Persistent Atrial Fibrillation Research Articles

Initial Clinical Experience with the Balloon-in-Basket Pulsed Field Ablation System: Acute Results of the VOLT CE Mark Feasibility Study.

Pulsed field ablation (PFA) for the treatment of atrial fibrillation (AF) potentially offers improved safety and procedural efficiencies compared to thermal ablation. Opportunities remain to improve effective circumferential lesion delivery, safety, and workflow of first generation PFA systems. Here we aim to evaluate the initial clinical experience with a balloon-in-basket, 3D integrated PFA system with a purpose-built form factor for pulmonary vein (PV) isolation. The VOLT CE Mark Study is a premarket, prospective, multi-centre, single-arm study to evaluate the safety and effectiveness of the Volt™ PFA System for the treatment of paroxysmal (PAF) or persistent AF (PersAF). Feasibility sub-study subjects underwent phrenic nerve evaluation, endoscopy, chest CT, and cerebral MRI. Study endpoints were the rate of primary serious adverse event within 7-days and acute procedural effectiveness. A total of 32 subjects (age 61.6 ± 9.6 years, 65.6% male, 84.4% PAF) were enrolled and treated in the feasibility sub-study and completed 30-day follow-up. Acute effectiveness was achieved in 99.2% (127/128) of treated PVs (96.9% of subjects, 31/32) with 23.8 ± 4.2 PFA applications/subject. Procedure, fluoroscopy, LA dwell and transpired ablation times were 124.6 ± 28.1, 19.8 ± 8.9, 53.0 ± 21.0, and 48.0 ± 19.9 minutes respectively. Systematic assessments of initial safety revealed no phrenic nerve injury, pulmonary vein stenosis, or esophageal lesions causally related to the PFA system, and 3 subjects with silent cerebral lesions (9.4%). There were no primary serious adverse events. The initial clinical use of the Volt PFA System demonstrates acute safety and effectiveness in the treatment of symptomatic, drug refractory AF.

Notched P‐wave on digital electrocardiogram predicts the recurrence of atrial fibrillation in patients who have undergone catheter ablation

AbstractBackgroundA notched P‐wave is associated with the occurrence of atrial fibrillation (AF). However, the association between a notched P‐wave and AF recurrence in patients who have undergone a catheter ablation for AF is unclear.MethodsWe enrolled 100 subjects who underwent catheter ablation for AF (paroxysmal AF: 60 cases; persistent AF: 40 cases). Twelve‐lead electrocardiography (ECG) was conducted, and the peak‐to‐peak distance in the M shape was calculated automatically using a 12‐lead ECG analysis system. A notched P‐wave was defined as a P‐wave with an M‐shape and a peak‐to‐peak distance of ≥20 ms in lead II. We compared the recurrence of AF in the patients with notched P‐wave and the others.ResultsThe mean follow‐up period was 12 ± 8 months, and a recurrence of AF was observed in 28 patients. The recurrence of AF in the notched P‐wave group was significantly higher than that in the controls (log rank 5.14, p = .023). A notched P‐wave was a significant predictor of the recurrence of AF after adjustment for age, gender, history of heart failure, history of catheter ablation, persistent AF, use of antiarrhythmic drugs, and the left atrial volume index (hazard ratio 2.470, 95% confidence interval 1.065–5.728, p = .035).ConclusionsAutomatically identified notched P‐waves with peak‐to‐peak distance ≥20 ms were associated with AF recurrence in patients who had undergone catheter ablation.

Catheter Ablation as First-Line Therapy in Persistent Atrial Fibrillation: Patient Characteristics and Clinical Outcomes.

