Ablation Of Persistent Atrial Fibrillation Research Articles

PO-02-172 CONDUCTION VELOCITY AND CONDUCTION VELOCITY DYNAMICS IN THE LEFT ATRIUM ARE IMPACTED BY STRUCTURAL AND AUTONOMIC MODULATION AND SITES OF CONDUCTION VELOCITY HETEROGENEITY CORRELATE TO RE-ENTRY ACTIVITY IN ATRIAL FIBRILLATION

Structural and autonomic remodelling is proposed to drive atrial fibrillation (AF). Conduction velocity (CV) heterogeneity predisposes cardiac tissue to re-entry mechanisms. The impact of structural and autonomic remodelling on CV dynamics and re-entry formation is unclear. Evaluate the impact structural and autonomic modulation has on CV dynamics and re-entry activity in AF. Local activation times (LATs), voltage and geometry data were obtained from 20 patients undergoing catheter ablation for persistent AF. LATs were obtained at 3 pacing intervals (PI) (600, 400 and 250ms) with pacing from two pacing sites. LATs were used to determine CV dynamics and their relationship to voltage using an automated algorithm. Relationship between sites of enhanced CV heterogeneity defined as rate dependent CV slowing (RDCV) sites (sites exhibiting CV difference (CVd) between PI=600ms and PI=250ms of ≥20% of the mean CVd seen between these PIs for that voltage zone) and re-entry activity in AF was evaluated. Re-entry activity was identified using an automated algorithm and defined as ≥1.5 rotations of 360 degrees. The impact of autonomic modulation on CV dynamics both pharmacologically and with ganglionated plexi stimulation was assessed. A total of 512,082 LAT and voltage points were analysed. Voltage impacts CV (1.36±0.98 nLVZ ≥0.5mV, 1.05±1.03 LVZ 0.2-0.49mV and 0.58±0.37 vLVZ <0.2mV) (Figure 1A-B) and CV dynamics, whereby at nLVZ the curves are steeper (0.03±0.02ms CVd PI 600-400ms, 0.54±1.1ms CVd PI 400-250ms), broader at LVZ (0.16±0.09ms CVd PI 600-400ms, 0.23±1.1ms CVd PI 400-250ms) and flat at vLVZ (0.04±0.01ms CVd PI 600-400ms, 0.05±0.02ms CVd PI 400-250ms) (Figure 1C). Per patient, 5.6±1.1 RDCV sites and 3.4±1.3 sites of re-entry activity were identified. Of the RDCV sites, 72.3% (81/112) correlated to 94.1% (64/68) of re-entry activity sites which were mainly confined to LVZs (59/68, 86.8%). Autonomic modulation affected the CV dynamic curves through increasing rate dependency slowing (Figure 1D). The number of RDCV sites identified were enhanced following autonomic modulation (3.4±1.2 increase per patient). CVs and CV dynamics are impacted by structural remodelling and are influenced by autonomic modulation which enhances CV heterogeneity. CV heterogeneity sites correlate to re-entry activity in AF. Assessment of CV dynamics and heterogenity may help to determine the mechanistic importance of LVZs.

PO-02-042 SAFETY AND EFFICACY OF VERY HIGH-POWER SHORT-DURATION TEMPERATURE-CONTROLLED ABLATION FOR THE TREATMENT OF PERSISTENT ATRIAL FIBRILLATION

Ablation targets of persistent atrial fibrillation (AF) remain poorly understood nowadays: due to structural alterations of the left atrium, isolation of the pulmonary veins alone has proved ineffective. New ablation targets such as the posterior wall, coronary sinus, and left atrial appendage were then sought. A new catheter (QDOT Micro) has recently been released which has the potential to increase the safety and efficacy of the procedure: it is connected to a new radiofrequency (RF) generator which allows for temperature controlled ablation by reducing power and increasing irrigation with the increase in tissue temperature and allows to deliver power up to 90 W for few seconds (vHP-SD). Evaluate safety and efficacy of posterior wall vHP-SD ablation for patients with persistent AF We enrolled 29 patients treated with catheter ablation of persistent AF. Pulmonary vein isolation was performed in all patients. Substrate mapping of the posterior wall of the left atrium was subsequently performed in sinus rhythm with a multipolar catheter (Pentaray) and pathological potentials were eliminated with RF 90 W for 4 sec duration (vHP - SD). AF, atrial flutter and atrial tachycardia recurrences were identified by in office follow-up, 12-lead ECG, and dynamic Holter ECG. The treated patients have a median age of 63±10 years, 25 (86%) are male. Mean left atrial volume is 44.9 ± 17 ml/m2. 25 (86%) patients had never undergone catheter ablation before. Total mean procedure time is 75 ± 10 minutes, mean fluoroscopy time is 8 ± 5 minutes. Pulmonary veins isolation and posterior wall isolation was achieved in 100% of patients. There were no complications such as atrioesophageal fistula, phrenic nerve palsy, pericardial effusion and/or cardiac tamponade, pulmonary vein stenosis, or arteriovenous fistula. Patients free from arrhythmic recurrences are 69% after 8 months mean follow-up. The results demonstrated the clinical feasibility and safety of posterior wall vHPSD ablation for persistent AF using this new temperature-controlled catheter without intraprocedural and periprocedural complications at follow-up. However, this remains a single center experience in a small group of patients. Comparative trials involving greater number of patients with long-term follow-up are necessary to definitive results.

