Successful Pulmonary Vein Isolation Research Articles

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.

A case of pulmonary vein reconnection after long‐term success of pulmonary vein isolation for atrial fibrillation

A case of pulmonary vein reconnection after long‐term success of pulmonary vein isolation for atrial fibrillation

The Role of P Wave Parameters in Predicting Pulmonary Vein Isolation Outcomes for Paroxysmal Atrial Fibrillation: An Observational Cohort Study.

Pulmonary vein isolation (PVI) is an effective management method for paroxysmal atrial fibrillation (PAF). The P wave in the 12-lead electrocardiogram (ECG) represents atrial depolarisation. This study aims to utilise the P wave to predict PVI outcomes for PAF. This single-centre retrospective study aimed to predict PVI outcomes using P wave parameters. It included 211 consecutive patients with first PVI for PAF between 2018 and 2019 and targeted the pulmonary veins (PVs). Procedure success was defined by freedom of ECG-documented AF at 12 months. Digital 12-lead ECGs with 1-50 hertz bandpass filters were monitored before the procedure. Corrected P wave duration (PWDc), P wave amplitude (PWV), P wave dispersion (PWDisp), intra-atrial block (IAB), P wave area (PWA), and P wave terminal force in V1 (PTFV1) were measured before ablation and correlated with the outcomes. Successful PVI occurred in 154 patients (73%). Demographics were similar between both arms. P wave parameters correlated with PVI failure included increased PWDc in all leads except for lead III, aVR, and V3, decreased PWV in lead I (hazard ratio [HR]: 0.7, 95% confidence interval [CI]: 0.53-0.95), lead II (HR: 0.45, 95% CI: 0.22-0.65), aVL (HR: 0.58, 95% CI: 0.22-0.98), and aVF (HR: 0.67, 95% CI: 0.58-0.87), decreased PWA in lead I (HR: 0.55, 95% CI: 0.21-0.76), lead II (HR: 0.48, 95% CI: 0.34-0.87), aVL (HR: 0.65, 95% CI: 0.45-0.96), and aVF (HR: 0.61, 95% CI: 0.32-0.89), and the presence of IAB (HR: 2, 95% CI: 1.4-4.2, p = 0.02). PWDisp and PTFV1 were not correlated with PVI outcome. PWDc, PWA, PWV, and IAB are valuable predictors for PVI outcome for PAF at 12 months.

Safety and feasibility of pulmonary vein isolation utilizing pulsed field ablation in patients with symptomatic atrial fibrillation and implanted Watchman devices.

Pulsed field ablation (PFA) is a novel method of non-thermal cardiac ablation for atrial fibrillation (AF). Its use on patients with pre-existing Watchman devices has not been studied. Pulmonary vein isolation (PVI) utilizing PFA was performed in 7 patients with symptomatic AF and implanted Watchman devices. All cases were conducted at a single academic center. Successful PVI in patients with Watchman devices implanted at a median time of 534days prior to the index ablation procedure (IQR 365days) was achieved in all cases. No major adverse events (intraprocedural CVA, post-procedural CVA, major or minor bleeding events, device embolization, or cardiac tamponade) were observed. In 6 of 7 patients, a low-dose direct oral anticoagulant (DOAC) strategy was implemented post-PFA. We present the first reported case series of PFA in patients with AF and implanted Watchman devices. This study highlights the safety and feasibility of the FARAPULSE PFA system in this patient population.

Catheter ablation approach targeting epicardial connections to the right pulmonary vein antrum detected before pulmonary vein isolation

BackgroundEpicardial connections from surrounding structures to the right pulmonary vein (PV) antrum impede PV isolation. ObjectiveThis study aimed to evaluate the efficacy of an ablation approach targeting epicardial connections for right PV isolation. MethodsWe prospectively enrolled 124 patients with atrial fibrillation undergoing initial PV isolation. We identified the activation breakthrough into the right PV antrum (BT-RPV) on the activation map created during high right atrial pacing before PV isolation. BT-RPV sites were targeted when right PV isolation was not achieved by wide antral circumferential ablation (WACA). ResultsBT-RPV was observed in 83 patients (67%). PV isolation was achieved by WACA in all 41 patients without BT-RPV. Among patients with BT-RPV, PV isolation was achieved by WACA in 48 patients when all BT-RPV sites were covered by the PV isolation line. Conversely, PV isolation was completed by WACA in only 5 of 35 patients when not all BT-RPV sites were covered. In patients where WACA failed, 35 sites were targeted for BT-RPV ablation. Initial BT-RPV ablation led to PV isolation at 20 sites, while the remaining 15 BT-RPV sites required repeat BT-RPV ablation. The ablated area of successful BT-RPV ablation was 0.9 (0.6–1.2) cm2, corresponding to the area activated within 15 (14–16) ms after BT-RPV emergence. Ablating the area activated within 14 ms of BT-RPV emergence was associated with successful PV isolation (sensitivity 91%; specificity 100%). ConclusionAblation targeting BT-RPV sites is effective for right PV isolation. Extensive ablation is required to eliminate BT-RPV.

