High Power Short Duration Research Articles

Efficacy and safety of very high-power short-duration posterior wall ablation in persistent atrial fibrillation: a propensity score-matched comparison with standard power long-duration ablation

Abstract Background Catheter ablation (CA) with pulmonary vein isolation (PVI) is an optimal treatment option in patients with paroxysmal atrial fibrillation (AF). PVI alone in patients with persistent AF has proved to have suboptimal results. Ablation of additional atrial structures, such as posterior wall (PW) and left atrial appendage has been investigated as a tool to improve procedural efficacy. Recently very high-power short-duration (vHPSD) ablation was developed to allow rapid PVI, limiting complication through the maximization of resistive heating, and minimization of conductive heating. Objectives Compare PVI plus PWI using vHPSD versus standard-power (SP) ablation index-guided CA among consecutive patients with persistent AF Methods Forty consecutive patients underwent PVI plus PW isolation using vHPSD, compared to 40 controls underwent standard power (SP) PVI plus PW isolation. The primary efficacy endpoint outcome was recurrence of atrial tachyarrhythmias after a 3-month blanking period. The primary safety outcome was a composite of major complications within 30 days of CA. Results Treated patients have a median age of 62.8±9 years, 68 (85%) are male. Median left atrial volume is 42.4 (36-50) ml/m2. 61 (78.8%) patients had never undergone catheter ablation before. There are no statistically significant differences between groups. PW isolation was obtained more commonly in the vHPSD compared to the SP group (98% vs. 75%, p=0.007), despite shorter procedure and fluoroscopy times (p<0.001). Survival free from recurrent atrial tachyarrhythmias at 18 months was 68% in the vHPSD and 47% in SP groups, respectively (log-rank p=0.071), without major adverse events. The vHPSD approach was significantly associated with reduced risk of recurrent AF at multivariable analysis (HR, 0.39, p=0.030). Conclusions The results show feasibility and safety of posterior wall vHPSD ablation for persistent AF using this new temperature-controlled catheter without intraprocedural and periprocedural major complications at follow-up. vHPSD ablation for PW isolation may be more effective in term of atrial tachyarrhythmias recurrences with a trend for superior efficacy. However, this remains a single center experience in a small group of patients. Comparative trials involving greater number of patients with long-term follow-up are necessary to definitive results.

Impact of different ablation strategies during very high power short duration ablation: insights from the multicentric AIR HPSD registry

Abstract Background The very high power short duration ablation by mean of the QDOT Micro catheter was demonstrated to be safe and effective to achieve pulmonary vein isolation (PVI) in atrial fibrillation (AF) patients. Data from large multicentric registries are still lacking. Purpose We sought to investigate whether different ablation approaches may impact procedural outcomes. First, the hybrid approach (Qmode+, 90 W for 4 sec, at the posterior wall of the left atrium and Qmode modality AI-guided at the anterior wall) was compared to the ablation performed exclusively with the Qmode+ modality. Second, we investigated the impact of the type of anesthesia. Methods The AIR HPSD registry is a multicentric real world data registry including patients undergoing AF ablation by mean of the QDOT Micro catheter. The ablation modality (hybrid/ Qmode+) and the type of anesthesia were left to operators’ preference. Results Overall, 330 patients were enrolled, 67% males, 71% had paroxysmal AF, the mean age was 61±11. Pulmonary vein isolation was reached in 100% regardless of the ablation modality or the anesthesia used. As for the first pass isolation (FPI) there was a trend toward higher rates in the hybrid group compared to the Qmode+ group (85% vs 74%, p=0.1). No differences in FPI were found between the general anesthesia/deep sedation group and the conscious sedation group (83% vs 81%, p=0.8), however when considering the Qmode+ group solely, the FPI was significantly higher in the general anesthesia/deep sedation group (84% vs 56%, p=0.006). As for the procedural time, this was significantly shorter in the general anesthesia/deep sedation compared to conscious sedation (82±21 vs 97±35 min, p<0.01), as well as in the Qmode+ group compared to the hybrid group (80±31 vs 102±30 min, p<0.01). Minor complications were observed in 1% of patients with no significant differences between groups. Conclusions The PVI can be safely and effectively obtained with both approaches, hybrid or Qmode+ solely, however the rate of FPI seems higher with the hybrid one. When adopting solely the Qmode+ modality the general anesthesia increases the rate of FPI.