PO-03-104 MRI VERSUS ULTRASOUND: EXPLORING THE INFLUENCE OF IMAGING MODALITY ON THE FIDELITY OF NON-CONTACT CHARGE DENSITY MAPPING

Non-contact charge density mapping of atrial fibrillation (AF) relies on an inverse algorithm and accurate representation of atrial geometry. Current clinical systems utilize intrachamber ultrasound (US) for endocardial surface mesh reconstruction. To compare intrachamber US and MRI derived left atrial (LA) reconstructions and investigate the impact of any geometric discrepancy on non-contact mapping derived conduction metrics. Five patients underwent LA ablation for persistent AF. Intrachamber US data was analyzed with AcQMap 8.5 (Acutus Medical) to produce individual LA surface meshes. Cardiac MRI was acquired up to 6 weeks prior to their procedure on a 3T clinical MR scanner. A proprietary graphical interface tool implemented in Matlab R2014a enabled 3D surface mesh reconstruction from 2D MRI slices. Prior to registration of MRI and US generated surface meshes, the mitral valve (MV), left atrial appendage, and pulmonary veins (PVs) were excluded. Registration was achieved with a two-step approach, using the iterative closest point algorithm followed by a rigid registration using 5 anatomic landmarks: center of 4 PVs and MV holes. Subsequently, non-contact intrachamber voltage measurements from the individuals’ procedures were processed to inversely derive cardiac activation on all surface meshes and measure the resulting conduction speeds (Figure 1A and B). The average distance between surfaces of intrachamber US and MRI reconstructed surface meshes was measured as 3.4±4.0mm. Histograms of non-contact mapping determined conduction speed over surface mesh area for each participant displayed similar overlapping distributions for intrachamber US and MRI (Figure 1C). Conduction speed statistics across the entire population did not show a significant difference between the two modalities (0.66±0.26m/s and 0.63±0.22m/s respectively) (Figure 1D). LA surface reconstructions produced by intrachamber US and cardiac MRI compare favorably. We demonstrate concordance between both modalities in subsequent application of the inverse algorithm required for non-contact charge density mapping and calculation of conduction speed.

CE-452776-3 IS RATE CONTROL EVER ADEQUATE? CATHER ABLATION IN RATE CONTROLLED ATRIAL FIBRILLATION WITH REDUCED EJECTION FRACTION

The optimal rate control target for atrial fibrillation (AF) in the setting of heart failure with reduced ejection fraction (HFrEF) is not defined. Prior clinical trials have demonstrated benefits of AF ablation for patients with HFrEF, including recovery in left ventricular ejection fraction (LVEF). However, it is unknown if degree of rate control prior to ablation affects outcomes. To evaluate whether degree of pre-ablation rate control impacts LVEF recovery following AF ablation in patients with HFrEF. A single center, retrospective cohort study of 75 consecutive patients with LVEF ≤35% who underwent first-time ablation for persistent AF at NYU Langone Health between January 2014 and January 2021. Patients were classified as having a LVEF recovery if their post-ablation LVEF was >35%. Proportion of patients with LVEF recovery were compared between multiple rate control cutoffs: 110 bpm, 90 bpm, and 70 bpm. A binomial logistic regression analysis was then performed examining the relationship of pre-ablation HR on LVEF recovery. The mean pre-ablation HR was 90±25 bpm, baseline LVEF was 27±6%, and 64% (48/75) of patients had at least 3 months of maximal GDMT prior to ablation (Table 1A). Significant improvement in LVEF was observed in all patient subgroups irrespective of rate control status (Figure 1A) and regardless of prior GDMT (Figure 1B). Overall, LVEF recovery to >35% occurred in 59% (44/75) of patients. Compared to patients with pre-ablation HR faster than evaluated rate control cutoffs (Table 1B), there were no differences in frequency of LVEF recovery when using ≤110 bpm (controlled: 58% vs. not controlled: 63%, p=0.73) or ≤90 bpm (controlled: 52% vs. not controlled: 66%, p=0.21). In contrast, patients achieving rate control ≤70 bpm were significantly less likely to have LVEF recovery (41%) compared to those with HR above the cutoff (66%; p=0.04). Binomial logistic regression analysis did not reveal HR as a significant predictor of LVEF recovery (OR=1.01; CI 95%=0.99-1.03; p=0.16). Catheter ablation of persistent in AF in patients with HFrEF frequently resulted in improvement in LVEF, irrespective of achieved rate control. LVEF recovery >35% following catheter ablation was reduced only with rate control of HR 70bpm. Catheter ablation should be considered in HFrEF patients regardless of degree of rate control achieved. Heart rate 70bpm should be evaluated as a goal for adequate rate control in patients with HFrEF in whom rhythm control is not pursued.

