High Power Short Duration Research Articles

In Vivo Tissue Temperature Characteristics of Contact Force Catheter With a Mesh-Shaped Irrigation Tip: A Porcine Study.

Neither the actual in vivo tissue temperatures reached with a novel contact force sensing catheter with a mesh-shaped irrigation tip (TactiFlex SE, Abbott) nor the safety profile has been elucidated. In a porcine model (n=8), thermocouples were implanted epicardially in the superior vena cava, right pulmonary vein, and esophagus close to the inferior vena cava following a right thoracotomy. After chest closure, endocardial ablation was conducted near the thermocouples under fluoroscopic guidance. We compared tissue temperatures during 50W/13-s high-power short-duration (HPSD) and 30W/30-s standard ablation. No steam pops were observed in 34 HPSD and 35 standard ablation applications. Tmax (maximum tissue temperature when the thermocouple was located ≤5mm from the catheter tip) was modestly higher in HPSD compared to standard ablation (60.1°C±12.4°C vs. 57.8°C±12.9°C; p = 0.46). The peak tissue temperature correlated inversely with the catheter tip-to-thermocouple distance (HPSD: r = -0.40; standard: r = -0.57). Lethal temperatures (≥50°C) were reached faster with HPSD (6.5±3.2s vs. 10.3±8.6s; p=0.04) and the distance from the catheter tip achieving a lethal tissue temperature ≥50°C (indicative of the lesion depth) was slightly shallower with HPSD (4.2 and 4.8mm, respectively). The esophageal injury occurred superficially in both settings (0.98±0.22mm vs. 1.16±0.18mm; p=0.29). HPSD ablation produced a modestly higher and more rapid increase in the tissue temperature around the veno-atrial junction with a shorter catheter tip-to-thermocouple distance required to reach lethal temperatures. This data contributes to understanding effective lesion creation and collateral injury prevention with the TactiFlex catheter.

Very High-Power Short-Duration Ablation for Atrial Fibrillation in Adults With Congenital Heart Disease.

Data regarding safety and long-term outcome of very high-power-short duration (vHPSD) ablation in adult congenital heart disease (ACHD) patients with paroxysmal or persistent atrial fibrillation (AF) are lacking. Retrospective observational single-center study. The data of 66 consecutive ACHD patients (mean age 60 ± 12.8 years, 46% male) with mild (69.7%), moderate (22.7%), or complex (7.6%) congenital heart disease (CHD) who underwent ablation for paroxysmal (40.9%) or persistent AF (59.1%) were analyzed. Circumferential PVI was performed in all patients and additional substrate ablation in 79,4% of persistent AF patients using irrigated RF energy with vHPSD settings of 70 W/5-7 s or 60 W/7-10 s. Mean procedure time was 123.6 ± 42 min with a mean RF time of 18.19 ± 10 min. No technique related adverse events occurred. Vascular access complications were detected in seven patients (10.6%) requiring intervention in four patients (6%). A median follow-up time of 491 days (IQR: 194-1054 days). Freedom from any atrial arrhythmia off antiarrhythmic drugs (AAD) at 1 year was present in 58% of patients (77.8% with paroxysmal AF, 43.6% with persistent AF). vHPSD for ablation of paroxysmal or persistent AF in ACHD patients is safe and effective. Regardless of CHD complexity, no vHPSD ablation modality related complications occurred. Long-term outcome for paroxysmal AF after one ablation was excellent whereas results for persistent AF were limited.

Optimized workflow with hybrid (very) high-power short-duration radiofrequency ablation renders point-by-point pulmonary vein isolation as fast and effective as cryoballoon ablation.

A hybrid approach with very high-power short-duration (vHPSD) posteriorly and ablation-index guided HPSD (50 W) anteriorly seems to be an optimal balance between efficiency and effectiveness for point-by-point pulmonary vein isolation (PVI). The aim of the current study is to compare vHPSD/HPSD ablation to cryoballoon ablation (CBA) in patients with symptomatic atrial fibrillation (AF). In this retrospective single-center study, we identified 110 consecutive patients who underwent their first PVI with either vHPSD/HPSD (n = 54) or CBA (n = 56). We compared procedural efficacy, efficiency, safety, and long-term outcomes. Baseline characteristics of both groups were comparable; however, patients in the vHPSD/HPSD group had larger left atrial volume index (35, IQR 27-45 vs. 28, IQR 21-36ml/m2, P = 0.005). Complete PVI was achieved in all patients except two CBA cases (100% vs. 96.4%, P = 0.50). First-pass isolation rate was 79.6% in the hybrid group. Procedure times were similar between groups (53, IQR 47-63 vs. 55, IQR 49-65min, P = 0.35), but fluoroscopy time was shorter in the vHPSD/HPSD group (3.9 [2.7, 5.6] vs. 11.9 [9.3, 14.9] min, P < 0.001). There were 3 temporary phrenic nerve palsies (5.4%) in the CBA group which resolved within 1year. The 1-year freedom from any atrial tachyarrhythmias after a single procedure was similar between groups (68.5% vs. 73.2%, P = 0.56). During repeat procedure, the durability of PVI was comparable. The use of vHPSD/HPSD ablation renders point-by-point PVI as fast and effective as CBA. Furthermore, it has lower radiation exposure compared to CBA.