Optimized workflow for pulmonary vein isolation using very high power short duration radiofrequency ablation

Abstract Background Point-by-point radiofrequency ablation is the most used invasive treatment of atrial fibrillation (AF). However, single-shot technologies are largely widespread due to their proved safety and efficacy. QDOT MICRO (QDM) is a novel contact force–sensing catheter optimized for temperature-controlled radiofrequency (RF) ablation that allows to maintain target temperature during 90 W ablations for ≤4 seconds. Purpose This study evaluates procedural safety and effectiveness as well as long-term effects of an optimized procedural workflow using QDM catheter to perform wide atrial circumferential ablation in patients with paroxysmal AF. Methods Consecutive patients referred for paroxysmal AF first ablation through pulmonary vein isolation (PVI) were prospectively enrolled. Every procedure was performed in general anesthesia by using CARTO3 Electroanatomical Mapping System BiosenseWebster QDM catheter and Deflectable Sheet VIZIGO as single sheet in left atrium. VHPSD was performed to encircling the posterior wall, while conventional-power temperature-controlled (CPTC) mode was used to encircling the anterior wall. The primary safety endpoint was incidence of primary adverse events within ≤7 days of ablation. The primary effectiveness endpoint was freedom from documented atrial tachyarrhythmia recurrence and acute procedural, repeat ablation, and antiarrhythmic drug failure. Results 120 enrolled participants (61 ± 12 years, 45% female) met eligibility criteria. Median procedural skin-to-skin time and RF application for ablating PVs were 56 and 17 minutes, respectively. Median ablation time was 22 minutes. First-pass isolation (entrance and exit block validation) was obtained in 98 % and inter-lesion distance was 4,8 ± 0,8 mm. In 100% of patients PVI was obtained without adverse events. The Kaplan-Meier estimated 12-month rate for clinical success (freedom from symptomatic recurrence of AF) was 93%, freedom from AF was 89% Conclusions PVI performed with point by point optimized workflow using VHPSD RF catheter in combination with steerable sheet is highly efficient and effective without compromising safety.

Role of BMI on radiation dose in patients undergoing pulmonary vein isolation by pulsed field, cryoballoon and high-power-short-duration radiofrequency ablation

Abstract Background Different ablation modalities for pulmonary vein isolation (PVI) have been established. Since recent data from a randomized trial showed non-inferiority for pulse field ablation (PFA) vs. cryoballoon (CBA) or radiofrequency ablation (RFA) it seems reasonable to evaluate procedural parameters of these modalities in specific subgroups. Purpose The aim of this study was to evaluate radiation dose and procedural parameters in patients with body mass index (BMI) >26 kg/m² vs. ≤26 kg/m² undergoing PVI with different modalities. Methods Data of n=409 patients (140 PFA, 125 CBA, 144 RFA) having undergone PVI in three German centers for either paroxysmal or persistent atrial fibrillation were analysed. The primary endpoint was total radiation dose (Dose Area Product, DAP). Patients were analyzed with respect to BMI> vs. ≤26 kg/m² in PFA, CBA and RFA (with high-power short duration applications) groups, respectively. Secondary endpoints were radiation time and procedure time. Results The study included predominantly male patients (63.1%) with a mean age of 67.8±10.5 years. Cardiovascular risk factors were comparable within the groups, while the overall CHA2DS2-VASc-score was higher in CBA patients, which was largely influenced by a higher proportion of women in the CBA group. BMI was well balanced between the modalities (PFA: 28.7±5.6 kg/m² vs CBA: 28.5±6.0 kg/m² vs HPSD-RFA: 28.3±4.8 kg/m², p=0.78) as well as the proportion of patients with extreme obesity (BMI >30 kg/m²). The overall DAP was the lowest in the PFA group (370.2±274.6 µGym2) followed by HPSD-RFA (471.4±385.3 µGym2) and the highest in the CBA (1260.9±1053.5 µGym2) group. The radiation time was longest in the CBA group (16.6±17.0min) while being comparatively lower in PFA and HPSD-RFA groups (9.4±6.8 vs. 9.4±5.8 min). Procedure time was the shortest in the PFA group (79.6±30.5min), while being longest in the HPSD-RFA group (111.9±55.3 min). When stratifying patients according to BMI> 26 kg/m², there was a significant increase in DAP in all modalities, with the lowest mean increase in DAP in the PFA group (Δ143.84 µGym2), followed by HPSD-RFA (Δ329.54 µGym2) and the highest increase in the CBA group (Δ691.17 µGym2) (Figure 1). No difference was observed in radiation or procedure time when stratifying patients to BMI. (Figure 2) Conclusion Our study analyzing differences of radiation exposure according to elevated BMI among various PVI techniques shows that while there is a significant increase of DAP in patients with BMI >26 kg/m² in all modalities, the lowest increase is registered in the PFA collective. These results suggest that PVI performed with PFA, if available, or HPSD-RFA should be the energy sources of choice in obese patients with respect to radiation exposure.

Association between left atrial wall thickness and residual potential after first-pass pulmonary vein isolation using very high-power short-duration ablation in patients with atrial fibrillation

