Drug-refractory Paroxysmal Atrial Fibrillation Research Articles

Predictors of Success for Pulmonary Vein Isolation With Pulsed-Field Ablation Using a Variable-Loop Catheter With 3D Mapping Integration: Complete 12-Month Outcomes From inspIRE.

We previously presented the safety and early efficacy of inspIRE study (Pulsed-Field Ablation (PFA) System for the Treatment of Paroxysmal Atrial Fibrillation by Irreversible Electroporation). With the study's conclusion, we report the outcomes of the full pivotal study cohort, with an additional analysis of predictors of success. InspIRE was a prospective, multicenter, single-arm clinical trial of drug-refractory paroxysmal atrial fibrillation. Pulmonary vein isolation was performed with a variable-loop circular catheter integrated with a 3-dimensional mapping system. Follow-up with 24-hour Holter was at 3, 6, and 12 months, as well as remote rhythm monitoring: weekly from 3 to 5 months, monthly from 6 to 12 months, and for symptoms. The primary effectiveness end point (PEE) was acute pulmonary vein isolation plus freedom from any atrial arrhythmia at 12 months. Additional subanalyses report predictors of PEE success. The patient cohort included 186 patients: aged 59±10 years, female 30%, and CHA2DS2-VASc 1.3±1.2. The previously reported primary adverse event rate was 0%. One serious procedure-related adverse event, urinary retention, was reported. The PEE was achieved in 75.6% (95% CI, 69.5%-81.8%). The clinical success of freedom from symptomatic recurrence was 81.7% (95% CI, 76.1%-87.2%). Simulating a monitoring method used in standard real-world practice (without protocol-driven remote rhythm monitoring), this translates to a freedom from all and symptomatic recurrence of 85.8% (95% CI, 80.8%-90.9%) or 94.0% (95% CI, 90.6%-97.5%), respectively. Multivariate analyses revealed that left ventricular ejection fraction ≥60% (adjusted odds ratio, 0.30) and patients receiving ≥48 PFA applications (adjusted odds ratio, 0.28) were independent predictors of PEE success. Moreover, PEE success was 79.2% in patients who received ≥12 PFA applications/vein compared with 57.1% in patients receiving fewer PFA applications. The inspIRE study confirms the safety and effectiveness of pulmonary vein isolation using the novel 3-dimensional mapping integrated circular loop catheter. An optimal number of PFA applications (≥48 total or ≥12 per vein) resulted in an improved 1-year success rate of ≈80%. URL: https://www.clinicaltrials.gov; Unique identifier: NCT04524364.

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.

Use of artificial intelligence and I-Score for prediction of recurrence before catheter ablation of atrial fibrillation

BackgroundBased solely on pre-ablation characteristics, previous risk scores have demonstrated variable predictive performance. This study aimed to predict the recurrence of AF after catheter ablation by using artificial intelligence (AI)-enabled pre-ablation computed tomography (PVCT) images and pre-ablation clinical data. MethodsA total of 638 drug-refractory paroxysmal atrial fibrillation (AF) patients undergone ablation were recruited. For model training, we used left atria (LA) acquired from pre-ablation PVCT slices (126,288 images). A total of 29 clinical variables were collected before ablation, including baseline characteristics, medical histories, laboratory results, transthoracic echocardiographic parameters, and 3D reconstructed LA volumes. The I-Score was applied to select variables for model training. For the prediction of one-year AF recurrence, PVCT deep-learning and clinical variable machine-learning models were developed. We then applied machine learning to ensemble the PVCT and clinical variable models. ResultsThe PVCT model achieved an AUC of 0.63 in the test set. Various combinations of clinical variables selected by I-Score can yield an AUC of 0.72, which is significantly better than all variables or features selected by nonparametric statistics (AUCs of 0.66 to 0.69). The ensemble model (PVCT images and clinical variables) significantly improved predictive performance up to an AUC of 0.76 (sensitivity of 86.7% and specificity of 51.0%). ConclusionsBefore ablation, AI-enabled PVCT combined with I-Score features was applicable in predicting recurrence in paroxysmal AF patients. Based on all possible predictors, the I-Score is capable of identifying the most influential combination.

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.

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.

Comparison of the 11-Day Adhesive ECG Patch Monitor and 24-h Holter Tests to Assess the Response to Antiarrhythmic Drug Therapy in Paroxysmal Atrial Fibrillation.

