Acute Pulmonary Vein Reconnection Research Articles

Evaluation of an Optimized Workflow for the Radiofrequency Catheter Ablation of Paroxysmal Atrial Fibrillation.

BACKGROUND A significant number of atrial fibrillation (AF) recurrences occur after initial ablation, often due to pulmonary vein reconnections or triggers from non-pulmonary veins. MATERIAL AND METHODS Patients with paroxysmal AF who underwent radiofrequency catheter ablation for the first time were enrolled. Base on propensity score matching (1: 1 matching), 118 patients were selected for an optimized workflow for the radiofrequency catheter ablation of paroxysmal AF (OWCA) group and a conventional group. Comparative analysis of the acute and 12-month clinical outcomes was conducted. Moreover, an artificial intelligence analytics platform was used to evaluate the quality of pulmonary vein isolation (PVI) circles. RESULTS PVI was successfully achieved in all patients. Incidence of first-pass isolation of bilateral PVI circles was higher (P=0.009) and acute pulmonary vein reconnections was lower (P=0.027) in the OWCA group than conventional group. The OWCA group displayed a significant reduction in the number of fractured points (P<0.001), stacked points (P=0.003), and a greater proportion of cases in which the radiofrequency index achieved the target value (P=0.003). Additionally, the contact force consistently met the force over time criteria (P<0.001) for bilateral PVI circles in the OWCA group, accompanied by a shorter operation time (P=0.017). During the 12-month follow-up period, the OWCA group exhibited a higher atrial arrhythmia-free survival rate following the initial ablation procedure than did the conventional group. CONCLUSIONS The optimized workflow for radiofrequency catheter ablation of paroxysmal AF could play a crucial role in creating higher quality PVI circles. This improvement is reflected in a significantly elevated 12-month atrial arrhythmia-free survival rate.

Where is the gap after a 90 W/4 s very-high-power short-duration ablation of atrial fibrillation?: Association with the left atrial-pulmonary vein voltage and wall thickness.

Although pulmonary vein isolation (PVI) for atrial fibrillation (AF) utilizing radiofrequency (RF) applications with a very high-power and short-duration (vHPSD) has shortened the procedure time, the determinants of pulmonary vein (PV) gaps in the first-pass PVI and acute PV reconnections are unclear. An extensive encircling PVI was performed with the QDOT MICRO catheter with a vHPSD (90 W-4 s) in 30 patients with AF (19 men, 64 ± 10 years). The association of the PV gap sites (first-pass PVI failure, acute PV reconnections [spontaneous reconnections or dormant conduction provoked by adenosine triphosphate] or both) with the left atrial (LA) wall thickness and LA bipolar voltage on the PVI line and ablation-related parameters were assessed. PV gaps were observed in 29 (6%) of 480 segments (16 segments per patient) in 17 patients (56%). The PV gaps were associated with the LA wall thickness, bipolar voltage, and the number of RF points (LA wall thickness, 2.5 ± 0.5 vs. 1.9 ± 0.4 mm, p < .001; bipolar voltage, 2.59 ± 1.62 vs. 1.34 ± 1.14 mV, p < .001; RF points, 6 ± 2 vs. 4 ± 2, p = .008) but were not with the other ablation-related parameters. Receiver operating characteristic curves yielded that an LA wall thickness ≥2.3 mm and bipolar voltage ≥2.40 mV were determinants of PV gaps with an area under the curve of 0.82 and 0.73, respectively. The LA voltage and wall thickness on the PV-encircling ablation line were highly associated with PV gaps using the 90 W/4 s-vHPSD ablation.

Acute epicardial pulmonary vein reconnection: Nondurable transmural lesion or late manifestation of conduction through intercaval bundle.

Acute pulmonary vein reconnection (PVR) via epicardial fibers can be found during observation period after PV isolation, the characteristics and related factors have not been fully studied. We aimed to investigate the prevalence, locations, electrogram characteristics, and ablation parameters related to acute epicardial pulmonary vein reconnection (AEPVR). Acute PVR was monitored during observation period after PV isolation. AEPVRs were mapped and distinguished from endocardial conduction gaps. The clinical, electrophysiological characteristics and lesion set parameters were compared between patients with and without PVR. They were also compared among AEPVR, gap-related reconnection, and epicardial PVR in repeat procedures. A total of 56.1% acute PVR were AEPVR, which required a longer waiting period (p < .001) than endocardial gap. The majority of AEPVR were connections from the posterior PV carina to the left atrial posterior wall, followed by late manifestation of intercaval bundle conduction from the right anterior carina to right atrium. AEPVR was similar to epicardial PVR in redo procedures in distribution and electrogram characteristics. Smaller atrium (p < .001), lower impedance drop (p = .039), and ablation index (p = .028) on the posterior wall were independently associated with presence of AEPVR, while lower interlesion distance (p = .043) was the only predictor for AEPVR in acute PVR. An integrated model containing multiple lesion set parameters had the highest predictive ability for AEPVR in receiver operating characteristics analysis. Epicardial reconduction accounted for the majority of acute PVR. AEPVR was associated with anatomic characteristics and multiple ablation-related parameters, which could be explained by nondurable transmural lesion or late manifestation of conduction through intercaval bundle.