Cavutilide (Refralon) for pharmacological cardioversion of early recurrence atrial fibrillation and flutter in blanking period after pulmonary veins isolation

Objective. Evaluate efficacy and safety of cavutilide (Refralon) for pharmacological cardioversion in patients with recurrent atrial fibrillation and flutter (AF/AFL), in 90days blanking period of catheter ablation.Materials and methods. included 56 patients: 46 patients with recurrent paroxysmal AF/AFL and 10 patients with recurrent persistent AF/AFL. In 45 patients (80.3%), sinus rhythm (SR) restoration was performed within 7 days from the moment of catheter ablation. Intraoperative confirmation of pulmonary vein (PV) isolation was noted in 85.7% cases (n=48). After excluding contraindications, cavutilide was administrated in the intensive care unit according to a 4-stage protocol (5 µg/kg – 5 µg/kg-10 µg/ kg – 10 µg/kg). Effectiveness of pharmacological cardioversion was assessed as the fact of restoring SR and the fact of preservation of SR 24 hours after cavutilide administration. Safety points – QT prolongation, ventricular arrhythmogenic effects, pauses and bradyarrhythmias.Results. The overall effectiveness of cavutilide among all included patients reached 98.2% (n=55), and preservation of SR 24 hours after cavutilide administration was observed in 94.5% (n=53) patients. All the patients with recurrent persistent AF/AFL successfully restored and maintained SR 24 hours after cavutilide administration 100% (n=10). In patients with recurrent paroxysmal AF/AFL restoration of SR observed in 97.8% (n=45) and preservation of SR after 24 hours – in 93.4% (n=43), respectively. The effectiveness of cavutilide did not depend on the results of the catheter ablation. Recurrences of AF/AFL after SR restoration were more common in patients without successful PV isolation. QT prolongation >500ms observed in 8.9% (n=5) of cases, including 1 case of self-terminating torsade de pointes, managed by MgSO4 infusion. Bradyarrhythmias that did not require urgent therapy were noted in 10.7% (n=6) of cases.Conclusion. Pharmacological cardioversion with Cavutilide (Refralon) is highly effective and safe method of SR restoration in patients with recurrent AF/AFL in 90days blanking period after catheter ablation.

Quantitative and qualitative assessment of left atrial cardiomyopathy as well as prediction of atrial fibrillation recurrences upon PVI using machine learning

Abstract Introduction Atrial fibrillation (AF) is one of the most common heart pathologies in daily clinical practice and confers significant mortality and morbidity. However, AF ablation often proves ineffective - even after successful pulmonary vein isolation (PVI). The prediction of PVI failure for the long-term treatment of AF as well as the improved assessment of the underlying substrate appears pivotal. We hypothesize, that ML can be applied to better characterize the substrate and recurrence in AF patients upon PVI. Methods & Results We retrospectively evaluated data from 205 patients that underwent AF ablation between 2019 and 2023, including high-density 3D electroanatomic maps (sinus rhythm), LA rotational angiography, invasive LA hemodynamic measurements (after transseptal passage), echocardiography, 12-lead ECG and laboratory testing. A neuronal net was trained on selected features extracted from those datasets using supervised learning and employed to predict measures of atrial cardiomyopathy and AF recurrence. Patients were 66±1 years old and received first or second pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation with 18% documented recurrences upon a mean follow-up of 23±1months. First, we extensively refined or developed tools for automated P-wave analysis from 12-lead ECGs as well as local LA voltage and volume quantification. Next, LA hemodynamics and volumes were assessed: Mean LA volume as derived from rotational angiography significantly correlated with LA volume index as obtained using echocardiography. Interestingly, LA size showed no correlation with NT-proBNP, LA low voltage or LA hemodynamics. In addition, global (25±2% of total LA area) and local (i.e. anterior, posterior, roof) LA voltage was determined and shown to be an independent predictor of AF recurrence. In our first unselected subset of 136 patients with 2nd PVI for atrial fibrillation, our ML models predicted LA fibrosis (i.e. low voltage regions; Utah stage) from 12-lead ECGs with an accuracy of 90%. Accuracy was 87% for the prediction of AF recurrences from LA pressure and low-voltage regions. In addition, the algorithm predicted AF recurrences from 12-lead SR ECGs obtained before PVI with an accuracy of 91%. Conclusion Artificial neural networks allow to quantitatively and qualitatively predict measures of atrial cardiomyopathy and atrial fibrillation recurrence probability upon complete PVI with high accuracy.Figures

