2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines.

AIM: The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation. METHODS: A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate. STRUCTURE: Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

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

BACKGROUND AND AIMS: Patterns of atrial fibrillation (AF) recurrence post-catheter ablation for persistent AF (PsAF) are not well described. This study aimed to describe the pattern of AF recurrence seen following catheter ablation for PsAF and the implications for healthcare utilization and quality of life (QoL). METHODS: This was a post-hoc analysis of the CAPLA study, an international, multicentre study that randomized 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 randomization groups (P = .508). Median AF burden was 27.4% in PsAF recurrence and .9% in paroxysmal AF (PAF) recurrence (P < .001). Patients with PsAF recurrence had lower baseline left ventricular ejection fraction (PsAF 50% vs. PAF 60%, P < .001) and larger left atrial volume (PsAF 54.2 ± 19.3 mL/m² vs. PAF 44.8 ± 11.6 mL/m², P = .008). Healthcare utilization was significantly higher in PsAF (45 patients [78.9%]) vs. PAF recurrence (45 patients [46.4%], P < .001) and lowest in those without recurrence (17 patients [9.5%], P < .001). Patients without AF recurrence had greater improvements in QoL 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 = .012) or PsAF (Δ13.4 ± 22.9 points, P < .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 utilization and antiarrhythmic drug use. The type of AF recurrence and AF burden may be considered important endpoints in clinical trials investigating ablation of PsAF.

Oral anticoagulation after atrial fibrillation catheter ablation: benefits and risks.

BACKGROUND AND AIMS: Few recent large-scale studies have evaluated the risks and benefits of continuing oral anticoagulant (OAC) therapy after catheter ablation (CA) for atrial fibrillation (AF). This study evaluated the status of continuation of OAC therapy and the association between continuation of OAC therapy and thromboembolic and bleeding events according to the CHADS2 score. METHODS: This retrospective study included data from the Japanese nationwide administrative claims database of patients who underwent CA for AF between April 2014 and March 2021. Patients without AF recurrence assessed by administrative data of the treatment modalities were divided into two groups according to continuation of OAC therapy 6 months after the index CA. The primary outcomes were thromboembolism and major bleeding after a landmark period of 6 months. After inverse probability of treatment weighting analysis, the association between OAC continuation and outcomes was determined according to the CHADS2 score. RESULTS: Among 231 374 patients included, 69.7%, 21.6%, and 8.7% had CHADS2 scores of ≤1, 2, and ≥3, respectively. Of these, 71% continued OAC therapy at 6 months. The OAC continuation rate was higher in the high CHADS2 score group than that in the low CHADS2 score group. Among all patients, 2451 patients (0.55 per 100 person-years) had thromboembolism and 2367 (0.53 per 100 person-years) had major bleeding. In the CHADS2 score ≤1 group, the hazard ratio of the continued OAC group was 0.86 [95% confidence interval (CI): 0.74-1.01, P = .06] for thromboembolism and was 1.51 (95% CI: 1.27-1.80, P < .001) for major bleeding. In the CHADS2 score ≥3 group, the hazard ratio of the continued OAC group was 0.61 (95% CI: 0.46-0.82, P = .001) for thromboembolism and was 1.05 (95% CI: 0.71-1.56, P = 0.81) for major bleeding. CONCLUSIONS: This observational study suggests that the benefits and risks of continuing OAC therapy after CA for AF differ based on the patient's CHADS2 score. The risk of major bleeding due to OAC continuation seems to outweigh the risk reduction of thromboembolism in patients with lower thromboembolic risk.

Catheter ablation for atrial fibrillation: indications and future perspective.