Efficacy and Safety of High-Power Short-Duration Ablation for Cavo-Tricuspid Isthmus With a Flexible-Tip Temperature-Controlled Power Regulation Catheter Performed by Electrophysiology Trainees.

The suitability of high-power short-duration (HPSD) cavo-tricuspid isthmus ablation (CTI-Abl) for electrophysiology (EP) trainees, as well as the underlying mechanisms of its efficacy, remain unknown. The aim of this study was to clarify the efficacy and safety of HPSD CTI-Abl performed by EP trainees and assess lesion characteristics between HPSD and moderate-power long duration (MPLD) ablations. Study 1: CTI-Abl was performed by first- to fourth-year EP trainees in consecutive 113 patients (67 ± 11 years, 27.2% female). Study cohort was historically divided into three groups: MPLD (30-35 W for up to 30 s) using TactiCath (TC-MPLD, N = 38) and MPLD and HPSD (50 W for 12 s) using TactiFlex (TF-MPLD, N = 23; TF-HPSD, N = 52). Primary endpoint was first-pass bidirectional isthmus block (BIB). Study 2: lesion geometries created by each ablation strategy were compared using an ex-vivo model. Study 1: TF-HPSD ablation strategy demonstrated a higher success rate of first-pass BIB than MPLD protocol (TC-MPLD, 58%; TF-MPLD, 48%; TF-HPSD, 94%, p < 0.001), without any complications. TF-HPSD group was associated with shorter total procedure and RF application times, as well as fewer ablation points and gaps, compared to the MPLD groups. Study 2: TF-HPSD created greater lesion surface length, width, and area than MPLD strategies. HPSD CTI-Abl performed by EP trainees using TactiFlex SE catheter demonstrated a higher first-pass BIB rate, shorter total procedure and RF application times, and fewer ablation points and gaps compared to the conventional method, without increasing complication rates.

Comparison of exvivo lesion formation for two adjacent radiofrequency applications with very high-power short-duration in various inter-lesion times.

Very high-power and short-duration (vHPSD) ablation with QDOT MICRO™ facilitates speedy and safe ablation for pulmonary vein isolation. A brief time interval between ablating two neighboring sites with vHPSD may potentially influence the size and geometry of the lesions. This study evaluates lesion formation when delivering adjacent applications using vHPSD at various inter-lesion times (ILTs). Radiofrequency applications were conducted by QDOT MICRO™ catheter with 90 W of strength and 4 s duration. Fresh swine heart tissue on the epicardium was ablated with 10 g of the contact force. Lesions were created using a single application (SA) and double applications (DA) of adjacent lesions with a 6 mm distance between them as measured on the 3D mapping system. The DA was performed with various ILTs, 60 s (DA-60 s), 10 s (DA-10 s), 5 s (DA-5 s), and 0 s (DA-0 s). Out of 90 lesions, 79 were analyzed. Eleven lesions were excluded for one steam pop event, seven out of the target distance, and three divided lesions of two applications. There were no significant differences in surface diameter, cross-sectional diameter, and maximal lesion depth in each application among the groups. The intermediate lesion depth was significantly more profound in groups with shorter and immediate ILT (DA-10, 5, and 0 s) compared to the group with a prolonged ILT between two applications (DA-60 s) (2.99, 3.03, 3.16 mm vs. 2.42 mm, respectively; p < .001). Two adjacent radiofrequency applications with vHPSD in short ILT may result in deeper lesions in the middle of combined double lesions.

High-Power Short-Duration Radiofrequency Application for Faster and Safer Pulmonary Vein Isolation: The POWER-FAST III Trial.

