Treatment Of Paroxysmal Atrial Fibrillation Research Articles

One-year outcomes of pulmonary vein isolation with a novel cryoballoon: Primary results of the FROZEN AF trial.

Cryoablation therapy for pulmonary vein isolation (PVI) to treat paroxysmal atrial fibrillation (PAF) is well established. A novel 28 mm cryoballoon system designed to operate under low pressure to safely reach a lower nadir temperature and maintain constant balloon size during cooling has not been prospectively studied in a large patient population for safety and efficacy. The FROZEN AF (NCT04133168) trial was an international multicenter, open-label, prospective, single-arm study on the safety and performance of a novel cryoballoon system for treatment of PAF. The study enrolled patients at 44 sites in 10 countries across North America, Europe, and Asia. Subjects were indicated for PVI treatment of PAF and had failed or were intolerant of one or more antiarrhythmic drugs. Procedural outcomes were defined based on the 2017 HRSconsensus statement. Follow-up was performed at 7 days, 3, 6, and 12 months. Data are reported as mean ± SD or median (IQR). PVI was performed with a 28 mm cryoballoon in 325 drug refractory PAF patients. Complete PVI was achieved in 95.7% of patients. In cryoablation lesions longer than 60 s, 60.1% of PV isolations required only a single cryoballoon application. Procedure related complications included: phrenic nerve palsy [temporary 4 (1.2%), persistent 0 (0.0%)], cardiac tamponade/perforation 2 (0.6%), and air embolism 1 (0.3%). Freedom from documented atrial arrhythmia recurrence at 12 months was 79.9% (AF 82.7%, AFL 96.5%, AT 98.1%), antiarrhythmic drugs (AAD) were continued or re-initiated in 26.8% of patients after the 3-month blanking period. Additionally, an extension arm enrolled 50 pts for treatment with 28/31 mm variable size cryoballoon. A single temporary PNP occurred in this group, which resolved before discharge. Freedom from documented recurrence at 12 months in these pts was 82.0%. This novel cryoballoon may facilitate PVI to treat PAF, providing more options to address the variety of anatomies present in patients with PAF. This cryoballoon system proved to be safe and effective for treatment of patients with drug refractory or drug intolerant PAF.

Cryoablation versus hybrid radiofrequency with high- and very-high-power short-duration catheter ablation for the treatment of paroxysmal atrial fibrillation

BackgroundHigh-power short-duration (HPSD) and very-high-power short-duration (vHPSD-90 W/4 s) radiofrequency (RF) technology has reduced the procedure time of pulmonary vein isolation (PVI) using RF without compromising the efficacy of the technique. The current study compares the novel technology of HPSD/vHPSD with cryoablation (CRYO) in terms of efficacy, safety, and procedure time in a cohort of symptomatic patients with paroxysmal atrial fibrillation (pAF). MethodsThis is a prospective, non-randomized trial. Patients with pAF received either CRYO or HPSD/vHPSD RF PVI. The primary endpoint of the study was arrhythmia recurrence in a 12 month follow-up period. Secondary endpoints included procedure time, fluoroscopy time, and safety. Results104 patients were included (45 in HPSD/vHPSD and 59 in CRYO), with comparable characteristics between groups. The follow-up was 12.4 ± 0.5 months. There was no significant difference regarding arrhythmia recurrences during the early post-procedural period of the first 3 months (8.9% recurrences in HPSD/vHPSD versus 5.1% in CRYO-p 0.463) and in the mid-term follow-up of 12 months (17.8% recurrences in HPSD/vHPSD versus 10.2% in CRYO-p 0.385). Safety was excellent for both procedures. CRYO was a procedure of significantly shorter duration (64.64 ± 8.94 min versus 75.29 ± 18.30 min, p 0.0001) at the expense of longer fluoroscopy time (HPSD/vHPSD 5.34 ± 1.83 versus 7.89 ± 3.70 min CRYO, p 0.001). ConclusionsHPSD/vHPSD and CRYO in pAF were comparable regarding the arrhythmia recurrence rates in a 12-month follow-up with excellent safety. The hybrid approach of HPSD/vHPSD has accelerated RF-PVI compared to conventional RF, but CRYO remains a procedure of significantly shorter duration at the expense of longer fluoroscopy time.

Cryoballoon ablation without use of contrast for the treatment of paroxysmal atrial fibrillation.