In patients with persistent atrial fibrillation (PerAF), antiarrhythmic drugs (AADs) are considered a first-line rhythm-control strategy, whereas catheter ablation is a reasonable alternative. This study sought to examine the prevalence, patient characteristics, and clinical outcomes of patients with PerAF who underwent catheter ablation as a first or second-line strategy. This multicenter observational study included consecutive patients with PerAF who underwent first-time ablation between January 2020 and September 2021 in 9 medical centers in the United States. Patients were divided into those who underwent ablation as first-line therapy and those who had ablation as second-line therapy. Patient characteristics and clinical outcomes were compared between the groups. A total of 2,083 patients underwent first-time ablation for PerAF. Of these, 1,086 (52%) underwent ablation as a first-line rhythm-control treatment. Compared with patients treated with AADs as first-line therapy, these patients were predominantly male (72.6% vs 68.1%; P=0.03), with a lower frequency of hypertension (64.0% vs 73.4%; P<0.001) and heart failure (19.1% vs 30.5%; P< 0.001). During a mean follow-up of 325.9 ± 81.6days, arrhythmia-free survival was similar between the groups (HR: 1.13; 95%CI: 0.92-1.41); however, patients in the second-line ablation strategy were more likely to continue receiving AAD therapy (41.5% vs 15.9%; P< 0.001). A first-line ablation strategy for PerAF is prevalent in the United States, particularly in men with fewer comorbidities. More data are needed to identify patients with PerAF who derive benefit from an early intervention strategy.

Stochastic Trajectory Analysis of Ranked Signals (STAR) Apollo Mapping System Approach to Treat Persistent Atrial Fibrillation: A Case Report

Stochastic Trajectory Analysis of Ranked Signals (STAR) Apollo Mapping System Approach to Treat Persistent Atrial Fibrillation: A Case Report

Persistent iatrogenic atrial septal defect after cryoballoon ablation for atrial fibrillation

Aims: Pulmonary vein isolation (PVI) by cryoballoon ablation (CB) technology is effective and safe treatment option for atrial fibrillation (AF). CB is performed by large diameter, 15Fr (4.95mm) transseptal sheath that may lead to creation of iatrogenic atrial septal defect (iASD). The objective of this study was to assess the incidence of iASD in patients who had undergone CB. Methods: Patients with AF having undergone Arctic Front® CB ablation and a subsequent transesophageal echocardiography (TEE) examination during post-ablation follow up period were consecutively enrolled. During all CB procedures, 15Fr transseptal sheath (Flex Cath, Medtronic, Minneapolis, MN) was utilized via single transseptal puncture (TsP). Results: Twenty-eight patients (15 females, mean age 55.8+15.5) with paroxysmal (n=24) or persistent (n=4) AF formed study group. iASD was present 11 (39.3%) of them after mean follow-up time of 17.3+6.2 months. The procedural time is significantly longer in patient with iASD (119.0+8.8 minutes, p=0.01). No patients died or suffered from any clinically significant cerebral ischemic event. There was no sign of increase in systolic pulmonary arterial pressure (sPAP). Conclusion: iASD after CB was found to be present in 39.3% of patient during a mean follow-up time of 17.3+6.2 months. The prolonged CB procedural time was the only factor that predicted iASD in our study. No adverse clinic events that might be related to iASD was observed during follow-up period.

A real-world study of different doses of rivaroxaban in patients with nonvalvular atrial fibrillation.

To explore the anticoagulant effect and safety of utilizing different doses of rivaroxaban for the treatment of patients with atrial fibrillation (AF) in the real world. A retrospective case-control analysis was performed by applying the hospital database, and 3595 patients with non-valvular atrial fibrillation (NVAF) who were hospitalized and taking rivaroxaban at Wuhan Asia Heart Hospital and Wuhan Asia General Hospital from March 2018 to December 2021 were included in the study, and were divided into the rivaroxaban 10 mg and 15 mg groups according to the daily prescribed dose, of which 443 cases were in the 10 mg group and 3152 cases were in the 15 mg group. The patients were followed up regularly, and the incidence of thrombotic events, bleeding events and all-cause deaths were recorded and compared between the 2 groups, and logistic regression was applied to analyze the influencing factors for the occurrence of adverse events. Comparison of the incidence of thrombosis, bleeding and all-cause death between the 2 groups of patients showed that the 10 mg group was higher than the 15 mg group, but the difference was not statistically significant (χ2 = 0.36, 3.26, 1.99, all P > .05); the incidence of total adverse events between the 2 groups of patients was higher in the 10 mg group than in the 15 mg group, with a statistically significant difference (χ2 = 4.53, P = .033); multifactorial logistic regression results showed that age [OR (95% CI) = 1.02 (1.00-1.04)], diabetes mellitus [OR (95% CI) = 1.69 (1.09-2.62)], D-dimer level [OR (95% CI) = 1.06 (1.00-1.11)] and persistent AF [OR (95% CI) = 1.54 (1.03-2.31)] were risk factors for adverse events (P < .05). In the real world, Asian clinicians recommend rivaroxaban 10 mg once daily for NVAF patients for a variety of reasons; however, this dose is not superior or even inferior to the 15 mg group in terms of effectiveness and safety. Advanced age, elevated D-dimer levels, history of diabetes mellitus, and persistent AF are risk factors for adverse events, and the optimal dosage of rivaroxaban or optimal anticoagulation strategy for Asian patients with nonvalvular AF requires further study.