The optimal radiofrequency application (RFa) parameters for safe and durable pulmonary vein isolation (PVI) are debated. High-power short-duration (HPSD) has been used as an alternative to conventional power delivery (CPD). This study sought to compare HPSD 70 W/9-10 s (HPSD-70) with CPD 25-40W in patients undergoing PVI. Patients were randomized to HPSD-70 or CPD (25-40). The primary outcomes were freedom from atrial arrhythmia recurrences and the incidence of esophageal thermal lesions (EDELs) after ablation. Among 304 patients randomized, 301 remained in the study (median age: 61 years; Q1-Q3: 53-69 years; 72% men): 294 patients (97.7%) underwent ablation, 285 (94.7%) underwent endoscopy, and 290 (98.6%) completed the follow-up. At 12months, 100 patients (73.5%) in the CPD (25-40) group and 87 patients (67%) in the HPSD-70 group were free from recurrences off antiarrhythmic drugs (HR: 1.28; 95%CI: 0.82-1.99; P=0.28). The incidences of EDELs were 2.7% in the CPD (25-40) group and 3.6% in the HPSD-70 group (P=0.94). Median left atrial dwell (153 vs 137min; P=0.03) and total RF times for definitive PVI (31 vs 11.2min; P< 0.001) were shorter with HPSD-70 ablation. Four symptomatic embolic events (2 strokes, 1 transient ischemic attack, and 1 splenic infarct) occurred with HPSD-70 and none with CPD (25-40) RFa (P=0.056). HPSD-70 RFa was noninferior to prevent arrhythmia recurrences, and the incidence of EDELs was similar compared with CPD (25-40) RFa. The embolic events were numerically higher in the HPSD-70 group. (High Radiofrequency Power for Faster and Safer Pulmonary Vein Ablation Trial [POWER FAST III]; NCT04153747).

Sex differences in overweight and obese patients undergoing high-power short-duration pulmonary vein isolation for atrial fibrillation: an observational cohort study

Atrial fibrillation (AF) is the most common heart rhythm disorder worldwide. As treatment methods evolve, optimizing personalized therapy based on patient characteristics, such as sex, becomes crucial. This study investigates sex differences in high-power short-duration (HPSD) pulmonary vein isolation (PVI) in overweight and obese patients. We analyzed data from 189 overweight and obese patients who underwent HPSD PVI for AF, comparing demographic information, procedural details, outcomes, and complications between male and female patients. Our analysis revealed fewer women underwent PVI compared to men, with women typically older and showing more pronounced changes in the left atrial substrate. Despite these differences, the safety and efficacy of PVI were comparable between sexes, including in the BMI ≥ 30 kg/m2 subgroup and after age adjustment. The findings emphasize the need for early AF screening in women to prevent treatment delays and show that considering sex-specific differences in fat distribution can improve procedural outcomes. These insights support the need for tailored management strategies for AF in overweight and obese populations, addressing sex-specific risks and anatomical variations.

Abstract 4114970: Comparing efficacy and safety between pulsed field ablation, cryoballoon ablation and high-power short duration radiofrequency ablation in atrial fibrillation: A systematic review and Network meta-analysis.

Background: Pulsed field ablation (PFA) and high-power short-duration radiofrequency ablation (HPSD) are emerging techniques for treating atrial fibrillation (AF), offering promising results compared to cryoballoon ablation (CBA). This network meta-analysis aims to evaluates the efficacy and safety of PFA, HPSD, and CBA. Method: PubMed, Embase, Cochrane Central Register of Controlled Trials, and EBSCO Information Services were systematically searched for relevant studies until April 2024. The primary outcome is freedom from atrial arrhythmia. A random-effects model was used for data synthesis, and P-scores were employed for outcome ranking. Point estimation (odd ratios) was calculated for comparisons. Results: Fifteen studies were included in our network meta-analysis, involving 5,093 atrial fibrillation patients: 812 (16%), 2,659 (52%), and 1,622 (32%) patients underwent PFA, CBA, and HPSD, respectively. PFA demonstrated the highest efficacy (P-scores 99.3%). Point estimation between PFA and HPSD, and PFA and CBA, were 1.394 (95% CI: 1.047-1.858) and 1.479 (95% CI: 1.134–1.929), respectively. PFA had higher complications compared to HPSD (OR=4.44, 95% CI: 1.405-14.031) and CBA (OR=2.581, 95% CI: 0.992–6.720). HPSD had the shortest fluoroscopic time (P-scores 100%), while CBA had the longest (P-scores 0%). PFA had the shortest procedural time compared to CBA and HPSD with P-scores of 100% 50% and 0%, respectively. Conclusion: PFA showed higher efficacy but higher complication risk than HPSD and CBA. HPSD and CBA demonstrated similar efficacy and safety.