Safety and efficacy of steerable versus non-steerable sheaths for catheter ablation of atrial fibrillation systematic review and meta-analysis

ObjectivesWith the development of radiofrequency (RF) ablation technology. In recent years, more and more patients with atrial fibrillation (AF) have been treated with RF ablation. Steerable sheaths (SS) have been...

Optimized workflow for pulmonary vein isolation using 90-W radiofrequency applications: a comparative study.

Ninety-watt applications are more sensitive to catheter instability and produce lesions that are shallower and smaller in diameter than 50-W applications. These characteristics were considered for the development of a combined (90-50 W) pulmonary vein isolation (PVI) strategy which was prospectively compared to a 50 W-only ablation index (AI)-guided PVI strategy. One hundred fifty consecutive paroxysmal AF patients underwent PVI under general anesthesia using CARTO. In the first 75 patients, PVI was performed with a combined (90-50 W) strategy using the QDOT-MICRO catheter in a temperature-controlled mode. This strategy consisted of 90 W-4s applications on the posterior LA wall (at sites of catheter stability and expectedly thin atrial tissue) with an interlesion distance (ILD) ≤ 4mm and 50-W applications elsewhere (at sites of catheter instability or expectedly thick atrial tissue) with ILD < 6mm. In the subsequent 75 patients, PVI was performed with a 50 W-only AI-guided strategy using the SmartTouch-SF catheter in a power-controlled mode. Both groups of patients had similar clinical characteristics and LA dimensions (123.1 ± 24.9ml vs 119 ± 26.8ml, P = 0.33). Total procedural times (61 [56-70] vs 65 [60-75] min, P = 0.12), first-pass PVI (82.6 vs 80%, P = 0.81), acute PV reconnection (0 vs 6.6%, P = 0.05), and 1-year SR maintenance (93.3 vs 90.6%, P = 0.57) rates were also similar in both groups of patients. There were no complications in the combined (90-50 W) group while only 2 groin hematomas were reported in the 50 W group. In paroxysmal AF patients, a combined (90-50 W) strategy for PVI did not improve safety, efficiency, or effectiveness compared to a 50 W-only AI-guided strategy.

Tailored ablation index based on left atrial wall thickness assessed by computed tomography for pulmonary vein isolation in patients with atrial fibrillation.

Although left atrial wall thickness (LAWT) is known to be varied, a fixed target Ablation Index (AI) based pulmonary vein isolation (PVI) has been suggested in catheter ablation for atrial fibrillation (AF). We aimed to evaluate the efficacy and safety of PVI applying tailored AI based on LAWT assessed by cardiac computed tomography (CT). The thick segment was defined as the segment including ≥LAWT grade 3 (≥1.5 mm). The fixed AI strategy was defined as AI targets were 450 on the anterior/roof segments and 350 on the posterior/inferior/carina segments regardless of LAWT. The tailored AI strategy consisted of AI increasing the targets to 500 on the anterior/roof segments and to 400 on the posterior/inferior/carina segments when ablating the thick segment. After PVI, acute pulmonary vein (PV) reconnection, defined by the composite of residual potential and early reconnection, was evaluated. A total of 156 patients (paroxysmal AF 72%) were consecutively included (86 for the fixed AI group and 70 for the tailored AI group). The tailored AI group showed a significantly lower rate of segments with acute PV reconnection than the fixed AI group (8% vs. 5%, p = .007). The tailored AI group showed a trend for shorter ablation time for PVI. One-year AF/atrial tachycardia free survival rate was similar in two groups (87.2% in the fixed AI group and 90.0% in the tailored AI group, p = .606). Applying tailored AI based on the LAWT was a feasible and effective strategy to reduce acute PV reconnection after PVI.

