High-power Short-duration Group Research Articles

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

Optimization of high-power short-duration pulmonary vein isolation using QDOT catheter - the A-Q-RATE POWER trial

Abstract Background/Introduction The safety and efficacy of novel ablation catheter QDOT Micro, capable of delivering high-power short-duration (HPSD) radio-frequency (RF) applications, has already been demonstrated in clinical trials. It has been shown that lesions performed with 90 Watts/4 sec (vHPSD) are shallower but wider compared to HPSD (50 Watts/4 sec) or conventional ablation settings. Thus, it may be speculated that vHPSD applications may not achieve transmurality at thick (up to 4 mm) parts of anterior aspects of pulmonary vein (PV) - left atrial (LA) wall junction. Purpose To compare acute completeness of PV isolation (PVI) focused on anterior wall achieved using vHSPD versus HPSD in patients undergoing ablation for atrial fibrillation (AF). Methods Prospective, dual-center, randomized study was conducted over a 8-month period. Patients were randomized 1:1 to vHPSD versus HPSD delivered at anterior aspects of PV. Posterior parts of PV were ablated with vHPSD in both arms. The carina region between ipsilateral PVs was ablated using 35 W and ablation index of 380. Need for additional RF applications to achieve complete PVI was the primary outcome. Results 70 patients (mean age 63.5±11.2; 57.1% male) with paroxysmal (61.4%) or persistent AF (38.6%) were randomized to vHPSD (n=35) or HPSD (n=35). Additional RF touch-up applications at the anterior aspects of PV were significantly more frequently needed in the vHPSD group compared with the HPSD group (46% vs 19%, p<0.001) and in the right PVs (57% vs 20%, p=0.001) versus left PVs (34% vs 17%, p=0.1). Median procedure duration, LA dwell time and fluoroscopy time were similar in both groups [112 (IQR 90, 130) min vs 107 (IQR 90,125) min, p= 0.58; 95 (IQR 70,106) min vs 90 (IQR 71,100) min, p=0.55; and 28 (IQR 14,69) sec vs 46 (IQR 0,89) sec, p=0.97, respectively). In one patient in vHPSD we were not able to isolate right superior pulmonary vein (RSPV) despite additional RF touch-up applications. Conclusions vHPSD RF applications using the QDOT Micro catheter may not achieve transmurality in a significant proportion of anterior parts of PV. The proposed hybrid strategy consisting of HPSD delivery at anterior aspects of PV with vHPSD delivered at other parts of PV ostia is associated with significantly higher rate of first-pass PVI without extending procedural and fluoroscopy duration.

Abstract 13239: Atrial Fibrillation Ablation With High-Power Short-Duration Setting Reduces Change in Periprocedural Thrombotic Marker and Suppresses the Onset of Silent Stroke

Background: Atrial fibrillation (AF) ablation with high-power short duration (HP-SD) setting has been widely recognized to decrease the procedure time and to improve the ablation outcome. Hypothesis: We hypothesized that AF ablation with HP-SD setting can minimize the change in periprocedural thrombotic markers and the risk of silent stroke (SS). Aims: The aim of the present study is to investigate the impact of HP-SD setting ablation for AF on thrombotic markers and SS. Methods: We enrolled 101 AF patients: HP-SD group (n =67) using 50W; and Conventional ablation group (n = 34) using 30 to 40W. D-dimer, thrombin antithrombin complex (TAT) and total plasminogen activator inhibitor-1 (tPAI-1) were analyzed pre, post and 1 day after procedure. Magnetic resonance imaging was performed 1 day after procedure. Results: Left atrial (LA) dwelling time was significantly shorter in HP-SD group (P<0.05). In Conventional ablation group, the D-dimer and tPAI-1 levels continued to increase until 1 day after, while the TAT peaked after the ablation. On the other hand, the range of the variation of these thrombotic markers in HP-SD group was smaller ( Figure 1 ). SS occurred more frequently in Conventional ablation group than in HP-SD group (26% vs 4%, P<0.05). In logistic regression analysis, HP-SD setting and TAT difference (post - pre-procedure) remained independent predictor for SS (Odds ratio: 0.141 and 5.838, P<0.05, respectively). Conclusion: HP-SD setting was associated with the shorter LA dwelling time and the smaller thrombotic markers change than conventional ablation, which could contribute to the lower prevalence of SS.