Recent advances in techniques, technologies and proven superiority over anti-arrhythmic drugs have made catheter ablation the cornerstone of management for atrial fibrillation (AF), which has shown a steady increase in prevalence in the ageing population worldwide. The aim of therapeutic interventions is to achieve stable sinus rhythm that would improve the quality of life and reduce the risk of AF-associated complications. Pulmonary veins (PVs) were first described as the source of initiation of ectopic triggers driving AF, which led to the establishment of PV isolation (PVI) as the most widely practiced procedure to treat AF. Antral PVI is still recognized as the stand-alone ablation strategy for newly diagnosed paroxysmal AF (PAF). However, in non-PAF patients, PVI seems to be inadequate and several adjunctive strategies, including ablation of left atrial posterior wall and non-PV triggers, AF mapping and ablation of rotors and drivers, ethanol infusion of vein of Marshall and renal denervation, etc. have been reported with mixed results. Recent trials have also documented the benefits of early rhythm control in preventing cardiovascular events in addition to slowing the progression of PAF to more persistent forms. Similarly, very late relapse of the arrhythmia after successful PVI has drawn attention to the critical role of non-PV triggers and highlighted their relevance as potential ablation targets during repeat procedures. Ablation technology is also under constant evolution with the introduction of non-thermal energy sources and new tools to create durable lesions. This review summarizes the indications, advancements, and future perspective of AF ablation.

Atrial tachyarrhythmia prevention by Shensong Yangxin after catheter ablation for persistent atrial fibrillation: the SS-AFRF trial.

BACKGROUND AND AIMS: Despite advances in technology and techniques, the recurrence rate of persistent atrial fibrillation (AF) following catheter ablation remains high. The Shensong Yangxin (SSYX) capsule, a renowned traditional Chinese medicine formula, is used in the treatment of cardiac arrhythmias. This trial aimed to investigate whether the SSYX can improve clinical outcomes in patients who have undergone catheter ablation for persistent AF. METHODS: A multi-centre, randomized, double-blind, placebo-controlled clinical trial was conducted at 66 centres in China among 920 patients with persistent AF undergoing first ablation. Participants were randomized to oral SSYX, 1.6 g (.4 g/granule) thrice daily (n = 460), or matched placebo (n = 460) for 12 months. The primary endpoint was recurrent atrial tachyarrhythmias lasting for ≥30 s following a blanking period of 3 months. Secondary endpoints included time to first documented atrial tachyarrhythmias, AF burden, cardioversion, stroke/systemic embolism, changes in echocardiographic parameters, and quality-of-life (QoL) score. Analyses were performed according to the intention-to-treat principle. RESULTS: A total of 920 patients underwent randomization (460 assigned to SSYX group and 460 assigned to placebo group). During the follow-up of 12 months, patients assigned to SSYX had a higher event-free rate from recurrent atrial tachyarrhythmias when compared with the placebo group (12-month Kaplan-Meier event-free rate estimates, 85.5% and 77.7%, respectively; hazard ratio, .6; 95% confidence interval .4-.8; P = .001). Patients assigned to receive SSYX had a better QoL score at 12 months compared to those randomized to placebo. There was no significant difference in the incidence of serious adverse events between the two groups. CONCLUSIONS: Treatment with SSYX following radiofrequency catheter ablation for persistent AF reduced the incidence of recurrent atrial tachyarrhythmias and led to clinically significant improvements in QoL during a 12-month follow-up in a Chinese population.

Multiomics analysis of canine myocardium after circumferential pulmonary vein ablation: Effect of neuropeptide Y on long-term reinduction of atrial fibrillation.

Catheter ablation (CA) is an essential method for the interventional treatment of atrial fibrillation (AF), and it is very important to reduce long-term recurrence after CA. The mechanism of recurrence after CA is still unclear. We established a long-term model of beagle canines after circumferential pulmonary vein ablation (CPVA). The transcriptome and proteome were obtained using high-throughput sequencing and TMT-tagged LC-MS/LC analysis, respectively. Differentially expressed genes and proteins were screened and enriched, and the effect of fibrosis was found and verified in tissues. A downregulated protein, neuropeptide Y (NPY), was selected for validation and the results suggest that NPY may play a role in the long-term reinduction of AF after CPVA. Then, the molecular mechanism of NPY was further investigated. The results showed that the atrial effective refractory period (AERP) was shortened and fibrosis was increased after CPVA. Atrial myocyte apoptosis was alleviated by NPY intervention, and Akt activation was inhibited in cardiac fibroblasts. These results suggest that long-term suppression of NPY after CPVA may lead to induction of AF through promoting cardiomyocyte apoptosis and activating the Akt pathway in cardiac fibroblasts, which may make AF more likely to reinduce.