Comparative Efficacy and Safety Profiles of High-power, Short-duration and Low-power, Long-duration Radiofrequency Ablation in Atrial Fibrillation: A Systematic Review and Meta-analysis.

High-power, short-duration (HPSD) radiofrequency (RF) ablation is expected to be more effective and safer than low-power, long-duration (LPLD) RF ablation in treating atrial fibrillation (AF). Given the limited data available, the findings are controversial. This meta-analysis evaluated whether the clinical effects of HPSD outweigh those of LPLD. A systematic search of PubMed, Embase, and Google Scholar databases identified studies comparing HPSD to LPLD ablation. All the analyses used the random-effects model. This analysis included 21 studies with a total of 4,169 patients. Pooled analyses revealed that HPSD was associated with a lower recurrence of atrial tachyarrhythmias (ATAs) at 1 year (relative risk [RR], 0.62; 95% confidence interval [CI], 0.50-0.78; P = .00001; I2 = 0%). Furthermore, the HPSD approach reduced the risk of AF recurrence (RR, 0.64; 95% CI, 0.40-1.01; P = .06; I2 = 86%). The HPSD approach was associated with a lower risk of esophageal thermal injury (ETI) (RR, 0.78; 95% CI, 0.58-1.04; P = .09; I2 = 73%). The HPSD strategy increased first-pass pulmonary vein (PV) isolation (PVI) and decreased acute PV reconnection (PVR), both of which were predominantly manifested in bilateral and left PVs. HPSD facilitated a reduction in procedural time, number of lesions created during PVI, and fluoroscopy time. The HPSD method reduces ETI, PVR, and recurrent AF. The HPSD approach also reduced the procedural time, number of lesions created during PVI, fluoroscopy time, and post-ablation AF relapse in 1 year, improving patient outcomes and safety.

Ostial vs. wide area circumferential ablation guided by the Ablation Index in paroxysmal atrial fibrillation.

Pulmonary vein isolation (PVI) guided by the Ablation Index (AI) has shown high acute and mid-term efficacy in the treatment of paroxysmal atrial fibrillation (AF). Previous data before the AI-era had suggested that wide-area circumferential ablation (WACA) was preferable to ostial ablation. However, with the use of AI, we hypothesize that ostial circumferential ablation is non-inferior to WACA and can improve outcomes in paroxysmal AF. Prospective, multicentre, non-randomized, non-inferiority study of consecutive patients were referred for paroxysmal AF ablation from January 2020 to September 2021. All procedures were performed using the AI software, and patients were separated into two different groups: WACA vs. ostial circumferential ablation. Acute reconnection, procedural data, and 1-year arrhythmia recurrence were assessed. During the enrolment period, 162 patients (64% males, mean age of 60 ± 11 years) fulfilled the study inclusion criteria-81 patients [304 pulmonary vein (PV)] in the WACA group and 81 patients (301 PV) in the ostial group. Acute PV reconnection was identified in 7.9% [95% confidence interval (CI), 4.9-11.1%] of PVs in the WACA group compared with 3.3% (95% CI, 1.8-6.1%) of PVs in the ostial group [P < 0.001 for non-inferiority; adjusted odds ratio 0.51 (95% CI, 0.23-0.83), P = 0.05]. Patients in the WACA group had longer ablation (35 vs. 29 min, P = 0.001) and procedure (121 vs. 102 min, P < 0.001) times. No significant difference in arrhythmia recurrence was seen at 1-year of follow-up [11.1% in WACA vs. 9.9% in ostial, hazard ratio 1.13 (95% CI, 0.44-1.94), P = 0.80 for superiority]. In paroxysmal AF patients treated with tailored AI-guided PVI, ostial circumferential ablation is not inferior to WACA with regard to acute PV reconnection, while allowing quicker procedures with less ablation time.

Pulmonary vein isolation with the novel radiofrequency balloon catheter: predictors of single-shot isolation