Skin sympathetic nerve activity in different ablation settings for atrial fibrillation

BackgroundModifying the autonomic system after catheter ablation may prevent the recurrence of atrial fibrillation (AF). Evaluation of skin sympathetic nerve activity (SKNA) is a noninvasive method for the assessment of sympathetic activity. However, there are few studies on the effects of different energy settings on SKNA. ObjectiveTo investigate the changes in SKNA in different energy settings and their relationship to AF ablation outcomes. MethodsSeventy-two patients with paroxysmal and persistent AF were enrolled. Forty-three patients received AF ablation with the conventional (ConV) energy setting (low power for long duration), and 29 patients using a high-power, short-duration (HPSD) strategy. The SKNA was acquired from the right arm 1 day before and after the radiofrequency ablation. We analyzed the SKNA and ablation outcomes in the different energy settings. ResultsBoth groups had a similar baseline average SKNA (aSKNA). We found that the median aSKNA increased significantly from 446.82 μV to 805.93 μV (p = 0.003) in the ConV group but not in the HPSD group. In the ConV group, patients without AF recurrence had higher aSKNA values. However, the 1-year AF recurrence rate remained similar between both groups (35 % vs. 28 %, p = 0.52). ConclusionThe post-ablation aSKNA levels increased significantly in the ConV group but did not change significantly in the HPSD group, which may reflect different neuromodulatory effects. However, the one-year AF recurrence rates were similar for both groups. These results demonstrate that the HPSD strategy has durable lesion creation but less lesion depth, which may reduce collateral damage.

High-Power Short-Duration Lesion Index-Guided Posterior Wall Isolation beyond Pulmonary Vein Isolation for Persistent Atrial Fibrillation.

Background: High-power short-duration (HPSD) radiofrequency (RF) ablation has been adopted to improve atrial fibrillation (AF) ablation. Although the role of HPSD is well-established in pulmonary vein isolation (PVI), fewer data have assessed the impact of HPSD when addressing extra-pulmonary veins (PVs) targets. Therefore, this study aims to determine the safety, effectiveness, and acute outcomes of HPSD lesion index (LSI)-guided posterior wall isolation (PWI) in addition to PVI as an initial strategy in persistent atrial fibrillation (Pe-AF). Methods: Consecutive patients who underwent ablation of Pe-AF in our center between August 2021 and January 2022 were retrospectively enrolled. All patients' ablation strategy was PVI plus PWI using HPSD LSI-guided isolation. RF parameters included 50 W targeting LSI values of ≥5 on the anterior part of the PVs and anterior roofline and ≥4 for the posterior PVs aspect, bottom line, and within the posterior wall (PW). We compared the LSI values with and without acute conduction gaps after the initial first-pass PWI. Left atrial mapping was performed with the EnSite X mapping system and a high-density multipolar Grid-shaped mapping catheter. We compared the procedural characteristics using HPSD (n = 35) vs. a control group (n = 46). Results: Thirty-five consecutive patients were included in the study. PWI on top of PVI was achieved in all cases in the HPSD group. First-pass PVI was achieved in 93.3% of PVs (n = 126/135). First-pass roofline block was obtained in most patients (n = 31, 88.5%), while first-pass block of the bottom line was only achieved in 51.4% (n = 18). There were no significant differences compared to the control group; first-pass PVI was achieved in 94.9% of PVs (n = 169/178), first-pass roofline block in 89.1%, and bottom-line in 45.6% of patients. To achieve complete PWI with HPSD, scattered RF applications within the PW were necessary. No electrical reconnection of the PW was found after adenosine administration and the waiting period. The procedure and RF times were significantly shorter in the HPSD group compared to the control group, with values of 116.2 ± 10.9 vs. 144.5 ± 11.3 min, and 19.8 ± 3.6 vs. 26.3 ± 6.4 min, respectively, p < 0.001. Fluoroscopy time was comparable between both groups. No procedural complications were observed. At the 12-month follow-up, 71.4% of patients remained free from AF, with no differences between the groups. Conclusions: HPSD LSI-guided PWI on top of PVI seems effective and safe. Compared to a control group, HPSD is associated with similar rates of first-pass PWI and PVI but with a shorter procedural and RF time.