Abstract Background In this study, we evaluated efficacy, efficiency, and safety of pulmonary vein isolation (PVI) applying vHPSD ablation strategy in patients with atrial fibrillation (AF) and explored the association between left atrial wall thickness (LAWT) and the residual potential after first-pass PVI. Methods Between April 2, 2023 and October 6, 2023, drug refractory symptomatic AF patients who underwent AF ablation using vHPSD ablation strategy with QDOT MICRO catheter were prospectively enrolled. All patients took cardiac computed tomography (CT) a day before procedure. Using CT image, LAWT map was created. PV segments were categorized into prespecified 14 segments, and LAWT of each segment, segments with residual potential (RP) after first-pass PVI and early reconnection after 20-minute waiting after PVI were evaluated. Total procedure time, ablation time for PVI, and occurrence of procedure-related complication were collected. Results A total of 40 patients were included (mean age 64 years, 45% of persistent AF). Additional ablation other than PV was performed in 48% of patients, total procedure time was 77 minutes, and total PVI time was 9.9 minutes. With vHPSD PVI, all PVs first pass isolation rate was 60%; in terms of per PV, RSPV first-pass isolation was 88%, followed by LSPV and LIPV 85%, RIPV showed lowest first-pass isolation rate, 75% (Figure A). Most common RP sites was right carina, followed by left carina (Figure A). Compared to historical comparator, vHPSD PVI showed shorter procedure time, shorter ablation time for PVI, with numerically lower but statistically comparable first-pass PVI rate (Figure B). In total 560 PV segments in 40 patients, RSPV anterior, left carina, and right carina showed higher prevalence to be thick PV segments (over 60% of patients), followed by RPSV posterior, LSPV posterior, and RIPV anterior (over 40% of patients). Looking into ablation parameter detail, mean contact force was 10g, mean temperature was 47°C, and mean impedance drop was 8.4Ω. Compared to segments without RP, segments with RP showed thicker mean left atrial wall thickness grades, lower minimum contact force, higher maximum temperature, and lower minimum impedance drop. According to the left atrial wall thickness, thick PV segments showed higher prevalence of RP after first-pass PVI with vHPSD ablation. In segments with LAWT grade 3 or more, the RP rate was 9.1%. This thickness means thicker than 1.5 to 2.0 mm of thickness (Figure C). In 10% of patients (n=4) had audible or tactile steam-pops, visible char was confirmed in 5% of patients (n=2). There were no clinical complications. Conclusion PVI using vHPSD achieved shorter procedure time, shorter ablation time for PVI, and comparable first-pass PVI rate compared to historical comparator using ablation-index guided conventional power ablation. Thick segments had higher chance to have residual potential after first-pass PVI with vHPSD.

Application of high-power ablation mode in patients with idiopathic ventricular extrasystole

Background. A new method of high-power short-duration ablation (HPSDA) with high impact energy, ranging from 60 to 90 W, is becoming widespread in the world. However, the number of studies on the use of HPSDA in patients with idiopathic ventricular arrhythmias (IVA) is limited. It is relevant to study the feasibility of using HPSDA to improve the outcomes of radiofrequency ablation (RFA) in patients with IVA. The aim of the study: to evaluate the immediate results of HPSDA in RFA for IVA and to compare it with the classic ablation mode. Materials and methods. We have retrospectively analyzed the results of RFA in 54 patients with symptomatic IVA. Their average age was 45.0 ± 11.7 years. The majority were men (72.3 %). Given the possible effect of intracardiac mapping on the results of ablation, the patients were divided into two groups. Group I include 27 (50 %) participants in whom mapping was performed using 3D navigation. Group II include 27 (50 %) patients in whom 3D navigation was not used. The decision to use HPSDA or classic ablation was made empirically, without considering any factors or characteristics of a patient. The following ablation parameters were used during HPSDA: temperature 45 °C, exposure time 7 seconds, energy 70 W. Results. In group I, where 3D navigation was used to localize the substrate, HPSDA was performed in 12 patients (44.4 %), and the classic mode was used in 15 cases (55.6 %). With conventional mapping, HPSDA was applied in 10 (37.0 %) patients, and the classic mode in 17 (63.0 %). Сlassic ablation allowed to achieve complete arrhythmia suppression in all patients, regardless of the mapping method. When using only HPSDA, the disappearance of arrhythmia was observed only in 45.5 % of cases. With the use of the classic mode, recurrence of IVA during the control time was observed in 16.6 % of patients, while with the use HPSDA in 33.3 %. Conclusions. The high-power regimen demonstrated significantly lower efficacy for permanent suppression of IVA compared to classic ablation methods (p = 0.007). The use of HPSDA to suppress IVA is associated with a high risk of arrhythmia recurrence during control time (p = 0.0010). It is advisable to convert the ablation mode for complete suppression of arrhythmia when the HPSDA is ineffective.

LOCK PROTOCOL: A NEW ROBUST WORKFLOW FOR A VERY HIGH FIRST PASS PULMONARY VEIN ISOLATION DURING ATRIAL FIBRILLATION ABLATION