Abstract Funding Acknowledgements Type of funding sources: None. Background Single-shot technologies have demonstrated comparable results to point-by-point ablation for pulmonary vein (PV) isolation (PVI). The novel multi-electrode radiofrequency (RF) Balloon catheter (RFB) has been developed to achieve safe and effective single-shot PVI. Purpose This single-centre study aimed to evaluate ablation parameters predictors of single-shot PVI with the novel RFB. Methods All consecutive patients with symptomatic paroxysmal or persistent atrial fibrillation (AF) undergoing first-time PVI with the RFB between August 2021 and November 2022 were prospectively included. Remapping was performed in all patients to confirm persistent intraprocedural PVI. Clinical, procedural and ablation parameters were systematically collected. First RF applications were categorized as follows: 1) single-shot PVI (SS-PVI), in case of PVI without acute intraprocedural reconnection and 2) non-single-shot PVI (NSS-PVI), if single-shot isolation was not obtained at first application or if isolation was followed by acute PV reconnection. Results A total of 492 first RF applications were analysed, 433 (88.1%) SS-PVI and 59 (11.9%) NSS-PVI. Overall, the mean impedance drop was 22.9 ± 5.4 Ω, and the mean temperature rise was 12.2 ± 3.3 °C. SS-PVI showed higher mean impedance drop and mean temperature rise compared to NSS-PVI (23.3 ± 5.3 Ω vs 20.1 ± 4.9 Ω, p&amp;lt;0.001; 12.4 ± 3.3 °C vs 10.8 ± 2.8 °C, p&amp;lt;0.001, respectively). SS-PVI showed higher values of mean impedance drop and temperature rise for all veins, except for the left superior PV. For the other PVs, impedance drop and temperature rise were significant predictors of SS-PVI (OR per 1 Ω increase, 1.22, 95% CI 1.13-1.32, p&amp;lt;0.001, and OR per 1 °C increase, 1.34, 95% CI 1.17-1.54, p&amp;lt;0.001, respectively). The best cut-offs to predict SS-PVI were: impedance drop &amp;gt;19.2 Ω (sensitivity 0.79, specificity 0.62, PPV 0.94, NPV 0.25, AUC 0.75) and temperature rise &amp;gt;11.1 °C (sensitivity 0.58, specificity 0.84, PPV 0.18, NPV 0.97, AUC 0.72); Figure 1. Conclusion Specific cut-offs of impedance drop and temperature rise are able to predict single-shot PVI with the novel RFB and may be implemented in the procedural workflow to optimize the ablation procedure.

Ablation of residual potentials along the circumferential line reduces acute pulmonary vein reconnection

IntroductionAcute pulmonary vein (PV) reconnection is frequently encountered in patients undergoing PV isolation (PVI) procedure for the treatment of atrial fibrillation. In this study, we investigated whether the identification and ablation of residual potentials (RPs), after the initial achievement of PVI, reduces acute PV reconnection rate. MethodsFollowing PVI in 160 patients, mapping along the ablation line was performed to identify RPs, defined as bipolar amplitude ≥0.2 mV or 0.1-0.19 mV combined with a negative component of the unipolar electrogram. Ipsilateral PV sets with RPs were randomized to either no further ablation (Group B) or to additional ablation of the identified RPs (Group C). The primary study endpoint was spontaneous or adenosine-mediated acute PV reconnection after a 30-min waiting period and was also evaluated in ipsilateral PV sets without RPs (Group A). ResultsAfter isolation of 287 PV pairs, 135 had no RPs (Group A), whereas the remaining PV pairs were randomized to either Group B (n = 75) or Group C (n = 77). Ablation of RPs resulted in a reduction of spontaneous or adenosine-mediated PV reconnection rate (16.9% in Group C vs 48.0% in Group B; p < 0.001). Group A was associated with a significantly lower percentage of acute PV reconnection as compared to Group B (5.9% vs 48.0%; p < 0.001) and Group C (5.9% vs 16.9%; p = 0.016). ConclusionAfter PVI achievement, the absence of RPs along the circumferential line is associated with a low likelihood of acute PV reconnection rate. Ablation of RPs significantly reduces spontaneous or adenosine-mediated acute PV reconnection rate.

Safety and Efficacy of a Novel Approach to Pulmonary Vein Isolation Using Prolonged Apneic Oxygenation