Cryoballoon ablation (CBA) for atrial fibrillation (AF) is usually preceded by demonstrating pulmonary vein (PV) occlusion using contrast. The aim of the study was to determine efficacy and safety of a simplified protocol for CBA performed without demonstrating PV occlusion and compare achieved results with conventional CBA. Paroxysmal AF patients undergoing a first-time CBA were prospectively included. In the non-contrast (NC) group CBA was performed using standardized protocol without demonstrating PV occlusion. In the conventional contrast (CC) group ablations were performed after confirmation of PV occlusion. The NC and CC groups comprised 51 and 22 patients, respectively. PVI according to the group assignment was achieved in 34 (67%) and 21 (95.5%) patients from the NC and CC groups, respectively (p < 0.001). In the NC group, 184 (90%) out of 204 veins were isolated without venography. There were no differences between the NC and CC groups in terms of procedure duration (89.7 ± 22.6 vs. 90.0 ± 20.6 min; p = 0.7) and fluoroscopy time (15.3 ± 6.3 vs. 15 ± 4.5 min; p = 0.8). In the NC group, the use of contrast was significantly lower compared to the CC group (4.9 ± 10.1 vs. 19.4 ± 8.6 mL, p < 0.001). There were no serious adverse events in both groups. A 1-year freedom from AF was achieved in 73.5% and 71.5% of patients from the NC and CC groups, respectively (p = 1). Cryoballoon ablation without demonstrating vein occlusion with contrast is safe and feasible. Proposed simplified approach enables isolation of the vast majority of pulmonary veins with a significant reduction in the amount of contrast used.

Comparative Safety of Pulsed Field Ablation and Cryoballoon Ablation Technologies for Pulmonary Vein Isolation in Patients with Paroxysmal Atrial Fibrillation: A Critical Literature Review and Indirect Treatment Comparison.

Cryoballoon ablation (CBA) is a standard catheter ablation technology with demonstrated clinical effectiveness for the treatment of paroxysmal atrial fibrillation (PAF); however, it can be associated with major adverse events, including phrenic nerve paralysis. Pulsed field ablation (PFA) is a novel, minimally thermal technology with comparable effectiveness and low safety risk. This study aimed to compare the safety profiles of PFA and CBA through critical analyses of the literature and indirect treatment comparisons. Studies were identified by searching the MEDLINE database and the Clinicaltrials.gov registry. Registered clinical trials and/or Food and Drug Administration Investigation Device Exemption (FDA IDE) studies evaluating PFA or CBA in adult patients with drug-refractory PAF between January 2008 and March 2023 were selected. Comparative safety between PFA and CBA was assessed for major and prespecified adverse events. Indirect comparisons were conducted using the proportion of patients experiencing adverse events and confirmed with single-arm meta-analyses and sensitivity analyses. Data were extracted from three PFA publications including a total of 497 patients and six CBA studies including a total of 1113 patients. The analysis revealed that PFA was associated with significantly lower risk of major adverse events {risk difference-4.3% [95% confidence interval (CI)-5.8,-2.8]; risk ratio 0.16 [95% CI 0.07, 0.45]} and prespecified adverse events [risk difference -2.5% (95% CI-4.4,-0.5); risk ratio 0.53 (95% CI 0.31, 0.96)]. Meta-analyses confirmed the lower rate of major adverse events for PFA [0.4% (95% CI 0.0, 1.3)] vs. CBA [5.6% (95% CI 2.6, 8.6)] and prespecified adverse events for PFA [2.7% (95% CI 1.2, 4.1)] vs. CBA [5.8% (95% CI 2.7, 9.0)]. Sensitivity analyses exploring heterogeneity across studies confirmed robustness of the main analyses. The findings of this study show that PFA has a more favorable safety profile than CBA, with significantly lower risks of major and prespecified adverse events. These indirect comparisons help contextualize the safety of PFA compared to CBA for the treatment of drug-refractory PAF in the absence of head-to-head studies.

Economic evaluation of first-line cryoballoon ablation versus antiarrhythmic drug therapy for the treatment of paroxysmal atrial fibrillation from an English National Health Service perspective

IntroductionThree recent randomised controlled trials have demonstrated that pulmonary vein isolation as an initial rhythm control strategy with cryoablation reduces atrial arrhythmia recurrence in patients with symptomatic paroxysmal atrial fibrillation...

Temperature to time Catch-Up: a novel procedural endpoint to predict durable pulmonary vein isolation after cryoballoon ablation of paroxysmal atrial fibrillation.