Temperature guided high and very high-power short duration ablation for atrial fibrillation treatment - The peQasus multicentre study.

Temperature-controlled high-power short-duration (HPSD) radiofrequency catheter ablation for pulmonary vein isolation (PVI) utilizing a novel ablation catheter (QDOT Micro) with real-time assessment of catheter tip temperature aims for safer, more effective and faster procedures. The peQasus study is a large European multicenter study set up to assess safety, acute efficacy and outcomes of temperature-controlled HPSD based PVI. The primary endpoints were safety, efficacy and 12-months freedom from atrial tachyarrhythmias. Additionally, two strategies namely very HPSD (90W for 4 seconds) only and a hybrid approach (HPSD with maximum of 50W and vHPSD) were compared. A total of 1,023 AF patients in 15 centers from 9 European countries received PVI with the QDOT. Complete PVI was successfully achieved in all patients. In 699/1023 (68.3%) the vHPSD only approach (vHPSD group) and in 324/(31.7%) patients the hybrid approach (hybrid group) was utilized. The mean procedure duration was 98.4±37.4 min (vHPSD: 88.2±34.9min, hybrid: 117.4±32.7min, p<0.001). The first pass isolation rate of all PVs was 64% (vHPSD: 62.6%, hybrid: 67.1%, p=0.187). Severe adverse events were observed in 1.7% (vHPSD: 1.6%, hybrid: 1.9%, p=0.746). 12-month arrhythmia-recurrence free survival was 77.1% (vHPSD: 76.8%, hybrid: 77.8%, p=0.241). In this large multicentre study temperature-controlled HPSD and vHPSD ablation via a novel ablation catheter provides safe and effective PVI with a relatively short procedure duration. Despite a shorter procedure time no differences in terms of safety and freedom from arrhythmia-recurrence were found irrespective of utilizing vHPSD or the hybrid approach.

Significance of the local largest bipolar voltage for the optimized ablation strategy using very high-power short duration mode.

Very high-power short-duration (vHPSD) ablation creates shallower lesions, potentially reducing efficacy. This study aims to identify factors leading to insufficient lesions during pulmonary vein antral isolation (PVAI) with vHPSD-ablation and to develop an optimized PVAI strategy using this technology. PVAI was performed on 41 atrial fibrillation patients using vHPSD-ablation (90 W/4 s). Lesion parameters were recorded and analyzed to identify predictors of insufficient lesions. An optimized PVAI strategy, based on these predictors, was tested in subsequent 42 patients. In total, 3099 RF-applications, including 103(3.3%) insufficient lesions, were analyzed. First-pass PVAI was achieved in 19/40(47.5%) right PVs and 24/41(58.5%) left PVs. Multivariate analysis identified significant predictors of insufficient lesions: local largest bipolar voltage (Bi-V), average contact force, baseline impedance, impedance drop, temperature rise, inter-lesion distance (ILD), and anatomical location (carina or not). An ILD:4-6 mm increased the risk of insufficient lesions 2.2-fold, and lesions at the carina increased it 3.6-fold for both ILD < 4 mm and ILD:4-6 mm. Local largest Bi-V was the strongest predictor for insufficient lesions. The optimized PVAI approach, utilizing vHPSD-ablation with an ILD < 4 mm in non-carinal areas with Bi-V < 4 mV, and high-power ablation-index guided ablation (HPAI, 50 W, ablation-index:450-550) in remaining areas, achieved first-pass PVAI in 92.7% of right PVs and 88.1% of left PVs, using vHPSD-ablation in approximately 65% of total RF-applications. The optimized PVAI achieved significantly higher first-pass PVI rate (p < .0001) with shorter ablation time (p = .04). Appropriate use of vHPSD and HPAI, based on local largest Bi-V and anatomical information, may achieve high first-pass PVAI rates in shorter ablation time with minimal energy delivery.

High Power Short Duration Atrial Fibrillation Ablation: Long-Term Predictors of Success and Recurrence - A Multivariate Analysis.