BackgroundImproved ablation catheter–tissue contact results in more effective ablation lesions. Respiratory motion causes catheter instability, which impacts durable pulmonary vein isolation (PVI). ObjectivesThis study sought to evaluate the safety and efficacy of a novel ablation strategy involving prolonged periods of apneic oxygenation during PVI. MethodsWe conducted a multicenter, prospective controlled study of 128 patients (mean age 63 ± 11 years; 37% women) with paroxysmal atrial fibrillation undergoing PVI. Patients underwent PVI under general anesthesia using serial 4-minute runs of apneic oxygenation (apnea group; n = 64) or using standard ventilation settings (control group; n = 64). Procedural data, arterial blood gas samples, catheter position coordinates, and ablation lesion characteristics were collected. ResultsBaseline characteristics between the 2 groups were similar. Catheter stability was significantly improved in the apnea group, as reflected by a decreased mean catheter displacement (1.55 ± 0.97 mm vs 2.25 ± 1.13 mm; P < 0.001) and contact force SD (4.9 ± 1.1 g vs 5.2 ± 1.5 g; P = 0.046). The percentage of lesions with a mean catheter displacement >2 mm was significantly lower in the apnea group (22% vs 44%; P < 0.001). Compared with the control group, the total ablation time to achieve PVI was reduced in the apnea group (18.8 ± 6.9 minutes vs 23.4 ± 7.8 minutes; P = 0.001). There were similar rates of first-pass PVI, acute PV reconnections and dormant PV reconnections between the two groups. ConclusionsA novel strategy of performing complete PVI during apneic oxygenation results in improved catheter stability and decreased ablation times without adverse events. (Radiofrequency Ablation of Atrial Fibrillation Under Apnea; NCT04170894)

The adjunctive effect for left pulmonary vein isolation of vein of Marshall ethanol infusion in persistent atrial fibrillation.

This study sought to assess the effect of ethanol infusion into the vein of Marshall (EIVOM) on the acute success of left pulmonary vein (LPV) isolation in persistent atrial fibrillation (PeAF). A total of 313 patients with drug-resistant PeAF were enrolled (135 in Group 1 and 178 in Group 2). In Group 1, EIVOM was firstly performed, followed by radiofrequency ablation (RFA) including bilateral pulmonary vein isolation (PVI) and linear ablation at roofline, cavotricuspid isthmus, and mitral isthmus (MI). In Group 2, PVI and linear ablations were completed with RFA. First-pass isolation of the LPV was achieved in 119 (88.1%) and 132 (74.2%) patients in Groups 1 and 2, respectively (P = 0.002). The rate of acute pulmonary vein reconnection (PVR) was significantly lower in Group 1 (9.6% vs. 22.5%, P = 0.003). About half of acute PVR occurred in the carina with or without EIVOM. EIVOM is effective in achieving a higher first-pass isolation and a lower acute PVR of LPV in PeAF.

Confirmation of Acute Pulmonary Vein Reconnection with The Utilization of PURE EP’s High-Frequency Algorithm (HFA)

Confirmation of Acute Pulmonary Vein Reconnection with The Utilization of PURE EP’s High-Frequency Algorithm (HFA)

High-power short-duration versus low-power long-duration ablation guided by the ablation index

AimsTo compare the two different ablation strategies, both guided by the Ablation Index (AI), in the setting of atrial fibrillation (AF) ablation: high-power short-duration (HPSD) ablation using 40 W on the posterior wall and 50 W elsewhere versus low-power long-duration (LPLD) using 25 W posteriorly and 35 W elsewhere. MethodsProspective, multicenter nonrandomized, noninferiority study of consecutive patients referred for paroxysmal AF ablation from January 2018 to July 2019. Ablation was guided by the AI (≥500 for anterior segments, ≥450 for the roof and inferior segments and 400 posteriorly) and an interlesion distance (ILD) ≤ 6 mm. Patients were separated into two groups: HPSD vs LPLD. Acute reconnection (after adenosine trial) and 2-year outcomes were assessed. Results160 patients (61% males, median age of 62 [IQR 51–69] years), fulfilled the study inclusion criteria – 80 patients (316 pulmonary veins [PV]) in the HPSD group and 80 patients (314 PV) in the LPLD. The probability of acute PV reconnection was similar between both groups: 2.2% in HPSD, 95%CI 0.6% to 3.8% vs. 3.4% in LPLD, 95%CI 1.4% to 5.4%; p < 0.001 for noninferiority. Median PV ablation time (20 min vs 30 min, p < 0.01) and procedure duration (80 min vs 100 min, p < 0.001) were shorter in the HPSD group. After a median follow-up of 26 months, arrhythmia recurrence was similar between groups (17.5% in HPSD group vs. 18.8% in LPLD group, p = 0.79). ConclusionsIn paroxysmal AF patients treated with the Ablation Index, a HPSD strategy is noninferior to the more standard LPLD ablation, while allowing for quicker procedures with shorter ablation times.