Greater distance between ablation lines reduces the arrhythmia recurrence rate after pulmonary vein isolation.

Pulmonary vein isolation (PVI) is a recommended strategy for rhythm control in atrial fibrillation (AF), but its success rate remains unsatisfactory. Continuous research is being conducted to explore new technologies and modifications to the existing ablation workflow in order to reduce the arrhythmia recurrence rate. This study aimed to determine the influence of the distance between ablation lines (DBL) on AF recurrence rate in patients undergoing their first PVI; and thus to optimize the procedure outcomes. This is a retrospective cohort study conducted at a tertiary care center in Poland. A total of 146 patients (median age, 62 years; women, 34.3%) referred for a first PVI for either paroxysmal (n = 103) or persistent (n = 43) AF were evaluated. The procedures were performed with the use of a very‑high‑power, short‑duration catheter (QDot MicroTM, Biosense Webster, Inc., Irvine, California, United States) or a conventional, ablation index-guided ThermoCool Smarttouch SF catheter (Biosense Webster, Inc.). Freedom from AF recurrence was used as a primary end point. The impact of DBL on the outcome of PVI, accounting for conventional risk factors, was evaluated. Greater distance between opposite circumferential PVI lines and its ratio to the transverse diameter of the left atrium (DLB/TD) were associated with a lower risk of AF recurrence (hazard ratio [HR], 0.966; 95% CI, 0.935-0.998 [per 1 mm]; P = 0.04 and HR, 0.968; 95% CI, 0.944-0.993 [per 1%]; P = 0.01, respectively). There was no correlation between DBL or DBL/TD ratio and the impedance level. Close distance between PVI lines contributes to AF recurrence; thus, increasing the DBL and ensuring a higher DBL/TD ratio may be an advantageous ablation strategy.

Atrial Fibrillation Ablation in Heart Failure With Reduced vs Preserved Ejection Fraction

Catheter ablation is associated with reduced heart failure (HF) hospitalization and death in select patients with atrial fibrillation (AF) and heart failure with reduced ejection fraction (HFrEF). However, the benefit in patients with HF with preserved ejection fraction (HFpEF) is uncertain. To investigate whether catheter ablation for AF is associated with reduced HF-related outcomes according to HF phenotype. A systematic search of MEDLINE, Embase, and Cochrane Central was conducted among studies published from inception to September 2023. Parallel-group randomized clinical trials (RCTs) comparing catheter ablation with conventional rate or rhythm control therapies in patients with HF, New York Heart Association functional class II or greater, and a history of paroxysmal or persistent AF were included. Pairs of independent reviewers screened 7531 titles and abstracts, of which 12 RCTs and 4 substudies met selection criteria. Data were abstracted in duplicate according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline. Pooled effect estimates were calculated using random-effects Mantel-Haenszel models. Interaction P values were used to test for subgroup differences. The primary outcome was HF events, defined as HF hospitalization, clinically significant worsening of HF, or unscheduled visits to a clinician for treatment intensification. Secondary outcomes included cardiovascular and all-cause mortality. A total of 12 RCTs with 2465 participants (mean [SD] age, 65.3 [9.7] years; 658 females [26.7%]) were included; there were 1552 participants with HFrEF and 913 participants with HFpEF. Compared with conventional rate or rhythm control, catheter ablation was associated with reduced risk of HF events in HFrEF (risk ratio [RR], 0.59; 95% CI, 0.48-0.72), while there was no benefit in patients with HFpEF (RR, 0.93; 95% CI, 0.65-1.32) (P for interaction = .03). Catheter ablation was associated with reduced risk of cardiovascular death compared with conventional therapies in HFrEF (RR, 0.49; 95% CI, 0.34-0.70) but a differential association was not detected in HFpEF (RR, 0.91; 95% CI, 0.46-1.79) (P for interaction = .12). Similarly, no difference in the association of catheter ablation with all-cause mortality was found between HFrEF (RR vs conventional therapies, 0.63; 95% CI, 0.47-0.86) and HFpEF (RR vs conventional therapies, 0.95; 95% CI, 0.39-2.30) groups (P for interaction = .39). This study found that catheter ablation for AF was associated with reduced risk of HF events in patients with HFrEF but had limited or no benefit in HFpEF. Results from ongoing trials may further elucidate the role of catheter ablation for AF in HFpEF.