Abstract Introduction Pulmonary vein isolation (PVI) is the gold standard for atrial fibrillation (AF) ablation. First pass PVI is often demanding when a raw geometry reconstruction is used in combination with an inaccurate automarks annotation, accounting for discontinuous or non–transmural lesions and related AF recurrences. We hypothesized that a magnetic–post processing of left atrial geometry in combination with an LSI–guided high power short duration (HPSD) automarks annotation could improve procedural efficiency. Purpose Aim of the study was to determine the impact on procedural outcomes of the new “Lock PVI protocol” during AF ablation with the new voxel mode EnSite X mapping system. Methods We included in the study consecutive patients with AF scheduled for pulmonary vein isolation (PVI) at our Departement between January 2021 and December 2022. Patients were divided in two Groups, the Lock–PVI Group and the control No Lock–PVI Group. The “Lock PVI” Group was ablated with the new Ensite X System using the new protocol, which consisted in (1) performing a road map with contact–force annotation at potential PVI sites after High Density reconstruction, (2) shaving the magnetic geometry reconstruction to unearth true 3D location of contact points, (3) Use of 3D–Automarks color–coded with a Lesion Index (LSI) target of 5.5 (anterior) and 4.5 (posterior) (4) Inter–lesion distance £6 mm (5) High Power Short Duration Approach (50 W). The No–Lock PVI was represented by patients ablated with and HPSD ablation with the previous version of the EnSite Precision mapping suit as per local standard practice. Groups were compared in term of procedural duration, radiological exposure and “first pass” isolation. Results Forty–four patients (22 “Lock PVI” and 22 controls mean age 63,3±8 years, 65,9% male, 47,7% persistent AF), for a total of 88 PVI circles were enrolled. Procedural duration was similar between approaches (121,1±43,6 vs 125,3±30,1 min; P=0,72) but RF time was shorter in the “Lock PVI” group (19,6±4 vs 29,55±9,1 min; P<0,001), even if with a longer fluoroscopy (19,5±10,1 vs 13,4±4,9 min; P=0,01). Of note, first pass isolation was significantly higher in the “Lock PVI” group: 40/44 (90,9%) vs 28/44 (63,6%) circles (P=0,002). Conclusion The new “Lock PVI” approach allowed a consistently better first pass isolation (>90%) with less RF time when compared to standard of care PVI.

Pulmonary Vein Isolation for Atrial Fibrillation: Comparison of a Very High-Power Very Short-Duration (vHPvSD) Ablation Protocol versus a Hybrid Ablation Approach-Procedural and Mid-Term Outcome Data.

Background: Pulmonary vein isolation (PVI) using radiofrequency ablation (RFA) is a standard-of-care treatment in the rhythm control strategy of symptomatic atrial fibrillation (AF). Ablation protocols, varying in the power and duration of energy delivery, have changed rapidly in recent years. Very high-power very short-duration ablation (vHPvSD) is expected to shorten procedural times compared to conventional ablation approaches. However, the existing data suggest that this might come at the cost of lower first-pass isolation rates, a predictor of poor ablation long-term outcomes. This study aims to compare a vHPvSD protocol to a hybrid strategy, in which the power and duration of the energy transfer are adapted depending on the anatomical location. Methods: We retrospectively analyzed procedural and outcome data from 93 patients (55 vHPvSD vs. 38 hybrid) scheduled for de novo pulmonary vein isolation. A vHPvSD ablation protocol (90 Watt (W), 4 s) was compared to a hybrid protocol using vHPvSD on the posterior wall and 50 W HPSD (high-power short-duration) ablation guided by the Ablation Index along the remaining spots. Results: Ablation times were significantly shorter in the vHPvSD cohort (5.4 min. vs. 14.2 min, p < 0.001), thus resulting in a significant reduction in the overall procedural duration (91 min vs. 106 min, p = 0.003). The non-significant slightly higher first-pass isolation rates in the vHPvSD cohort (85% vs. 76%, p = 0.262) did not affect freedom from AF 6 months after the procedure (83% vs. 87%, p = 0.622). Conclusions: vHPvSD helps in shortening the PVI procedural duration, thus neither affecting first-pass isolation rates nor freedom from atrial tachyarrhythmia recurrence at 6 months after the index procedure.

Incidence and predictors of thermal oesophageal and vagus nerve injuries in Ablation Index-guided high-power-short-duration ablation of atrial fibrillation: a prospective study.

High-power-short-duration (HPSD) ablation is an effective treatment for atrial fibrillation but poses risks of thermal injuries to the oesophagus and vagus nerve. This study aims to investigate incidence and predictors of thermal injuries, employing machine learning. A prospective observational study was conducted at Leipzig Heart Centre, Germany, excluding patients with multiple prior ablations. All patients received Ablation Index-guided HPSD ablation and subsequent oesophagogastroduodenoscopy. A machine learning algorithm categorized ablation points by atrial location and analysed ablation data, including Ablation Index, focusing on the posterior wall. The study is registered in clinicaltrials.gov (NCT05709756). Between February 2021 and August 2023, 238 patients were enrolled, of whom 18 (7.6%; nine oesophagus, eight vagus nerve, one both) developed thermal injuries, including eight oesophageal erythemata, two ulcers, and no fistula. Higher mean force (15.8 ± 3.9 g vs. 13.6 ± 3.9 g, P = 0.022), ablation point quantity (61.50 ± 20.45 vs. 48.16 ± 19.60, P = 0.007), and total and maximum Ablation Index (24 114 ± 8765 vs. 18 894 ± 7863, P = 0.008; 499 ± 95 vs. 473 ± 44, P = 0.04, respectively) at the posterior wall, but not oesophagus location, correlated significantly with thermal injury occurrence. Patients with thermal injuries had significantly lower distances between left atrium and oesophagus (3.0 ± 1.5 mm vs. 4.4 ± 2.1 mm, P = 0.012) and smaller atrial surface areas (24.9 ± 6.5 cm2 vs. 29.5 ± 7.5 cm2, P = 0.032). The low thermal lesion's rate (7.6%) during Ablation Index-guided HPSD ablation for atrial fibrillation is noteworthy. Machine learning based ablation data analysis identified several potential predictors of thermal injuries. The correlation between machine learning output and injury development suggests the potential for a clinical tool to enhance procedural safety.