Cryoballoon ablation is a widely used single-shot technique for pulmonary vein isolation (PVI) in the treatment of paroxysmal atrial fibrillation (AF). Procedural endpoints ensuring maximal PVI durability are important. To assess the performance of cryoablation procedural markers to predict long-term PVI. In a single center, consecutive patients who underwent redo ablation with high-density mapping for symptomatic AF recurrence after cryoballoon ablation were included and cryoballoon procedural data were collected, including temperature values at 30 and 60s, time to isolation, nadir temperature and the velocity of temperature decline estimated with the temperature/time catch-up point (T2T-Catch-Up) defined as positive when the freeze temperature in minus degree equals the time in seconds after cryoablation initiation (e.g. -15°C in the first 15s of the ablation impulse). 47 patients (62% male; 58.3 ± 11.2years) were included. Overall, 38 (80.9%) patients had ≥ 1 reconnected PV. Among 186 PVs, 56 (30.1%; 1.2 per patient on average) were reconnected. Univariate analysis revealed T2T-Catch-Up in 103 (56%) and more frequent in durably isolated than in reconnected PVs (93 [72%] vs 10 [19%], p < 0.0001). Among binary endpoints, T2T-Catch-Up had the highest specificity (82%) and predictive value for durable PVI at redo ablation (90%). In multivariable analyses, absence of T2T-Catch-Up (Odds-ratio 0.12, 95% CI [0.05-0.31], p < 0.0001) and right superior PV (Odds-ratio 3.14, 95% CI [1.27-7.74], p = 0.01) were the only variables independently associated with PV reconnection. T2T-Catch-Up, a new and simple cryoballoon procedural endpoint demonstrated excellent predictive value and strong statistical association with durable PVI.

Long-term success rates of a stable, low pressure cryo balloon for the treatment of paroxysmal atrial fibrillation - results of the prospective, international, multicenter POLAR-ICE study

Abstract Background/Introduction Pulmonary vein isolation (PVI) using a cryo balloon is well-established for the treatment of paroxysmal atrial fibrillation (PAF). Compared to other available technologies, the usage of a stable, low pressure cryo balloon (POLARx, Boston Scientific) has demonstrated lower nadir temperatures and longer thawing times. However, long term efficacy and safety still needs to be proven. Purpose The aim of the POLAR-ICE Study was to evaluate long-term efficacy and safety outcome of cryo balloon ablation in patients with paroxysmal atrial fibrillation. Methods POLAR ICE, a prospective, non-randomized, international, multicenter study, enrolled 399 patients across 19 centers, between Aug 2020 and May 2021. Patients with paroxysmal atrial fibrillation undergoing de novo PVI were included into the study. During the index procedure, procedural characteristics, such as time to isolation (TTI), cryoablations per pulmonary vein, balloon nadir temperature, and occlusion grade were recorded. Procedural success was defined as successful isolation of each vein proven by entrance block. Follow up visits were at 3, 6, and 12 months. Recurrence is defined as any documented (ECG/Holter) episode of atrial fibrillation / atrial tachycardia longer than 30sec. after a blanking period of 3 months. Results 399 patients (mean age 61 years, 36% female) were included into the study. After 12 months, freedom from any arrhythmia was 83.5% and freedom from atrial fibrillation 88.1% (Figure 1). Procedure/ablation related Serious adverse events occurred in 8.7% of patients, and included access complications (2.6%), cardiac tamponade (0.5%), air embolism (0.3%), AV block (0.3%), effusion (0.3%) phrenic nerve palsy (0.3%), stroke (0.3%), transient ischemic attack (0.3%). Redo procedures have been conducted in 19 patients. In 14/19 pts reconnection of at least one PV could be identified (RSPV n=8, RIPV n=12, LSPV n=9, LIPV n=11). Freedom from any arrhythmia was associated with lower nadir temperature (p=0.008) and longer time to thaw (p=0.05) during the index procedure. Conclusions In this prospective, non-randomized, international, multicenter study, isolation of the pulmonary veins using a stable, low pressure cryo balloon was highly effective and safe in patients treated for paroxysmal atrial fibrillation. Lower nadir temperatures and a longer thawing time were predictors of clinical success.

An economic evaluation of first-line cryoballoon ablation versus antiarrhythmic drug therapy for the treatment of paroxysmal atrial fibrillation from a German healthcare service payer perspective