Comprehensive atrial fibrillation burden and symptom reduction post-ablation: insights from DECAAF II.

Traditional atrial fibrillation (AF) recurrence after catheter ablation is reported as a binary outcome. However, a paradigm shift towards a more granular definition, considering arrhythmic or symptomatic burden, is emerging. We hypothesize that ablation reduces AF burden independently of conventional recurrence status in patients with persistent AF, correlating with symptom burden reduction. Ninety-eight patients with persistent AF from the DECAAF II trial with pre-ablation follow-up were included. Patients recorded daily single-lead electrocardiogram (ECG) strips, defining AF burden as the proportion of AF days among total submitted ECG days. The primary outcome was atrial arrhythmia recurrence. The AF severity scale was administered pre-ablation and at 12 months post-ablation. At follow-up, 69 patients had atrial arrhythmia recurrence and 29 remained in sinus rhythm. These patients were categorized into a recurrence (n = 69) and a no-recurrence group (n = 29). Both groups had similar baseline characteristics, but recurrence patients were older (P = 0.005), had a higher prevalence of hyperlipidaemia (P = 0.007), and had a larger left atrial (LA) volume (P = 0.01). There was a reduction in AF burden in the recurrence group when compared with their pre-ablation burden (65 vs. 15%, P < 0.0001). Utah Stage 4 fibrosis and diabetes predicted less improvement in AF burden. The symptom severity score at 12 months post-ablation was significantly reduced compared with the pre-ablation score in the recurrence group, and there was a significant correlation between the reduction in symptom severity score and the reduction in AF burden (R = 0.39, P = 0.001). Catheter ablation reduces AF burden, irrespective of arrhythmia recurrence post-procedure. There is a strong correlation between AF burden reduction and symptom improvement post-ablation. Notably, elevated LA fibrosis impedes AF burden decrease following catheter ablation.

Vein of Marshall Ethanol Infusion for AF Ablation; A Review.

The outcomes of persistent atrial fibrillation (AF) ablation are modest with various adjunctive strategies beyond pulmonary vein isolation (PVI) yielding largely disappointing results in randomised controlled trials. Linear ablation is a commonly employed adjunct strategy but is limited by difficulty in achieving durable bidirectional block, particularly at the mitral isthmus. Epicardial connections play a role in AF initiation and perpetuation. The ligament of Marshall has been implicated as a source of AF triggers and is known to harbour sympathetic and parasympathetic nerve fibres that contribute to AF perpetuation. Ethanol infusion into the Vein of Marshall, a remnant of the superior vena cava and key component of the ligament of Marshall, may eliminate these AF triggers and can facilitate the ease of obtaining durable mitral isthmus block. While early trials have demonstrated the potential of Vein of Marshall 'ethanolisation' to reduce arrhythmia recurrence after persistent AF ablation, further randomised trials are needed to fully determine the potential long-term outcome benefits afforded by this technique.

Atrial fibrillation ablation compared to pacemaker therapy in patients with tachycardia-bradycardia syndrome: A systematic review and updated meta-analysis.

