First-pass Isolation Research Articles

Importance of the relative epicardial connection locations and right-sided pulmonary vein isolation line for successful pulmonary vein isolation.

The presence of an epicardial connection (EC) decreases the success rate of pulmonary vein isolation (PVI); however, the effect of designing isolation lines has not been evaluated. We sought to clarify the effects of designing an anterior line for right-sided PVI considering the presence and location of the EC. Seventy-four consecutive patients who underwent initial catheter ablation for atrial fibrillation were retrospectively included in this study. The presence of the EC was determined by the left atrial (LA) activation map during right atrial pacing, and patients were divided into EC-positive (n = 23, 31%) and EC-negative (n = 51, 69%) groups. EC-positive patients were further subdivided based on the EC location: on-the-line group, (EC on the PVI line, n = 11); inside-line group (EC on the pulmonary vein [PV]side, n = 10); and outside-line group (EC on the LA side, n = 2). The PVI parameters were compared among the three groups. The success rates of the first-pass isolation were comparable between the EC-negative and EC-positive groups (70.6% vs. 60.9%, ns), but the success rate was significantly higher in the on-the-line group than in the inside-line group (91% vs. 20%, p = 0.002). First-pass isolation was successful in both patients in the outside-line group. Additional carina ablation was required only in the inside-line group. The association between the EC site and the right-sided PV anterior isolation line affected the success rate of first-pass isolation. For successful right-sided PVI, it is important to consider the EC site when designing the PVI line.

Network meta-analysis and systematic review comparing efficacy and safety between very high power short duration, high power short duration, and conventional radiofrequency ablation of atrial fibrillation.

High-power short-duration (HPSD) atrial fibrillation (AF) ablation with a power of 40-50 W was proved to be safe and effective. Very high-power short-duration (vHPSD) AF ablation is a novel method using >50 W to obtain more durable AF ablation. This study aimed to evaluate the efficacy and safety of vHPSD ablation compared with HPSD ablation and conventional power ablation. A literature search for studies that reported AF ablation outcomes, including short-term freedom from atrial arrhythmia, first-pass isolation (FPI) rate, procedure time, and major complications, was conducted utilizing MEDLINE, EMBASE, and Cochrane databases. All relevant studies were included in this analysis. A random-effects model of network meta-analysis and surface under cumulative ranking curve (SUCRA) were used to rank the treatment for all outcomes. A total of 29 studies with 9721 patients were included in the analysis. According to the SUCRA analysis, HPSD ablation had the highest probability of maintaining sinus rhythm. Point estimation showed an odds ratio of 1.5 (95% confidence interval [CI]: 1.2-1.9) between HPSD ablation and conventional power ablation and an odds ratio of 1.3 (95% CI: 0.78-2.2) between vHPSD ablation and conventional power ablation. While the odds ratio of FPI between HPSD ablation and conventional power ablation was 3.6 (95% CI: 1.5-8.9), the odds ratio between vHPSD ablation and conventional power ablation was 2.2 (95% CI: 0.61-8.6). The procedure times of vHPSD and HPSD ablations were comparable and, therefore, shorter than that of conventional power ablation. Major complications were low in all techniques. vHPSD ablation did not yield higher efficacy than HPSD ablation and conventional power ablation. With the safety concern, vHPSD ablation outcomes were comparable with those of other techniques.

Very High-Power Ablation for Contiguous Pulmonary Vein Isolation: Results From the Randomized POWER PLUS Trial

BackgroundVery high-power, short-duration (90-W/4-second) ablation for pulmonary vein isolation (PVI) may reduce procedural times. However, shorter applications with higher power may impact lesion quality. ObjectivesIn this multicenter, randomized controlled trial, the authors compared procedural efficiency, efficacy, and safety of PVI using 90-W/4-second ablation to 35/50-W ablation. MethodsPatients with paroxysmal or persistent atrial fibrillation undergoing first-time PVI were randomized to pulmonary vein encirclement with contiguous applications using very high-power, short-duration applications (90 W over 4 seconds) or 35/50-W applications (titrated up to ablation index >550 anteriorly and >400 posteriorly). Prospective endpoints were procedural efficiency (procedure time and first-pass isolation), safety (including esophageal endoscopic evaluation), and 6-month effectiveness using repetitive Holter monitoring. ResultsA total of 180 patients were randomized, 90 to the 90-W group (mean age: 64.2 ± 8.9 years) and 90 to the 35/50-W group (mean age: 62.3 ± 10.8 years). Procedural time was shorter in the 90-W group vs the 35/50-W group (70 [IQR: 60-80] minutes vs 75 [IQR: 65-88.3] minutes; P = 0.009). A nonsignificant trend towards lower rates of first-pass isolation was seen in the 90-W group (83.9% vs 90%; P = 0.0852). No major complications were observed in both groups with esophageal injury occurring in 1 patient per group. At 6 months, 17% of patients in the 90-W group vs 15% in the 35/50-W group experienced recurrent arrhythmia (P = 0.681). ConclusionsContiguous ablation using very high-power, short-duration applications results in a significant but modest reduction in procedure time with similar safety and 6-month efficacy vs a conventional approach. A hybrid approach combining both ablation modalities might be the most optimal strategy. (POWER PLUS [Very High Power Ablation in Patients With Atrial Fibrillation Schedule for a First Pulmonary Vein Isolation]; NCT04784013)