Safety and Effectiveness of Pulsed Field Ablation to Treat Atrial Fibrillation: One-Year Outcomes From the MANIFEST-PF Registry.

BACKGROUND: Pulsed field ablation is a novel nonthermal cardiac ablation modality using ultra-rapid electrical pulses to cause cell death by a mechanism of irreversible electroporation. Unlike the traditional ablation energy sources, pulsed field ablation has demonstrated significant preferentiality to myocardial tissue ablation, and thus avoids certain thermally mediated complications. However, its safety and effectiveness remain unknown in usual clinical care. METHODS: MANIFEST-PF (Multi-National Survey on the Methods, Efficacy, and Safety on the Post-Approval Clinical Use of Pulsed Field Ablation) is a retrospective, multinational, patient-level registry wherein patients at each center were prospectively included in their respective center registries. The registry included all patients undergoing postapproval treatment with a multielectrode 5-spline pulsed field ablation catheter to treat atrial fibrillation (AF) between March 1, 2021, and May 30, 2022. The primary effectiveness outcome was freedom from clinical documented atrial arrhythmia (AF/atrial flutter/atrial tachycardia) of ≥30 seconds on the basis of electrocardiographic data after a 3-month blanking period (on or off antiarrhythmic drugs). Safety outcomes included the composite of acute (<7 days postprocedure) and latent (>7 days) major adverse events. RESULTS: At 24 European centers (77 operators) pulsed field ablation was performed in 1568 patients with AF: age 64.5±11.5 years, female 35%, paroxysmal/persistent AF 65%/32%, CHA2DS2-VASc 2.2±1.6, median left ventricular ejection fraction 60%, and left atrial diameter 42 mm. Pulmonary vein isolation was achieved in 99.2% of patients. After a median (interquartile range) follow-up of 367 (289-421) days, the 1-year Kaplan-Meier estimate for freedom from atrial arrhythmia was 78.1% (95% CI, 76.0%-80.0%); clinical effectiveness was more common in patients with paroxysmal AF versus persistent AF (81.6% versus 71.5%; P=0.001). Acute major adverse events occurred in 1.9% of patients. CONCLUSIONS: In this large observational registry of the postapproval clinical use of pulsed field technology to treat AF, catheter ablation using pulsed field energy was clinically effective in 78% of patients with AF.

Identification of Human Ventricular Tachycardia Demarcated by Fixed Lines of Conduction Block in a 3-Dimensional Hyperboloid Circuit.