Lesion metrics and 12-month outcomes of very-high power short duration radiofrequency ablation (90W/4 s) under mild conscious sedation.

Pulmonary vein isolation (PVI) is often performed under general anaesthesia (GA) or deep sedation. Anaesthetic availability is limited in many centers, and deep sedation is prohibited in some countries without anaesthetic support. Very high-power short duration (vHPSD-90W/4 s) PVI using the Q-Dot catheter is generally well tolerated under mild conscious sedation (MCS) though an understanding of catheter stability and long-term effectiveness is lacking. We analyzed lesion metrics and 12-month freedom from atrial arrythmia with this approach. Our approach to radiofrequency (RF) PVI under MCS is standardized and includes a single catheter approach with a steerable sheath. We identified patients undergoing Q-Dot RF PVI between March 2021 and December 2022 in our center, comparing those undergoing vHPSD ablation under MCS (90W/MCS) against those undergoing 50 W ablation under GA (50 W/GA) up to 12 months of follow-up. Data were extracted from clinical records and the CARTO system. Eighty-three patients met our inclusion criteria (51 90W/MCS; 32 50 W/GA). Despite shorter ablation times (353 vs. 886 s; p < .001), the 90 W/MCS group received more lesions (median 87 vs. 58, p < .001), resulting in similar procedure times (149.3 vs. 149.1 min; p = .981). PVI was achieved in all cases, and first pass isolation rates were similar (left wide antral circumferential ablation [WACA] 82.4% vs. 87.5%, p = .758; right WACA 74.5% vs. 78.1%, p = .796; 90 W/MCS vs. 50 W/GA respectively). Analysis of 6647 ablation lesions found similar mean impedance drops (10.0 ± 1.9 Ω vs. 10.0 ± 2.2 Ω; p = .989) and mean contact force (14.6 ± 2.0 g vs. 15.1 ± 1.6 g; p = .248). Only median 2.5% of lesions in the 90 W/MCS cohort failed to achieve ≥ 5 Ω drop. In the 90 W/MCS group, there were no procedural related complications, and 12-month freedom from atrial arrhythmia was observed in 78.4%. vHPSD PVI is feasible under MCS, with encouraging acute and long-term procedural outcomes. This provides a compelling option for centers with limited anaesthetic support.

Personalized pulmonary vein isolation with very high-power short-duration lesions guided by left atrial wall thickness: the QDOT-by-LAWT randomized trial.

Pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (PAF) using very high-power short-duration (vHPSD) radiofrequency (RF) ablation proved to be safe and effective. However, vHPSD applications result in shallower lesions that might not be always transmural. Multidetector computed tomography-derived left atrial wall thickness (LAWT) maps could enable a thickness-guided switching from vHPSD to the standard-power ablation mode. The aim of this randomized trial was to compare the safety, the efficacy, and the efficiency of a LAWT-guided vHPSD PVI approach with those of the CLOSE protocol for PAF ablation (NCT04298177). Consecutive patients referred for first-time PAF ablation were randomized on a 1:1 basis. In the QDOT-by-LAWT arm, for LAWT ≤2.5 mm, vHPSD ablation was performed; for points with LAWT > 2.5 mm, standard-power RF ablation titrating ablation index (AI) according to the local LAWT was performed. In the CLOSE arm, LAWT information was not available to the operator; ablation was performed according to the CLOSE study settings: AI ≥400 at the posterior wall and ≥550 at the anterior wall. A total of 162 patients were included. In the QDOT-by-LAWT group, a significant reduction in procedure time (40 vs. 70 min; P < 0.001) and RF time (6.6 vs. 25.7 min; P < 0.001) was observed. No difference was observed between the groups regarding complication rate (P = 0.99) and first-pass isolation (P = 0.99). At 12-month follow-up, no significant differences occurred in atrial arrhythmia-free survival between groups (P = 0.88). LAWT-guided PVI combining vHPSD and standard-power ablation is not inferior to the CLOSE protocol in terms of 1-year atrial arrhythmia-free survival and demonstrated a reduction in procedural and RF times.

Impact of weight adjusted high frequency low tidal volume ventilation and atrial pacing in lesion metrics in high-power short-duration ablation: Results of a pilot study.