Very high-power short-duration ablation for pulmonary vein isolation utilizing a very-close protocol-the FAST AND FURIOUS PVI study.

The very high-power short-duration (vHP-SD) radiofrequency (RF) ablation concept of atrial fibrillation (AF) treatment by pulmonary vein isolation (PVI) aims for safer, more effective, and faster procedures. Utilizing conventional ablation, the 'close protocol' has been verified. Since lesion formation of vHP-SD ablation creates wider but shallower lesions we adapted the close protocol to an individualized and tighter 'very-close protocol' of 3-4 mm of inter-lesion distance (ILD) at the anterior and 5-6 mm at the posterior aspect of the left atrium using vHP-SD only. Here, we evaluated the safety and efficacy of vHP-SD ablation for PVI utilizing a very-close protocol in comparison with standard ablation. A total of 50 consecutive patients with symptomatic AF were treated with a very-close protocol utilizing vHP-SD (vHP-SD group). The data were compared with 50 consecutive patients treated by the ablation-index-guided strategy (control group). The mean RF time was 352 ± 81 s (vHP-SD) and 1657 ± 570 s (control, P < 0.0001), and the mean procedure duration was 59 ± 13 (vHP-SD) and 101 ± 38 (control, P < 0.0001). The first-pass isolation rate was 74% (vHP-SD) and 76% (control, P = 0.817). Severe adverse events were reported in 1 (2%, vHP-SD) and 3 (6%, control) patients (P = 0.307). A 12-month recurrence-free survival was 78% (vHP-SD) and 64% (control, P = 0.142). PVI durability assessed during redo-procedures was 75% (vHP-SD) vs. 33% (control, P < 0.001). PVI solely utilizing vHP-SD via a very-close protocol provides safe and effective procedures with a high rate of first-pass isolations. The procedure duration and ablation time were remarkably low. A 12-month follow-up and PVI durability are promising.

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

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

Impact of high-power and very high-power short-duration radiofrequency ablation on procedure characteristics and first-pass isolation during pulmonary vein isolation

Abstract Introduction High-power short-duration (HPSD) radiofrequency ablation has been proposed as a method for producing rapid and effective lesions for pulmonary vein isolation (PVI). We aimed to evaluate the procedural characteristics and the first-pass isolation (FPI) rate of HPSD and very high-power short-duration (vHPSD) ablation compared to low-power long-duration (LPLD) ablation technique. Methods 156 patients with atrial fibrillation (AF) were enrolled and assigned to LPLD, HPSD, or vHPSD PVI. The energy setting was 30W, 50W, and 90W in the LPLD, HPSD, and vHPSD groups, respectively. Results Bilateral PVI was achieved in all cases. The procedure time was 85 [75–101] min, 79 [65–91] min, and 70 [53–83] min in the LPLD, HPSD, and vHPSD groups, respectively (p&amp;lt;0.0001). Left atrial (LA) dwelling times were also decreased significantly with the increase of RF energy (61 [55–70] min, 53 [41–56] min, and 45 [34–52] min, in the LPLD, HPSD, and vHPSD groups, respectively, p&amp;lt;0.0001). The total RF ablation time was 1567 [1366–1761] sec, 1398 [1021–1711] sec, and 336 [247–386] sec in the LPLD, HPSD, and vHPSD group, respectively (p&amp;lt;0.0001). The bilateral FPI rate was 57%, 78%, and 80% in the LPLD, HPSD, and vHPSD groups, respectively (p=0.0097). On the left side, FPI was achieved in 66% in the LPLD, 92% in the HPSD, and 85% in the vHPSD ablation group (p=0.0015). FPI on the right side was achieved in 72% in the LPLD, 88% in the HPSD, and 88% in the vHPSD ablation group (p=0.0188). The univariate analysis revealed that the use of HPSD (both sides: OR=2.72, 95% CI 1.15–6.44, p=0.023; right side: OR=2.90, 95% CI 1.02–8.20, p=0.045; left side: OR=5.91, 95% CI 1.84–19.04, p=0.003) and vHPSD (both sides: OR=2.90, 95% CI 1.24–6.44, p=0.014; right side: OR=3.09, 95% CI 1.09–8.74, p=0.045; left side: OR=2.89, 95% CI 1.13–7.43, p=0.027) ablation techniques were associated with a higher probability of FPI. The mid-term arrhythmia-free survival was similarly high in all three groups. Conclusion Our prospective, observational cohort study showed that both HPSD and vHPSD RF ablation is effective, as it shortens procedure time and RF time and results in a higher rate of FPI compared to LPLD ablation. Moreover, the mid-term arrhythmia-free survival was similarly high in all three groups. In our study, no safety concerns were raised for HPSD or vHPSD ablation. Funding Acknowledgement Type of funding sources: None.