Tachycardia-bradycardia syndrome (TBS) is a subtype of sick sinus syndrome characterized by prolonged sinus pause (≥3 s) following termination of tachyarrhythmias, primarily atrial fibrillation (AF). There is controversy regarding whether the long-term prognosis of AF ablation is superior to pacemaker implantation. This study aimed to compare the effects of AF ablation and pacemaker therapy in patients with TBS. We conducted a comprehensive search of electronic databases, including PubMed, Cochrane, EmBase, Web of Science, and Chinese BioMedical, up until December 1, 2023. We included studies that reported the effects of AF ablation vs pacemaker therapy in patients with TBS. From this search, we identified 5 studies comprising 843 participants with TBS who underwent catheter AF ablation or pacemaker therapy. Our meta-analysis revealed that AF ablation and pacemaker therapy had similar effects on cardiovascular death (odds ratio [OR] = 0.62 and 95% confidence interval [CI]: 0.14-2.65), procedural complications (OR = 1.53 and 95% CI: 0.67-3.48), and cardiovascular rehospitalization (OR = 0.57 and 95% CI: 0.26-1.22). However, AF ablation provided greater benefits than pacemaker therapy in terms of all-cause mortality (OR = 0.37 and 95% CI: 0.17-0.82), thromboembolism (OR = 0.25 and 95% CI: 0.12-0.49), stroke (OR = 0.28 and 95% CI: 0.13-0.57), heart failure (OR = 0.27 and 95% CI: 0.13-0.56), freedom from AF (OR = 23.32 and 95% CI: 7.46-72.92), and prevention of progression to persistent AF (OR = 0.12 and 95% CI: 0.06-0.24). Furthermore, AF ablation resulted in a reduced need for antiarrhythmic agents (OR = 0.21 and 95% CI: 0.08-0.59). AF ablation can effectively reduce the risk of all-cause mortality, thromboembolism, stroke, heart failure, and progression to persistent AF in patients with TBS. Additionally, it may eliminate the need for further pacemaker therapy in most cases after ablation. Therefore, AF ablation is considered superior to pacemaker therapy in the management of patients with TBS.

Three-year incidence of pacemaker implantation in patients with atrial fibrillation and sinus node dysfunction receiving ablation versus antiarrhythmic drugs.

Sinus node dysfunction (SND) is commonly seen in patients with atrial fibrillation (AF). The purpose of this study was to compare the incidence of pacemaker implantation among patients with SND and AF treated with catheter ablation (CA) versus anti-arrhythmic drugs (AADs). The 2013-2022 Optum Clinformatics database, an administrative claims database for commercially insured individuals in the United States (US), was used for this study. Patients with AF and SND and a history of at least one AAD prescription were identified and classified into CA or AAD cohorts based on subsequent treatment received. Inverse probability treatment weighting was applied to balance socio-demographic and clinical characteristics between the cohorts. Weighted Cox regression modeling was used to evaluate the differential risk of incident permanent pacemaker (PPM) implantation. Sub-analyses were performed by AF type (paroxysmal versus persistent). A total of 1206 patients in the AAD cohort and 1624 patients in the CA cohort were included. Study cohorts were well-balanced post-weighting. The incidence rate of PPM implantation (per 1000 person-year) was 55.8 for the CA cohort and 117.8 for the AAD cohort. Regression analysis demonstrated that the CA cohort had 42% lower risk of incident PPM implantation than those treated with AADs (hazard ratio [HR], 0.58; 95% CI, 0.46-0.72, p < 0.001). CA-treated patients had lower risks of PPM implantation versus AAD-treated patients among those with paroxysmal AF (HR, 0.48; 95% CI, 0.34-0.69, p < 0.001) and persistent AF (HR, 0.57; 95% CI, 0.40-0.81, p = 0.002). Patients with AF and SND treated with CA have significantly lower risks of incident PPM implantation compared with those treated with an AAD.

Incremental value of tricuspid annular enlargement to progressive tricuspid regurgitation in patients with longstanding persistent atrial fibrillation.