PO-02-075 ASSOCIATIONS OF DEMOGRAPHICS AND COMORBIDITIES WITH LEFT ATRIAL SCAR BURDEN IN PATIENTS WITH PERSISTENT ATRIAL FIBRILLATION UNDERGOING CATHETER ABLATION FROM THE REAL-AF REGISTRY

Previous research has shown that women are more likely to suffer significant complications of atrial fibrillation (AF). Scar burden at catheter ablation (CA) may indicate substrate and disease progression, but data are conflicting from small studies. Issues with voltage data include choice of mapping catheter, rhythm mapping was performed in, voltage cut-off used, and how truly representative low voltage is of scar. To examine the relationship of LA scar to demographics and patient comorbidities in a large registry of patients undergoing first-time radiofrequency AF ablation for persistent AF (PsAF). The Real-world Experience of Catheter Ablation for the Treatment of Symptomatic Paroxysmal AF and PsAF Using Novel Contact Force Technologies registry (Real-AF) is a prospective, observational, multicenter registry of over 5,000 patients undergoing CA with follow-up at 6 and 12 months. We evaluated 1,431 eligible patients among this cohort by using independent sample t and chi square testing to identify associations of demographics and comorbidities with degree of LA scar burden >= 5%, calculated from CARTO as total % LA area < 0.50mV bipolar. Mapping was performed using the Pentaray catheter and subgroup analysis was prespecified in those mapped during sinus. Mean age was greater among patients with LA scar burden ≥ 5% (66 vs 72 years, p<0.001). Women were more likely than men to have LA scar (55% vs 31%, p <0.001). Congestive heart failure (CHF) was associated with greater LA scar burden as well (46% vs 37%, p = <0.001). CHADSVASc was also greater in patients with LA scar (2.8 vs 3.6, p<0.001). Patients with scar were more likely to undergo substrate modification (SM) during ablation (85% vs 47%, p = <0.001). Among a subgroup of patients presenting in sinus (n=344), all above associations remained significant other than that of CHF and increased LA scar (46% vs 37%, p = 0.12). In early outcome data, LA scar was not predictive of increased AF recurrence 12 months following ablation compared to scar burden < 5% (24% vs 17%, p = 0.075). Increased LA scar burden was associated with female sex, greater age, CHADSVASc and CHF. As a categorical variable, there was no significant correlation between scar burden at time of first ablation and AF recurrence at 12 months, but further data is pending. This is the largest study to our knowledge to investigate correlation of patient characteristics and AF recurrence with degree of LA scarring in patients with persistent AF.

PO-01-162 INFLUENCE OF POSTERIOR WALL ACTIVITY ON AF ABLATION OUTCOMES: A CAPLA SUBSTUDY

A randomised trial (CAPLA study) of pulmonary vein isolation (PVI) vs empiric PVI + posterior wall isolation (PWI) did not improve AF outcomes in catheter ablation for persistent AF (PsAF). However PV and/or PW electrogram characteristics may identify a subset of patients in whom additional PWI is beneficial. To determine whether PV or PW AF cycle length predicts ablation outcomes in PVI with or without PWI for PsAF. Consecutive participants in spontaneous AF at the time of ablation were enrolled as part of the CAPLA study. PV, PW and left atrial appendage (LAA) cycle length (CL) were measured (longest, shortest, median) using a multipolar catheter for 100 consecutive cycles. We then evaluated the long-term impact of PV and PW CL on AF recurrence at 12 months follow up using twice daily ECG transmissions. 120 participants (24% female, 66±10 years, 20% LsPsAF, mean LAVI 52.4±15.7ml/m2, mean duration of continuous AF 8.6±10.0 months) were randomised to PVI alone (47.5%) vs PVI+PWI (52.5%) groups. Baseline clinical and echocardiographic characteristics were similar between groups (all p>0.05). Mean PV and PW CL were similar between groups (184±23 vs 176±21ms in PVI+PWI, p=0.053 and 180±21 vs 173±19ms p=0.082, respectively) with no difference in AF recurrence (54% in PVI vs 58% in PVI+PWI, Log Rank p =0.74. Shortest PW activity was independently associated with AF recurrence (HR 1.72 95% CI 1.24-4.23, p=0.040), whereas the presence of PV AF (p=0.14), PVCL (individual PVs or average of all 4 PVs) and PVCL heterogeneity were not (all p>0.05) regardless of ablation strategy. The addition of PWI was associated with greater arrhythmia-free survival (LogRank p=0.017, figure 1) in those with shorter PW activity (based on median PW<140ms). Short CL PW activity is associated with increased risk of AF recurrence post catheter ablation. The addition of PWI to PVI improved freedom from AF in the subset of patients with persistent AF with rapid PW activity.