Composite Index Tagging for PVIinParoxysmal AF: A Prospective, Multicenter Postapproval Study.

VISITAG SURPOINT (VS)-guided ablation of paroxysmal atrial fibrillation has demonstrated good short- and long-term success rates with low rates of complications in recent, predominantly European, studies. However, there is a lack of multicenter data from the United States. This U.S. study evaluated the safety and effectiveness of VS ablation using a contact force-sensing catheter for the treatment of drug-refractory symptomatic paroxysmal atrial fibrillation. The prospective, nonrandomized VS postapproval study was conducted at 32 U.S. sites. Ablation consisted of pulmonary vein isolation with recommended VS index targets (anterior, roof, or ridge: 550; posterior or inferior: 380). Additional non-pulmonary vein triggers were ablated at the investigators' discretion. Subjects were followed for 12months, including a 3-month blanking period. The primary safety endpoint was the primary adverse event rate up to 7days postablation. The primary effectiveness endpoint was 12-month freedom from atrial tachyarrhythmia recurrence and an additional set of failure modes based on stringent monitoring (weekly transtelephonic monitoring [TTM] [day 91 through month 5], monthly TTM [months 6 to 12], and any symptomatic cardiac episode using TTM, plus electrocardiogram [atdischarge, 1month, 3months, 6months, and 12months] with 24-hour Holter monitoring [12months]). Of 283 patients enrolled, 261 had the catheter inserted and underwent ablation (safety cohort); 246 metall eligibility criteria (effectiveness cohort). Mean fluoroscopy time was 2.2minutes. Mean amount of catheter-delivered fluid was 671mL; only 18.0% of patients utilized a Foley catheter. Primary safety and effectiveness endpoints were met. The raw primary adverse event rate was 4.3% (14 events, n=11). At 12months, the Kaplan-Meier estimate of freedom from primary effectiveness failure was 76.4%; estimates of 12-month freedom from documented atrial fibrillation, atrial tachycardia, or atrial flutter recurrence were 81.5% and 92.7% per stringent monitoring and standard-of-care monitoring (excluding TTM), respectively. The first-pass isolation rate was 83.1%, represented by no acute reconnection after the 30-minute waiting period. Freedom from repeat ablation at 12months was 94.0%. The VS postapproval study confirms reproducibility of clinical safety and effectiveness of the standardized VS paroxysmal atrial fibrillation ablation workflow with &gt;80% 12-month freedom from atrial tachyarrhythmia recurrence and first-pass isolation rate of 83.1%. Procedures were performed with minimal fluoroscopy. (Evaluation of VISITAG SURPOINT™ Module With External Processing Unit [EPU]; NCT03624881).

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.

Procedural Efficiency, Efficacy, and Safety of High-Power, Short-Duration Radiofrequency Ablation Delivered by STSF Catheter for Paroxysmal Atrial Fibrillation.