Accurate assessment of the response to the antiarrhythmic drug (AAD) in atrial fibrillation (AF) is crucial to achieve adequate rhythm control. We evaluated the effectiveness of extended cardiac monitoring using an adhesive ECG patch in the detection of drug-refractory paroxysmal AF. Patients diagnosed with paroxysmal AF and receiving AAD therapy were enrolled. The subjects simultaneously underwent 11-day adhesive ECG patch monitoring and a 24-h Holter test. The primary study outcome was a detection rate of drug-refractory AF or atrial tachycardia (AT) lasting ≥30 s. A total of 59 patients were enrolled and completed the study examinations. AF or AT was detected in 28 (47.5%) patients by an 11-day ECG patch monitor and in 8 (13.6%) patients by a 24-h Holter test (p < 0.001). The 11-day ECG patch monitor identified an additional 20 patients (33.8%) with drug-refractory AF not detected by the 24-h Holter, and as a result, the treatment plan was changed in 11 patients (10 catheter ablations, one medication change). In conclusion, extended cardiac rhythm monitoring using an adhesive ECG patch in patients with paroxysmal AF under AAD therapy led to over a threefold higher detection of drug-refractory AF episodes, compared to the 24-h Holter test.

Four typical pulmonary venous pressure curves displaying the level of occlusion during atrial fibrillation ablation by cryoballoon.

Cryoballoon ablation is safe and effective for pulmonary vein isolation in patients with symptomatic drug-refractory paroxysmal atrial fibrillation. To monitor adhesion between the balloon and the pulmonary vein, an alternative technique to pulmonary venography is to analyze changes in the pressure curve. We have described the adhesion level characterized by four types of pressure waveforms. These correlated with the extent of contrast agent leakage (Cohen's kappa of 0.81 [IC 95%: 0.63-0.99]). Monitoring the venous pressure curve is easy to perform and has the advantage of being able to detect balloon movement during the first few seconds of treatment.

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.)

Atrial fibrillation progression after cryoablation vs. radiofrequency ablation: the CIRCA-DOSE trial.

Atrial fibrillation (AF) is a chronic progressive disorder. Persistent forms of AF are associated with increased rates of thromboembolism, heart failure, and death. Catheter ablation modifies the pathogenic mechanism of AF progression. No randomized studies have evaluated the impact of the ablation energy on progression to persistent atrial tachyarrhythmia. Three hundred forty-six patients with drug-refractory paroxysmal AF were enrolled and randomly assigned to contact-force-guided RF ablation (CF-RF ablation, 115), 4 min cryoballoon ablation (CRYO-4, 115), or 2 min cryoballoon ablation (CRYO-2, 116). Implantable cardiac monitors placed at study entry were used for follow-up. The main outcome was the first episode of persistent atrial tachyarrhythmia. Secondary outcomes included atrial tachyarrhythmia recurrence and arrhythmia burden on the implantable monitor. At a median of 944.0 (interquartile range [IQR], 612.5-1104) days, 0 of 115 patients (0.0%) randomly assigned to CF-RF, 8 of 115 patients (7.0%) assigned to CRYO-4, and 5 of 116 patients (4.3%) assigned to CRYO-2 experienced an episode of persistent atrial tachyarrhythmia (P = .03). A documented recurrence of any atrial tachyarrhythmia ≥30 s occurred in 56.5%, 53.9%, and 62.9% of those randomized to CF-RF, CRYO-4, and CRYO-2, respectively; P = .65. Compared with that of the pre-ablation monitoring period, AF burden was reduced by a median of 99.5% (IQR 94.0%, 100.0%) with CF-RF, 99.9% (IQR 93.3%-100.0%) with CRYO-4, and 99.1%% (IQR 87.0%-100.0%) with CRYO-2 (P = .38). Catheter ablation of paroxysmal AF using radiofrequency energy was associated with fewer patients developing persistent AF on follow-up.

Fractal complexity alternations in paroxysmal atrial fibrillation patients with and without recurrence after pulmonary vein isolation.