Ablation of residual potentials along the circumferential line reduces acute reconnection in patients undergoing pulmonary vein isolation

Abstract Introduction Acute pulmonary vein (PV) reconnection is frequently encountered in patients with atrial fibrillation (AF) subjected to PV isolation (PVI). Purpose In this prospective, multicenter, randomized study, we investigated whether the identification and ablation of sites along the circumferential line with specific electrogram criteria indicative of nontrasmurality, after initial achievement of PVI, reduces acute PV reconnection rate. Methods Patients referred for AF ablation at five European centers were enrolled. PVI with antral circumferential isolation of ipsilateral PVs was performed using a contact force sensing ablation catheter delivering 35–40W at the anterior/superior and 30W at the posterior wall with target ablation index of 550 at the anterior wall/roof and 400 at the posterior/inferior segments. Following PVI, mapping with the ablation catheter was performed to identify residual potentials (RP) along the ablation line, defined as bipolar amplitude ≥0.2 mV or 0.1–0.19 mV combined with negative component of the unipolar electrogram as recorded by the 3D mapping system. Ipsilateral PV sets with RPs were randomized to either no further ablation (Group B) or to additional ablation of RPs (Group C). The primary study endpoint was defined as spontaneous or adenosine-mediated recovery of conduction after 30-minute waiting period which was also evaluated in ipsilateral PV sets without residual potentials (Group A). Results In total, 109 patients (59.3±10.6 years, 47% hypertension, 9.3% diabetes, left atrial diameter 39.1±4.6mm) were enrolled in the study. After initial isolation of 194 PV pairs, 98 PV pairs had no RPs (Group A) while the remaining 96 with RPs were randomized to either Group B or C (48 PV pairs each). The number of sites with RPs did not differ between groups B and C (4.1±2.5 vs 4.7±3.2, p=0.27). The occurrence of the primary endpoint in Group A was 7.1%. Ablation of residual potentials resulted in significant reduction of spontaneous or adenosine mediated reconnection (14.6% vs 47.9%, p&amp;lt;0.001). Conclusion Following initial PVI achievement, ablation of RPs along the antral circumferential line reduces spontaneous or adenosine-mediated acute PV reconnection rate in patients undergoing first-time AF ablation. Therefore, scanning of the PVI line in search of weak links with specific electrogram criteria indicative of nontrasmurality, and subsequent deployment of bonus lesions, could represent a convenient and practical way to reduce acute PV reconnection. Further studies are required to assess long term effects on AF recurrence rates. Funding Acknowledgement Type of funding sources: None.

Pulsed field ablation for atrial fibrillation: acute procedural efficacy and safety of an initial German multicenter experience

Abstract Background Pulsed field ablation (PFA) is a novel non-thermal energy source to conduct catheter ablation of atrial fibrillation (AF). However, real-world multi-center data regarding acute procedural efficacy and safety is sparse. Purpose To study acute procedural success and safety in patients undergoing PFA for catheter ablation of AF in a multicenter registry. Methods Consecutive paroxysmal and persistent AF patients undergoing PFA-based catheter ablation using a multispline catheter were enrolled. The cohort included first and repeat ablation procedures. Procedural parameters, acute success and in-hospital safety were evaluated. A follow-up of all patients was conducted. Results Five German centers enrolled a total of 154 patients undergoing PFA in this study. Mean age was 68±12 years, median CHA2DS2-VASc Score was 3 (Q1-Q3: 2–4). Patients suffered from paroxysmal AF (n=55; 36%), persistent AF (n=93; 60%) and consecutive atrial tachycardias (AT) due to previous CA (n=6; 4%). The median left atrial (LA) PFA and total procedure times were 33 (Q1-Q3: 24–53) and 90 (Q1-Q3: 73–116) minutes, respectively. Mean LA PFA fluoroscopy and total fluoroscopy times were 12.1±5.5 and 20.2±8.7 minutes. Of all 154 procedures, 130 (84%) were index ablation procedures with isolation of pulmonary veins (PVI) only and 24 (16%) were repeat procedures (including re-PVI and ablation of consecutive AT). Acute PV reconnection following primary PVI and the initial set of PFA-applications was found in 20/130 (15%) patients, necessitating additional PFA ablation. Finally, successful PFA-guided PVI was achieved in all patients. Additional PFA lesion sets (including LA posterior wall isolation, anterior ablation, mitral isthmus ablation) were applied in 17/154 (11%) patients. Complications occurred in a total of 6/154 (3.8%) patients (including three groin site complications, two pericardial tamponades, one transient coronary spasm without sequela). The follow up data is still being assessed and will be provided by the time of the ESC 2022 meeting. Conclusion PFA performed in patients with atrial fibrillation demonstrates high acute procedural success rates and a favorable safety profile in this first real-world multicenter registry. Funding Acknowledgement Type of funding sources: None.