Objectives To investigate the procedural efficiency, efficacy, and safety of high-power, short-term radiofrequency ablation delivered by the SmartTouch Surround Flow (STSF) catheter for paroxysmal atrial fibrillation (AF). Methods We retrospectively analyzed a total of 72 patients who were admitted with paroxysmal AF, and who underwent radiofrequency catheter ablation (RFCA) for the first time. Of these patients, 36 cases underwent low-power, long-duration (LPLD, (30–35 W/20–40 s) pulmonary vein isolation (PVI) delivered by an SmartTouch (ST) catheter (control group), and the other 36 cases underwent high-power, short-duration (HPSD, (45–50 W/10–20 s) PVI delivered by a STSF catheter (study group). The baseline data, duration of PVI, procedural time, fluoroscopy time, the rate of first-pass isolation, irrigation perfusion, eschar and steam pop occurrences, intraoperative complications, and the rate of stable sinus rhythm maintenance following a blanking period of three months were analyzed between the two groups. Results The isolation time of bilateral PVI and procedural time in the study group were markedly less than in controls (p < 0.01). The rate of first-pass isolation in the study group was significantly higher than in the control group (95.8% vs. 84.7%, p = 0.023), while the fluid perfusion in the study group was approximately 20% less than that in the control group (767 ± 171 vs. 966 ± 227 ml, p < 0.001). We observed no severe complications in any patients. The rate of freedom from AF recurrences following a blanking period of three months showed a tendency to be higher than in controls (93.9% vs. 87.1%, p = 0.348). Conclusions The HPSD strategy delivered by the STSF catheter was superior to conventional LPLD ablation through the ST catheter with respect to efficiency, acute procedural effectiveness, short-term safety, and the risk of heart failure in patients with paroxysmal AF.

Ablation index-guided ablation with milder targets for atrial fibrillation: Comparison between high power and low power ablation.

BackgroundHigh power-ablation index (HP-AI)-guided ablation for atrial fibrillation (AF) targeting high AIs has been implemented in European countries. However, milder AI targets are widely used in Asia. The safety and efficacy of HP-AI-guided ablation compared with those of low-power AI-guided ablation in a milder AI-targeting setting are unknown. The goal of this study was to explore the efficacy and safety of HP-AI-guided ablation in a milder AI-targeting setting.MethodsPatients who underwent pulmonary vein isolation (PVI) for AI-guided atrial fibrillation ablation in our center were enrolled and divided into 2 groups according to the ablation power used. In the HP-AI group, the ablation power was over 45 W, while the low power-AI group was ablated with <35 W power. The targeted AIs were 450–500 in the anterior wall and 350–400 in the posterior wall. The efficacy outcome was expressed as the single-procedure atrial arrhythmia-free survival between 91 days and 1 year. Safety outcomes included severe adverse events (SAEs), including symptomatic pulmonary vein (PV) stenosis, atrioesophagal fistula, cardiac tamponade, stroke, thromboembolism events, myocardial infarction, and major bleeding.ResultsA total of 134 patients were enrolled, of whom 74 underwent PVI using HP-AI, while 60 received low power-AI ablation. After a mean follow-up time of 7.4 months, 22 (16.4%) patients showed arrhythmia recurrence: 5 (6.8%) patients in the HP-AI group and 17 (28.3%) patients in the low power-AI group. The HP-AI group showed a significantly higher arrhythmia-free survival than the low power-AI group (p = 0.011). Two patients in the low power-AI group and 1 patient in the HP-AI group developed an SAE (p = NS). Compared with the low power-AI group, the HP-AI group demonstrated a higher PV first-pass isolation rate, shorter ablation time, and fewer patients with anatomical leakages and sites of unreached AI.ConclusionIn a milder AI setting, HP-AI ablation might result in significantly higher arrhythmia-free survival than low power-AI ablation and a similar safety profile.

Characteristics of Very High-Power, Short-Duration Radiofrequency Applications.

IntroductionPulmonary vein isolation is the cornerstone of rhythm-control therapy for atrial fibrillation (AF). The very high-power, short-duration (vHPSD) radiofrequency (RF) ablation is a novel technology that favors resistive heating while decreasing the role of conductive heating. Our study aimed to evaluate the correlations between contact force (CF), power, impedance drop (ID), and temperature; and to assess their role in lesion formation with the vHPSD technique.MethodsConsecutive patients who underwent initial point-by-point RF catheter ablation for AF were enrolled in the study. The vHPSD ablation was performed applying 90 W for 4 s with an 8 ml/min irrigation rate.ResultsData from 85 patients [median age 65 (59–71) years, 34% female] were collected. The median procedure time, left atrial dwelling time, and fluoroscopy time were 70 (60–90) min, 49 (42–58) min, and 7 (5–11) min, respectively. The median RF time was 312 (237-365) sec. No steam pop nor major complications occurred. A total of 6,551 vHPSD RF points were analyzed. The median of CF, maximum temperature, and ID were 14 (10–21) g, 47.6 (45.1–50.4) °C, and 8 (6–10) Ohms, respectively. CF correlated significantly with the maximum temperature (p < 0.0001). A CF of 5 g and above was associated with a significantly higher temperature compared to those lesions with a CF below 5 grams (p < 0.0001). Bilateral first-pass isolation rate was 84%. The 6-month AF-recurrence rate was 7%.ConclusionThe maximum temperature and CF significantly correlate with each other during vHPSD applications. A CF ≥ 5 g leads to better tissue heating and thus might be more likely to result in good lesion formation, although this clinical study was unable to assess actual lesion sizes.