Safety and efficacy outcomes in 100 consecutive cases of pulsed field ablation

Abstract Background Pulsed field ablation (PFA) an emerging technology for ablation of atrial fibrillation (AF). This non-thermal ablation modality uses ultrarapid electrical pulses to destabilise cell membranes and can selectively ablate myocardial tissue. Successful pulmonary vein isolation (PVI) and reductions in procedure times compared to other modalities have been observed in initial studies. Aim To report initial outcomes and fluoroscopic times in the first 100 consecutive cases using PFA in AF ablation. Methods The first 100 consecutive PFA cases carried out by a single operator in a single centre were examined. All cases were performed under general anaesthesia, using ultrasound-guided vascular access and TOE-guided transseptal puncture. Outcomes were recorded from the first case in June 2022 to the present day. Electroanatomic mapping (EAM) was carried out using two proprietary systems. Results Procedural information and follow-up was achieved in all 100 patients (see table). The majority (77) were male. Mean age 61. Cardiovascular comorbidities included: hypertension (41), heart failure (12), ischaemic heart disease (10), stroke (4), diabetes mellitus (3). Antiarrhythmic drugs were used by 45 patients (Amiodarone in 22, Dronedarone in 18, Flecainide in 10, Sotalol in 8, Mexiletine in 1) with 55 taking beta blockers only or no rhythm control drugs. Persistent AF accounted for 57 cases, and 91 patients had no prior ablation procedure. Median CHA2DS2VASC 1. Warfarin was used on 1 patient, the other 99 patients underwent ablation on uninterrupted DOAC, most commonly Apixaban. EAM was conducted in 59 patients. Stand-alone PVI was carried out in 68, while 30 underwent an additional posterior wall box isolation, and a mitral isthmus line was added in a further 2 who had atrial flutter (AFl) during the procedure following successful PVI. There were no serious peri-procedural complications. (vascular access complications, pericardial effusion, stroke or death). All 100 patients were discharged following a one-night stay. Clinical pericarditis without effusion occurred in 1 patient on day 2, and resolved with a short course of Colchicine. Mean fluoroscopy time was 9minutes, 12seconds, and reductions in fluoroscopy times correlated significantly with case number (see figure). Mean fluoroscopy time was 2mins, 30secs higher where EAM was used. Sinus rhythm was achieved in 100%. Atrial arrhythmia recurred in 12 patients, 7 with AF and 3 atrial flutter, 2 with typical symptoms which could not be documented. Two of the recurrences were within 24 hours of the procedure. Conclusions This registry data shows that PFA was used to achieve PVI safely, with effective additional substrate ablation also demonstrated. There were no serious peri-procedural complications, and procedural improvements in fluoroscopic times were observed throughout the 100 cases. Long term follow-up data is required to validate the safety and efficacy of this new technology.

Increased left atrial pressure is associated with fibrosis, elevated mechanical load and ventricular diastolic dysfunction in patients undergoing AF catheter ablation

Abstract Background Increased left atrial filling pressures might be a hallmark feature of atrial cardiomyopathy which has been associated with an increased incidence of atrial fibrillation (AF) recurrence even after successful pulmonary vein isolation (PVI). The interplay between left atrial pressure, measured during the ablation procedure, and other parameters characterising atrial and ventricular remodelling in patients with AF remains elusive. Methods and Results Between 2018 and 2022, 182 patients undergoing PVI for paroxysmal or persistent AF were included in the study. Mean left atrial pressure (mLAP) was measured invasively during the ablation procedure after transseptal puncture. A mLAP higher than 15 mmHg was considered the cut-off value for LA hypertension. Bipolar high-density 3D electro-anatomical maps (Carto) obtained during the procedure were used to manually quantify low-voltage (<0.5 mV) and normal voltage areas of the LA surface and a global low-voltage/normal voltage ratio index was derived. Contemporary transthoracic echocardiography data were included to evaluate LV systolic and diastolic function and blood samples were obtained post-procedurally from all patients. In bivariate linear regression analysis, mLAP reached only modest correlation with E/e’ as an imaging marker of diastolic dysfunction (R=0.31, p=0.005) (Figure 1A), with particular differences in mLAP values between patients with marked diastolic impairment (E/e’ > 15) vs. subgroups with mild dysfunction ( 8 < E/e’ ≤ 15) or normal diastolic function (E/e’ ≤ 8 ) (Figure 1B), log NT proBNP (R=0.34, p<0.001) (Figure 1C) and low-voltage/normal voltage ratio index (R=0.21, p=0.014) (Figure 1D). For a total of 158 patients, data about 1 year recurrence of AF were available, of these 22 (13.9%) had a recurrence after two procedures using cryo-energy for the index PVI and radiofrequency ablation for the re-PVI (second procedure). A Kaplan-Meier analysis and log-rank test showed a trend but no statistical significance regarding an increased AF recurrence rate between patients with and without LA hypertension (χ2 = 2.63, p= 0.09) (Figure 2). Conclusion Direct intra-procedural invasive measurement of LA pressures can offer an important and convenient novel piece of information for patients undergoing catheter ablation procedures for AF, with potential implication for post-procedural recurrence risk stratification. Atrial hypertension is only partially related to LV diastolic impairment, atrial fibrosis and myocardial mechanical load burden.

High power short duration and very high power short duration protocol: a comparison between two effective strategies of atrial fibrillation transcatheter ablation with radiofrequency