BACKGROUND: The circuit boundaries for reentrant ventricular tachycardia (VT) have been historically conceptualized within a 2-dimensional (2D) construct, with their fixed or functional nature unresolved. This study aimed to examine the correlation between localized lines of conduction block (LOB) evident during baseline rhythm with lateral isthmus boundaries that 3-dimensionally constrain the VT isthmus as a hyperboloid structure. METHODS: A total of 175 VT activation maps were correlated with isochronal late activation maps during baseline rhythm in 106 patients who underwent catheter ablation for scar-related VT from 3 centers (42% nonischemic cardiomyopathy). An overt LOB was defined by a deceleration zone with split potentials (≥20 ms isoelectric segment) during baseline rhythm. A novel application of pacing within deceleration zone (≥600 ms) was implemented to unmask a concealed LOB not evident during baseline rhythm. LOB identified during baseline rhythm or pacing were correlated with isthmus boundaries during VT. RESULTS: Among 202 deceleration zones analyzed during baseline rhythm, an overt LOB was evident in 47%. When differential pacing was performed in 38 deceleration zones without overt LOB, an underlying concealed LOB was exposed in 84%. In 152 VT activation maps (2D=53, 3-dimensional [3D]=99), 69% of lateral boundaries colocalized with an LOB in 2D activation patterns, and the depth boundary during 3D VT colocalized with an LOB in 79%. In VT circuits with isthmus regions that colocalized with a U-shaped LOB (n=28), the boundary invariably served as both lateral boundaries in 2D and 3D. Overall, 74% of isthmus boundaries were identifiable as fixed LOB during baseline rhythm or differential pacing. CONCLUSIONS: The majority of VT circuit boundaries can be identified as fixed LOB from intrinsic or paced activation during sinus rhythm. Analysis of activation while pacing within the scar substrate is a novel technique that may unmask concealed LOB, previously interpreted to be functional in nature. An LOB from the perspective of a myocardial surface is frequently associated with intramural conduction, supporting the existence of a 3D hyperboloid VT circuit structure. Catheter ablation may be simplified to targeting both sides around an identified LOB during sinus rhythm.

Pulsed Field Ablation for the Treatment of Atrial Fibrillation: PULSED AF Pivotal Trial.

BACKGROUND: Pulsed field ablation uses electrical pulses to cause nonthermal irreversible electroporation and induce cardiac cell death. Pulsed field ablation may have effectiveness comparable to traditional catheter ablation while preventing thermally mediated complications. METHODS: The PULSED AF pivotal study (Pulsed Field Ablation to Irreversibly Electroporate Tissue and Treat AF) was a prospective, global, multicenter, nonrandomized, paired single-arm study in which patients with paroxysmal (n=150) or persistent (n=150) symptomatic atrial fibrillation (AF) refractory to class I or III antiarrhythmic drugs were treated with pulsed field ablation. All patients were monitored for 1 year using weekly and symptomatic transtelephonic monitoring; 3-, 6-, and 12-month ECGs; and 6- and 12-month 24-hour Holter monitoring. The primary effectiveness end point was freedom from a composite of acute procedural failure, arrhythmia recurrence, or antiarrhythmic escalation through 12 months, excluding a 3-month blanking period to allow recovery from the procedure. The primary safety end point was freedom from a composite of serious procedure- and device-related adverse events. Kaplan-Meier methods were used to evaluate the primary end points. RESULTS: Pulsed field ablation was shown to be effective at 1 year in 66.2% (95% CI, 57.9 to 73.2) of patients with paroxysmal AF and 55.1% (95% CI, 46.7 to 62.7) of patients with persistent AF. The primary safety end point occurred in 1 patient (0.7%; 95% CI, 0.1 to 4.6) in both the paroxysmal and persistent AF cohorts. CONCLUSIONS: PULSED AF demonstrated a low rate of primary safety adverse events (0.7%) and provided effectiveness consistent with established ablation technologies using a novel irreversible electroporation energy to treat patients with AF. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT04198701.

Ventricular arrhythmias in patients with bicuspid aortic valves.

INTRODUCTION: Bicuspid aortic valves (BAV) are the most common congenital heart defects and the extent of ventricular arrhythmias (VA) in patients with BAV is unclear. The objective of this study is to describe VAs and late gadolinium enhancement cardiac magnetic resonance imaging (LGE-CMR) in patients with BAV. METHODS: A total of 19 patients with BAV (18 males, age: 58 ± 13 years) were referred for VA ablation procedures. Ten patients had BAVs at the time of ablation, nine patients had prior aortic valve replacement for a BAV. All but one patient had LGE-CMR and all patients underwent programmed ventricular stimulation at the time of the ablation. RESULTS: Frequent PVCs were the targeted VAs in 17/19 patients and VT in 2/19 patients. Monomorphic ventricular tachycardia (VT) was inducible in 6 patients. A total of 15 VTs were inducible (2.5 ± 1.0 VTs per patient with a mean cycle length of 322 ± 83 msec). LGE was present in 13 patients. Patients with inducible VT had larger borderzone and core scar compared to non-inducible patients (7.8 ± 2.1 cm3 vs. 2.5 ± 3.1 cm3 and 5.1 ± 2.6 cm3 vs. 1.9 ± 3.0 cm3, p-value < .05 for both). PVCs and VTs were mapped to the periaortic valve area in 12 patients and 4 patients, respectively. The PVC burden was reduced from 27 ± 13 to 3 ± 6 (p < .001) and the ejection fraction improved from 49 ± 13% to 55 ± 9% (p = .005). CONCLUSIONS: VAs in patients with BAV often originate from the perivalvular area and patients often have LGE and inducible VT. LGE may be due to ventricular remodeling secondary to the presence of BAV and harbors the arrhythmogenic substrate for VT.