Tricuspid annular enlargement in patients with atrial fibrillation (AF) can induce tricuspid regurgitation (TR). However, risk factors associated with TR progression in patients with AF have not been defined. This study aimed to clarify an association between tricuspid annular diameter (TAD) and TR progression in patients with longstanding persistent AF. We retrospectively analyzed data from 228 patients who had longstanding persistent AF for > 1year and mild or less TR on baseline echocardiograms. We defined significant TR as moderate or greater TR, graded according to the jet area and vena contracta. The optimal cut-off value of the TAD index (TADI), based on body surface area for predicting progression to significant TR, was estimated using receiver operating characteristic (ROC) curves. The independence and incremental value of the TADI were evaluated using multivariate Cox proportional hazard regression analysis and likelihood ratio tests. Over a median follow-up of 3.7years, 55 (24.1%) patients developed significant TR. The optimal cut-off value of 21.1mm/m2 for the TADI at baseline and ROC curves predicted TR progression with 70.4% sensitivity and 86% specificity. Furthermore, TADI was an independent predictor of TR progression (hazard ratio, 1.32; 95% confidence interval, 1.17-1.49, P < 0.001) and had a significant incremental value that exceeded that of models constructed using clinical parameters. In conclusion, TADI was significantly associated with TR progression and was an independent predictor of TR progression in longstanding persistent AF.

Pressure waveform analysis for occlusion assessment significantly reduces contrast medium use in cryoballoon pulmonary vein isolation.

Pulmonary vein (PV) occlusion is crucial for adequate lesion formation during cryoballoon-guided pulmonary vein isolation (CB-PVI). PV occlusion is usually confirmed by angiographies over the inflated balloon device. The aim of our study was to analyze the safety and efficacy of pressure waveform-based PV occlusion assessment during CB-PVI utilizing a novel fully integrated pressure analysis tool. Consecutive patients with symptomatic atrial fibrillation (AF) scheduled for CB-PVI were prospectively enrolled for pressure waveform-based PV occlusion assessment. A patient cohort receiving conventional angiographies served as control group. Patients with common PV ostia were excluded. The study group consisted of 40 patients (16 females, mean age was 64.5 ± 9.7, 45% persistent AF). The control group consisted of 40 matched patients. All 160 PVs in the study group were successfully isolated without the use of additional venograms confirming PV occlusion. The mean procedure duration was 69 ± 12min in the study group with a mean fluoroscopy duration of 11.5 ± 4.4min. The mean contrast medium volume was 22 ± 9ml in the study group and 36 ± 12ml in the control group (p = 0.0001). Mean procedure duration, mean balloon temperatures, and mean ablation application durations did not differ significantly between the study and the control group. No periprocedural complications occurred. CB-PVI utilizing a fully integrated pressure waveform analysis tool to assess PV occlusion is feasible and safe and significantly reduces the amount of contrast medium without impact on procedural parameters and freedom from arrhythmia recurrence.

Pulmonary Vein Isolation with a Novel Size-Adjustable Cryo-Balloon Catheter: A Tailored Ablation Protocol.

Background: Pulmonary vein isolation (PVI) is a common therapeutic approach for symptomatic atrial fibrillation (AF). Among various techniques, cryo-balloon (CB) PVI is widely adopted, but, to date, established CB systems have had fixed balloon sizes. A novel size-adjustable CB, allowing balloon size adjustments during ablation, lacks sufficient data on optimal utilization in patient care. This study aims to systematically investigate this feature with a tailored ablation protocol. Methods: Our single-center prospective study included patients with paroxysmal or persistent atrial fibrillation undergoing first-time PVI with the size-adjustable CB from July 2023 to February 2024. Ablation was performed using the balloon size that provided better occlusion. The ablation protocol involved an initial occlusion test with the small balloon size (28 mm). If optimal occlusion (occlusion level 4) could not be achieved, an attempt with the larger balloon (31 mm) was initiated. Ablation was conducted using the balloon configuration that provided better occlusion of the pulmonary vein ostium. Results: Our prospective study includes 50 patients (median age [interquartile range, IQR]: 72 [65; 79] years, 24 [48.0%] females, and 35 [70.0%] patients with paroxysmal AF). The median procedure duration (IQR) was 77 (65; 96) minutes, and the median fluoroscopy time (IQR) was 17.7 (12.5; 22.0) min. PVI was successfully accomplished in each treated pulmonary vein (PV), with 87.4% of PVs isolated during the first freeze. The large balloon configuration was used to isolate 16.8% of PVs. Conclusions: The utilization of the size-adjustable CB, combined with the presented tailored ablation workflow, appears to facilitate effective and efficient pulmonary vein isolation. The use of a larger balloon configuration appears beneficial in isolating a significant proportion of the PVs.