Point-by-point ablation with a high-power short-duration (HPSD) technique in atrial fibrillation (AF) ablation is used worldwide. Little data is available with the HPSD and dragging technique (DT). To perform a multivariate analysis of clinical and procedural predictors of success and recurrence in HPSD with DT. 214 patients in the first AF ablation in sinus rhythm were prospectively enrolled. DT with radiofrequency power of 50 W and contact force (CF) of 10-20 g and 5-10 g at a flow rate of 40 mL/min were applied on the anterior and posterior walls, respectively. Statistical significance was defined as p < 0.05. 143 (66.8%) males, paroxysmal AF (PAF) in 124 (57.9%), with 61.1±12.3 years and followed for 32.8±13.2 months. After 90 days, AF occurred in 43 (20.1%) patients, 19 (15.3%) from PAF, and 24 (26.7%) in persistent AF (PersAF). Multivariate analysis indicated as clinical predictors of recurrence: age ≥ 65 years (p=0.006); obesity [body mass index > 30 (p=0.009)]; CHA2DS2VASC score ≥ 3 (p=0.003); and PersAF (p=0.045). The procedural predictor of recurrence was a heart rate increase < 10% (p=0.006). Predictors of success were an increase in heart rate ≥ 30% (p=0.04) and < 60 min in left atrium time (LAT) (p=0.007). AF ablation with DT and HPSD clinical and procedural predictors of recurrence were ≥ 65 years, obesity, a CHA2DS2VASC ≥ 3, PersAF, and a heart rate increase of < 10% after ablation. Success predictors were an increase of ≥ 30% in heart rate and low LAT (< 60 min).

High-frequency very low-tidal volume ventilation during very high-power short-duration ablation for pulmonary vein isolation. A case series of patients with atrial fibrillation.

High-frequency very low-tidal volume ventilation during very high-power short-duration ablation for pulmonary vein isolation. A case series of patients with atrial fibrillation.

Impact of combining ablation index-guided and very high-power short-duration ablation at posterior wall adjacent to esophagus during perioperative period on procedural factors.

The impact of combining ablation index (AI)-guided and very high-power short-duration (vHPSD) ablation on procedural factors at the posterior wall near the esophagus is unclear. Atrial fibrillation patients who underwent initial ablation using three-dimensional mapping were enrolled. Patients were classified into two groups: those who underwent only AI-guided pulmonary vein isolation (PVI) (AI group) and those who underwent vHPSD ablation at the posterior wall adjacent to the esophagus in addition to AI-guided PVI (AI + vHPSD group). Differences in myocardial injury, inflammation, procedural characteristics, and pulmonary vein (PV) reconnection patterns were assessed between the two groups. This study included 167 patients (AI group, 83 patients; AI+vHPSD group, 84 patients). No significant differences in high-sensitive troponin I or changes in inflammatory markers between pre- and Postablation were observed in either group. Total application time and total application energy were significantly lower in the AI+vHPSD group than in the AI group (p < 0.001 for both) despite no significant difference in the total number of applications between the groups. The incidence of esophagus temperature ≥40 degrees was significantly lower in the AI+vHPSD group than in the AI group (p = 0.036). However, the incidence of PV reconnections near the esophagus was significantly higher in the AI+vHPSD group than in the AI group (11.9% vs 3.6%, p = 0.046), despite no significant difference in the incidence of PV reconnections overall. The combination of AI-guided PVI and vHPSD adjacent to the esophagus demonstrated reduced application energy requirements and maintained safety and effectiveness during the perioperative period.

Comparing cerebral microembolisation patterns between high power short duration and pulsed field ablation techniques using artificial intelligence based robotic transcranial doppler monitoring