Trans-aortic mitral isthmus ablation after surgical patch closure for an atrial septal defect.

INTRODUCTION: In patients with prior atrial septal defect (ASD) closure and atrial tachyarrhythmias, transseptal puncture can be challenging. METHODS AND RESULTS: This case report discusses a 65-year-old man who had previously undergone pulmonary vein isolation (PVI) and cavo-tricuspid isthmus ablation for atrial fibrillation before ASD closure, respectively. He developed atrial tachycardia (AT) and underwent catheter ablation. AT was diagnosed as peri-mitral flutter and the mitral isthmus (MI) linear ablation via a trans-aortic approach successfully terminated it. CONCLUSION: This case demonstrates the feasibility and safety of transaortic MI linear ablation in patients with ASD closure devices or anatomical challenges when transseptal puncture is difficult.

Acute procedural efficacy and safety of a novel expandable diameter cryoballoon in atrial fibrillation ablation: Early results from a multicenter ablation registry.

INTRODUCTION: The major limitation of the current cryoballoon (CB) system is a fixed 28 mm balloon-size. We sought to analyze real-world early experience with novel-sized adjustable CB. METHODS: This multicenter observational study included 140 consecutive atrial fibrillation patients (71 years, 94 men, 86 paroxysmal) who underwent pulmonary vein (PV) isolation using expandable diameter CB capable of ablation at 28 or 31 mm. RESULTS: Out of 544 targeted PVs, 526 (96.7%) were successfully isolated by a size-adjustable CB with a 770 [690-870] second median application dose, while the remaining 18 required touch-up ablation. Among them, 326 (62.0%) PVs were isolated by a 31 mm balloon, and the rate was significantly higher for upper than lower PVs (73.0% vs. 45.7%, p < .0001) and highest for right superior (78.5%) and lowest for right inferior (39.9%) PVs. The biophysical parameters and time to isolation were comparable between the 28 and 31 mm balloons, however, the real-time PV potential monitoring capability was significantly higher for 31 mm than 28 mm balloons for the left superior PV. The esophageal temperature reached 15°C during left inferior PV ablation significantly more often with 31 mm than 28 mm balloons (43.1% vs. 18.2%, p = .008). Right phrenic nerve injury (PNI) occurred in 9 (6.4%) patients during applications (6 right superior, 2 right inferior PVs), and most occurred with a 31 mm balloon. CONCLUSIONS: Our real-world early data demonstrated high acute efficacy and safety of the novel-sized adjustable CB. The biophysical parameters were similar between the 28 and 31 mm balloons. No marked decrease in the incidence of PNI was observed even with 31 mm balloons.

Catheter ablation of typical atrial flutter improves cardiac chamber size and function.