Abstract Background Three recent randomized controlled trials demonstrated that, in patients with symptomatic paroxysmal atrial fibrillation (PAF), first-line pulmonary vein isolation (PVI) with cryoballoon ablation reduces atrial arrhythmia recurrence when compared to initial antiarrhythmic drug (AAD) therapy. Purpose To evaluate the cost-effectiveness of initial rhythm control therapy from a German healthcare service payer perspective. Methods The cost-effectiveness model (CEM) structure consisted of a hybrid decision tree and Markov model, where the decision tree informed the initial health state allocation in the first cycle of the Markov model and had a one-year time horizon. The Markov model had a 40-year time horizon using a three-month cycle length. Health benefits were expressed in quality-adjusted life years (QALYs). Costs and benefits were discounted at 3.5% p.a. Individual patient-level data from 703 participants with untreated PAF enrolled into Cryo-FIRST (NCT01803438), STOP AF First (NCT03118518) and EARLY-AF (NCT02825979) were used to estimate efficacy, resource use and health-related quality of life parameters. Cost inputs were sourced from diagnosis-related groups and the Institute for the Hospital Remuneration System (InEK). Where parameters could not be derived, inputs were sourced from available published literature or determined through clinical expert opinion. Probabilistic sensitivity analyses were conducted to explore the impact of any assumptions on model outputs. Results In those treated with cryoablation, the three-month rate of AF recurrence was reduced by 46.7% (p&amp;lt;0.001) on average. Similarly, the average monthly rate of receiving an ablation following initial treatment was reduced by 72.8% (p&amp;lt;0.001). Cryoablation was also associated with a 4.3% (p=0.025) increase in health-related quality of life at 12 months, assessed through the standard EQ-5D-3L instrument. There was no difference in the rate of AF resolution in those who failed initial treatment. CEM results are shown in Table 1. Analysis shows that cryoablation is cost-effective, incurring a cost of ∼€1,000 per patient over a lifetime compared to AADs, while offering an increase in QALYs. Cryoablation attains an average ICER of ∼€5,500, with a 94.1% probability of being cost-effective at a willingness-to-pay threshold of €35,000 per QALY gained. Through 5,000 iterations, the probabilistic sensitivity analysis indicates that cryoablation has ∼20% probability of being cost-saving. Individuals are expected to receive a total of ∼1.2 ablations over a lifetime, regardless of initial treatment. Although, those initially treated with cryoablation as opposed to AADs experience a 45% reduction in time spent in AF health states. Conclusion Initial rhythm control with cryoballoon ablation in PAF is a cost-effective treatment option in a German healthcare setting.Table 1:Key results (per patient)

Abstract 13916: Patient Outcomes 6 Months Following Pulmonary Vein Isolation for Atrial Fibrillation With a Novel RF Catheter: Initial Data From NEwTON AF

Introduction: The combination of local impedance (LI), a direct measure of electrical resistance at the catheter tip, and contact force (CF) may facilitate treatment of atrial fibrillation (AF). This trial is designed to examine the safety and effectiveness of a novel RF catheter that allows measurement of both LI and CF. Hypothesis: Demonstrate the safety and effectiveness of a novel radiofrequency catheter with LI and CF for treatment of drug refractory, recurrent, symptomatic Paroxysmal AF (PAF). Methods: NEwTON AF is a multi-center, global, prospective, single arm study. Patients received index treatment for PAF with the study catheter. The present 6-month endpoint analysis was prospectively planned. Results: The study treated 299 patients at 45 sites in North America, Europe, and Asia. Patients were 39.5% female with a mean age of 62yrs (±12), and had a mean LVEF of 59% and an LA diameter of 3.9cm. Procedure time, LA dwell, and fluoroscopy times were 166, 136, and 15 minutes, respectively. High-power short-duration (HSPD, 45-50W) was exclusively used in 210 cases, which had notably shorter procedure times than the 82 cases that used conventional power, 148 vs 208 min, respectively. Acute procedural success was observed in 98.3% of cases. As of 6 months, freedom from documented recurrence of any atrial arrhythmia was 79.9% (Figure). Recurrence in relation to LI shows that pts with a 20Ω LI drop (in at least 60% of lesions) had better 6m outcomes (84.2% vs 73.3, p=0.04). The freedom from safety event rate at 30d was 96.0%; events included pericarditis (6), access complications (2), pulmonary edema (2), embolism (2), cerebrovascular accident (1), tamponade (1). Pericarditis was higher in pts with a history of COVID at enrollment, 16.3% vs 5.9%, p=0.025. Conclusions: This data suggests that patient outcomes and safety for this novel catheter are promising. Further data from this study, including 12m outcomes, and detailed analysis of local impedance data are forthcoming.

Safety and effectiveness of the first contact force ablation catheter with a flexible tip

Catheter ablation is an established therapy for paroxysmal atrial fibrillation (PAF). The TactiFlex Ablation Catheter, Sensor Enabled (TactiFlex SE) is a next-generation radiofrequency ablation catheter incorporating fiber optics-based contact force-sensing technology with a flexible, laser-cut tip. The study sought to evaluate the safety and effectiveness of the TactiFlex SE ablation catheter for treatment of drug-refractory PAF. The TactiFlex AF investigational device exemption was a prospective, nonrandomized, multicenter clinical study. Enrollment began on June 26, 2020 and completed June 18, 2021. Subjects with PAF underwent de novo pulmonary vein isolation and, if indicated, ablation for typical atrial flutter. Subjects were followed for 12 months. Of the 355 subjects enrolled at 37 sites worldwide, 334 underwent ablation with the TactiFlex SE catheter. The Kaplan-Meier estimate of 12-month freedom from AF/atrial flutter (AFL)/atrial tachycardia recurrence was 72.9% (95% confidence interval [CI] 95% CI 67.2%-77.8%) and clinical success was 83.6% (95% CI 95% CI 78.1%-87.2%). As-treated analyses compared subjects treated at high power (left atrium time-averaged power setting 40-50 W; n = 222) vs low power (<40 W; n = 97). The Kaplan-Meier estimate of 12-month freedom from AF/AFL/atrial tachycardia recurrence was 76.4% (95% CI 69.3%-82.0%) and clinical success was 83.9% (95% CI 77.5%-88.6%) in the high-power group compared with 66.8% (95% CI 56.1%-75.5%) and 80.7% (95% CI 70.8%- 87.5%), respectively, in the low-power group. The primary safety event rate in all treated subjects was 4.3%; 4.1% in the HP group and 5.2% in the LP group (P = .7671). TactiFlex SE is safe and effective for treatment of drug-refractory PAF and concomitant AFL and enables more efficient procedures than previous generation catheters.