Abstract Introduction Radiofrequency (RF) is the most widely used technique for atrial fibrillation (AF) ablation. Aiming to achieve durable pulmonary vein isolation (PVI) with reduced procedural time and potential thermal side effects, high power short duration (HPSD) and very-high power short duration (v-HPSD) protocols have been developed, exploiting the use of the latest catheter generations. Purpose To assess safety and efficacy of AF ablation using two distinct HPSD settings, aiming to determine the most effective protocol for trans-catheter RF AF ablation. Methods We conducted a retrospective study including patients with paroxysmal or persistent AF: 100 were treated with the HPSD protocol and 100 patients with the v-HPSD one. In the HPSD protocol, RF energy at 40 W was applied for up to 20 seconds for the anterior segments of the pulmonary vein (PV), and 50 W up to 10 seconds for the posterior segments of the PV and the posterior wall (PW). Conversely, in the v-HPSD protocol RF pulses were applied at 50 W with an ablation index (AI) 500 in the anterior segments of PV and 90 W up to 4 sec for the posterior segment of the PV and the PW. Safety and efficacy were assessed during the procedure, during the hospital stay and throughout the entire follow-up duration. Results No relevant clinical and echocardiographic differences were identified between the two groups. Successful PVI and PW isolation was achieved in all cases. The v-HPSD group demonstrated a higher first-pass isolation (FPI) rate compared to the HPSD group. In contrast, the HPSD group exhibited a greater impedance drop (ID), supported by a higher contact force (CF). The RF total time, the procedural time, and the dose-area product (DAP) were significantly lower in the v-HPSD group. No periprocedural complications were reported. During the follow-up no significant differences in AF recurrence rates have been observed. Conclusions The absence of procedural complications underscores the high safety of both protocols. In our study, the v-HPSD group exhibited a superior FPI rate, indicative of enhanced acute efficacy; however it is crucial to underline that the HPSD group included a higher proportion of patients with a history of prior AF ablation. The more elevated ID observed in the HPSD group, indicating the exceptional quality of lesions, could be related to the major conductive heating component compared to v-HPSD. This results in deeper lesions and a more significant ID. Conversely, the brief duration of applications in the v-HPSD protocol contributes to reduce procedural times and diminish radiation exposure. Despite procedural disparities, the follow-up period reveals a low recurrence rate of AF in both groups, emphasizing the effectiveness of both HPSD and v-HPSD protocols in AF treatment.Kaplan-Meier Curve

First multicenter experience of pulmonary vein and posterior wall isolation via a novel focal 9mm lattice tip catheter in a real-world scenario

Abstract Background Pulsed field ablation (PFA) is an innovative technology recently adopted for the treatment of atrial fibrillation (AF). Preclinical and clinical studies have reported a remarkable safety profile, as a result of its tissue specific effect targeting cardiomyocytes and sparing adjacent tissues. The AfferaTM system is a focal 9-mm lattice tip catheter that has recently received regulatory approval. No data currently exist on the feasibility of this technology for first-time pulmonary vein isolation (PVI) and posterior wall isolation (PWI) in a real-world scenario. Objective To evaluate the safety and efficacy of the focal 9-mm lattice tip catheter Sphere-9 (Affera Inc) in a real-world population undergoing PVI and PWI. Methods Consecutive AF patients undergoing first-time PVI plus PWI with the AfferaTM system in two different centres between August and November 2023 were prospectively included. PFA was always used to ablate the posterior left atrium, whereas anterior applications were performed using either radiofrequency energy (RF/PF strategy) or PFA (PF/PF strategy) based on operator's discretion. Primary efficacy endpoint was acute procedural success (successful PVI with evidence of bidirectional block at the end of the procedure). Primary safety endpoint included major technology-related complications occurring within 7 days post-ablation. Secondary endpoints were first pass isolation, acute reconnection, overall complications, procedural, dwelling, and fluoroscopy time. Results Thirty consecutive patients [mean age: 68±6.8 years; 61.7% males; CHA2DS2-VASc Score 2.0 (1.5 – 3.5)] were included. Among them, 66.7% (n=20) had non-paroxysmal AF. PVI was performed with an RF/PF strategy or PF/PF one in 10 (33.3%) and 20 (66.7%) patients, respectively. Posterior wall isolation (PWI) was performed in 30 (100%) cases. The primary endpoint was achieved in 100% of patients for both PVI and PWI with average procedural time of 95 min (77-120 min), dwelling time of 78 min (55-92 min) and fluoroscopy time of 6 min (5-10.5 min) (Figure 1). No technology-related complications were observed. First-pass isolation occurred in 100% of PVI and PWI, with no acute reconnection for PW and 1 case of right PV reconnection in the RF/PF strategy group. Conclusions AF ablation with the focal 9-mm lattice tip catheter Sphere-9 confirmed high efficacy and safety in PVI + PW in a real-world population.Figure 1

Biochemical markers of neuro-myocardial damage after pulmonary vein isolation: the effect of different energy sources