INTRODUCTION: Cavo-tricuspid isthmus (CTI) dependent atrial flutter (AFL) is one of the most common atrial arrhythmias involving the right atrium (RA) for which radiofrequency catheter ablation has been widely used as a therapy of choice. However, there is limited data on the effect of this intervention on cardiac size and function. METHODS: A retrospective study was conducted on 468 patients who underwent ablation for CTI dependent typical AFL at a single institution between 2010 and 2019. After excluding patients with congenital or rheumatic heart disease, heart transplant recipients, or those without baseline echocardiogram, a total of 130 patients were included in the analysis. Echocardiographic data were analyzed at baseline before ablation, and at early follow-up within 1-year postablation. Follow-up echocardiographic data was available for 55 patients. RESULTS: Of the 55 patients with CTI-AFL, the mean age was 64.2 ± 14.8 years old with 14.5% (n = 8) female. The average left ventricular ejection fraction (LVEF) significantly improved on follow-up echo (40.2 ± 16.9 to 50.4 ± 14.9%, p < .0001), of which 50% of patients had an improvement in LVEF of at least 10%. There was a significant reduction in left atrial volume index (82.74 ± 28.5 to 72.96 ± 28 mL/m2 , p = .008) and RA volume index (70.62 ± 25.6 to 64.15 ± 31 mL/m2 , p = .046), and a significant improvement in left atrial reservoir strain (13.04 ± 6.8 to 19.10 ± 7.7, p < .0001). CONCLUSIONS: Patients who underwent CTI dependent AFL ablation showed an improvement in cardiac size and function at follow-up evaluation. While long-term results are still unknown, these findings indicate that restoration of sinus rhythm in patients with typical AFL is associated with improvement in atrial size and left ventricular function.

The effect of an initial catheter ablation with an adjunctive ethanol infusion into the vein of Marshall on persistent atrial fibrillation.

INTRODUCTION: Some previous studies have reported that a first-step ethanol infusion into the vein of Marshall (EIVOM) with touch-up radiofrequency (RF) ablation can facilitate mitral isthmus (MI) block and improves the ablation outcomes in persistent atrial fibrillation (PeAF) patients. However, the effect of an initial RF ablation with an adjunctive EIVOM has not been fully investigated. METHODS: This study enrolled 233 PeAF patients undergoing pulmonary vein isolation and linear ablation including an MI, roof line, and cavotricuspid isthmus ablation. An EIVOM was performed when endocardial ablation with or without coronary sinus ablation failed to create MI block. RESULTS: Bidirectional MI block was achieved in 224 patients (96.1%). Among them, MI block was obtained by only RF ablation in 174/224 patients (77.7%) (RF group) and an adjunctive EIVOM was needed in 50/224 (22.3%) (EIVOM group). During the follow-up, 113 (64.9%) RF group patients were free from AF/atrial tachycardia compared to 41 (82.0%) EIVOM group patients (log-rank p = .045). In a multivariate Cox regression analysis, an adjunctive EIVOM was associated with a lower recurrence rate (hazard ratio = 0.39, 95% confidence interval = 0.17-0.78, p = .006). CONCLUSION: An initial RF ablation with an adjunctive EIVOM strategy improved MI ablation's acute success rate and was associated with better clinical outcomes.

Body mass index as a determinant of scar formation post-AF ablation: Insights from DECAAF II.

INTRODUCTION: Obesity is implicated in adverse atrial remodeling and worse outcomes in patients with atrial fibrillation. The objective of this study is to assess the effect of body mass index (BMI) on ablation-induced scar formation on late gadolinium enhancement cardiac magnetic resonance imaging (LGE-CMR). METHODS: We conducted an analysis of DECAAF II participants who underwent LGE-CMR scans to measure scar formation 3 months after catheter ablation. Ablation parameters and lesion delivery were not dependent on BMI. The effect of BMI on ablation success was explored. RESULTS: Our analyses included 811 patients. Comorbidities were more prevalent in obese patients. Baseline left atrial volume was higher in obese individuals, 118, 126, 135, 140, and 143 mm3 for normal weight, overweight, obese grade 1, 2, and 3, respectively (p < .001). BMI was associated with scar formation (R = -0.135, p < .001), with patients with Class 3 obesity having the lowest percentage of ablation-induced scar, 11.1%, 10.3%, 9.5%, 8.8%, 6.8% by ascending BMI group. There was an inverse correlation between BMI and the amount of fibrosis covered by ablation scar, 24%, 23%, 21%, and 18% by ascending BMI group (p = .001). For the fibrosis-guided ablation group, BMI was associated with residual fibrosis (R = 0.056, p = .005). CONCLUSION: Obese patients have lower ablation scar formation, covered fibrosis, and more residual fibrosis postablation compared to nonobese patients, regardless of ablation parameters including impedance drop.