Repeat catheter ablation after very late recurrence of atrial fibrillation after pulmonary vein isolation.

Atrial fibrillation (AF) recurs in about one-third of patients after catheter ablation (CA), mostly in the first year. Little is known about the electrophysiological findings and the effect of re-ablation in very late AF recurrences (VLR) after more than 1 year. The aim of this study was to determine the characteristics and outcomes of the first repeat CA after VLR of AF after index CA. We analysed patients from a prospective Swiss registry that underwent a first repeat ablation procedure. Patients were stratified depending on the time to recurrence after index procedure: early recurrence (ER) for recurrences within the first year and late recurrence (LR) if the recurrence was later. The primary endpoint was freedom from AF in the first year after repeat ablation. Out of 1864 patients included in the registry, 426 patients undergoing a repeat ablation were included in the analysis (28% female, age 63 ± 9.8 years, 46% persistent AF). Two hundred and ninety-one patients (68%) were stratified in the ER group and 135 patients (32%) in the LR group. Pulmonary vein reconnections were a common finding in both groups, with 93% in the ER group compared to 86% in the LR group (P = 0.052). In the LR group, 40 of 135 patients (30%) had a recurrence of AF compared to 90 of 291 patients (31%) in the ER group (log-rank P = 0.72). There was no association between the time to recurrence of AF after initial CA and the characteristics and outcomes of the repeat procedure.

Strategy to achieve mitral isthmus flutter ablation by radiofrequency: the SHERIFF plan.

Achieving mitral isthmus (MI) block can be challenging. This prospective study evaluated the feasibility and efficacy of a systematic strategy comprising three consecutive steps to achieve MI block. Twenty consecutive patients (mean (± SD) age 71.4 ± 6.98 years) undergoing ablation of perimitral atrial tachycardia (PMAT) between December 2019 and November 2021 were included. MI was ablated using a systematic strategy comprising up to three consecutive steps: (1) endocardial ablation from the superolateral mitral annulus to the left pulmonary veins; (2) additional epicardial ablation in the coronary sinus (CS) on the opposite side of the endocardial line; and (3) ablation of early activation sites between endocardial and epicardial breakthroughs. MI block was successfully achieved in 19/20 patients (95%). MI block after endocardial radiofrequency ablation alone (step 1) was observed in 7/20 patients (35%). Epicardial ablation within the CS on the other side of the endocardial line (step 2) resulted in bidirectional MI block in three more patients. Endocardial ablation of epicardial conduction was successful for nine additional patients (95% success). At the 12-month follow-up, five patients (25%) displayed recurrence of arrhythmia after a single procedure. One patient had electrical cardioversion for persistent atrial fibrillation. Four patients had a redo procedure for left atrial flutter and only two patients (10%) had conduction across the MI and showed recurrence of PMAT. No complications occurred. The three-step ablation strategy resulted in a high rate of acute and durable MI block. PMAT recurrence after a single procedure was 10% at 1-year follow-up.

Long-Term Results of the Mini Maze Standalone Bi-Atrial Surgical Ablation: A 10-Year Follow-Up.