Abstract Background Pulmonary vein isolation (PVI) by thermal energy, both radiofrequency (RF) and cryoenergy(Cryo), is associated with a significant release of myocardial and collateral neural injury markers. Damage to periatrial ganglionated plexi also results in a substantial change in cardiac autonomic regulations. On the contrary, pulsed electric field (PEF) energy tends to spare cardiac neural tissue. Purpose To quantify the impact of different ablation energy sources that are used for PVI on neuro-myocardial damage by the assessment of specific biomarkers. Methods A study enrolled 85 patients with paroxysmal atrial fibrillation who underwent PVI (age: 61 ± 12 years, 74% males). In 23 patients, RF energy was delivered by the irrigated-tip catheter, while 30 patients were ablated using a second-generation cryoballoon catheter. In 32 patients, PVI was performed using a multipolar pentaspline catheter and PEF energy. Peripheral venous blood samples for assessing the plasmatic levels of S100 calcium-binding protein B (S100B), neuron-specific enolase (NSE), high-sensitivity troponin I and T (hsTnI and hsTnT) were obtained before, immediately after the PVI, and the next day (usually 18-24 hours after the procedure). Study groups were compared regarding absolute biomarker levels and hsTnT/S100B ratio (a surrogate of cardioselectivity). Results Following successful PVI, a significant increase in plasma levels of all biomarkers was observed: DhsTnT = 1040±434 ng/L, 1731±830 ng/L and 1010±397 ng/L; DhsTnI = 1504±918 ng/L, 16464±11911 ng/L and 10789±7589 ng/L; DS100B: 0.04±0.02 mg/L, 0.03±0.04 mg/L and 0.14±0.08 mg/L; DNSE: 34±72 ng/mL, 27±53 ng/mL and 45±52 ng/mL (all with P <0.001) for RF, PEF and Cryo groups, respectively. A direct comparison of maximal biomarker levels between study groups is depicted in the Figure. The hsTnT/S100B ratio was 23±14, 12±6, and 6±3 in PEF, RF, and Cryo groups, respectively (ANOVA P <0.01), indicating that PEF was 1.9-times and 3.8-times more cardioselective than RF and Cryo, respectively. Following the PVI, the heart rate accelerated by 2±8, 13±14, and 9±11 bpm in the PEF, RF, and Cryo groups, respectively. No correlation was observed between S100B release and HR acceleration (R = 0.07, P = 0.55). Conclusion Compared to thermal energy sources, PEF energy induces more specific damage to cardiomyocytes than cardiac nerves. There was no correlation between S100B release and HR acceleration.

Radiofrequency catheter ablation for redo procedures after pulmonary vein isolation with the cryoballoon technique: 9-year outcome

Abstract Catheter ablation has become the first line of therapy in patients with symptomatic, recurrent, drug-refractory atrial fibrillation. Cryoablation has been shown to be a safe and effective technique for pulmonary vein isolation. However, there is a significant arrhythmia recurrence rate after cryoablation procedures and there are no established strategies for redo procedures in these patients. Therefore, we have summarized our experience with radiofrequency catheter ablation for redo procedures after pulmonary vein isolation with the cryoballoon technique (including an analysis of pulmonary vein conduction recovery patterns after procedures performed with the first or second generation cryoballoon). Methods Two hundred and twenty patients (paroxysmal AF: 140 patients, persistent AF: 80 patients) had to undergo a redo procedure after initially successful circumferential PV isolation with the cryoballoon technique (First generation: 110 patients (group A); second generation: 110 patients (group B)). The redo ablation procedures were performed using a segmental approach or a circumferential ablation strategy (three-dimensional mapping system) depending on the intra-procedural findings. Results During the redo procedure, a mean number of 1.6 re-conducting PVs were detected (using a circular mapping catheter; group A: 2.2 re-conducting PVs, group B: 1.0 re-conducting PVs). There was a slightly higher incidence of chronic PV reconnections related to the left-sided PV ostia than to the right-sided PVs in both groups. Furthermore, sites of chronic PV reconnection were found more frequently in the inferior parts of the PV ostia than in the superior parts. In 97 patients in group A, a segmental approach was sufficient to eliminate the residual PV conduction because there were only a few recovered PV fibers (1-3 reconnected PVs; group A1). In the remaining 13 patients in group A, a circumferential ablation strategy was used because of a complete recovery of the PV-LA conduction of all four pulmonary veins (group A2). In group B, a segmental approach was sufficient in nearly all patients (109/110) because there was only a minor reconnection of 1-2 PVs. All recovered PVs could be isolated sucessfully again. At 108-month follow-up, 69.1 % of all patients were free from an arrhythmia recurrence (152/220 patients; group A: 72/110 patients (65.5 %), group B: 80/110 patients (72.3 %)). There were no major complications in both groups. Conclusions In patients with an initial circumferential PVI using the cryoballoon technique, a repeat ablation procedure can be performed safely and effectively using radiofrequency catheter ablation. In most cases only a few re-conducting PV fibers were found and therefore, a segmental re-ablation approach seems to be sufficient in the majority of patients (especially in patients treated with the second generation cryoballoon).

LINAC-Based STereotactic Arrhythmia Radioablation (STAR) for paroxysmal atrial fibrillation in elderly: a prospective phase II trial

Abstract Background and aims Stereotactic arrhythmia radioablation (STAR) is a novel therapeutic approach for cardiac arrhythmias. The aim of this trial is to investigate the feasibility of STAR for the treatment of paroxysmal atrial fibrillation (AF) in elderly patients. Method inclusion criteria were: age > 70 years, symptomatic AF, antiarrhythmic drugs failure or intolerance. All patients underwent to 4D cardiac Computed Tomography simulation. The clinical target volume was identified in the area around pulmonary veins (PV). STAR was performed with a total dose of 25 Gy (single fraction) delivered in 3 minutes. Results Twenty patients were enrolled and 18 underwent STAR. One patient withdrew informed consent before treatment and 1 patient was excluded due to unfavorable esophagus position. With a median follow-up (FU) of 16 months (range 12-23), no acute toxicity more than grade 3 was reported. Five patients had a grade 1 esophagitis 24 hours after STAR; eight patients had an asymptomatic grade 1 pericardial effusion, one patient had a torsade de pointes treated effectively by electrical cardioversion and subsequent cardiac ICD implantation. Most patients had a significant reduction in AF episodes. Five patients, due to arrhythmias recurrences after STAR, performed electrophysiological study documenting successful PV isolation. Finally, a significant improvement of quality of life was documented (48 ± 15 at enrollment vs 75 ± 15 at 12 months FU; p < 0.001). Conclusion The present phase II trial demonstrated the feasibility of STAR in paroxysmal AF elderly patients and its potential role in increasing the quality of life. Surely, more robust data are needed about safety and efficacy.