Acute procedural safety of the latest radiofrequency ablation catheters in atrial fibrillation ablation: Data from a large prospective ablation registry.

BACKGROUND: Safety data of the latest radiofrequency (RF) technologies during atrial fibrillation (AF) ablation in real-world clinical practice are limited. OBJECTIVES: We sought to evaluate the acute procedural safety of the four latest ablation catheters commonly used for AF ablation. METHODS: A total of 3957 AF ablation procedures performed between January 2022 and December 2023 at 20 centers with either the THERMOCOOL SMARTTOUCH SF (STSF), TactiCath (TC), QDOT Micro (QDM), or TactiFlex (TF) were retrospectively analyzed. RESULTS: In total, QDM, STSF, TF, and TC were used in 343 (8.7%), 1793 (45.3%), 1121 (28.4%), and 700(17.7%) procedures. Among 2406 index procedures, electrical pulmonary vein isolations were successfully achieved in 99.5%. Despite similar total procedure times in the four groups, the total fluoroscopic time was significantly shorter for QDM/STSF with CARTO than TF/TC with EnSite (18.7 ± 14 vs. 27.6 ± 20.6 min, p < .001) and longest in the TF group. The incidence of cardiac tamponade was 0.7% (0.5% and 0.9% during index and redo procedures, 0.8% and 0.3% for paroxysmal and non-paroxysmal AF) and was significantly lower for QDM/STSF than TF/TC (0.2% vs. 1.1%, p = .008) and highest in the TF group. The incidence of cardiac tamponade was higher for TF than TC and STSF than QDM. In the multivariate analysis, TF/TC with EnSite was a significant independent predictor of cardiac tamponade during both the index (odds ratio [OR] = 4.8, 95% confidence interval [CI] = 1.3-17.5, p = .02) and all procedures (OR = 3.0, 95% CI = 1.3-7.2, p = .01). CONCLUSIONS: The incidence of cardiac tamponade and the fluoroscopic time during AF ablation significantly differed among the latest RF catheters and mapping systems in real-world clinical practice.

Convergent ablation for persistent atrial fibrillation: A UK multicentre perspective.

Atrial fibrillation (AF) is the most common sustained arrhythmia worldwide and remains a major cause of morbidity and mortality. Unfortunately, a significant proportion of patients have persistent AF, for which conventional catheter ablation is less effective. However, convergent ablation has emerged in recent years as a hybrid treatment targeting both the epicardium and endocardium in a multidisciplinary joint cardiothoracic and electrophysiology procedure, with promising efficacy outcomes in recent studies. This treatment is increasingly being performed in the United Kingdom. This review article discusses the rationale and evidence behind convergent ablation, along with factors that need to be considered when setting up a successful ablation service.

Risk assessment of esophageal ulceration following left atrial radiofrequency linear ablation.