Lesion size index (LSI) was introduced with the use of Tacticath™ and as a surrogate of lesion quality. The metric used to achieve the predetermined values involves combined information of contact force (CF), power and radiofrequency time. Rapid atrial pacing (RAP) and high-frequency low-tidal volume ventilation (HFLTV) independently or in combination improve catheter stability and CF and quality of lesions. Data of the impact of body weight adjusted HFLTV ventilation strategy associated with RAP in the lesion metrics still lacking. The study aimed to compare the results of high-power short-duration (HPSD) atrial fibrillation ablation using simultaneous weight adjusted HFLTV and RAP and standard ventilation (SV) protocol. Prospective, nonrandomized study with 136 patients undergoing de novo ablation divided into two groups; 70 in RAP (100 ppm) + HFLTV with 4 mL/kg of tidal volume and 25 breaths/min (group A) and 66 patients with SV in intrinsic sinus rhythm (group B). Ablation using 50 W, CF of 5-10 g/10-20 g and 40 mL/minute flow rate on the posterior and anterior left atrial wall, respectively. No procedure-related complications. Group A: Mean LSI points 70 ± 16.5, mean total lower LSI 3.4 ± 0.5, mean total higher LSI 8.2 ± 0.4 and mean total LSI 5.6 ± 0.6. Anterior and posterior wall mean total LSI was 6.0 ± 0.4 and 4.2 ± 0.3, respectively. Mean local impedance drop (LID) points were 118.8 ± 28.4, mean LID index (%) 12.9 ± 1.5, and mean LID < 12% points 55.9 ± 23.8. Anterior and posterior wall mean total LID index were 13.6 ± 2.0 and 11.9 ± 1.7, respectively. Recurrence in 11 (15.7%) patients. Group B: Mean LSI points 56 ± 2.7, mean total lower LSI 2.9 ± 0.7, mean total higher LSI 6.9 ± 0.9, and mean total LSI 4.8 ± 0.8. Anterior and posterior wall mean total LSI was 5.1 ± 0.3 and 3.5 ± 0.5, respectively. Mean LID points were 111.4 ± 21.5, mean LID index (%) 11.4 ± 1.2, and mean LID < 12% points 54.9 ± 25.2. Anterior and posterior wall mean total LID index were 11.8 ± 1.9 and 10.3 ± 1.7, respectively. Recurrence in 14 (21.2%) patients. Mean follow up was 15.2 ± 4.4 months. Weight adjusted HFLTV ventilation with RAP HPSD ablation produced lower recurrence rate and better LSI and LID parameters in comparison to SV and intrinsic sinus rhythm.

Efficacy and safety of high-power short-duration ablation for atrial fibrillation: a systematic review and meta-analysis of randomized controlled trials.

High-power short-duration (HPSD) ablation has emerged as an alternative to conventional standard-power long-duration (SPLD) ablation. We aim to assess the efficacy and safety of HPSD versus SPLD for atrial fibrillation (AF) ablation. A systematic review and meta-analysis of randomized controlled trials (RCTs) retrieved from PubMed, WOS, SCOPUS, EMBASE, and CENTRAL were performed through August 2023. We used RevMan V. 5.4 to pool dichotomous data using risk ratio (RR) and continuous data using mean difference (MD) with a 95% confidence interval (CI). CRD42023471797. We included six RCTs with a total of 694 patients. HPSD was significantly associated with a decreased total procedure time (MD: -22.88 with 95% CI [-36.13, -9.63], P = 0.0007), pulmonary vein isolation (PVI) time (MD: -19.73 with 95% CI [-23.93, -15.53], P < 0.00001), radiofrequency time (MD: -10.53 with 95% CI [-12.87, -8.19], P < 0.00001). However, there was no significant difference between HPSD and SPLD ablation with respect to the fluoroscopy time (MD: -0.69 with 95% CI [-2.00, 0.62], P = 0.30), the incidence of esophageal lesions (RR: 1.15 with 95% CI [0.43, 3.07], P = 0.77), and the incidence of first pass isolation (RR: 0.98 with 95% CI [0.88, 1.08], P = 0.65). HPSD ablation was significantly associated with decreased total procedure time, PVI time, and radiofrequency time compared with SPLD ablation. On the contrary, SPLD ablation was significantly associated with low maximum temperature.

Durable pulmonary vein isolationwith optimized high-power and very high-power short-duration temperature-controlled ablation: A step-by-step guide.

Through systematic scientific rigor, the CLOSE guided workflow was developed and has been shown to improve pulmonary vein isolation durability. However, this technique was developed at a time when using power-controlled ablation catheters with conventional power ranges was the norm. There has been increased adoption of a high-power and very high-power short-duration ablation practice propelled by the availability of the temperature-controlled radiofrequency QDOT MICRO catheter. There are fundamental differences in biophysics between very high-powered temperature guided ablation and conventional ablation strategy that may impact patient outcomes. The catheter's design and ablation modes offer flexibility in technique while accommodating the individual operator's clinical discretion and preference to deliver a durable, transmural, and contiguous lesion set. Here, we provide recommendations for 3 different workflows using the QDOT MICRO catheter in a step-by-step manner for pulmonary vein isolation based on our cumulative experience as early adopters of the technology and the data available in the scientific literature. With standardization, temperature-controlled ablation with the QDOT MICRO catheter provides operators the flexibility of implementing different ablation strategies to ensure durable contiguous pulmonary vein isolation depending on patient characteristics.