Can lesion parameters predict effective pulmonary vein isolation in very-high-power short-duration radiofrequency ablation?

Abstract Background Pulmonary vein isolation (PVI) is the cornerstone treatment for patients with atrial fibrillation (AF) refractory to medical therapy. Recent advancements have led to the development of contact-force (CF) sensing very-high-power short-duration (vHPSD) radiofrequency (RF) ablation (90W/4 seconds). Previous RF ablation utilized Ablation Index (AI) as a marker of lesion quality to guide the operator which is not utilized in QMODE+ (vHPSD) and thus, there is limited information on effective lesion formation. In this study, we evaluated the correlation between various lesion parameters to identify relationships and potential surrogate markers for effective lesion formation. Moreover, we studied the relationship between different anatomical locations on these parameters to gain further insight. Methods 50 consecutive AF patients (33 males, age 62.0±1.31 years, 66% paroxysmal AF) underwent first time PVI using QMODE+. All wide antral circumferential ablation (WACA) QMODE+ lesions (n=5022) were analyzed for force-time integral (FTI), impedance drop, average CF, maximum temperature attained and anatomical location. The anatomical regions assessed across both left and right WACA were posterior-superior (region 1–2), posterior-inferior (region 3–4), anterior-inferior (region 5–6), anterior-superior (region 7–8) and pulmonary vein carina (region 9). All pulmonary veins (PVs) were checked with pacing maneuvers to examine for gaps in ablation lesions and adenosine for acute pulmonary vein reconnection post-ablation. Results PVI was successful in all patients while a first pass isolation was observed in 26 patients (52%). A total of 5022 lesions were performed with 2461 and 2561 lesions in the left and right WACA respectively. The average CF exhibited positive correlation with maximum temperature attained and impedance drop (p&amp;lt;0.0001) while displaying negative correlation with FTI (p&amp;lt;0.0001) (Figure 1). The PV carina (region 9) of the right WACA had the smallest impedance drop (p&amp;lt;0.0001) while the PV carina of the left WACA exhibited the lowest average CF and temperature attained (p&amp;lt;0.0001) (Figure 2). The highest number of gaps or acute reconnection (12 out of 24 patients) were seen in the region of the left pulmonary vein carina (p&amp;lt;0.0001). Conclusion This is the first study that has investigated the characteristics of vHPSD ablation lesions at different regions in the left atrium. CF was positively correlated with maximum temperature and impedance drop but negatively correlated with FTI. Furthermore, ablation at both right and left PV carina demonstrates lower impedance drop and average CF which may potentially explain the greater prevalence of gaps or reconnections. This study provides detailed insight into the relationship between the anatomical region, contact force, temperature and impedance drop, and will facilitate the optimization for effective vHPSD lesion formation. Funding Acknowledgement Type of funding sources: None.

Comparison of Effectiveness and Safety between High-Power Short-Duration Ablation and Conventional Ablation for Atrial Fibrillation: A Systematic Review and Meta-Analysis.

Aim We aimed to evaluate the effectiveness and safety between high-power short-duration (HPSD) radiofrequency ablation (RFA) and conventional RFA in patients with atrial fibrillation (AF). Methods Studies comparing HPSD and traditional applications in patients undergoing initial catheter ablation for atrial fibrillation from inception through December 2021 were searched on Pubmed, Medline, Cochrane, and Clinicaltrials.gov. Results The meta-analysis included seventeen studies with a total of 4934 patients. HPSD group decreased procedure duration (mean difference (MD) −38.28 min, P < 0.001), RF duration (MD −20.51 min, P < 0.001), fluoroscopy duration (MD −5.19 min, P < 0.001), and acute pulmonary vein reconnection (Odds ratio (OR) 0.40, P < 0.001), while improving the freedom from atrial arrhythmia at one year (OR 1.48, 95% confidence interval (CI) 1.12–1.94, P=0.005) and rates of first-pass isolation (OR 8.92, P=0.001). Compared with the conventional group, freedom from atrial arrhythmia at one-year follow-up was higher in the HPSD group without the guidance of AI/LSI (OR 1.66, P=0.01) and studies with a power setting of 40–50 W (OR 1.93, P=0.002). Nevertheless, the two groups had similar effectiveness with a power setting of 50 W in the HPSD RFA (OR 1.10, P=0.52). There was no difference in complications between the two groups (P=0.71). Conclusion HPSD RFA was associated with shorter procedure duration, higher freedom from atrial arrhythmia, and comparable safety compared to conventional RFA.