PO-04-029 TRIANGULATING THE LV SUMMIT: A NOVEL BIPOLAR RADIOFREQUENCY CATHETER ABLATION STRATEGY

Bipolar radiofrequency catheter ablation (RFCA) is an off-label strategy used to target ventricular arrhythmias (VA) from difficult substrates such as the LV summit. To achieve greater transmural RFCA lesions in challenging anatomy with a novel bipolar RFCA strategy. N/A A 51-year-old male with familial HCM and prior catheter ablation for persistent AF presented with pallor and palpitations in the setting of wide complex tachycardia of 210 BPM (Figure A). The patient was given a bolus of IV amiodarone and externally cardioverted. Amiodarone was discontinued given his history of amiodarone-induced hyperthyroidism. During the hospitalization, he had recurrences of sustained VAs that were suppressed with lidocaine. Cardiac MRI was obtained, which showed LVEF 42% and an extensive LGE in the LV (Figure B). The patient was brought to the EP lab for VT ablation. Extensive mapping in the RVOT, distal CS, and peri-aortic area was performed. The best pacemap was achieved with the 2F EPstar catheter (Baylis Medical) in the AIV. The ablation catheter was not able to be advanced into the distal branch in the coronary sinus. A total of 17 unipolar RFCA lesions were delivered from endocardial LV but the clinical VA remained easily inducible. A second ablation catheter was advanced to the posteroseptal RVOT on the opposite side of the septum for bipolar RFCA. The 2F EPstar catheter was positioned in the AIV near the region of best pacemap for tripolar effect (Figure C). A significant difference in the ablation impedance decline was noted between unipolar and bipolar ablations utilizing this novel strategy (Figure D top - unipolar, D bottom - bipolar). Following five bipolar RCFA lesions, the clinical VA was no longer inducible. The patient tolerated the procedure well with no further recurrence of VAs. Bipolar RFCA with a mapping catheter triangulating the target may help achieve deeper lesions.

AB-452675-4 CORONARY ARTERIAL SPASM DURING CAVO-TRICUSPID ISTHMUS ABLATION WITH A NOVEL FOCAL PULSED FIELD ABLATION CATHETER: FINDINGS FROM CORONARY ANGIOGRAPHY AND FRACTIONAL FLOW RESERVE MEASUREMENTS

Pulsed field ablation (PFA) has been shown to avoid esophageal damage, PV stenosis and permanent phrenic nerve paralysis. But not studied in these trials was ablation of the cavo-tricuspid isthmus (CTI), a not uncommon adjunct target for ablation during pulmonary vein isolation (PVI) procedures. Indeed, recent studies demonstrated that when PFA is performed adjacent to a coronary artery, there is a susceptibility for vasospasm: in a study of right coronary artery (RCA) angiography during PFA of the cavo-tricuspid isthmus (CTI), there was universally severe RCA spasm, albeit subclinical. However, these studies were performed with a pentaspline PFA catheter designed to create a broad electrical field, not with a focal spot ablation catheter. To evaluate the potential for PFA to cause coronary spasm during CTI ablation, but using a focal PFA catheter. As part of a clinical trial of persistent AF ablation (PersAFOne 3, NCT05272852), after PVI and posterior wall ablation using a 12F commercial pentaspline PFA catheter (Farawave, BSC Inc.), CTI ablation was performed using an investigational 8F deflectable focal catheter (Farapoint, BSC Inc.). PFA was performed at 2kV (2 x 2.5 sec applications per site) with fluoroscopy and ICE guidance. Coronary angiography of the RCA with FFR measurement (Abbott PressureWire X) was performed before, during and after PFA at each application site. Spasm was categorized as mild (<50%), moderate (50-90%) or severe (>90%). At a single center, PFA of the CTI was performed in 8 patients. Bidirectional CTI conduction block was achieved in all patients after a mean of 13.3 lesions/pt (range 8-18). One patient had a left dominant coronary arterial system, and a de minimis RCA; of the remaining, 6 of 7 patients developed moderate (n=5) to severe (n=1) spasm as determined by both angiography and FFR (mean pressure differential 0.60, range 0.31-0.78 among patients developing spasm). There were no EKG changes and no symptoms (albeit sedated patients). The mean time for spasm resolution was 13.8 min. In an additional patient, intracoronary NTG pretreatment (1 mg) was administered before PFA lesions were delivered to the CTI: no coronary spasm was provoked. Focal PFA to the CTI provokes subclinical coronary vasospasm when delivered adjacent to the RCA. Additional investigation is necessary to determine the optimal NTG dosing strategy to prevent this phenomenon.

Incidental left atrial appendage isolation after catheter ablation of persistent atrial fibrillation: Mechanisms and long-term risk of thromboembolism.

Incidental left atrial appendage (LAA) isolation may occur during radiofrequency ablation of persistent atrial fibrillation (AF). The study aims to describe the mechanisms and long-term thromboembolic risk related to incidental LAA isolation. Patients who experienced incidental LAA isolation after AF ablation were included. Culprit sites where ablation resulted in LAA isolation were identified. Thromboembolic risk despite oral anticoagulation (OAC) was compared to that in a propensity-matched control group without LAA isolation. Forty-one patients with LAA isolation, and 82 matched patients without LAA isolation were included. The patient age, ejection fraction, LA diameter, and CHA2 DS2 -VASc score were 64 ± 11 years, 55 ± 12%, 45.0 ± 7 mm and 2.62 ± 1.5, respectively. Culprit sites included the LAA base, mitral isthmus, inferior LA, Bachmann's bundle, coronary sinus, and Marshall vein. After 4.2 ± 3.6 years follow-up, thromboembolism occurred in 7 of 41 patients (17%) with LAA isolation versus 3 of 82 patients (4%) without isolation (log rank p < .009, HR 5.14, 95% CI [1.32-19.94], p = .02). Patients with and without thromboembolism had similar CHA2 DS2 -VASc scores (2.65 ± 1.3 vs. 2.71 ± 0.76, p = .89). Thromboembolism occurred during noncompliance with or temporary discontinuation of OAC in four of the sevenpatients. Incidental LAA isolation may occur during ablation of atrial arrhythmias in the vicinity of, or even at sites remote from the appendage. Patients with incidental LAA isolation had higher rates of thromboembolism compared to patients without isolation. Since thromboembolism may occur despite prescription for OAC, the risks of LAA isolation must be weighed against clinical benefit and appendage occlusion devices should be considered in vulnerable patients.