The new tactiflex ablation catheter: reducing the time for radiofrequency atrial fibrillation ablation

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): Azienda Ospedaliero-Univerisitaria delle Marche Background Pulmonary vein isolation (PVI) by radiofrequency (RF) ablation is a well-established and effective treatment for paroxysmal and persistent atrial fibrillation (AF). Compared to low-power-long-duration (LPLD) RF ablation, the high-power-short duration (HPSD) one produces shallower lesions reducing potential adverse effects, without affecting efficacy. The new TactiFlex Ablation Catheter, Sensor Enabled (TFSE), combining a flexible tip with fiber optic-based contact force sensing, can deliver HSPD RF, obtaining a faster PVI. Objective To test feasibility, safety, and effectiveness of RF AF ablation performed by TFSE, comparing it with LPLD RF AF ablation using TactiCath Contact Force Ablation catheter, Sensor Enabled (TCSE). Methods We conducted a prospective study including 50 consecutive patients admitted to our centre for paroxysmal or persistent AF catheter ablation. The patients were randomly divided into 2 groups according to ablation protocol: 25 patients were treated with HPSD performed by TFSE [63 (53-68) years, male 19]; 25 patients were treated with LPLD by TCSE [62 (51-69); male 12). In the HPSD group, the lesions were performed delivering 50W up to 10 seconds with a contact force (CF) index ranging from 5g to 20g. In the LPLD group, the lesions were performed delivering 40W in the anterior segments of veins (LSI 5-5.5) and 35W in the posterior segments (LSI 4-4.5). Results PVI was achieved in 100% of patients in both groups. No periprocedural complication was reported. No statistically significant differences were found in terms of clinical and echocardiographic characteristics. A significant decrease in PVI time was reported in TFSE group for every pulmonary vein (LSPV: 2.14±0.13 min vs 10.63±5.34, p&amp;lt;0.005; LIPV 2.10±0.12 min vs 10.50±5.56 min, p&amp;lt;0.005; RSPV: 2.20±0.14 min vs 10±6.35 min, p&amp;lt;0.005; RIPV 3.10±5.21 min vs 10.40±8.54 min, p&amp;lt;0.005). No difference was reported for the impendence drop (17 Ω, range 15.3-18 in TFSE vs 15 Ω, range 14.5-17.5 in TCSE, p=0.114). A shorter total procedural time (110 min, range 90-121 vs 155 min, range 128-190, p&amp;lt;0.005) and LA mapping time (8 min, range 6-10 vs 13 min, range 11-14, p&amp;lt;0.005) were reported in TFSE group, while no difference was reported in total fluoroscopy time (16 min, range 12-19.30 vs 19 min, range 14-27, p=0,062). The RF total time was superior in the TCSE group. Conclusions In our initial experience, TactiFlex catheter allows a safe, effective and faster PVI in patients affected by paroxysmal and persistent AF undergoing RF ablation. The shorter time for PVI is the main contributor for shortening total procedural times. However, our results have to be confirmed in larger studies.

PO-03-004 VISITAG SURPOINT GUIDED HIGH-POWER SHORT-DURATION ABLATION FOR CAVOTRICUSPID ISTHMUS DEPENDENT ATRIAL FLUTTER

VISITAG SURPOINT (VS) guided high-power short-duration (HPSD) ablation has been shown to be safe and effective for the treatment of paroxysmal atrial fibrillation. However, there is limited data on its utility in guiding ablation of cavotricuspid isthmus (CTI) dependent atrial flutter and the effect of CTI anatomy on HPSD procedural success. The purpose of this study was to assess the safety and efficacy of VS guided HPSD ablation for CTI dependent atrial flutter compared to standard ablation strategies and determine the impact of CTI anatomy on reconnection rates. Sixty-four consecutive patients underwent HPSD ablation for atrial flutter at 50W, with a target VS index of 400 and an inter-lesion distance < 6mm. Retrospective data from 35 patients receiving standard CTI ablation at 40W without VS were analyzed as controls. CTI anatomy was assessed using intracardiac echocardiography and categorized as either flat/concave, discrete diverticulum or having an underlying vascular structure. CTI morphology, radiofrequency (RF) time, first-pass bidirectional block (BDB), reconnection rates and ablation complications were compared. CTI morphology, mean CTI length and post-CTI waiting period were not significantly different between HPSD and standard 40W groups. Four patients (7%) in the HPSD group had CTI reconnection. Of these, 3 had evidence of a diverticulum and 1 had an underlying vascular structure. None of the HPSD patients with flat/concave CTI morphology had reconnection. In the standard 40W ablation group, 7 patients (20%) had reconnection (p < 0.05). Of these, 3 were flat/concave, 3 had a diverticulum and 1 had an underlying vascular structure. First pass BDB was achieved in 88% of HPSD patients and 77% of standard 40W patients (p = 0.18). Total RF delivery was significantly shorter in the HPSD group (p < 0.001) with a mean time of 3.65 ± 1.27 minutes, corresponding to 21 ± 10 ablation lesions. Durable bidirectional block was achieved in all HPSD and standard ablation patients, including those with reconnection. There were no complications in either group. HPSD with a target VS index of 400 is safe and effective for typical flutter ablation, with a lower rate of CTI reconnection and shorter RF time compared to standard ablation. The presence of diverticula or underlying vascular structures decreases procedural success. The absence of these anatomical variants may preclude the need for a standard waiting period when using VS guided HPSD technique.Tabled 150W (n = 64)40W (n = 35)p-valueAge (years)66 ± 1065 ± 100.81Gender (male)37 (58%)19 (54%)0.74Flat/Concave39 (61%)22 (63%)0.85Diverticulum22 (34%)11 (31%)0.77Underlying Vessel3 (5%)2 (6%)0.82CTI Length (cm)3.16 ± 0.623.21 ± 0.780.67RF Time (min)3.65 ± 1.278.73 ± 2.77< 0.001First Pass Block56 (88%)27 (77%)0.18Reconnection Rate4 (7%)7 (20%)< 0.05 Open table in a new tab

