic patients with persistent AF were randomized 1:1 to either PVI with PWI or PVI alone. Patients were enrolled July 2018-March 2021, with 1-year follow-up completed March 2022. Interventions: The PVI with PWI group (n = 170) underwent wide antral pulmonary vein isolation followed by posterior wall isolation involving linear ablation at the roof and floor to achieve electrical isolation. The PVI-alone group (n = 168) underwent wide antral pulmonary vein isolation alone. Main Outcomes and Measures: Primary end point was freedom from any documented atrial arrhythmia of more than 30 seconds without antiarrhythmic medication at 12 months, after a single ablation procedure. The 23 secondary outcomes included freedom from atrial arrhythmia with/without antiarrhythmic medication after multiple procedures, freedom from symptomatic AF with/without antiarrhythmic medication after multiple procedures, AF burden between study groups at 12 months, procedural outcomes, and complications. Results: Among 338 patients randomized (median age, 65.6 [IQR, 13.1] years; 76.9% men), 330 (97.6%) completed the study. After 12 months, 89 patients (52.4%) assigned to PVI with PWI were free from recurrent atrial arrhythmia without antiarrhythmic medication after a single procedure, compared with 90 (53.6%) assigned to PVI alone (between-group difference, -1.2%; hazard ratio [HR], 0.99 [95% CI, 0.73-1.36]; P = .98). Of the secondary end points, 9 showed no significant difference, including freedom from atrial arrhythmia with/without antiarrhythmic medication after multiple procedures (58.2% for PVI with PWI vs 60.1% for PVI alone; HR, 1.10 [95% CI, 0.79-1.55]; P = .57), freedom from symptomatic AF with/without antiarrhythmic medication after multiple procedures (68.2% vs 72%; HR, 1.20 [95% CI, 0.80-1.78]; P = .36) or AF burden (0% [IQR, 0%-2.3%] vs 0% [IQR, 0%-2.8%], P = .47). Mean procedural times (142 [SD, 69] vs 121 [SD, 57] minutes, P < .001) and ablation times (34 [SD, 21] vs 28 [SD, 12] minutes, P < .001) were significantly shorter for PVI alone. There were 6 complications for PVI with PWI and 4 for PVI alone. Conclusions and Relevance: In patients undergoing first-time catheter ablation for persistent AF, the addition of PWI to PVI alone did not significantly improve freedom from atrial arrhythmia at 12 months compared with PVI alone. These findings do not support the empirical inclusion of PWI for ablation of persistent AF. Trial Registration: anzctr.org.au Identifier: ACTRN12616001436460.

Retrospective Window of Interest Annotation Provides New Insights Into Functional Channels in Ventricular Tachycardia Substrate.

BACKGROUND: Accurate annotation of local activation time is crucial in the functional assessment of ventricular tachycardia (VT) substrate. A major limitation of modern mapping systems is the standard prospective window of interest (sWOI) is limited to 490 to 500 milliseconds, preventing annotation of very late potentials (LPs). A novel retrospective window of interest (rWOI), which allows annotation of all diastolic potentials, was used to assess the functional VT substrate. OBJECTIVES: This study sought to investigate the utility of a novel rWOI, which allows accurate visualization and annotation of all LPs during VT substrate mapping. METHODS: Patients with high-density VT substrate maps and a defined isthmus were included. All electrograms were manually annotated to latest activation using a novel rWOI. Reannotated substrate maps were correlated to critical sites, with areas of late activation examined. Propagation patterns were examined to assess the functional aspects of the VT substrate. RESULTS: Forty-eight cases were identified with 1,820 ± 826 points per map. Using the novel rWOI, 31 maps (65%) demonstrated LPs beyond the sWOI limit. Two distinct patterns of channel activation were seen during substrate mapping: 1) functional block with unidirectional conduction into the channel (76%); and 2) wave front collision within the channel (24%). In addition, a novel marker termed the zone of early and late crowding was studied in the rWOI substrate maps and found to have a higher positive predictive value (85%) than traditional deceleration zones (69%) for detecting critical sites of re-entry. CONCLUSIONS: The standard WOI of contemporary mapping systems is arbitrarily limited and results in important very late potentials being excluded from annotation. Future versions of electroanatomical mapping systems should provide longer WOIs for accurate local activation time annotation.

Higher power short duration vs. lower power longer duration posterior wall ablation for atrial fibrillation and oesophageal injury outcomes: a prospective multi-centre randomized controlled study (Hi-Lo HEAT trial).

AIMS: Radiofrequency (RF) ablation for pulmonary vein isolation (PVI) in atrial fibrillation (AF) is associated with the risk of oesophageal thermal injury (ETI). Higher power short duration (HPSD) ablation results in preferential local resistive heating over distal conductive heating. Although HPSD has become increasingly common, no randomized study has compared ETI risk with conventional lower power longer duration (LPLD) ablation. This study aims to compare HPSD vs. LPLD ablation on ETI risk. METHODS AND RESULTS: Eighty-eight patients were randomized 1:1 to HPSD or LPLD posterior wall (PW) ablation. Posterior wall ablation was 40 W (HPSD group) or 25 W (LPLD group), with target AI (ablation index) 400/LSI (lesion size index) 4. Anterior wall ablation was 40-50 W, with a target AI 500-550/LSI 5-5.5. Endoscopy was performed on Day 1. The primary endpoint was ETI incidence. The mean age was 61 ± 9 years (31% females). The incidence of ETI (superficial ulcers n = 4) was 4.5%, with equal occurrence in HPSD and LPLD (P = 1.0). There was no difference in the median value of maximal oesophageal temperature (HPSD 38.6°C vs. LPLD 38.7°C, P = 0.43), or the median number of lesions per patient with temperature rise above 39°C (HPSD 1.5 vs. LPLD 2, P = 0.93). Radiofrequency ablation time (23.8 vs. 29.7 min, P < 0.01), PVI duration (46.5 vs. 59 min, P = 0.01), and procedure duration (133 vs. 150 min, P = 0.05) were reduced in HPSD. After a median follow-up of 12 months, AF recurrence was lower in HPSD (15.9% vs. LPLD 34.1%; hazard ratio 0.42, log-rank P = 0.04). CONCLUSION: Higher power short duration ablation was associated with similarly low rates of ETI and shorter total/PVI RF ablation times when compared with LPLD ablation. Higher power short duration ablation is a safe and efficacious approach to PVI.