Postcardiac injury syndrome caused by radiofrequency catheter ablation of persistent atrial fibrillation: severe pulmonary arterial hypertension with severe tricuspid regurgitation: a rare case report and literature review

BackgroundPostcardiac injury syndrome (PCIS) is an easy-to-miss diagnosis, but it is not an uncommon complication. The phenomenon of echocardiography (ECHO) showing both severe pulmonary arterial hypertension (PAH) and severe tricuspid regurgitation (TR) is indeed rare in PCIS after extensive radiofrequency ablation.Case presentationA 70-year-old male was diagnosed with persistent atrial fibrillation. The patient received radiofrequency catheter ablation due to his atrial fibrillation being refractory to antiarrhythmic drugs. After the anatomical three-dimensional models were created, ablations were performed on the left and right pulmonary veins, roof linear and bottom linear of the left atrium, and the cavo-tricuspid isthmus. The patient was discharged in sinus rhythm (SR). After 3 days, he was admitted to the hospital for gradually worsening dyspnea. Laboratory examination showed a normal leukocyte count with an increased percentage of neutrophils. The erythrocyte sedimentation rate, C-reactive protein concentration, interleukin-6, and N-terminal pro-B-type natriuretic peptide were elevated. ECG exhibited SR, V1-V4 of precordial lead P-wave amplitude which was increased but not prolonged, PR segment depression, and ST-segment elevation. Computed tomography angiography of the pulmonary artery revealed that the lung had scattered high-density flocculent flakes and a small amount of pleural and pericardial effusion. Local pericardial thickening was seen. ECHO showed severe PAH with severe TR. Diuretics and vasodilators did not relieve the symptoms. Tumors, tuberculosis, and immune system diseases were all excluded. Considering the patient’s diagnosis of PCIS, the patient was treated with steroids. The patient recovered on the 19th day post ablation. The patient’s condition was maintained until 2 years of follow-up.ConclusionsThe phenomenon of ECHO showing severe PAH with severe TR is indeed rare in PCIS. Due to the lack of diagnostic criteria, such patients are easily misdiagnosed, leading to a poor prognosis.

Relationship between coronary blood flow and improvement of cardiac function after catheter ablation for persistent atrial fibrillation.

The relationship between coronary blood flow during atrial fibrillation (AF) and improvement of cardiac function after catheter ablation (CA) for persistent AF (PeAF) is not prominent; this study was conducted to evaluate this relationship. This was a retrospective case-control study. Eighty-five patients with PeAF (resting heart rate < 100bpm) and heart failure with reduced ejection fraction (left ventricular ejection fraction (LVEF) < 40%) who had undergone coronary angiography within 1week before CA were included. All patients could maintain a sinus rhythm for > 6months after CA. The primary outcome was improvement of cardiac function with an LVEF cutoff value of > 50% during sinus rhythm 6months after CA. In the LVEF improvement group (N = 57), patients were younger, with a higher baseline diastolic blood pressure and lower baseline brain natriuretic peptide level than the no LVEF improvement group (N = 28). Heart rate at baseline and 6months after CA and AF duration did not differ between the two groups. Thrombolysis in myocardial infarction frame count parameters was significantly higher in the LVEF improvement (P < 0.001) than in the no LVEF improvement group. Multivariate logistic regression analysis revealed mean thrombolysis in myocardial infarction frame count as an independent factor for LVEF improvement (odds ratio, 1.72 (95% confidence interval 1.17-2.54); P = 0.006). Coronary blood flow in patients with PeAF is strongly associated with improved left ventricular systolic function after the restoration of sinus rhythm by CA for PeAF and heart failure with reduced ejection fraction.

An evaluation of the clinical efficacy of the application of 28mm cryoballoon for linear ablation of left atrial apex combined with enlarged pulmonary vein vestibule ablation for persistent atrial fibrillation

Objectiveto retrospectively investigate the efficacy and safety of the application of 28 mm cryoballoon for pulmonary vein electrical isolation (PVI) combined with top left atrial linear ablation and pulmonary vein vestibular expansion ablation for persistent atrial fibrillation. MethodsFrom July 2016 to December 2020, 413 patients diagnosed with persistent atrial fibrillation were evaluated, including 230 (55.7%) in the PVI group (PVI only) and 183 (44.3%) in the PVIPLUS group (PVI plus ablation of the left atrial apex and pulmonary vein vestibule). The safety and efficacy of the two groups were retrospectively analyzed. ResultsThe AF/AT/AFL-free survival rates at 6, 12, 18, 24 and 30 months after procedure was 86.6%, 72.6%, 70.0%, 61.1% and 56.3% in the PVI group and 94.5%, 87.0%, 84.1%, 75.0% and 67.9% in the PVIPLUS group, respectively. At 30 months after procedure, the AF/AT/AFL-free survival rate was significantly higher in the PVIPLUS group than in the PVI group (P = 0.036; HR:0.63; 95% CI:0.42 to 0.95). ConclusionThe application of 28-mm cryoballoon for pulmonary vein electrical isolation combined with linear ablation of the left atrial apex and expanded ablation of the pulmonary vein vestibule improves the outcome of persistent atrial fibrillation.