Liquid Nitrogen Cryoballoon Ablation System for Paroxysmal Atrial Fibrillation: A Multicenter, Prospective, Single-Arm Clinical Trial

BackgroundCryoballoon ablation (CBA) has emerged as an effective treatment for atrial fibrillation (AF). ObjectivesThis study sought to assess the performance of a novel liquid nitrogen–driven CBA system and evaluate its safety and efficacy in the treatment of drug-resistant paroxysmal atrial fibrillation (PAF). MethodsThis was a prospective multicenter single-arm clinical trial with 10 participating tertiary hospitals enrolling 176 patients with PAF. All participants received liquid nitrogen–driven CBA developed by the Cryofocus Medtech Company. Scheduled follow-up was performed before discharge and 3 months, 6 months, and 12 months after CBA. The primary endpoints were defined as 1) treatment success (freedom from antiarrhythmic drugs and atrial tachycardia at 12 months after CBA); and 2) immediate success rate of pulmonary vein isolation. The safety endpoint was the incidence of device- and procedure-related adverse events (AEs) and all-cause mortality. ResultsA total of 172 participants were included, with an average age of 59.22 ± 9.25 years and 99 (57.56%) of them men. Immediate success rate was 97.67% (95% CI: 94.15%-99.36%) and 12-month treatment success rate was 82.56% (95% CI: 76.89%-88.23%), including a late recurrence rate of 13.61%. Incidences of device- and procedure-related AEs were 2.27% and 25.00%, respectively. Phrenic nerve palsy (PNP) occurred in 6 patients, of which 5 recovered during follow-up. Although the incidence of total severe AEs was 17.05%, including an all-cause mortality of 0.57%, only 1 case of permanent PNP was related to the CBA procedure. ConclusionsThis premarketing prospective multicenter single-arm clinical trial demonstrated that the liquid nitrogen cryoablation system is safe and effective in the treatment of PAF.

An economic evaluation of first-line cryoballoon ablation vs antiarrhythmic drug therapy for the treatment of paroxysmal atrial fibrillation from a U.S. Medicare perspective.

Three recent randomized controlled trials have demonstrated that, as an initial rhythm control strategy, first-line cryoballoon ablation (cryoablation) reduces atrial arrhythmia recurrence compared with antiarrhythmic drugs (AADs) in patients with symptomatic paroxysmal atrial fibrillation (PAF). The study sought to evaluate the cost-effectiveness of first-line cryoablation compared with first-line AADs for treating symptomatic PAF from a U.S. Medicare payer perspective. Individual patient-level data from 703 participants with PAF enrolled into the Cryo-FIRST (NCT01803438), STOP AF First (NCT03118518), and EARLY-AF (NCT02825979) trials were used to derive parameters for the cost-effectiveness model. The cost-effectiveness model used a hybrid decision tree and Markov structure. The decision tree had a 1-year time horizon and was used to inform the initial health state allocation in the first cycleof the Markov model. The Markov model used a 40-year time horizon (3-month cycle length). Health benefits were expressed in quality-adjusted life years (QALYs). Costs and benefits were discounted at 3% per year. Cryoablation was estimated to yield higher QALYs (+0.17) and higher costs (+$4274) per patient over a 40-year time horizon than AADs. Ultimately, this produced an average incremental cost-effectiveness ratio of $24,637 per QALY gained. Independent of initial treatment, individuals were expected to receive ∼1.2 ablations over a lifetime. There was a 45% relative reduction in time spent in atrial fibrillation health states for those initially treated with cryoablation compared with AADs. Initial rhythm control with first-line cryoballoon ablation is highly cost-effective compared with first-line AADs from a U.S. Medicare payer perspective.