Effectiveness and Safety of High-Power Radiofrequency Ablation Guided by Ablation Index for the Treatment of Atrial Fibrillation.

Background To investigate the efficacy and safety of ablation index- (AI-) guided high-power radiofrequency ablation in the treatment of atrial fibrillation (AF). Methods Outcomes of radiofrequency (RF) applications were compared in a swine ventricular endocardial model (n = 10 each for 50 W, 40 W, and 30 W; AI = 500). And a total of 100 consecutive patients with paroxysmal AF undergoing pulmonary vein isolation (PVI) were included. The patients were divided into two groups (n = 50 for each) as follows: control group, treated with conventional power (30 W) ablation mode; and study group, treated with high power (40 W) radiofrequency ablation mode. All groups were treated with the same AI value guided the ablation (target AI = 400/500 on posterior/anterior wall, respectively). Acute pulmonary vein (PV) reconnection was assessed post adenosine administration 20 minutes after ablation. Subsequently, pathological observation of porcine heart lesions and necrotic tissue was performed. Additionally, statistical analyses were carried out on patients' baseline clinical characteristics, surgical data, and total RF energy. Results In swine ventricular endocardial RF applications, compared with 40 W and 30 W, the use of 50 W was associated with shallower tissue lesion depth (p < 0.001) and greater lesion maximum diameter (p < 0.001). Compared with 40 W and 30 W, tissue necrosis caused by 50 W was the deepest and largest (p < 0.001). In pulmonary vein isolation (PVI), there was no significant difference in baseline data between the study group and control group (p > 0.05). In patients with paroxysmal atrial fibrillation, the procedure time in the high-power group was significantly shortened (p < 0.001). The ablation time was significantly shorter (p < 0.001). Compared with control group, RF energy per point and acute pulmonary vein (PV) reconnection were lower (p < 0.001), and first-pass PVI was higher (p < 0.01) in study group. There were no significant differences in complications and sinus rhythm maintenance at 12 months between the two groups (p > 0.05). Conclusions Compared with conventional (30 W) PVI, AI-guided high-power (40 W) was safe and associated with shorter procedure time and reduced acute PV reconnection.

Comparison between High-Power Short-Duration and Conventional Ablation Strategy in Atrial Fibrillation: An Updated Meta-Analysis.

High-power short-duration (HPSD) setting during radiofrequency ablation has become an attempt to improve atrial fibrillation (AF) treatment outcomes. This study ought to compare the efficacy, safety, and effectiveness between HPSD and conventional settings. PubMed, Embase, and Cochrane Library were searched. Studies that compared HPSD and conventional radiofrequency ablation settings in AF patients were included while studies performed additional ablations on nonpulmonary vein targets without clear recording were excluded. Data were pooled with random-effect model. Efficacy endpoints include first-pass pulmonary vein isolation (PVI), acute pulmonary vein (PV) reconnection, free from AF, and free from atrial tachycardia (AT) during follow-up. Safety endpoints include esophagus injury rate and major complication rate. Effectiveness endpoints include complete PVI rate, total procedure time, PVI time, and PVI radiofrequency ablation (PVI RF) time. We included 22 studies with 3867 atrial fibrillation patients in total (2393 patients received HPSD radiofrequency ablation). Perioperatively, the HPSD group showed a higher first-pass PVI rate (risk ratio, RR = 1.10, P = 0.0001) and less acute PV reconnection rate (RR = 0.56, P = 0.0004) than the conventional group. During follow-up, free from AF (RR = 1.11, P = 0.16) or AT (RR = 1.06, P = 0.24) rate did not differ between HPSD and conventional groups 6-month postsurgery. However, the HPSD group showed both higher free from AF (RR = 1.17, P = 0.0003) and AT (RR = 1.11, P < 0.0001) rate than the conventional group 12-month postsurgery. The esophagus injury (RR = 0.99, P = 0.98) and major complications (RR = 0.76, P = 0.70) rates did not differ between the two groups. The HPSD group took shorter total procedure time (MD = −33.71 95% CI: -43.10 to -24.33, P < 0.00001), PVI time (MD = −21.60 95% CI: -25.00 to -18.21, P < 0.00001), and PVI RF time (MD = −13.72, 95% CI: -14.45 to -13.00, P < 0.00001) than conventional groups while complete procedure rate did not differ between two groups (RR = 1.00, P = 0.93). HPSD setting during AF radiofrequency ablation has better effectiveness, efficacy, and similar safety compared with the conventional setting.