Extensive Posterior Wall Isolation on Top of Pulmonary Vein Isolation Guided by Ablation Index in Persistent Atrial Fibrillation Ablation

Durable pulmonary vein isolation (PVI) is recommended for symptomatic paroxysmal atrial fibrillation (AF) treatment, but it has been demonstrated that it may not be enough to treat persistent AF (Pe-AF). Therefore, posterior wall isolation (PWI) is among the strategies adopted on top of PVI to treat Pe-AF patients. However, PWI using contiguous and optimized radiofrequency lesions remains challenging, and few studies have evaluated the impact of the Ablation Index (AI) on the efficacy of PWI. Moreover, previous papers did not evaluate arrhythmia recurrences using continuous monitoring. This is a prospective, observational, single-center study on patients affected by Pe-AF undergoing treated PVI plus AI-guided PWI. Procedures were performed using the CARTO mapping system, SmartTouch SF ablation catheter, and PentaRay multipolar mapping catheter. The AI settings were 500-550 for the anterior PV aspect and roofline, while the settings were 450-500 for the posterior PV aspect, bottom line, and/or PW lesions. All patients received an implantable loop recorder (ILR). All patients underwent clinical evaluation in the outpatient clinic at 1, 3, 6, 12, 18, and 24 months. A standard 12-lead ECG was performed at each visit, and device data from the ILR were reviewed to assess for arrhythmia recurrence. Between January 2021 and December 2021, forty-one consecutive patients underwent PVI plus PWI guided by AI at our center and were prospectively enrolled in the study. PVI was achieved in all patients, first-pass roofline block was obtained in 82.9% of the patients, and first-pass block of the bottom line was achieved in 36.5% of the patients. In 39% of the patients, PWI was not performed with a "box-only" lesion set, but with scattered lesions across the PW to achieve PWI. AI on the anterior aspect of the left PVs was 528 ± 22, while on the posterior aspect of the left PVs, it was 474 ± 18; on the anterior aspect of the right PVs, it was 532 ± 27, while on the posterior aspect of the right PVs, it was 477 ± 16; on the PW, AI was 468 ± 19. No acute complications occurred at the end of the procedure. After the blanking period, 70.7% of the patients reported no arrhythmia recurrence during the 12-month follow-up period. In patients with Pe-AF undergoing catheter ablation, PWI guided by AI seems to be an effective and feasible strategy in addition to standard PVI.

Predictors of Maintenance of Sinus Rhythm After Radiofrequency Catheter Ablation for Long-Standing Persistent Atrial Fibrillation

Little has been reported on the predictors of maintenance of sinus rhythm (SR) after radiofrequency catheter ablation (RFCA) for long-standing persistent atrial fibrillation (AF). We enrolled 151 patients with long-standing persistent AF (defined as AF lasting more than 12months) who underwent an initial RFCA between October 2014 and December 2020 in our hospital. These patients were categorized into 2 groups on the basis of the absence and presence of the late recurrence (LR, defined as a recurrence of atrial tachyarrhythmia between 3 and 12months after RFCA): SR group and LR group. The SR group comprised 92 patients (61%). In the univariate analysis, there were significant differences in gender and preprocedural average heart rate (HR) between the 2 groups (p=0.042 and p=0.042, respectively). A receiver operating characteristics analysis revealed that a cut-off value of preprocedural average HR to predict the maintenance of SR was 85beats/min (sensitivity: 37%, specificity: 85%, area under curve: 0.58). A multivariate analysis showed that preprocedural average HR ≥85beats/min was independently associated with the maintenance of SR after RFCA (odds ratio 3.30, 95% confidence interval 1.47 to 8.04, p=0.003). In conclusion, a relatively high preprocedural average HR might be a prognostic factor of maintenance of SR after RFCA for long-standing persistent AF.

Acute oesophageal safety and long-term follow-up of AI-guided high-power short-duration with 50 W for atrial fibrillation ablation.