High-Power, Short-Duration Ablation under the Guidance of Relatively Low Ablation Index Values for Paroxysmal Atrial Fibrillation: Long-Term Outcomes and Characteristics of Recurrent Atrial Arrhythmias.

The purpose of this study was to evaluate the difference in effectiveness and safety of high-power, short-duration (HPSD) radiofrequency catheter ablation (RFA) guided by relatively low ablation index (AI) values and conventional RFA in paroxysmal atrial fibrillation (PAF) patients. The HPSD RFA strategy (40-50 W, AI 350-400 for anterior, 320-350 for posterior wall; n = 547) was compared with the conventional RFA strategy (25-40 W, without AI; n = 396) in PAF patients who underwent their first ablation. Propensity-score matching analyses were used to compare the outcomes of the two groups while controlling for confounders. After using propensity-score matching analysis, the HPSD group showed a higher early recurrence rate (22.727% vs. 13.636%, p = 0.003), similar late recurrence rate, and comparable safety (p = 0.604) compared with the conventional group. For late recurrent atrial arrhythmia types, the rate of regular atrial tachycardia was significantly higher in the HPSD group (p = 0.013). Additionally, the rate of chronic pulmonary vein reconnection and non-pulmonary vein triggers during repeat procedures was similar in both groups. For PAF patients, compared with the conventional RFA strategy, the HPSD RFA strategy at relatively low AI settings had a higher early recurrence rate, similar long-term success rate, and comparable safety.

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.

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.

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.

Shorter distance between the esophagus and the left atrium is associated with higher rates of esophageal thermal injury after radiofrequency ablation.

Esophageal thermal injury (ETI) is a known and potentially serious complication of catheter ablation for atrial fibrillation. We intended to evaluate the distance between the esophagus and the left atrium posterior wall (LAPW) and its association with esophageal thermal injury. A retrospective analysis of 73 patients who underwent esophagogastroduodenoscopy (EGD) after LA radiofrequency catheter ablation for symptomatic atrial fibrillation and pre-ablation magnetic resonance imaging (MRI) was used to identify the minimum distance between the inner lumen of the esophagus and the ablated atrial endocardium (pre-ablation atrial esophageal distance; pre-AED) and occurrence of ETI. Parameters of ablation index (AI, Visitag Surpoint) were collected in 30 patients from the CARTO3 system and compared with assess if ablation strategies and AI further impacted risk of ETI. Pre-AED was significantly larger in patients without ETI than those with ETI (5.23 ± 0.96 mm vs. 4.31 ± 0.75 mm, p < .001). Pre-AED showed high accuracy for predicting ETI with the best cutoff value of 4.37 mm. AI was statistically comparable between Visitag lesion markers with and without associated esophageal late gadolinium enhancement (LGE) detected by postablation MRI in the low-power long-duration ablation group (LPLD, 25-40 W for 10-30 s, 393.16 [308.62-408.86] vs. 406.58 [364.38-451.22], p = .16) and high-power short-duration group (HPSD, 50 W for 5-10 s, 336.14 [299.66-380.11] vs. 330.54 [286.21-384.71], p = .53), respectively. Measuring the distance between the LA and the esophagus in pre-ablation LGE-MRI could be helpful in predicting ETI after LAPW ablation.