Impact of High-Power and Very High-Power Short-Duration Radiofrequency Ablation on Procedure Characteristics and First-Pass Isolation During Pulmonary Vein Isolation.

IntroductionHigh-power short-duration (HPSD) radiofrequency ablation has been proposed to produce rapid and effective lesions for pulmonary vein isolation (PVI). We aimed to evaluate the procedural characteristics and the first-pass isolation (FPI) rate of HPSD and very high-power short-duration (vHPSD) ablation compared to the low-power long-duration (LPLD) ablation technique.MethodsOne hundred fifty-six patients with atrial fibrillation (AF) were enrolled and assigned to LPLD, HPSD, or vHPSD PVI. The energy setting was 30, 50, and 90 W in the LPLD, HPSD, and vHPSD groups, respectively. In the vHPSD group, 90 W/4 s energy delivery was used in the QMODE+ setting. In the other groups, ablation index-guided applications were delivered with 30 W (LPLD) or 50 W (HPSD).ResultsBilateral PVI was achieved in all cases. Compared to the LPLD group, the HPSD and vHPSD groups had shorter procedure time [85 (75–101) min, 79 (65–91) min, and 70 (53–83) min], left atrial dwelling time [61 (55–70) min, 53 (41–56) min, and 45 (34–52) min], total RF time [1,567 (1,366–1,761) s, 1,398 (1,021–1,711) s, and 336 (247–386) s], but higher bilateral FPI rate (57, 78, and 80%) (all p-values < 0.01). The use of HPSD (OR = 2.72, 95% CI 1.15–6.44, p = 0.023) and vHPSD (OR = 2.90, 95% CI 1.24–6.44, p = 0.014) ablation techniques were associated with a higher probability of bilateral FPI. The 9-month AF-recurrence rate was lower in case of HPSD and vHPSD compared to LPLD ablation (10, 8, and 36%, p = 0.0001). Moreover, the presence of FPI was associated with a lower AF-recurrence rate at 9-month (OR = 0.09, 95% CI 0.04–0.24, p = 0.0001).ConclusionOur prospective, observational cohort study showed that both HPSD and vHPSD RF ablation shortens procedure and RF time and results in a higher rate of FPI compared to LPLD ablation. Moreover, the use of HPSD and vHPSD ablation increased the acute and mid-term success rate. No safety concerns were raised for HPSD or vHPSD ablation in our study.

Impact of high-power and very high-power short-duration radiofrequency ablation on procedure characteristics and first-pass isolation during pulmonary vein isolation