Characterization of conduction recovery and atrial electrophysiological properties after pulmonary vein isolation using pulsed field ablation

Abstract Background Pulsed field ablation (PFA) is a relatively new technology for isolation of pulmonary veins in patients with atrial fibrillation (AF). Data addressing reasons for recurrent atrial fibrillation despite primarily successful pulmonary vein isolation (PVI) using PFA are scarce, due to an up to date limited number of patients treated this way. Objective The aim of this study was to analyze electrophysiological characteristics of reconduction and / or left atrial substrate of patients referred to our center for Re-Do procedures for recurrent AF after an initial PVI using PFA. Methods 90 patients (mean age 66±9 years, 69 male (77%)) had been treated in our center from November 2021 to July 2023 with PVI using PFA. 9 (10%) of these patients were referred for Re-Do procedures. These were performed by radiofrequency ablation (RFA) using Carto system including high density mapping and high power / short duration (HPSD) ablation. We analyzed location of PV reconnection and low voltage areas (LVA) in the left atria. Results 7 out of 9 patients (77%) presented with reconnections of pulmonary veins. In one patient a single vein showed reconduction (RSPV), in 5 patients 2 veins were conducting (1x LSPV, 3x LIPV, 1 left sided common os (LCo), 1x RSPV, 3x RIPV). None of the patients showed 3 or 4 reconnected veins. Areas of reconduction in each vein were: LSPV 1x ridge, 1x posterior; LIPV 1x posterior, 1x anterior and posterior; LCo 1x posterior, RSPV 1x anterior, 2x carina, 1x anterior and posterior; RIPV 1x complete, 2x carina. In 7 patients a fibrotic atrial cardiomyopathy (FACM) was diagnosed via high density mapping of LVA’s. In 2 of these patients all 4 pulmonary veins were chronically isolated after the initial PVI. All patients except one (very small anterior LVA) with FACM ≥1 were treated with additional linear or encircling lesions according to the individual extent of the fibrotic areas. 2 patients had no LVA’s detectable. In one of those 2 patients 2 veins had reconnected. The other patient had chronically isolated veins (no proof of dormant conduction with adenosine) and no detectable non-PV-triggers under isoprenaline. Conclusion In the population of patients undergoing PVI using PFA in our center, only 10% had clinically relevant recurrences leading to the necessity of a Re-Do procedure. Most patients (77%) in this setting had reconnections of pulmonary veins. There is a tendency of posterior reconnections of the left pulmonary veins and reconnections of the carina of the right pulmonary veins, but the number of patients is too small to clearly define predilection sites that have to be paid attention to when using PFA. Additionally, left atrial substrate is an important problem in patients with recurrent AF despite primarily successful PVI and has to be considered and thoroughly addressed in Re-Do procedures.Reconnection of LSPV and anterior LVAAblation of RSPV and LSPV (posterior)

Very high-power short duration ablation metrics predictors of successful pulmonary vein isolation in atrial fibrillation ablation

Abstract Background Previous studies have shown that very high-power short duration (vHPSD) is a safe ablation modality, with similar rate of first pass isolation (FPI) but faster ablation times compared to standard CLOSE protocol guided ablation. While CLOSE protocol uses ablation index to guide energy titration no such index exists for vHPSD ablations yet. Purpose Our aim was to evaluate ablation metrics as predictors of FPI in atrial fibrillation ablation (AF) using vHPSD ablation modality. Methods In a single centre retrospective analysis, we analysed consecutive patients treated for paroxysmal (PAF) or persistent atrial fibrillation (PeAF) with PVI using vHPSD ablation from May 2021 to January 2023. We excluded patients with previous PVI procedures. The analysis was done via a cloud-based commercially available ablation analysis tool CARTONET. We analysed catheter stability, average contact force, absolute impedance drop, number of ablations and cumulative ablation time in relation to first pass isolation (FAAVI – first attempt all veins isolated). Results This is the first larger data study to evaluate ablation metrics in vHPSD using commercially available CARTONET (Figure 1). Based on the inclusion criteria 150 patients were included in the analysis. Baseline characteristics and procedural metrics are presented in Figure 2 - Table. We observed a numerical trend towards higher FAAVI rate with increasing patients number (p=0.10). Complication rate was low (1 pericardial effusion requiring drainage and 1 vascular access site complication). Ablation metrics analysis yielded statistical differences between FAAVI and no FAAVI groups (Figure 2 - Table). Multivariate analysis identified average contact force (odds ratio (OR) 1.001; 95% confidence interval (CI): 0.999-1.003; p=0.047) and catheter stability (OR 0.985; 95% CI: 0.973-0.997; p=0.019) to be independent predictors of FAAVI. Additionally, number of applications (OR 1.000; 95% CI: 0.999-1.000; p=0.042) and total ablation time (OR 0.995; 95% CI: 0.991-0.999; p=0.021) were also independent predictors of FAAVI, possibly indicating larger vein and/or ablation circumferent line to be predictive of no FAAVI. Catheter stability of less than 1.16mm (AUC 0.61; p=0.015) was shown to be discriminative of FAAVI, however discrimination value was poor. Average contact force was not discriminative of FAAVI (AUC 0.58; p=0.105) in our patient cohort. Conclusion Average contact force and catheter stability were predictive of first pass isolation, however only catheter stability was discriminative of FAAVI. Larger data with standardised ablation protocol (interlesion distance) and wider range of ablation metrics is needed to corroborate and further build on these early findings.