Modern technologies for radiofrequency pulmonary vein isolation. Comparison of radiofrequency balloon catheter with high power-short duration ablation in patients with paroxysmal atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Background Pulmonary vein isolation (PVI) is an established therapy for symptomatic atrial fibrillation (AF). Traditional point by point ablation can be time consuming requiring advanced training. Novel radiofrequency (RF) ablation techniques sought to facilitate PVI. Point by point ablation using high power short duration (HPSD) settings has already shown to be safe and effective whereas there is paucity of data using a novel multi-electrode balloon catheter (Heliostar™, Biosense Webster, CA, USA). Purpose We aimed to assess procedure characteristics, efficacy, and safety of the Heliostar™ RF-balloon catheter in direct comparison with the latest RF ablation technique. Methods All patients undergoing PVI using the Heliostar™ between September and November 2021 were included in this ongoing single center registry. Procedural data and outcome were assessed and compared with data from patients undergoing initial PVI for paroxysmal AF with the HPSD approach from our specifically designed database. A power setting of 70W/7s (70W/5s at posterior wall) was considered as HPSD. Results A total of 51 consecutive patients (61±16 years, 49% male) were included. Of those 13 patients undergoing RF-balloon and 38 patients HPSD ablation. Baseline parameters did not differ between groups. Acute PVI was achieved in all patients. For every RF-application with the RF-balloon all necessary criteria were met: Inflation index was between 0.9 and 1.0 and a minimum of 9/10 electrodes were within impedance range. A mean of 2.8±1.4 applications per vein (LSPV 3.2±2.9, LIPV 2.6±2.5, RSPV 2.8±2.0 and RIPV 1.8±0.8) were necessary to achieve durable isolation. The mean maximum esophageal temperature was 40.2±0.8°C. When comparing procedural parameters with HPSD no statistically significant difference was seen regarding procedure duration (Heliostar™ 111±28min and HPSD 100±25min; p=0.3) and left atrial dwell time (Heliostar™ 90±23min and HPSD 80±26min; p=0.08). Fluoroscopy time (Heliostar™ 17±4min and HPSD 13±5min; p=0.005) and dose (Heliostar™ 3961±1325mGy*cm2 vs. HPSD 3153±1833mGy*cm2; p=0.04) were higher in the Heliostar™ group. No major complication occurred in both groups. A three month follow up was available for 10 patients in the Heliostar™ and for 38 patients in the HPSD group. All 10 Heliostar™ patients and 79% of the HPSD patients were free from atrial arrhythmias at follow up. Conclusion The novel multi-electrode RF-balloon has shown to be safe and effective in the first clinical routine AF ablation procedures. The tendency towards longer LA dwell times, procedure durations and the significantly higher fluoroscopy exposition in comparison with the HPSD PVI can be attributed to the learning curve applying a new ablation system. More experience is needed in the future to determine the benefits of the novel RF-balloon.

Effect on sinus cycle length and atrioventricular node function after high-power short-duration versus conventional radiofrequency catheter ablation in paroxysmal atrial fibrillation

BackgroundThe efficacy and safety of high-power, short-duration (HPSD) radiofrequency catheter ablation for atrial fibrillation (AF) have been demonstrated in several studies. We aimed to evaluate and compare the effects of the conventional method and the HPSD method for AF ablation on the sinus and AV node function in patients with paroxysmal AF.MethodsThe medical records of patients with paroxysmal AF who underwent pulmonary vein isolation (PVI) were retrieved from a prospectively collected AF ablation registry at a large-sized tertiary center. The HPSD group (n = 41) was distinguished from the conventional ablation group (n = 198) in terms of the power (50 W vs. 20–40 W) and duration (6–10 s vs. 20–30 s) of radiofrequency energy delivery during PVI. Peri-procedural changes in cardiac autonomy were assessed in terms of the changes in sinus cycle length (SCL), block cycle length (BCL), and effective refractory period (ERP) of the atrioventricular node (AVN).ResultsThe SCL, BCL, and ERP of the AVN at baseline and post-ablation were not significantly different between the conventional ablation group and the HPSD group. Shortening of the SCL, BCL, and ERP of the AVN was observed immediately after AF ablation in both groups. One-year recurrence of AF/atrial flutter (35.1% vs. 20.3%; P = 0.011) and atrial flutter (13.8% vs. 4.7%; P = 0.015) were higher in the HPSD group than in the conventional ablation group.ConclusionBoth the HPSD and the conventional ablation method resulted in post-ablation vagal modification as evidenced by the shortening of SCL, BCL, and ERP of the AVN. One-year recurrence of atrial flutter and AF/atrial flutter was higher in patients who underwent the HPSD method.