Background: One way to treat atrial fibrillation is through surgical ablation. However, the literature only provides information on patient follow-up results for up to 5 years. Methods: In order to assess long-term monitoring data over ten years, this retrospective study included 58 patients with paroxysmal or persistent atrial fibrillation who underwent Mini Maze surgical ablation at Santaros Clinics between 1 February 2009 and 1 June 2014. The follow-up time after surgery was 144 ± 48 months. We evaluated the absence of atrial fibrillation, echocardiographic and clinical parameters, and EHRA score. Results: Sinus rhythm remained in 69.4%, 75.5%, 55.6%, and 44.1% of patients with paroxysmal AF, and 68,2%, 59.1%, 50%, and 41.9% of patients with persistent AF (p = 0.681). In the post-operative period, one patient (1.7%) had a transient ischemic attack, and another patient (1.7%) had a thoracotomy for post-operative bleeding. A total of 20% of patients were diagnosed with a post-operative respiratory tract infection. EHRA scores showed that patients' quality of life improved after they underwent Mini Maze surgical ablation. Conclusions: Despite AF recurrences after surgery, quality of life remains better than before surgery, showing that Mini Maze surgery is an effective and safe second-line treatment method for atrial fibrillation.

Ablation-induced left atrial mechanical dysfunction recovers in weeks after ablation.

The immediate impact of catheter ablation on left atrial mechanical function and the timeline for its recovery in patients undergoing ablation for atrial fibrillation (AF) remain uncertain. The mechanical function response to catheter ablation in patients with different AF types is poorly understood. A total of 113 AF patients were included in this retrospective study. Each patient had three magnetic resonance imaging (MRI) studies in sinus rhythm: one pre-ablation, one immediate post-ablation (within 2days after ablation), and one post-ablation follow-up MRI (≤ 3months). We used feature tracking in the MRI cine images to determine peak longitudinal atrial strain (PLAS). We evaluated the change in strain from pre-ablation, immediately after ablation to post-ablation follow-up in a short-term study (< 50days) and a 3-month study (3months after ablation). The PLAS exhibited a notable reduction immediately after ablation, compared to both pre-ablation levels and those observed in follow-up studies conducted at short-term (11.1 ± 9.0days) and 3-month (69.6 ± 39.6days) intervals. However, there was no difference between follow-up and pre-ablation PLAS. The PLAS returned to 95% pre-ablation level within 10days. Paroxysmal AF patients had significantly higher pre-ablation PLAS than persistent AF patients in pre-ablation MRIs. Both type AF patients had significantly lower immediate post-ablation PLAS compared with pre-ablation and post-ablation PLAS. The present study suggested a significant drop in PLAS immediately after ablation. Left atrial mechanical function recovered within 10days after ablation. The drop in PLAS did not show a substantial difference between paroxysmal and persistent AF patients.

Does radiofrequency ablation procedural data improve the accuracy of identifying atrial fibrillation recurrence?

Radiofrequency ablation (RFA) using the CARTO 3D mapping system is a common approach for pulmonary vein isolation to treat atrial fibrillation (AF). Linkage between CARTO procedural data and patients' electronical health records (EHR) provides an opportunity to identify the ablation-related parameters that would predict AF recurrence. The objective of this study is to assess the incremental accuracy of RFA procedural data to predict post-ablation AF recurrence using machine learning model. Procedural data generated during RFA procedure were downloaded from CARTONET and linked to deidentified Mercy Health EHR data. Data were divided into train (70%) and test (30%) data for model development and validation. Automate machine learning (AutoML) was used to predict 1 year AF recurrence, defined as a composite of repeat ablation, electrical cardioversion, and AF hospitalization. At first, AutoML model only included Patients' demographic and clinical characteristics. Second, an AutoML model with procedural variables and demographical/clinical variables was developed. Area under receiver operating characteristic curve (AUROC) and net reclassification improvement (NRI) were used to compare model performances using test data. Among 306 patients, 67 (21.9%) patients experienced 1-year AF recurrence. AUROC increased from 0.66 to 0.78 after adding procedural data in the AutoML model based on test data. For patients with AF recurrence, NRI was 32% for model with procedural data. Nine of 10 important predictive features were CARTO procedural data. From CARTO procedural data, patients with lower contact force in right inferior site, long ablation duration, and low number of left inferior and right roof lesions had a higher risk of AF recurrence. Patients with persistent AF were more likely to have AF recurrence. The machine learning model with procedural data better predicted 1-year AF recurrence than the model without procedural data. The model could be used for identification of patients with high risk of AF recurrence post ablation.