Pulmonary vein isolation combined with a new protocol of linear ablation to treat persistent atrial fibrillation: a prospective cohort with 1 year follow-up

Abstract Background The clinical value of ablation strategies beyond pulmonary vein isolation (PVI) in patients with persistent atrial fibrillation (perFA) is not clearly established and the optimal strategy to cure perFA remains a challenge due to the high recurrence rate after PVI alone (up to 50% of patients during 1-year follow-up). Purpose To determine the additional therapeutic value of a new design of linear ablation in the left atrium (LA) added to PVI in patients with perFA. Methods In this prospective study consecutive patients with perFA were included and underwent PVI combined with a predefined homogeneous protocol of linear ablation in the LA: anterolateral line from the mitral annulus to the left superior pulmonary vein around the left atrial appendage, anteroseptal line and posterior wall isolation. Patients were followed during 12 months after ablation with daily 30 s single-lead ECG obtained with mobile applications. The main endpoint was the incidence of recurrences, defined as any documented, sustained (>30 s) episodes of atrial arrhythmia that occurred after a 3 months blanking period. Antiarrhythmic drugs were avoided after the blanking period. Results 59 patients were included (61 [IQR 53-69] years old, 76% male sex). Acutely successful PVI was achieved in all patients and the linear ablation protocol was performed in 52 (89,7%) patients. The linea ablation protocol was not completed in 6 patients due to the following reasons: repetitive AF triggering from the same PV in 2 patients, induction and successful focal ablation of left atrial flutter in 1 patient, respiratory failure in 1 patient with severe obstructive lung disease and excessively prolonged procedure time in 2 patients. 58 patients completed the 12 months follow-up period and 1 patient was lost due to end-stage heart failure. The survival free of atrial arrhythmia recurrences was 69.1% [95%CI 55.1-79.5] (Figure). No patient had recurrences of perAF (>7 days continuous AF). 9 (53%) patients had at least 1 episode of self-limited paroxysmal AF. In these patients the average paroxysmal AF burden during the follow-up was 24 hours/year [IQR 9-24 hours/year]. In another 8 (47%) patients the recurrent arrhythmia was atypical left atrial flutter exclusively The incidence of procedure-related complications was 6,9%: 1 pericardial bleeding, 1 acute pulmonary edema, 1 splenic infarction and 1 stroke); no patient died during the study period. Conclusions A combined strategy of PVI plus the specific linear ablation protocol used in this study is associated with a low rate of atrial arrhythmia recurrences and total absence of persistent AF after ablation. A randomized multicenter clinical trial is ongoing to validate these results.Ablation strategy.Kaplan-Meier curve: recurrences

Percutaneous left atrial appendage occlusion can impair pulmonary vein isolation with pulse field ablation

Abstract Background Pulsed-field ablation (PFA) is a promising new ablation modality for pulmonary vein isolation (PVI). However, the feasibility in the presence of a percutaneous left atrial appendage occluder (LAAO) has not yet been investigated. We observed that PFA applications in the left pulmonary veins after LAAO can be interrupted. The aim of this analysis was to investigate the feasibility of PFA with a single-shot device for PVI after LAAO. Methods / Results: Retrospective multicenter analysis. A total of 16 patients (male 81.3%, mean age 71.6 +/-7.4) underwent PVI with PFA after LAAO at 5 different centers in Switzerland and Germany, from August 2021 until July 2023. In 5 patients PFA application at the left-sided PVs was aborted due to interference with the LAAO (Figure). In one patient, the left superior PV could be isolated by repositioning the PFA catheter, in 2 cases successful PVI was achieved after switching to radiofrequency ablation, and in 2 cases the respective left sided PV was not isolated. In all 5 patients the LAAO was an Amplatzer Amulet device (Amplatzer Amulet vs. other LAAO, p=0.069). Mean LAAO size was not significantly different among both groups. Conclusions LAAO can interfere with PFA applications around the left superior pulmonary vein. This effect may be associated with the design of the LAAO.