Comparison of outcomes with low-power long duration versus high-power short duration of ablation: the role of the acute change in sinus rhythm after the ablation as a predictor of long-term success.

Different results are described after atrial fibrillation ablation and multiple predictors of recurrence are well established. Evaluate and analyze if heart rate increase (HRI) during a first atrial fibrillation (AF) ablation with low-power long-duration (LPLD) and subsequently with high-power short-duration (HPSD) can impact. Retrospectively analyzed 340 consecutive patients (pts) undergoing first AF ablation. There were 158 pts in LPLD group: 113 (71.5%) paroxysmal AF with ablation with a power of 30/20w, on anterior and posterior left atrial (LA) wall, respectively, and contact force of 10-30g for 30s. There were 182 pts in HPSD group: 106 (58.2%) paroxysmal AF, who underwent ablation with 45/50w, contact force of 8-15g/10-20g and 35mL/min flow rate on anterior and posterior left atrial wall, respectively. Median follow-up was 32 ± 16months. Success was observed in 94 (59.5%) patients in LPLD and 152 (83.5%) in HPSD, in LPLD group we documented a median HRI of 4.3bpm (8%), compared to preablation heart rate, while a higher HRI in HPSD group of HRI 13.5bpm (27.2%) was noted. Heart rate increase was associated with a higher success rate in both ablation techniques and independently showed an important impact on the success rate after AF ablation. HPSD compared to LPLD showed a higher proportion of HRI and also demonstrated a superiority in maintaining sinus rhythm at a long-term follow-up.

High power short duration (HPSD) versus lower power longer duration (LPLD) atrial fibrillation ablation: a multi-centre randomised controlled trial (HiLo-HEAT study)

Abstract Funding Acknowledgements Type of funding sources: None. Background Lower power (25W) longer duration (LPLD) radiofrequency (RF) ablation has conventionally been used on the posterior wall during pulmonary vein isolation (PVI) for atrial fibrillation (AF), to attenuate the risk of esophageal thermal injury (ETI). High power (40-50 W) short duration (HPSD) RF ablation results in shorter procedural times with no increase in ETI. However evidence had been limited by non-randomised studies. Purpose To compare HPSD versus LPLD ablation and the effects on esophageal thermal injury (ETI) and procedural outcomes. Methods In this multi-centre, prospective, randomised control trial, 88 patients with paroxysmal/persistent AF undergoing their first RF ablation procedure were randomised 1:1 to HPSD or LPLD ablation. Anterior wall ablation was done in both arms using 40-50 W, with ablation target of AI 500-500/ LSI 5-5.5. Posterior wall ablation was done using 40-50W (HPSD group) versus 25 W (LPLD group), with target AI 400/ LSI 4. Ablation involves wide antral circumferential PVI using contact force sensing ablation catheters, with additional ablation lines as per operator discretion. Circa multi-sensor esophageal temperature monitoring (ETM) probe was utilized. Endoscopy was performed within 24 hours to assess for ETI. The primary outcome was incidence of ETI, with secondary outcomes including acute procedural endpoints. Results Mean age of the cohort was 61+/-9 years, with 31% females. 36 (41%) had PAF. PVI was achieved in 100% of patients, with posterior wall isolation (PWI) added in 19 PsAF patients (21.6%). There were more hypertensive patients in HPSD (p = 0.02). Significant esophageal luminal temperature rises (≥ 38 c) were seen in 93.2% of patients, with no difference between groups (p = 0.69). First pass isolation rates for left and right PVs were 85% and 61% respectively, with similar rates in both groups (p = 0.37, p = 0.65 respectively). HPSD group had shorter RF time (1613 vs 2303 secs, p &amp;lt;0.04), and fluoroscopy times (11.4 vs 13.1 mins, p = 0.05). Procedural times were lower in HPSD, although not significant (133.7 vs 150.8 mins, p = 0.10). Post ablation endoscopy showed 4 cases of ETI (4.5%), with equal occurrence in HPSD and LPLD (p = 1.0). All ETIs were class 2a (superficial ulcer), and treated with PPI therapy. Esophageal injuries not attributable to RF ablation occurred in 9 (10%), with no difference between groups (p = 0.29). There was no difference in AF recurrence between the 2 groups (post 3 months blanking period) after a mean follow up of 6.3 months (p = 0.71). Conclusion HPSD ablation was associated with lower RF ablation and fluoroscopy times compared to LPSD, with comparably low rates of ETI on post ablation endoscopy. Our findings suggest that HPSD ablation is a safe and efficacious approach to PVI. However clinicians should be cognisant of the potential injury risk related to esophageal instrumentation from transesophageal echo/ ETM probes.