Abstract Funding Acknowledgements Type of funding sources: None. Introduction High-power short-duration (HPSD) radiofrequency ablation has been proposed as a method for producing rapid and effective lesions for pulmonary vein isolation.We aimed to evaluate the procedural characteristics and the FPI rate of HPSD and very high-power short-duration (vHPSD) compared to low-power long-duration (LPLD) ablation techniques. Methods 156 patients with atrial fibrillation (AF) were enrolled and assigned to LPLD, HPSD, or vHPSD PVI. The energy setting was 30W, 50W, and 90W in the LPLD, HPSD, and vHPSD groups, respectively. Results Bilateral PVI was achieved in all cases. The procedure time was 85 [75-101] min, 79 [65-91] min, and 70 [53-83] min in the LPLD, HPSD, and vHPSD groups, respectively (p&amp;lt;0,0001). LA dwelling times were also decreased significantly with the increase of RF energy (61 [55-70] min, 53 [41-56] min, and 45 [34-52] min, in the LPLD, HPSD, and vHPSD groups, respectively, p&amp;lt;0.0001). The total RF ablation time was 1398 [1021-1711] sec, 1567 (1366-1761) sec, and 336 [247-386] sec in the LPLP, HPSD, and vHPSD group, respectively ( p&amp;lt;0,0001). Bilateral FPI was rate was 57%, 78% and 80% in the LPLD, HPSD, and vHPSD groups, respectively (p=0,0097). On the left side, FPI was achieved in 66% in the LPLD, in 92% in the HPSD, and in 85% in the vHPSD ablation group (p=0.0015). FPI on the right side was achieved in 72% in the LPLD, in 88% in the HPSD, and in 88% in the vHPSD ablation group (p=0,0188). FPI rates were significantly higher in the HPSD group compared to the LPLD group: both sided FPI rate was 57% vs. 78% (p=0.021), left sided FPI rate was 66% vs. 92% (p=0.0015), and right sided FPI rate was 72% vs. 88% (p=0.0401). Further increase in the RF power did not result in a significant additional increase in the FPI rate. In the HPSD vs. vHPSD group both sided FPI rate was 78% vs. 80% (p=0,8080), left sided FPI rate was 92% vs. 85% (p= 0,5275), and right sided FPI rate was 88% vs. 88% (p= 0,7561). Univariate analysis revealed that the use of HPSD ablation technique is associated with a higher probability of FPI (both sides: OR=2.72, 95% CI 1.15-6.44, p=0.023; right side: OR=2.90, 95% CI 1.02-8.20, p=0.045; left side: OR=5.91, 95% CI 1.84-19.04, p=0.003). The mid-term arrhythmia-free survival was similarly high in all three groups. Conclusion Our prospective, observational cohort study showed that both HPSD and vHPSD RF ablation is effective, as it shortens procedure time and RF time and results in a higher rate of FPI compared to LPLD ablation. Moreover, the mid-term arrhythmia-free survival was similarly high in all three groups. In our study, no safety concerns were raised due to HPSD ablation.

Personalized persistent atrial fibrillation ablation guided by left atrial wall thickness: a multicenter study

Abstract Funding Acknowledgements Type of funding sources: None. Background Pulmonary vein isolation (PVI) has been proven to be effective in treating persistent atrial fibrillation (PeAF), although long-term ablation outcomes have been significantly less satisfactory than in paroxysmal AF (1). A recent personalized PVI approach, aiming for contiguous lesions with ablation index (AI) titration according to the local left atrial wall thickness (LAWT) as per multidetector cardiac tomography (MDCT), has demonstrated to achieve an arrhythmia-free survival &amp;gt; 95% at 12 months in patients with paroxysmal AF (2). Purpose We sought to investigate the safety and clinical outcomes of this personalized PVI approach guided by LAWT in patients with PeAF. Methods Consecutive patients referred for PeAF first ablation were prospectively enrolled from three referral centers. PeAF was defined in the presence of at least one AF episode sustained beyond 7 days. LAWT three-dimensional maps were obtained from MDCT and integrated into the navigation system. LAWT was categorized into 1 mm layers and AI was titrated to the LAWT. The ablation line was personalized to avoid thicker regions (Figure 1) while encircling PV antrum. Follow-up was scheduled at 1, 3, 6, and every 12-months thereafter. Results One hundred twenty-seven patients [89 (70.6%) male, age 64 ± 10 years] were included. 68 (60.7%) patients were hypertensive, 10 (18%) patients suffered of type 2 diabetes, and mean CHA2DS2-VASc score was 2.3 ± 2.1. Mean procedure time was 61 ± 20 minutes and mean fluoroscopy time was 1.3 ± 2.2 minutes. Radiofrequency (RF) time was 9.0 ± 2.3 minutes for the right pulmonary veins with a first-pass isolation in 109 (85.8%) patients and 7.6 ± 1.9 minutes for the left pulmonary veins with first-pass in 110 (86.6%). No major complication occurred. The rate of survival free from AF recurrences at a mean follow-up of 12 ± 6 months was 82% (Figure 2). Conclusions Personalized Persistent AF ablation by wide circle PV isolation guided by LAWT, proved to be safe and highly efficient, requiring a low amount of RF delivery, procedure time, and fluoroscopy use, while obtaining a high rate of first-pass isolation and of freedom from AF recurrences.