Pulmonary vein isolation using radiofrequency ablation is an effective treatment option for patients with symptomatic atrial fibrillation (AF). Application of high power over a short period of time (HPSD) is reported to create more efficient lesions and may prevent collateral thermal oesophageal injury. This study aims to compare efficacy and safety of two different HPSD ablation approaches using different ablation index settings. Consecutive patients undergoing AF ablation with HPSD (50 W; ablation index-guided) using the ThermoCool SmartTouch SF catheter were included. Patients were grouped by ablation protocol: ablation with target ablation index (AI) of 400 on the anterior left atrial wall vs. 300 at the posterior left atrial wall (AI 400/300) or AI 450/350 was performed upon the operator's preference and compared. Peri-procedural parameters and complications were recorded, and incidences of endoscopically detected thermal oesophageal lesions (EDEL) analysed. Recurrence rates after a mean follow-up of 25 ± 7 months and reconnection patterns in patients undergoing redo procedures were investigated. A total of 795 patients (67 ± 10 years; 58% male; 48% paroxysmal AF) underwent a first AF ablation with HPSD (211 in group AI 400/300 and 584 in group 450/350). Median procedure time was 82.9 ± 24.6 min with longer ablation times in patients with target AI 400/300 due to higher intraprocedural reconnection rates, increased box lesions, and additional right atrial isthmus ablations. EDEL rates among target AI 400/300 procedures were significantly lower (3% vs. 7%; P = 0.019). Correspondingly, AI 450/350 was the strongest independent predictor of post-ablation EDEL (OR 4.799, CI 1.427-16.138, P = 0.011). Twelve-month (76% vs. 76%; P = 0.892) and long-term ablation single procedure success (68% vs. 71%; log-rank P = 0.452) after a mean of 25 ± 7 months were comparable among both target AI groups; however, long-term success was significantly higher for paroxysmal AF compared to persistent AF (12 months: 80% vs. 72%; P = 0.010; end of follow-up: 76% vs. 65%; log-rank P = 0.001). One hundred three patients (16%) underwent a redo procedure during follow-up documented comparable pulmonary vein (PV) reconnection among groups. Multivariate predictors of AF recurrence were age, left atrium (LA) size, persistent AF, and extra-PV ablation targets. High-power short-duration AF ablation with target AI of 400 for non-posterior wall and 300 for posterior wall lesions resulted in comparable long-term results compared to higher AI (450/350) ablations with significantly lower risk for thermal oesophageal lesions. Older age, larger LA size, persistent AF, and extra-PV ablation targets were identified in a multivariate analysis as independent risk factors for recurrences of atrial arrhythmias.

Relationship between left atrial appendage peak flow velocity and nonvalvular atrial fibrillation recurrence after cryoablation.

Previous studies revealed the connection between left atrial appendage peak flow velocity (LAA-PEV) and postoperative persistent atrial fibrillation (AF) recurrence. Yet, this association is not necessarily generalizable to persistent AF patients undergoing initial cryoballoon ablation due to current gaps in the literature. We prospectively studied 74 consecutive individuals with persistent atrial fibrillation undergoing a cryoballoon ablation for the first time between January 2018 and January 2020. Before ablation, LAA-PEV was documented by transesophageal echocardiography (TEE). Subsequently, demographic information and other clinical characteristics of these participants were collected. A 96-h continuous cardiac monitor was reviewed regularly for recurrence of atrial fibrillation. Cox proportional hazards regression was used to investigate LAA-PEV as well as other clinical characteristics as a predictor of AF recurrence. Our study found that AF recurrences had lower LAA-PEV than those without AF recurrence. A nonlinear relationship between the LAA-PEV and AF recurrence was observed in this study, which had an inflection point of 34.9. Subgroup analysis of female participants showed that LAA-PEV had a positive correlation with AF recurrence [β = 0.8, 95% CI (0.7, 0.9), p < 0.05]. A low LAA-PEV is related to recurrence of atrial fibrillation and may predict AF recurrence after initial cryoballoon ablation for persistent atrial fibrillation. This finding may help improve treatment and care strategies for patients with persistent atrial fibrillation.

The results of persistent atrial fibrillation with radiofrequency energy after a six-month follow-up

Objective: To evaluate the efficacy and safety of the radiofrequency ablation of persistent atrial fibrillation (AF) after a 6-month follow-up. Subject and method: A prospective study of 40 patients with persistent AF who underwent catheter ablation using a three-dimensional (3D) system at the Vietnam Heart Institute, Bach Mai Hospital. Result: The mean age of patients was 54.25 ± 12.54. The procedure time was 256.25 ± 48.61 minus, the irradiation time was 29.55 ± 14.29 minus, and the number of ablation points was 132.77 ± 53.79 points. The ablation time was 64.10 ± 24.76 minus, and the number of cardioversion shocks was 1.17 ± 1.1 times. No severe complications occurred during and after the procedure, and there and 2D echocardiography before the procedure and during the follow-up period. The success rates of maintaining sinus rhythm (SR) after 6 months, isolating the pulmonary vein alone, and the additional ablation group were 60.7%, 55%, and 75%, respectively. The successfully maintained SR group had no other AF symptoms [European Heart Rhythm Association (EHRA) class I], and patients with AF recurrence showed symptoms (EHRA class IIb). Conclusion: AF radiofrequency ablation is a new method with a success rate of 60.7% after a 6-month follow-up. Patients with successful ablation showed symptom improvement. The ablation procedure is safe, with a low rate of severe complications.