Procedural characteristics of pulmonary vein isolation with high-power short-duration setting compared to conventional setting

PurposeThe purpose of this study was to investigate the safety and efficacy of high-power short-duration (HP-SD) ablation compared to conventional ablation in patients with atrial fibrillation (AF).MethodsWe enrolled consecutive 158 drug-refractory symptomatic AF patients (119 males, mean age 63 ± 10 years) who had undergone first radiofrequency pulmonary vein isolation (PVI). PVI was performed using the conventional setting (20–35 W) in 73 patients (Conventional group) and using the HP-SD setting (45–50 W) in 85 patients (HP-SD group). The rate of first pass isolation, remaining gaps after circumferential ablation, dormant conduction, and the radiofrequency application time in each pulmonary vein (PV) were compared between the groups.ResultsThe first pass isolation ratio was significantly higher in the HP-SD group than in the Conventional group (81% vs. 65%, P = 0.027) in the right PV, but did not differ in the left PV. The remaining gaps were fewer in the right superior PV (4% vs. 21%, P = 0.001) and left inferior PV (1% vs. 8%, P = 0.032) areas, and the radiofrequency application time in each PV was shorter (right PV, 12.0 ± 8.9 min vs. 34.0 ± 31.7 min, P < 0.001; left PV, 10.6 ± 3.6 min vs. 25.7 ± 22.3 min, P < 0.001) in the HP-SD group than in the Conventional group.ConclusionThe use of the HP-SD setting might contribute to improve the first pass isolation rate and to shorten the radiofrequency application time in each PV.

Meta-analysis comparing outcomes of high-power short-duration and low-power long-duration radiofrequency ablation for atrial fibrillation.

High power short duration (HPSD) ablation strategy is proposed to be more effective than low power long duration (LPLD) for radiofrequency ablation of atrial fibrillation. Although small trials abound, data from a large cohort are lacking. This meta-analysis compares all the existing studies comparing these two approaches to evaluate perceived advantages of one over the other. A systematic search of PubMed, EMBASE, and Cochrane databases identified studies comparing HPSD to LPLD ablation. All the analyses used the random-effects model. Ablation settings varied widely across 20 studies comprising 2,136 patients who underwent HPSD and 1,753 patients who underwent LPLD. The pooled incidence of atrial arrhythmia recurrence after HPSD ablation was 20% [95% confidence interval (CI): 0.16-0.25; I2=88%]. Atrial arrhythmia recurrences were significantly less frequent with HPSD ablation (incidence risk ratio=0.66; 95% CI: 0.49-0.88; I2=72%; p=0.004). Procedural, fluoroscopy, and ablation times were significantly shorter with HPSD ablation. First-pass pulmonary vein isolations (PVIs) were significantly more [odds ratio (OR)=2.94; 95% CI: 1.50-5.77; I2=89%; p=0.002), and acute pulmonary vein reconnections (PVRs) were significantly lesser (OR=0.41; 95% CI: 0.28-0.62; I2=62%; p<0.001) in the HPSD group. Although radiofrequency energy was significantly higher, esophageal thermal injuries (ETI) were lower with HPSD ablation. Acute complications, including steam-pops, were rare and statistically similar in both the groups. HPSD ablation enables faster first-pass PVI with fewer PVRs, similar ETI rates, rare collateral damage, and lower recurrence of atrial arrhythmia in the long term than LPLD. Randomized controlled studies with a larger cohort are indicated both to confirm the benefit of HPSD ablation and standardize the ablation protocol.