Atrial fibrillation ablation workflow optimization facilitated by high-power short-duration ablation and high-resolution mapping.

Pulmonary vein isolation (PVI) for catheter ablation of atrial fibrillation (AF) is a time-demanding procedure. High-power short-duration (HPSD) ablation protocols and high-density mapping catheters have recently been introduced to clinical practice. We investigated the impact of high-density mapping and HPSD ablation protocols on procedural timing, efficacy, and safety by comparing different standardized set-ups. Three electrophysiology (EP) laboratory set-ups were analysed: (i) circular catheter for mapping and HPSD ablation with 30/35 W guided by an ablation index (AI); (ii) pentaspline catheter for mapping an HPSD ablation with 50 W guided by an AI; and (iii) pentaspline catheter for mapping and HPSD ablation with 90 W over 4 s using a novel ablation catheter. All patients underwent PVI without additional left atrial ablation strategies. Procedural data and operating intervals in the EP laboratory were systematically analysed. Three hundred seven patients were analysed (30/35 W AI: n = 102, 50 W AI: n = 102, 90 W/4 s: n = 103). Skin-to-skin times [105.3 ± 22.7 (30/35 W AI) vs. 81.4 ± 21.3 (50 W AI) vs. 69.5 ± 12.2 (90 W/4 s) min, P ≤ 0.001] and total laboratory times (132.8 ± 42.1 vs. 107.4 ± 25.7 vs. 95.2 ± 14.0 min, P < 0.001) significantly differed among the study groups. Laboratory interval analysis revealed significant shortening of mapping and ablation times. Arrhythmia-free survival after 12 months was not different among the study groups (log-rank P = 0.96). The integration of high-density mapping and HPSD protocols into an institutional AF ablation process resulted in reduced procedure times without compromising safety or efficacy.

Using computed tomogram atrial myocardial thickness maps in high-power short-duration radiofrequency pulmonary vein isolation: UTMOST AF.

High-power short-duration (HPSD) ablation creates wide, shallow lesions using radiofrequency (RF) heating. It is uncertain if adjusting RF energy based on atrial wall thickness provides extra benefits. We studied the safety and effectiveness of tailored HPSD energy based on left atrial (LA) wall thickness (LAWT) for circumferential pulmonary vein isolation (CPVI) in patients with paroxysmal atrial fibrillation (PAF). We enrolled 212 patients (68.4% male, mean age: 59.5 ± 11.0 years) and randomly assigned them to two groups: LAWT-guided CPVI (WT, n = 108) and conventional CPVI (control, n = 104). Both groups used an open irrigated-tip deflectable catheter to apply 50 W for 10 s to the posterior LA, while controls used 60 W for 15 s on other LA regions. RF delivery time in WT was titrated (15 s at LAWT > 2.1 mm, 13 s at 1.4-2.1 mm, and 11 s at <1.4 mm) according to the computed tomogram-myocardial thickness color map. After a mean follow-up of 13.4 ± 7.0 months, the WT and control groups showed no significant difference regarding clinical recurrence rate (13.9% vs. 5.8%, respectively; p = .061) and major complication rate (4.6% vs. 3.8%, respectively; p > .999). The total procedure time, cardioversion rate, and post-procedural AAD prescription rates did not significantly differ between the groups. The LAWT-guided energy titration strategy did not result in improved procedural safety and efficacy compared to the conventional 50-60 W-HPSD CPVI in patients with PAF.

Efficacy and Safety of High-power Short-duration Radio Frequency Ablation in the Treatment of Atrial Fibrillation: A Meta-analysis of Prospective Study

Background: Radiofrequency ablation is a critical therapeutic method used in the management of atrial fibrillation (AF). This study systematically evaluates the effectiveness and safety of two catheter radio frequency ablation approaches: high-power short-duration (HPSD) and traditional low-power long-duration (LPLD), in treating AF. Methods: Four databases were searched for prospective studies (eight cohort studies and three randomised controlled trials) that evaluated the effect of HPSD treatment on AF recurrence, occurrence rate of complications and procedural time in patients with AF from the establishment of the databases to March 2023. We utilised RevMan 5.20 and Stata 11.0 statistical software to conduct a meta-analysis, and publication bias was assessed using funnel plots and Egger's test. The effect estimates were synthesised as relative risks (RRs) or standardised mean differences (SMDs) along with their corresponding 95% confidence intervals (CIs). Results: A total of 536 relevant studies were retrieved, and 11 prospective studies were collected. The combined value of the estimated effect of HPSD versus LPLD treatment on AF recurrence in patients with AF had an RR of 0.59 (95% CI: 0.45–0.78; p &lt; 0.001), the effects of HPSD versus LPLD treatment on procedural time in patients with AF had an SMD of –1.17 (95% CI: –1.56– –0.77; p &lt; 0.001), and the effect of HPSD versus LPLD treatment on oesophageal thermal injury in patients with AF had an RR of 0.84 (95% CI: 0.22–3.28; p = 0.80). Notably, the estimated combined effects of HPSD and LPLD on other major complications (steam pop) in patients with AF had an RR of 0.57 (95% CI: 0.22–1.47; p = 0.24). Conclusions: HPSD is more effective than traditional LPLD and has a lower AF recurrence rate after surgery. Meanwhile, HPSD treatment can improve surgical efficiency and has a shorter procedural time than LPLD treatment.