Catheter ablation for supraventricular arrhythmias in adults with congenital heart disease: Recurrence rates and predictors of acute procedural success

AimsTo define the cohort of adult congenital heart disease (ACHD) patients undergoing catheter ablation for supraventricular arrhythmia in a large tertiary centre, characterise outcomes, and determine factors associated with arrhythmia recurrence. MethodsSingle centre retrospective study of all catheter ablations for atrial arrhythmias in ACHD patients between September 2014 and October 2021. Patients were identified using a field search through a centralised database. Pre-specified clinical and procedural data of interest, and time from ablation to recurrence, were determined. Cox regression analyses were used to determine potential predictors of acute procedural success and arrhythmia recurrence. ResultsCardiac ablation for supraventricular arrhythmia was undertaken in 142 cases across 100 unique patients (median age 41, interquartile range 31–52), with 70 (49%) cases treated for macro-reentrant atrial tachycardia, 16 (11%) for focal atrial tachycardia, 19 (13%) for multifocal atrial tachycardia, 17 (12%) for atrial fibrillation, 7 (5%) for atrioventricular nodal reentrant tachycardia, and 8 (6%) for atrioventricular reentrant tachycardia; and 68 cases (48%) had recurrent arrhythmia with a median time to recurrence of 800 days. Multivariable analysis identified acute procedural success as an independent predictor of freedom from arrhythmia, and ablation for persistent atrial fibrillation as an independent predictor for recurrence of arrhythmia. ConclusionCatheter ablation for supraventricular arrhythmia in ACHD patients is safe and effective, with most patients achieving multiple arrhythmia-free months. Procedural success and arrhythmia mechanism are important predictors of recurrence.

Prospective randomized comparison between upgraded ‘2C3L’ vs. PVI approach for catheter ablation of persistent atrial fibrillation: PROMPT-AF trial design

In randomized studies, the strategy of pulmonary vein antral isolation (PVI) plus linear ablation has failed to increase success rates for persistent atrial fibrillation (PeAF) ablation when compared with PVI alone. Peri-mitral reentry related atrial tachycardia due to incomplete linear block is an important cause of clinical failures of a first ablation procedure. Ethanol infusion (EI) into the vein of Marshall (EI-VOM) has been demonstrated to facilitate a durable mitral isthmus linear lesion. This trial is designed to compare arrhythmia-free survival between PVI and an ablation strategy termed upgraded '2C3L' for the ablation of PeAF. The PROMPT-AF study (clinicaltrials.gov 04497376) is a prospective, multicenter, open-label, randomized trial using a 1:1 parallel-control approach. Patients (n = 498) undergoing their first catheter ablation of PeAF will be randomized to either the upgraded '2C3L' arm or PVI arm in a 1:1 fashion. The upgraded '2C3L' technique is a fixed ablation approach consisting of EI-VOM, bilateral circumferential PVI, and 3 linear ablation lesion sets across the mitral isthmus, left atrial roof, and cavotricuspid isthmus. The follow-up duration is 12 months. The primary end point is freedom from atrial arrhythmias of >30 seconds, without antiarrhythmic drugs, in 12 months after the index ablation procedure (excluding a blanking period of 3 months). The PROMPT-AF study will evaluate the efficacy of the fixed '2C3L' approach in conjunction with EI-VOM, compared with PVI alone, in patients with PeAF undergoing de novo ablation.

Hybrid epicardial-endocardial ablation for long-standing persistent atrial fibrillation: A subanalysis of the CONVERGE Trial.

Favorable clinical outcomes are difficult to achieve in long-standing persistent atrial fibrillation (LSPAF) with catheter ablation (CA). The CONVERGE (Convergence of Epicardial and Endocardial Ablation for the Treatment of Symptomatic Persistent Atrial FIbrillation) trial evaluated the effectiveness of hybrid convergent (HC) ablation vs endocardial CA. The study sought to evaluate the safety and effectiveness of HC vs CA in the LSPAF subgroup from the CONVERGE trial. The CONVERGE trial was a prospective, multicenter, randomized trial that enrolled 153 patients at 27 sites. A post hoc analysis was performed on LSPAF patients. The primary effectiveness was freedom from atrial arrhythmias off new or increased dose of previously failed or intolerant antiarrhythmic drugs (AADs) through 12 months. The primary safety endpoint was major adverse event incidence through 30 days with HC. Key secondary effectiveness measures included (1) percent of patients achieving ≥90% AF burden reduction vs baseline and (2) AF freedom. Sixty-five patients (42.5% of total enrollment) had LSPAF; 38 in HC and 27 in CA. Primary effectiveness was 65.8% (95% confidence interval [CI] 50.7%-80.9%) with HC vs 37.0% (95% CI 5.1%-52.4%) with CA (P = .022). Through 18 months, these rates were 60.5% (95% CI 50.0%-76.1%) with HC vs 25.9% (95% CI 9.4%-42.5%) with CA (P = .006). Secondary effectiveness rates were higher than CA with HC at 12 and 18 months. Freedom from atrial arrhythmias off AADs was 52.6% (95% CI 36.8%-68.5%) and 47.4% (95% CI 31.5%-63.2%) with HC at 12 and 18months vs 25.9% (95% CI 9.4%-42.5%) and 22.2% (95% CI 6.5%-37.9%) with CA, respectively (12 months: P = .031; 18 months: P = .038). Three (7.9%) major adverse events occurred within 30 days of HC. Post hoc analysis demonstrated effectiveness and acceptable safety of HC compared with CA in LSPAF.