Abstract Thromboembolism is a rare (&amp;lt;1%) complication of atrial fibrillation (AF) ablation , but the incidence of silent ischaemic lesions (SIL) is 5-15% (1). Artificial intelligence (AI)-based robotic transcranial Doppler (r-TCD) enables real-time cerebral embolisation detection. We aimed to investigate the cerebral microembolization signal (MES) load with r-TCD of patients undergoing PF ablation, comparing the number of detected MES-s between 90 W radiofrequency (RFA) "very high power short duration (vHPSD) ablation" and "pulsed field ablation (PFA)" techniques. Our interim analysis included r-TCD registratums of 26 patients. 16 interventions were performed with VHPSD, 10 with PFA, during which we recorded the flow curve of the arteria cerebri media (ACM) bilaterally with r-TCD and analyzed the MES-s quantitatively and qualitatively with AI-based embolisation detection software. Postoperative cranial MRI exams were performed. Continuous variables were compared between the groups using a two-sample t-test, and categorical variables were compared using a Fisher exact test. The MES load by the different pulmonary veins was compared using Wilcoxon test and Bonferroni correction. A p-value below 0,05 was considered significant. The two groups were comparable regarding baseline parameters (mean age: 63 vs.58 p=0,253; EF:59% vs.62 .2% p=0,33). Ablations with vHPSD were significantly longer compared to PFA (88,7 min vs. 54,7 min p&amp;lt;0,001), left atrial time was significantly shorter with PFA (52,1 min vs. 29 min p&amp;lt;0 001), but the fluoroscopic time was significantly longer (5,4 min vs. 9,3 min p=0,009) during ablation with PFA. Neither solid emboli, nor ischaemic lesion or neurological deficit was detected. During the ablations, we saw an average of 246 gas MES-s with PFA and 138 with RFA (p=0,216). During PFA we analyzed the MES load per pulmonary vein: by the left superior vein we detected a median of 56,5 (IQR: 21,5-116,5), by the left inferior there were a median of 23 MES-s (IQR: 4,5 115,5), by the right inferior a median of 32 (IQR: 12-84,5), and by the right superior a median of 22,5(IQR: 8,5-70) respectively, p=0,03. While comparing each veins to each other, by the right vs. left superior vein, the p value resulted 0,01. On an initial sample,we detected known differences in the procedural parameters of the two interventions. There tended to be more MES-s during PFA, but this difference was not significant. Regarding the MES load by the ablation of different pulmonary veins, we found a significant overall difference between the MES load by the four veins, especially between the left and right superior vein. A larger number of interventions and r-TCD registratums is needed to determine the cerebral safety of PFA compared to RFA.

Atrial fibrillation ablation with temperature-controlled very high-power short-duration, with conventional-power, or with combined modes in clinical practice: 12-month outcomes from SECURE

Abstract Background/Introduction QDM is a contact force-sensing catheter optimized for temperature-controlled radiofrequency ablation in very high-power short-duration (vHPSD; 90 W/4 s), conventional-power (CP; ≤50 W), or vHPSD/CP combined modes. Purpose Evaluate 12-month (M) safety and effectiveness of atrial fibrillation (AF) ablations performed with 3 different ablation modes using the QDM catheter, a frequently used single tip catheter in Europe. Methods SECURE is an observational, prospective, post-market study collecting data on procedures performed per standard-of-care with up to 12M follow-up, in 16 enrolling sites in 8 countries across Europe and Israel. Index pulmonary vein (PV) isolation procedures are reported here. The primary safety endpoint is the incidence of primary adverse events (PAEs); the primary effectiveness endpoint is PV isolation (entrance block) of targeted PVs. Additional endpoints include acute reconnections, incidence of char and steam pop, 12M recurrence, repeat ablation, and healthcare utilization (HCU). Ablation strategy, impedance drop, and catheter stability were analysed with a cloud-based data management and artificial intelligence-powered algorithm. Results Since Feb 2021, 291 patients (70% male, 61±11 yrs, CHA2DS2-VASc 1.9±1.5) completed 12M follow-up in 11 sites. Most patients (175 [60.1%]) were treated for paroxysmal (PAF), 85 (29.2%) for persistent (PsAF), and 31 (10.7%) for long-standing persistent (LsPsAF) AF, under general anaesthesia (44.0%) or sedation (55.7%). A combined workflow was used in 66.0% of ablations, while vHPSD-only and CP-only were used in 13.4% and 20.6% of cases, respectively. Four (1.4%) patients reported a PAE; all resolved, and none were catheter related. Acute effectiveness was achieved in all targeted veins; 5.0% of PVs had acute reconnections, with the most common being the left superior PV. No steam pops were reported; 2 counts of char were noted in PsAF ablations with combined modes. Freedom from documented recurrence were 95.8% for PAF, 88.1% for PsAF, and 73.5% for LsPsAF (Fig 1). Freedom from repeat ablation post-blanking and freedom from cardioversion were both 96.8%. Cardiovascular hospitalization and emergency room visits decreased by 65.3% and 76.5% from 12M pre- to 12M post-procedure, respectively. Application-level analyses showed larger impedance drop and greater catheter stability with vHPSD. In procedures using a combined workflow, vHPSD was used preferentially for most PV segments, except anteriorly on the left wide area circumferential ablation (Fig 2). Conclusions Real-world data demonstrates that AF ablation with the QDM catheter is safe and effective with a low PAE rate, high 12M effectiveness, and reduced HCU. Most procedures were done with combined modes, where vHPSD was used preferentially, except at left anterior thicker regions. Larger impedance drop and greater catheter stability were observed with vHPSD applications.