Pulsed Field or Conventional Thermal Ablation for Paroxysmal Atrial Fibrillation

BackgroundCatheter-based pulmonary vein isolation is an effective treatment for paroxysmal atrial fibrillation. Pulsed field ablation, which delivers microsecond high-voltage electrical fields, may limit damage to tissues outside the myocardium. The efficacy and safety of pulsed field ablation as compared with conventional thermal ablation are not known.MethodsIn this randomized, single-blind, noninferiority trial, we assigned patients with drug-refractory paroxysmal atrial fibrillation in a 1:1 ratio to undergo pulsed field ablation or conventional radiofrequency or cryoballoon ablation. The primary efficacy end point was freedom from a composite of initial procedural failure, documented atrial tachyarrhythmia after a 3-month blanking period, antiarrhythmic drug use, cardioversion, or repeat ablation. The primary safety end point included acute and chronic device- and procedure-related serious adverse events.ResultsA total of 305 patients were assigned to undergo pulsed field ablation, and 302 were assigned to undergo thermal ablation. At 1 year, the primary efficacy end point was met (i.e., no events occurred) in 204 patients (estimated probability, 73.3%) who underwent pulsed field ablation and 194 patients (estimated probability, 71.3%) who underwent thermal ablation (between-group difference, 2.0 percentage points; 95% Bayesian credible interval, −5.2 to 9.2; posterior probability of noninferiority, >0.999). Primary safety end-point events occurred in 6 patients (estimated incidence, 2.1%) who underwent pulsed field ablation and 4 patients (estimated incidence, 1.5%) who underwent thermal ablation (between-group difference, 0.6 percentage points; 95% Bayesian credible interval, −1.5 to 2.8; posterior probability of noninferiority, >0.999).ConclusionsAmong patients with paroxysmal atrial fibrillation receiving a catheter-based therapy, pulsed field ablation was noninferior to conventional thermal ablation with respect to freedom from a composite of initial procedural failure, documented atrial tachyarrhythmia after a 3-month blanking period, antiarrhythmic drug use, cardioversion, or repeat ablation and with respect to device- and procedure-related serious adverse events at 1 year. (Funded by Farapulse–Boston Scientific; ADVENT ClinicalTrials.gov number, NCT04612244.)

Short-term and long-term effects of cryoballoon ablation versus antiarrhythmic drug therapy as first-line treatment for paroxysmal atrial fibrillation: A systematic review and meta-analysis.

Cryoballoon ablation (CBA) is an effective treatment for drug-refractory atrial fibrillation (AF) patients. Whether CBA as a first-line treatment is superior in the rhythm control of AF than antiarrhythmic drugs (AAD) remains unclear.CBA is superior to AAD as initial therapy for rhythm control of paroxysmal atrial fibrillation(PAF). A comprehensive database search was performed in PubMed, Embase, Cochrane, and Web of Science from inception to March 22, 2023. Treatment efficacy was pooled using risk ratio (RR) and standardized mean difference (SMD) with a 95% confidence interval (CI). This study was registered with Prospero (CRD42023401596).Five randomized-controlled trials involving 923 patients and an observational study were included in this study. The CBA group had a significantly lower overall recurrence rate than theAAD group (CBA vs.AAD: RR = 0.59, 95% CI = 0.49-0.71, p < .05, I2  = 0). The incidence of persistent AF could be better controlled in the CBA group than in the AAD (CBA vs.AAD: RR = 0.17, 95% CI = 0.06-0.49, p < .05, I2  = 0). CBA could improve the quality of life (QoL) of patients better than AAD (CBA vs.AAD: SMD = 0.40, 95% CI = 0.14-0.67, p < .05, I2  = 68.5%). CBA can reduce hospitalization rate significantly than AAD at 36-month follow-up (CBA vs.AAD: RR = 0.29, 95% CI = 0.15-0.58, p < .05, I2  = 0%). Compared to AAD, CBA as first-line therapy could reduce the recurrence rate of atrial arrhythmia and incidence of persistent AF and improve QoL in PAF patients with lower incidences of hospitalization.

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

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

An economic evaluation of first-line cryoballoon ablation versus antiarrhythmic drug therapy for the treatment of paroxysmal atrial fibrillation from an English NHS perspective