Multidetector computed tomography identification of previous ablation lines: insights for left atrial flutter ablation

Abstract Funding Acknowledgements Type of funding sources: None. Background Left atrial flutter (LAFL) frequently occurs in patients with history of previous left atrial (LA) ablation. LAFL ablation is still considered a challenging and time-consuming procedure (1). Conduction gaps on ablation lines are frequently due to non-transmural or non-contiguous lesions. It was recently demonstrated that aiding AF ablation procedures with the integration of multidetector computed tomography (MDCT)-derived left atrial wall thickness (LAWT) maps into the navigation system allowed decreasing radiofrequency (RF) delivery, fluoroscopy, and procedure time while obtaining a high rate of first-pass isolation (2). Purpose We hypothesized that MDCT-derived 3D-LAWT map could be useful to aid LAFL ablation procedure in patients with previous LA ablation lines. Methods Consecutive patients with history of previous LA ablation who underwent LAFL ablation were prospectively enrolled from a single referral center. LAWT three-dimensional maps were obtained from MDCT and integrated into the navigation system. LAWT information was used to focus mapping in the areas of the probable crucial isthmus: the presence of previous ablation lines was searched at the level of linear segments with reduced parietal thickness at the LAWT-maps (LAWT &amp;lt;1mm), while the search for conduction gaps was started at the level of the thicker areas of these lines. Conduction gap was defined as the presence of peak-to-peak bipolar potentials &amp;gt; 0.5 mV at the level of the previous ablation line or as the presence during arrhythmia of a LAT delay &amp;lt;30 ms between contiguous points lying in the same axial plane at the two sides of the line. Ablation was performed transecting the crucial isthmus with the documentation of bidirectional block; ablation first-attempt was guided by color-coded maps by connecting the parts of identified previous ablation lines with reduced LAWT. Finally, RF delivery was adapted to the local LAWT. Results Five patients [4 (80%) male, age 62 years (57-73)] were included. LAWT-aided LAFL ablation procedures had a median procedure time of 78 minutes (75-114) and a RF time of 5.9 minutes (4.7-8.5); fluoroscopy time was 3.2 minutes (1.5-3.6) with a fluoroscopy dose of 6.1 Gy*cm2 (2.8-8.2). Mean wall thickness of the gap zone was significantly higher with respect to the thickness of the zones of previous ablation lines (1.8 ± 0.5 mm vs. 1.0 ± 0.4 mm, p=0.047). All patients presented sinus rhythm at the end of the procedure and no acute complication occurred. No patient reported arrhythmic recurrence at 1-year follow-up (Figure 2). Conclusions LAWT-aided approach for LAFL ablation can facilitate identifying the wall thinning produced by the previous RF ablation line and the gap (seen as relative wall thickening) acting as the isthmus for the reentry circuit. This, in turn might help analysis of reentry circuits and increase procedure efficacy and efficiency. Further data are needed to reproduce these findings in a larger study cohort.

Wide area circumferential ablation for pulmonary vein isolation using radiofrequency versus laser balloon ablation.

BackgroundPersistent atrial fibrillation (AF) is associated with high recurrence rates of AF and atypical atrial flutters or tachycardia (AFT) postablation. Laser balloon (LB) ablation of the pulmonary vein (PV) ostia has similar efficacy as radiofrequency wide area circumferential ablation (RF‐WACA); however, an approach of LB wide area circumferential ablation (LB‐WACA) may further improve success rates.ObjectiveTo evaluate freedom from atrial tachyarrhythmia (AFT/AF) recurrence postablation using RF‐WACA versus LB‐WACA in persistent AF patients.MethodsThis was a retrospective multicenter study. Patients were followed for up to 24 months via office visits, Holter, and/or device monitoring. The primary endpoint was freedom from AFT/AF after a single ablation procedure. Secondary endpoints included freedom from AF, freedom from AFT, first‐pass isolation of all PVs, and procedural complications.ResultsTwo hundred and four patients were studied (LB‐WACA: n = 103; RF‐WACA: n = 101). Patients’ baseline characteristics were similar except patients in the RF‐WACA group were older (64 vs. 68, p = .03). First‐pass isolation was achieved more often during LBA (LB‐WACA: 88% vs. RF‐WACA 75%; p = .04). Procedure (p = .36), LA dwell (p = .41), and fluoroscopy (p = .44) time were similar. The mean follow‐up was 506 ± 279 days. Sixty‐six patients had arrhythmic events including 24 AFT and 59 AF recurrences. LB‐WACA group had higher arrhythmia‐free survival (p = .009) after single ablation procedures. In the multivariate Cox regression model, RF‐WACA was associated with a higher recurrence of AFT compared with LB‐WACA (Adjusted HR 3.16 [95% CI: 1.13–8.83]; p = .03).ConclusionsLB‐WACA was associated with higher freedom from atrial arrhythmias mostly driven by the lower occurrence of AFT compared with RF‐WACA.