Procedural outcomes of fluoroscopy-less catheter ablation for atrial fibrillation

Abstract Background Radiofrequency catheter ablation is superior therapy to antiarrhythmic drugs for maintaining sinus rhythm in atrial fibrillation (AF) patients. Traditional fluoroscopy-guided AF ablation poses risks of prolonged radiation exposure for both patients and medical staff. Recent advancements in fluoroscopy-less catheter ablation techniques offer potential solutions, but comprehensive data on their effectiveness and safety are lacking. Purpose To evaluate the procedural outcomes and safety of fluoroscopy-less catheter ablation for AF compared to fluoroscopy-guided ablation. Methods Retrospective observational study of consecutive AF ablations (N=881) conducted at a university teaching hospital (Hamilton Health Sciences, Hamilton, Ontario) from November 2017 to September 2022. An electro-anatomical mapping system and ICE was used in all cases. Baseline characteristics and procedural outcomes between the fluoroscopy-less and fluoroscopy-guided groups were compared. Cases that used &amp;lt;60 seconds of fluoroscopy (occasionally used by operators during the placement of an esophageal probe) were included in the fluoroscopy-less group (N= 68). Results Mean age of individuals was 60.6 ± 11 years, 71.7% were male, 72.6% had paroxysmal AF, mean CHA2DS2-VASc score was 1.6 ± 1.4, 11.1% had prior heart failure, and mean left ventricular ejection fraction was 57.5 ± 15%. There were no significant differences in patient baseline characteristics between the fluoroscopy-less and fluoroscopy groups. Total procedure and fluoroscopy times were lower in the fluoroscopy-less group compared to the fluoroscopy-guided group (169.3 ±42 minutes vs. 192.1 ±54 minutes, p&amp;lt;0.0001 and 0.024 ±0.10 vs. 10.0 ±7.4 minutes , p&amp;lt;0.0001). Fluoroscopy-less AF ablation remained an independent predictor of lower procedure times following adjusting for the use of general anesthesia, high-power short-duration, presence of trainees, AF pattern, redo cases, and type of mapping system. Complication rates were similar between fluoroscopy-less and fluoroscopy-guided ablation (1.9% vs. 3.8%, p=0.11). Conclusion Fluoroscopy-less catheter ablation for AF appears to have similar procedural outcomes and safety than fluoroscopy-guided AF ablation.

Early ablation leads to better outcome in patients < 55 years with persistent atrial fibrillation

The question of optimal timing for catheter ablation of atrial fibrillation (AF) to achieve best outcomes remains a crucial clinical issue. As AF occurs less frequently in younger patients, data regarding Diagnosis-to-Ablation Time (DAT) is especially limited in patients under the age of 55 years with persistent AF. We therefore analyzed the temporal relationship between initial AF presentation and timing of catheter ablation in this cohort. We conducted a retrospective single-centre study of patients ≤ 55 years with persistent AF who underwent first-time catheter ablation at our center. The cohort was divided into patients that underwent catheter ablation after diagnosis of persistent AF within a DAT of ≤ 12 months and patients with a DAT of > 12 months. A total of 101 patients (median age 51 years; female n = 19 (18.8%)) with persistent AF were included. Ablation was performed within 12 months (“early DAT”) in 51 patients and > 12 months (“late DAT”) in 50 patients. Pulmonary vein isolation was performed using high-power short-duration (HPSD) radiofrequency ablation. Median DAT was 5 months (1–12 months) in the early ablation group and 36 months (13–240 months) in the late ablation group. The median follow-up was 11.3 months (0.03–37.1 months). The rate of any atrial arrhythmia recurrence after a 30-day blanking period was significantly lower in the early DAT group (13/51 patients; 25.5%) as compared to the late DAT group (26/50 patients; 52.0%) (log rank test; p = 0.003). Catheter ablation performed > 12 months after the initial AF diagnosis was an independent predictor for the occurrence of any atrial arrythmia (OR: 2.58; (95%-CI: 1.32–5.07). Early first-time catheter ablation (DAT ≤ 12 months) in patients ≤ 55 years with persistent AF is associated with a significantly lower rate of arrhythmia recurrence.