Abstract Funding Acknowledgements Type of funding sources: Other. Main funding source(s): This cost-effectiveness study was funded by Medtronic Background The UK National Institute of Care Excellence (NICE) recommend the use of pulmonary vein isolation (PVI) to treat paroxysmal atrial fibrillation (PAF) in those who have not responded to drug treatment. Recently, three randomized controlled trials have demonstrated that as an initial rhythm control strategy, PVI with cryoballoon ablation, reduces atrial arrhythmia recurrence compared to antiarrhythmic drug (AAD) therapy in patients with symptomatic PAF. Purpose To evaluate the cost-effectiveness of first-line cryoablation versus first-line optimized AADs in an English National Health Service (NHS) setting. Methods Individual patient-level data from 703 participants with untreated PAF recruited into Cryo-FIRST, STOP AF First and EARLY-AF were used to derive equations to predict the following outcomes: rates of ablation, AF recurrence and resolution, AF-related hospital attendance, and health-related quality of life (HRQoL) utilities. Where parameters could not be sourced from the trial data, inputs were taken from the published literature or derived using clinical expert opinion. The cost-effectiveness model (CEM) was a hybrid of a decision tree with a one-year time horizon and a Markov model (three-month cycle length) with a lifetime time horizon and was developed from the perspective of the English NHS. Health benefits were expressed in quality-adjusted life years (QALYs), and all benefits and costs were discounted at 3.5% per year in line with NICE requirements. Uncertainty in the CEM inputs was explored using probabilistic sensitivity analysis. The results include an initial 12-week blanking period for all studies. Results The three-monthly rate of AF recurrence was reduced on average by 46.7% (p&amp;lt;0.001) in those treated with cryoablation. Similarly, the monthly rate of receiving an ablation following initial treatment was reduced by 72.8% (p&amp;lt;0.001) in the cryoablation arm. Furthermore, the average cryoablation patient was associated with a 4.3% (p=0.025) increase in their HRQoL. While the likelihood of failure was greater in the AAD group, in those who failed initial treatment, there was no difference in the rate of AF symptom resolution. The CEM indicates that cryoablation is more effective (+0.17 QALYs) and more costly (+£1,414) over a lifetime compared to optimized AADs. Cryoablation resulted in an Incremental Cost-Effectiveness Ratio of £8,435 with a 78.5% probability of being cost-effective at a willingness-to-pay threshold of £20,000 per QALY gained. Individuals in both treatment arms were predicted to receive ~1.2 ablations over a lifetime regardless of initial treatment. However, there was a 45% relative reduction in the amount of time spent in symptomatic AF states for those initially treated with cryoablation. Conclusions AF rhythm control in drug naïve patients with cryoballoon ablation is cost-effective compared to optimized AADs in an English NHS setting.

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

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

AB-452675-3 CHARACTERISTICS OF RESIDUAL SIGNALS AFTER PULSED FIELD ABLATION OF THE PULMONARY VEINS

Pulsed field ablation (PFA) is a new energy source for isolation of the pulmonary veins in the treatment of paroxysmal atrial fibrillation (PAF). Dose titration is challenging but important to avoid reversible electroporation. Analysis of high resolution unipolar electrograms after PFA might be of value to analyze the tissue response to PFA deliveries. Unipolar and bipolar electrograms were recorded from a proprietary pentaspline basket catheter (Boston Scientific Inc., USA) before and after PFA energy delivery using a novel electrophysiology recording system (ECGenius System, CathVision, Denmark) with resolution at a 0.05 mV level and a sampling rate of 2 KHz. Data was recorded from 12 consecutive patients diagnosed with PAF and scheduled for pulmonary vein isolation. The treatment protocol consisted of conventional PFA delivery in two baskets and two flower positions for each vein. Both unipolar and bipolar signals were analyzed manually. Overall, 790 EGMs from 12 patients were analyzed. In 131 out of 160 EGMs (82%) recorded after first PFA delivery, we observed a residual sharp downward deflection in the unipolar signal that matched the timing of the corresponding bipolar signal (Fig. 1). Median amplitude of the deflection was 0.18 mV (IQR = 0.09 - 0.32 mV). The sharp deflections were eliminated with further PFA delivery in 29.7% of cases (suggesting true local activation) but persisted in 71.3%. High resolution electrogram recording allows identification of residual sharp deflections in the unipolar electrogram after PFA delivery. The coincident timing with the bipolar EGM together with elimination by further PFA suggests that this EGM signature reflects true local activity. It remains to be seen whether persisting deflections are a measure for non-isolation or reversible electroporation.

PO-01-169 CLINICAL APPLICATION OF A NOVEL 31MM CRYOBALLOON FOR PULMONARY VEIN ISOLATION FOR PAROXYSMAL ATRIAL FIBRILLATION: PROCEDURAL DATA FROM THE FIT ARM OF FROZEN AF