INTRODUCTION: Esophageal safety following radiofrequency (RF) left atrial (LA) linear ablation has not been established. To determine the esophageal safety profile of LA linear RF lesions, we performed systematic esophagogastroduodenoscopy in all patients with intraesophageal temperature rise (ITR) ≥ 38.5°C. METHODS AND RESULTS: Between December 2021 and July 2023, a total of 200 consecutive patients with atrial tachyarrhythmia (ATA) underwent linear ablation with posterior dome (roof or floor) or posterior mitral isthmus line transection. Patients with ITR ≥ 38.5°C were scheduled for esophageal endoscopy ~3 weeks after ablation. Patient and ATA characteristics, procedural parameters, endoscopy findings and ablation lesion data were collected and analyzed. One hundred thirty-three out of 200 (67%) patients showed ITR ≥ 38.5°C during LA linear ablation. ITR (with maximal temperature of 45.7°C) was more frequently observed during floor line ablation (82% of cases). ITR was less observed during roof line ablation (34%) and posterior mitral isthmus ablation (4%). Endoscopy, performed in 115 patients after 24 ± 10 days, showed esophageal ulceration in four patients (two patients Kansas City classification [KCC] 2a and two patients KCC 2b). No patient showed esophageal perforation or fistula. CONCLUSION: Temperature rise during LA linear ablation is frequent and ulceration risk exists, particularly when floor line is performed. Safety measures are needed to avoid potential severe complications like esophageal perforation and fistula.

Premature ventricular complexes after catheter ablation for atrial fibrillation: Accounting for regression to the mean.

INTRODUCTION: Prior studies have indicated that the frequency of premature ventricular complexes (PVC) increases after catheter ablation for atrial fibrillation (AF). However, these studies have primarily focused on patients whose PVC burden increased rather than including the full spectrum of outcomes. METHODS AND RESULTS: We performed a single-center retrospective cohort study of consecutive patients who underwent first-time AF ablation from 1/2018 to 12/2022 for paroxysmal or persistent AF and had both preablation and postablation rhythm monitoring within 6 months of the procedure. Patients were excluded if they had prior AF or PVC ablation or were prescribed a class I or III antiarrhythmic medication. Among 2945 patients who underwent AF ablation during the study period, 130 patients underwent first-time AF ablation and received both pre and post ambulatory monitoring. The median PVC burden before ablation was <1%. Most patients (63%) had no change in PVC burden after AF ablation compared with preablation, and patients who had an increase in PVC burden were offset by those with reductions in PVCs. A paired analysis pre- and post-AF ablation showed no significant change in PVC burden (p = .495). CONCLUSION: Although an elevated PVC burden after AF ablation may be seen clinically, the majority of patients have no change in burden. Studies that suggest an increase in PVC burden after AF ablation may suffer from incomplete sample selection and thus omit the important effect of regression to the mean.

Predictors of low-voltage zones in patients with persistent atrial fibrillation eligible for catheter ablation: An observational study.

INTRODUCTION: The presence of low-voltage zones (LVZs) in the left atrium (LA) is associated with the recurrence of atrial fibrillation (AF) following pulmonary vein isolation (PVI). However, there is variability and conflict in the data regarding predictors of LVZs as reported in previous studies. The objective of this study was to identify predictors for the presence of LVZs in a cohort of patients with persistent AF. METHODS: The study prospectively enrolled 439 patients with persistent AF who were scheduled for ablation. Voltage map of the LA was collected using a multipolar catheter. An LVZ was defined as an area of ≥3 cm2 exhibiting a peak-to-peak bipolar voltage of <0.5 mV. RESULTS: The mean age of the cohort was 65.3 ± 8.6 years and 26.4% were female. Additionally, 25.7% had significant LVZs, most frequently located in the anterior wall of the LA. Multivariable analysis identified the following independent predictors for LVZ: advanced age (OR [odds ratio] = 1.08, 95% CI [confidence interval] = 1.03-1.13, p = .002); female sex (OR = 4.83, 95% CI = 2.66-8.76, p < .001); coronary artery disease (CAD) (OR = 3.20, 95% CI = 1.32-7.77, p = .01) and enlarged LA diameter (OR = 1.10, 95% CI = 1.04-1.17, p = .001). The area under the curve (AUC) of the receiver operating characteristic (ROC) curve for the final model was 0.829. CONCLUSION: Approximately 25% of the patients with persistent AF had LVZs. Advanced age, female sex, CAD, and a larger LA were independent predictors for LVZs with the model demonstrating a very good AUC for the ROC curve. These findings hold the potential to be used to tailor the ablation procedure for the individual patient.