High-power short-duration setting prevents changes of periprocedural thrombotic markers and the onset of silent stroke in patients with atrial fibrillation

BackgroundIt remains unclear whether the newly adopted high-power/short duration (HP-SD) setting in ablation for atrial fibrillation (AF) impacts periprocedural thrombotic markers or silent stroke (SS) onset. ObjectiveThe aim of the present study is to investigate the clnical impact of HP-SD setting ablation on changes in periprocedural thrombotic markers and the onset of SS. MethodsWe enrolled 101 AF patients: the HP-SD group (n =67) using 50W; and the 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 the day before, immediately after and 1 day after the procedure. Magnetic resonance imaging was performed within 48 hours after the procedure. ResultsLeft atrial (LA) dwelling time was significantly shorter in the HP-SD group (P<0.05). In the conventional ablation group, the D-dimer and tPAI-1 levels continued to increase until 1 day post preocedure, while the TAT peaked immediately after the ablation. On the other hand, the range of the variation of these thrombotic markers in the HP-SD group was smaller. SS occurred more frequently in the conventional ablation group than in the HP-SD group (26% vs 5%, P<0.05). In the logistic regression analysis, the HP-SD setting and TAT difference (post – pre-procedure) were independent predictors for SS (odds ratio: 0.141 and 5.838, P<0.05, respectively). ConclusionsThe HP-SD setting led to a shorter LA dwelling time and reduced change in thrombotic markers, resulting in lower prevalence of SS.

Lesion characteristics using high-frequency low-tidal volume ventilation versus standard ventilation during ablation of paroxysmal atrial fibrillation.

High-frequency low-tidal-volume (HFLTV) ventilation during radiofrequency catheter ablation (RFCA) for paroxysmal atrial fibrillation (PAF) has been shown to be superior to standard ventilation (SV) in terms of procedural efficiency, acute and long-term clinical outcomes. Our study aimed to compare ablation lesions characteristics utilizing HFLTV ventilation versus SV during RFCA of PAF. A retrospective analysis was conducted on patients who underwent pulmonary vein isolation (PVI) for PAF between August 2022 and March 2023, using high-power short-duration ablation. Thirty-five patients underwent RFCA with HFLTV ventilation and were matched with another cohort of 35 patients who underwent RFCA with SV. Parameters including ablation duration, contact force (CF), impedance drop, and ablation index were extracted from the CARTONET database for each ablation lesion. A total of 70 patients were included (HFLTV = 35/2484 lesions, SV = 35/2830 lesions) in the analysis. There were no differences in baseline characteristics between the groups. While targeting the same ablation index, the HFLTV ventilation group demonstrated shorter average ablation duration per lesion (12.3 ± 5.0 vs. 15.4 ± 8.4 s, p < .001), higher average CF (17.0 ± 8.5 vs. 10.5 ± 4.6 g, p < .001), and greater impedance reduction (9.5 ± 4.6 vs. 7.7 ± 4.1 ohms, p < .001). HFLTV ventilation group also demonstrated shorter total procedural time (61.3 ± 25.5 vs. 90.8 ± 22.8 min, p < .001), ablation time (40.5 ± 18.6 vs. 65.8 ± 22.5 min, p < .001), and RF time (15.3 ± 4.8 vs. 22.9 ± 9.7 min, p < .001). HFLTV ventilation during PVI for PAF was associated with improved ablation lesion parameters and procedural efficiency compared to SV.

Comparative analysis of recurrence predictors and outcomes for atrial tachyarrhythmia following atrial fibrillation ablation: high-power short-duration vs. conventional pulmonary vein isolation.

Atrial fibrillation (AF) is a common cardiac arrhythmia, with structural and electrical remodeling being significant risk factors for recurrence post-catheter ablation. The advent of high-power short-duration pulmonary vein isolation (HPSD-PVI) presents a novel approach, potentially enhancing procedural success rates through the creation of transmural lesions without overheating. This study investigates the predictors of atrial tachyarrhythmia (ATA) recurrence and compares outcomes between HPSD-PVI and conventional PVI techniques. A total of 1005 patients undergoing radiofrequency catheter ablation (RFA) for AF were retrospectively analyzed in this study. The cohort was divided based on the ablation strategy: conventional PVI from February 2013 to September 2018, and HPSD-PVI from October 2018 onwards. The primary objective was to compare the predictors of ATA recurrence and the outcome between the two groups. Among 969 patients analyzed after exclusions, independent predictors of recurrence differed between groups; higher CHADS2/CHA2DS2-VASc scores and lower left ventricular ejection fraction (LVEF) were significant in the HPSD-PVI group, while non-paroxysmal AF, larger left atrial volume index (LAVI), and longer AF history were predictors in the conventional PVI group. The HPSD-PVI group showed a trend toward lower ATA recurrence rates compared to the conventional PVI group in the propensity-score-matched (PSM) cohort (log-rank test, p = 0.06). Higher CHADS2/CHA2DS2-VASc scores and lower LVEF were also independent predictors of ATA recurrence in the PSM cohort.