Cryoablation of pulmonary veins (PV)s to treat paroxysmal atrial fibrillation (PAF) is well established, however there are limited choices in balloon sizes for cryoablation. Data have recently been collected on a new cryoballoon system with novel capability to deliver cryoablation in a standard 28mm diameter balloon or an expanded 31mm diameter, using the same catheter. Demonstrate the clinical utility of an expandable diameter cryoballoon, and discuss the potential advantages for occlusion, antral positioning, and lesion size. As part of the FROZEN AF Trial (NCT04133168) 50 patients received PVI ablation to treat PAF with a cryoballon capable of ablation at 28mm or 31mm. Follow-up is continuing, but we present procedural data and clinical application of this balloon. The extension arm of the FROZEN AF trial (NCT04133168) included 50 pts, 46% female and aged 64±13 years, indicated for PV isolation for treatment of PAF. Acute isolation was successful in all pts. Average procedure time was 101±59 min, with LA dwell of 51 min, and fluoroscopy of 7 min. General anesthesia was used in all patients, and the majority (49/50) underwent a single transeptal puncture. The novel 31mm configuration was used in 65% of ablations. In the 198 ablations performed at 31mm, 97.5% achieved a Grade 3 or 4 occlusion. Average nadir temperature was -54.89°C, and average TTI was 44s. In PVs where the first ablation was performed at 31mm the single shot isolation rate was significantly higher than in PVs where the first ablation was performed at 28mm. Data by PV are listed in Table 1. Notably, there was a low rate of phrenic nerve impairment, with only 1 instance of transient paralysis which resolved prior to discharge. Additionally, in a subset of pts at a single center, occlusion was assessed at both 28mm and 31mm, Figure 1. Preliminary landmark-based analysis of a subset of veins suggests that inflation to 31mm results in a marked antral shift of balloon position. The combination of maneuverability and variable size may make this balloon particularly useful in addressing challenges resulting from patient-to-patient variability in PV size and geometry. In particular, the choice between 28 and 31mm diameter in a single device may facilitate obtaining good occlusion, and the more antral positioning of a large balloon may give physicians more discretion as to the size and location of PVI lesions. As, the FROZEN AF trial is ongoing, long-term results in these patients are awaited.Tabled 1Usage, Occlusion and Single Shot Isolation rate of 28 and 31mm Balloon Sizesn Grade 4 Occlusion / N Total Ablation (%)n Single Shot Isolation / N PV (%)Pulmonary Vein28mm31mm28mm31mmLeft superior (LSPV)18 / 23 (78.3)41 / 45 (91.1)2/8 (25%)19/34 (55.9%)Left inferior (LIPV)17 / 19 (89.5)29 / 38 (76.3)4/12 (33.3%)23/30 (76.7%)Left common (LCPV)5 / 7 (71.4)6 / 19 (31.6)0/0 (%)1/8 (12.5%)Left middle (LMPV)1 / 1 (100)-1/1 (100%)0/0 (%)Right superior (RSPV)9 / 18 (50)49 / 56 (87.5)1/5 (20%)27/43 (62.8%)Right inferior (RIPV)21 / 38 (58.3)33 / 37 (89.2)10/24 (41.7%)17/24 (70.8%)Right common (RCPV)1 / 3 (33.3)2 / 3 (66.7)0/1 (0%)0/1 (0%)Total72 / 109 (67.3)160 / 198 (80.8)18/51 (35.3%)87/140 (62.1%)Single shot success in veins where first ablation was performed with specified balloon size. Only ablations with duration > 60s included in ablation counts Open table in a new tab

A Narrative Literature Review Addressing Causal, Risk, and Treatment of Paroxysmal Atrial Fibrillation

This study analyzes the causal and risk factors as well as different ways of treating paroxysmal atrial fibrillation to inform healthcare professionals and physicians in order to save many lives from Atrial fibrillation related death. Factually, it is estimated that 12.1 million people in the United States will have Atrial fibrillation in 2030. In 2019, Atrial fibrillation was mentioned on 183,321 death certificates and was the underlying cause of death in 26,535 of those deaths. Also, people of European descent are more likely to have Atrial fibrillation than African Americans. Because the number of Atrial fibrillation cases increases with age and women generally live longer than men, more women than men experience Atrial fibrillation. The study adopted a narrative literature review and Boolean search technique to identify 22 researches and review articles that are related to causal and risk factors as well as different ways of treating paroxysmal atrial fibrillation. As part of the study’s findings, out of the twenty-two articles, five of the researchers, thus 22%, revealed in the literature that Heart palpitation or flutter in the chest is one of the symptoms of Atrial fibrillation. Researchers of 4 articles—thus 18% -- clearly stated in their research that one of the symptoms of Atrial fibrillation (AF) is “patient’s chest pain/pressure”. The study further revealed that some of the causes and risk factors of Symptomatic Paroxysmal Atrial Fibrillation include the following: Advancing age, High blood pressure, Obesity, Diabetes, Heart failures, European Ancestry, patient’s lifestyles such as smoking and alcohol intake, as well as Chronic kidney disease, and Hyperthyroidism. Above all, this study revealed that Medications, Heart Rate Controls, Heart Rhythm Control, Blood Clots and Stroke Prevention, Electrical Cardioversion, Cardiac Ablation, Catheter Ablation, Surgical Ablation, and Maze Procedure are some of the different options of treating or curing Symptomatic Paroxysmal Atrial Fibrillation identified in the literature. Therefore, in order for healthcare professionals and physicians to help minimize mortality rate caused by Atrial fibrillation, they should pay more attention to patients’ symptoms, the AF risk factors, and to also align them with appropriate treatment options to help save many lives across the globe. Keywords: Atrial, Fibrillation, Symptomatic, Treatment, Risk-Factors, Heart, Stroke, Paroxysmal, Cardiac, Arrhythmia, Ablation, Surgical, Maze DOI: 10.7176/JHMN/107-03 Publication date: April 30 th 2023