High-Power Short-Duration Ablation of Paroxysmal and Persistent Atrial Fibrillation.

Catheter ablation has become a cornerstone in atrial fibrillation (AF) therapy, improving freedom from all-atrial arrhythmias, as well as outperforming antiarrhythmic drugs in alleviating AF-related symptoms, reducing hospitalizations, and enhancing quality of life. Nevertheless, the success rate of traditional radiofrequency ablation (RFA) methods remains less than ideal. To address these issues, refinement in RFA strategies has been developed to improve efficacy and laboratory efficiency during pulmonary vein isolation (PVI). High-power short-duration (HPSD) RFA has emerged as a safe strategy to reduce the time required to produce durable lesions. This article reviews critical aspects of HPSD ablation in the management of both paroxysmal and persistent AF, covering aspects such as effectiveness, safety, procedural intricacies, and the underlying biophysics.

Pulmonary vein isolation durability after very high-power short-duration ablation utilizing a very-close protocol – The FAST AND FURIOUS redo study

BackgroundVery high-power short-duration (vHP-SD) radiofrequency (RF) ablation of atrial fibrillation (AF) treatment by pulmonary vein isolation (PVI) aims for safer, more effective and faster procedures. Although acute efficacy and safety for PVI was recently shown data on chronic PVI durability is limited. Here chronic PVI durability was evaluated during repeat electrophysiological procedures in patients after initial vHP-SD and conventional RF based PVI. MethodsA total of 25 consecutive patients with repeat left atrial procedures after initial vHP-SD based PVI were included in this study. Twenty-five patients with previous conventional RF based PVI and repeat left atrial procedures served as control (control group). ResultsFor index procedures the median RF time was 328 (277, 392) seconds (vHP-SD) and 1470 (1310, 1742) seconds (control); p < 0.001, the median procedure time was 55 (53, 68) minutes (vHP-SD) and 110 (94, 119) (control); p < 0.001). First pass isolation rate was 84 % (vHP-SD) and 88 % (control, p = 0.888). No differences for severe adverse events (vHP-SD: 1/25, 4 % vs. control: 0/25, 0 %; p = 0.676 were detected.Chronic durability of all PVs was assessed in vHP-SD: 16/25 (64 %) and control: 8/25 (32 %) patients (p = 0.023) and vHP-SD: 81 % and control: 62 % of PVs were found to be isolated (p = 0.003). For right PVs vHP-SD: 84 % vs. control: 60 % of PVs (p < 0.001) and for left PVs vHP-SD: 78 % vs. control: 64 % (p = 0.123) were found to be isolated. ConclusionsPVI solely utilizing vHP-SD via a very close-protocol provides fast, safe and effective acute PVI. High rates of chronically isolated pulmonary veins have been detected.

Myocardial injury and inflammation following pulsed-field ablation and very high-power short-duration ablation for atrial fibrillation.

Pulmonary vein isolation (PVI) using radiofrequency ablation (RFA) is an established treatment strategy for atrial fibrillation (AF). To improve PVI efficacy and safety, high-power short-duration (HPSD) ablation and pulsed-field ablation (PFA) were recently introduced into clinical practice. This study aimed to determine the extent of myocardial injury and systemic inflammation following PFA, HPSD, and standard RFA using established biomarkers. We included 179 patients with paroxysmal AF receiving first-time PVI with different ablation technologies: standard RFA (30-40 W/20-30 s, n = 52), power-controlled HPSD (70 W/5-7 s, n = 60), temperature-controlled HPSD (90 W/4 s, n = 32), and PFA (biphasic, bipolar waveform, n = 35). High-sensitivity cardiac troponin T (hs-cTnT), creatine kinase (CK),CK MB isoform(CK-MB), and white blood cell (WBC) count were determined before and after ablation. Baseline characteristics were well-balanced between groups (age 63.1 ± 10.3 years, 61.5% male). Postablation hs-cTnT release was significantly higher with PFA (1469.3 ± 495.0 ng/L), HPSD-70W (1322.3 ± 510.6 ng/L), and HPSD-90W (1441.2 ± 409.9 ng/L) than with standard RFA (1045.9 ± 369.7 ng/L; p < .001). CK and CK-MB release was increased with PFA by 3.4-fold and 5.8-fold, respectively, as compared to standard RFA (p < .001). PFA was associated with the lowest elevation in WBC (Δ1.5 ± 1.5 × 109 /L), as compared to standard RFA (Δ3.8 ± 2.5 × 109 /L, p < .001), HPSD-70W (Δ2.7 ± 1.7 × 109 /L, p = .037), and HPSD-90W (Δ3.6 ± 2.5 × 109 /L, p < .001). Among the four investigated ablation technologies, PFA was associated with the highest myocardial injury and the lowest inflammatory reaction.