A tertiary centre experience comparing new temperature-controlled high-power short-duration ablation technology with standard radiofrequency and cryo-energy ablation

Abstract Introduction Pulmonary vein isolation (PVI) is an established treatment strategy for atrial fibrillation (AF). Radiofrequency (RF) ablation technology has evolved over the last decade with the very high-power short-duration (vHPSD) temperature-controlled ablation approach emerging as the latest development. The aim of this study was to determine the procedural efficacy, metrics and safety of vHPSD ablation with conventional power-controlled RF (PCRF) ablation and cryo-energy ablation (CRYO). Methods A prospective single tertiary centre analysis was performed on patients undergoing first time PVI ablation from 2019 to 2020. The population was divided in to 4 treatment arms; vHPSD, high-power short-duration (HPSD), PCRF and CRYO. Demographics, clinical and procedural metrics such as PVI duration, ablation time and sedation requirement were collated. Patients were monitored for perioperative complications. Results One hundred patients underwent ablation with 25 cases conducted in each arm. Complete PVI was attained in all study subjects. For the vHPSD group, PVI procedural duration, ablation and fluoroscopy times were 71.7±6.35 min, 9.21±0.76 min and 15.1±1.50 min respectively. The HSPD group exhibited total PVI, burn and fluoroscopy times of 90.2±5.59 min (p=0.03), 10.3±2.40 min (p&amp;lt;0.0001) and 34.1±1.67 min (p=0.1) respectively. In comparison, the PCRF group exhibited longer procedure duration, ablation and fluoroscopy times of 93.3±6.50 min (p=0.01), 15.2±1.73 min (p&amp;lt;0.0001), 37.8±2.47 min (p=0.870). Whereas procedural and fluoroscopy times of 96.3±7.1 min (p=0.01) and 18.8±1.31 (p=0.05) were observed in the cryo-ablation group. Procedural doses of morphine and midazolam for the vHPSD, HPSD, PCRF and CRYO group were 11.3 mg + 4.00 mg, 15.5 mg (p=0.0003) + 9.33 mg (p=0.0003), 15.7 mg (p=0.0002) + 8.03 mg (p=0.02), and 8.19 mg (p=0.01) + 4.84 mg (p=0.303) respectively. No adverse procedural events were recorded for the vHPSD while 2 pericardial effusions occurred in the PCRF group, 1 cardiac tamponade in the HPSD group and 2 transient ischaemic attacks in the CRYO group. Conclusion With the emergence of vHPSD RF ablation, preliminary findings indicate significant potential in reduction of procedural and ablation time. Further analysis is ongoing in order to ascertain longer-term efficacy and patient safety. Funding Acknowledgement Type of funding sources: None. Intraprocedural outcomesIntraprocedural outcomes

Efficacy and Safety of High-Power Short-Duration Radiofrequency Catheter Ablation of Atrial Fibrillation.

Introduction: Whereas, high-power short-duration (HPSD) radiofrequency (RF) ablation is generally used in atrial fibrillation (AF) catheter ablation (CA), its efficacy, safety, and influence on autonomic function have not been well established in a large population. This study compared HPSD-AFCA and conventional power (ConvP)-AFCA in propensity score matched-population.Methods: In 3,045 consecutive patients who underwent AFCA, this study included 1,260 patients (73.9% male, 59 ± 10 years old, 58.2% paroxysmal type) after propensity score matching: 315 in 50~60W HPSD group vs. 945 in the ConvP group. This study investigated the procedural factors, complication rate, rhythm status, and 3-month heart rate variability (HRV) between the two groups and subgroups.Results: Procedure time was considerably short in the HPSD group (135 min in HPSD vs. 181 min in ConvP, p < 0.001) compared to ConvP group, but there was no significant difference in the complication rate (2.9% in HPSD vs. 3.7% in ConvP, p = 0.477) and the 3-month HRV between the two groups. At the one-year follow-up, there was no significant difference in rhythm outcomes between the two groups (Overall, Log-rank p = 0.885; anti-arrhythmic drug free, Log-rank p = 0.673). These efficacy and safety outcomes were consistently similar irrespective of the AF type or ablation lesion set. The Cox regression analysis showed that the left atrium volume index estimated by computed tomography (HR 1.01 [1.00–1.02]), p = 0.003) and extra-pulmonary vein triggers (HR 1.59 [1.03–2.44], p = 0.036) were independently associated with one-year clinical recurrence, whereas the HPSD ablation was not (HR 1.03 [0.73–1.44], p = 0.887).Conclusion: HPSD-AFCA notably reduced the procedure time with similar rhythm outcomes, complication rate, and influence on autonomic function as ConvP-AFCA, irrespective of the AF type or ablation lesion set.