Intraprocedural and outcome findings in repeat left atrial procedures after pulsed field ablation for pulmonary vein isolation in paroxysmal and persistent atrial fibrillation

Abstract Background Pulsed Field Ablation (PFA) has emerged as a promising novel technique for pulmonary vein isolation (PVI) in the setting of atrial fibrillation. First outcome data revealed comparable success rates to radiofrequency and cryoablation. However, data on lesion dimensions and reconnection of PV after PFA potentially causing recurrence of AF is sparse. We, therefore report on pivotal reconnection sites and ablation extend after PFA-PVI. Methods All patients after PFA-PVI for paroxysmal or persistent AF at our center between September 2021 and October 2023 were included in this retrospective analysis. Baseline characteristics, procedural and outcome data were obtained. Furthermore, in all redo procedures of these patients lesion dimensions and the occurrence and location of PV gaps were evaluated. Results A total of 123 patients with atrial fibrillation underwent successful PFA-PVI during index procedure. The study cohort comprised [n= 52; 42%] paroxysmal and [n= 71; 58%] persistent atrial fibrillation cases. After a median follow-up of 123 (IQR 93-150) days recurrence of atrial arrhythmia (all AF) occurred in 9 [14. 5%] patients. Of these, 6 [9.6%] patients underwent a redo procedure due to recurrence of atrial fibrillation (3 PAF and 3 persAF [50%]; p=1). All left atrial maps and 24 PVs were analyzed. All 6 [100%] patients exhibited electrical reconnection of one or more pulmonary vein. Analysis of redo procedures revealed that the dimensions of PFA-induced lesions varied among patients: The right inferior pulmonary vein (RIPV) showed reconnection in all redo-patients (100%). Also frequent reconnection was observed for the RSPV (3 pts [50%]) and LIPV (2 pts [33%]). The gap size was 66±40% of the circumference in the reconnected RPVs and 61±31% in the reconnected LPVs. A roof-line lesion set was performed in 4 out of 6 pts (67%) due to the initially antral PV lesions affecting the posterior wall and LA roof potentially creating an isthmus for roof-dependent atrial tachycardia (AT). Conclusion Outcome data for PFA-PVI are comparable to other energy sources used for PVI. However, reconnection of PV also occurs after PFA-PVI. This retrospective analysis of redo procedures after initially successful PVI identified the RIPV as pivotal for reconnection. Furthermore, map analysis revealed that reconnection gaps extend to up to 2/3 of the initial circumferential PV ablation area. Furthermore, PFA seems to create new critical isthmuses potentially causing AT. No difference in reconnection was seen comparing PAF and persAF.

Strategies for recurrent atrial fibrillation in patients despite durable pulmonary vein isolation

Abstract Background Pulmonary vein isolation (PVI) is the cornerstone in treatment of atrial fibrillation (AF). Despite initially successful PVI patients experience recurrence of AF mostly due to reconnection of pulmonary veins (PVs). However, a certain number of patients presents with recurrent AF despite durable PVI. The optimal ablation strategy for these patients has yet to be discerned. Aim The aim of this study was to compare outcomes for different ablation strategies for recurrent AF despite persistent PVI. Methods All redo procedures for recurrence of AF from 01/2016 – 6/2022 at our center were analyzed. Only patients with proven durable PVI (entrance/exit block and high density (HD) mapping) were included. Patients were excluded, if re-PVI or right atrial ablation was necessary. In all procedures (HD) 3-D mapping and radiofrequency ablation were performed. Ablation strategy was at operators’ discretion. A 12-month follow up (FU) was obtained. Results A total of 405 left-atrial procedures for the recurrence of AF were analyzed. In 85 (21.0%) procedures all PVs were still isolated. Of these 30 patients (35.3 %) were female and 70 patients (82.4 %) suffered from persistent AF. In 49 patients (57.6 %) LA scar was detectable (85.7 % persAF). The ablation strategies consisted of: roof line (n=9; 10.6 %), left atrial anterior line (n=8, 9.4 %), roof line and left atrial anterior line (n=8, 9.4%), roof line and left atrial inferior line (n=18, 21.2 %), box lesion (n=6, 7.1 %), other left atrial ablation lines (n=20, 23.5 %) and substrate modification (CFAE and substrate encirclement) (n=16, 18.8 %). In patients with PAF (n=15), 3 patients received a roof line (20.0 %), 3 patients received the latter and left atrial inferior line (20.0 %), 5 patients received other left atrial ablation lines (33.3 %) and 4 patients received substrate modification (CFAE and substrate encirclement) (26.7 %). After a mean follow up of 401 +/- 125 days 55.3 % (n=47) of patients were free from any atrial arrhythmia (roof line 77.8 +/- 15 %, left atrial anterior line 87.5 +/- 13 %, roof line and left atrial anterior line 37.5 +/- 18 %, roof line and left atrial inferior line 50 +/- 12 %, box lesion 83.3 +/- 17 %, other left atrial ablation lines 45.0 +/- 11 %, substrate modification (CFAE and substrate encirclement) 43.8 +/- 13 %, p=0.122), 35.3 % (n=30) showed recurrence of AF (p=0.287) and 9.4 % (n=8) showed atrial tachycardia (AT) (p=0.693). None of the ablation strategies led to a significantly superior outcome. Conclusion In patients suffering from recurrence of AF despite durable pulmonary vein isolation different substrate modification strategies did not show any superiority for one or the other. Despite the necessity of additional ablation beyond PVI the optimal ablation strategy needs to be yet determined to improve outcome for redo procedures.