PO-710-02 PATIENT COMORBIDITIES AND ABLATION TECHNIQUE ARE IMPORTANT DETERMINANTS OF FIRST PASS PULMONARY VEIN ISOLATION

First pass isolation (FPI) of the pulmonary veins (PVs) is a good predictor of durability of PV isolation and success rate of AF ablation. Systematic analysis of predictors of FPI has not previously been performed. To investigate how variations in ablation technique and patient comorbidities influence acute durable isolation during PVI. Raw data was exported from first time PVIs performed using the CARTO system for 62 consecutive patients. Cases were imported into Matlab using openEP and lesion characteristics and locations were extracted. Separate multivariate logistic regression analyses for both ablation technique and patient characteristics were performed for each vein. Left sided FPI was achieved in 42 patients (68%) and right sided FPI in 31 (50%). The commonest sites needing reinforcement were carina and anterior left superior (LS)PV on the left and the carina and posterior right inferior (RI)PV on the right (Figure). In terms of predictors of FPI for the LIPV, increased patient weight predicted reduced success (OR 0.93, p=0.018) and closer lesion-ostium distance posteriorly predicted increased success (OR 0.88, p=0.037). For the LSPV, larger atrial surface area in comparison to area ablated predicted reduced success (OR 0.83, p=0.024). For the RSPV, the presence of hypertension (OR 0.20, p=0.039) and coronary disease (OR 0.29, p=0.033) significantly reduced the chance of FPI. In addition, lower lesion-ostium distance anteriorly increased the chance of FPI (OR 0.87, p=0.024). For the RIPV, an enhanced impedance drop in the posterior (OR 1.61, p=0.004) and anterior (OR 1.12, p=0.03) segments, significantly increased success. The acute success of AF ablation in terms of FPI is affected by ablation technique and comorbidities. It seems particularly important to ablate closer to the ostium to achieve FPI in the anterior RSPV and posterior LIPV. At the posterior and anterior RIPV it is of particular importance to obtain a good impedance drop during ablation. Increased patient weight appears to increase the difficulty of isolating the LIPV while hypertension and coronary disease are associated with reduced chance of FPI at the RSPV. It is possible that the operator being mindful of these associations could increase success rates and/or durability of PVI.

PO-636-05 CLINICAL AND PROCEDURAL PREDICTORS OF FIRST PASS PULMONARY VEIN ISOLATION- FINDINGS FROM THE ANALYSIS OF 1539 FIRST TIME ATRIAL FIBRILLATION ABLATIONS IN THE REAL-AF REGISTRY

First pass isolation (FPI) has been shown to be associated with improved long-term freedom from atrial arrhythmia recurrence following atrial fibrillation ablation (AFA). The clinical and procedural predictors of FPI are not as well described.

High-Frequency, Low-Tidal-Volume Mechanical Ventilation Safely Improves Catheter Stability and Procedural Efficiency During Radiofrequency Ablation of Atrial Fibrillation

High-Frequency, Low-Tidal-Volume Mechanical Ventilation Safely Improves Catheter Stability and Procedural Efficiency During Radiofrequency Ablation of Atrial Fibrillation

Two years after pulmonary vein isolation guided by ablation index-a multicenter study.

BackgroundThe use of the Ablation Index (AI) software for paroxysmal atrial fibrillation (AF) has been associated with higher acute effectiveness and higher 1‐year arrhythmia freedom. There is, however, a lack of data concerning longer follow‐up. We aim to evaluate the 2‐year outcomes after a standardized AI‐guided pulmonary vein isolation (PVI).MethodsProspective, multicenter study of consecutive patients referred for paroxysmal AF ablation from January 2018 to July 2019. PVI was guided by a tailored AI value (≥500 for anterior segment, ≥450 for the roof segments and inferior segments, and 400 for the posterior wall) and an ILD ≤6 mm. The primary endpoints were acute and long‐term effectiveness.ResultsThe study included 218 (842 PV) patients (61% males, median age of 60 [IQR 49–68] years) with paroxysmal AF. First‐pass isolation was obtained in 93% of the patients, with an acute reconnection occurring in 10.6% of the patients (3.2% of the PV) following adenosine trial. After a median follow‐up of 26 (IQR 20–30) months, freedom from any documented atrial arrhythmia was 83.4%, off‐AAD. The rate of adverse events was 1.4%. Although procedural parameters differ across centers (p < 0.001), the acute (p = 0.56) and long‐term effectiveness (p = 0.83) were consistent between centers.ConclusionsPatients with paroxysmal AF submitted to an AI‐guided PVI workflow presented high arrhythmia freedom at 2‐years of follow‐up.