Pulmonary vein isolation (PVI) is a cornerstone therapy for paroxysmal atrial fibrillation (PAF). The variations in nonlinear heart rate variability (HRV) between patients with and without recurrences remain unclear. We aimed to characterize the nonlinear HRV before and after PVI in patients with and without recurrence. Twenty-five drug-refractory PAF patients (56.0 ± 9.1 years old, 20 males) who received PVI were enrolled. Holter electrocardiography were performed before, 1-3, and 6-12 months after PVI. After 8.2 ± 2.5 months of follow-ups after PVI, patients were divided into two groups: the recurrence (n = 8) and non-recurrence (n = 17) groups. Linear and nonlinear HRV variables were analyzed, including the Poincaré Plot analysis and the Detrended Fluctuation Analysis (DFA). The non-recurrence group, but not the recurrence group, had decreased high-frequency component (HF), the root mean square of successive RR interval differences (RMSSD), and the Poincaré Plot index SD1 1-3 months after PVI and increased DFAslope2 6-12 months after PVI. The non-recurrence group's LF/HF ratio and DFAslope1 decreased significantly 1-3 and 6-12 months after PVI, respectively, whereas there was no significant change in the recurrence group after PVI. Significantly reduced vagal tone 1-3 months after PVI, increased long-term fractal complexity 6-12 months after PVI, and decreased sympathetic tone as well as short-term fractal complexity 1-3 and 6-12 months after PVI led to a better AF-free survival after PVI. These findings suggest that neuromodulation and heart rate dynamics play crucial roles in AF recurrence following PVI.

Novel Radiofrequency Balloon Catheter　- Impact of Ablation Parameters on Single-Shot Isolation.

A novel multielectrode radiofrequency balloon (RFB) catheter has been released for pulmonary vein isolation (PVI).Methods and Results: In this observational study consecutive patients with drug-refractory paroxysmal or persistent atrial fibrillation (AF) undergoing first-time PVI were enrolled in 2 high-volume ablation centers. All procedures were conducted in conjunction with a 3D-mapping system. Clinical, procedural and ablation parameters were systematically analyzed. 105 patients (58% male; 52% paroxysmal AF, 68±11.3 years mean age, left atrial volume index 38.6±14.8 mL/m2) were included. 241/412 (58.5%) PVs were successfully isolated with a single shot (SS), with a time-to-isolation of 11.6±8 s. Total number of radiofrequency applications was 892 (mean 2.2/PV), resulting in successful isolation of 408/412 (99%) PVs at the end of the procedure. Mean electrodes' impedance drop was significantly higher in the SS-PVI compared with non-SS applications (21.5±6.6 vs. 18.6±6.5 Ohm). Concordantly, higher temperature rise was observed in the SS vs. non-SS applications (10.9±4.9℃ vs. 9.6±4.7℃). In this multicenter real-world study, mean impedance drop and temperature rise were associated with successful SS-PVI applying the novel RFB catheter. These parameters may help to guide efficient usage of the new RF balloon.

Sex differences in paroxysmal atrial fibrillation catheter ablation: A difference-in-difference propensity score matched analysis.

Whether male and female patients with atrial fibrillation (AF) differ in their risk of recurrence after catheter ablation remains controversial. Large differences in baseline characteristics between males and females often affect study results. Patients with drug-refractory paroxysmal AF who received their first catheter ablation procedure between January 2018 and December 2020 were retrospectively enrolled. Propensity score matching was used to adjust for age, body mass index, and AF duration. Our main concerns were sex differences in comorbidities, procedures, arrhythmia recurrences, and procedure-related complications. For this study, 352 patients (176 pairs) were matched, and baseline characteristics were comparable between the two groups. Intraprocedural sex differences were apparent as more male patients received cavotricuspid isthmus ablation (55.00%vs. 31.43%, p=.005). Full follow-up, 1-year, 2-year, and 3-year AF recurrence rates were comparable between male and female groups. Multivariable Cox regression showed that the recurrence risk of paroxysmal AF was similar between male and female patients. AF duration was the only potential risk factor and occurred for only male patients. There were no significant differences in the subgroup analyses. Procedure-related complications were comparable between the male and female groups. We did not observe differences in baseline characteristics, arrhythmia recurrences, or procedure-related complications between male and female patients. Sex differences were reflected mainly in the finding that male patients received more cavotricuspid isthmus ablations, and atrial fibrillation duration was the only potential risk factor for recurrence and only for male patients.

Pulmonary vein isolation with a novel radiofrequency balloon catheter: real-world predictors of single shot isolation

Abstract Funding Acknowledgements Type of funding sources: None. Background A novel multi-electrode radiofrequency balloon (RFB) catheter has been released for pulmonary vein isolation (PVI). Objectives First multicenter real-world study to evaluate predictors of single shot PVI with the novel RFB catheter. Methods In this observational study consecutive patients with drug refractory paroxysmal or persistent atrial fibrillation (AF) undergoing first-time PVI were enrolled in two high-volume ablation centers. All procedures were conducted in conjunction with a 3D-mapping system. Clinical, procedural and ablation parameters were systematically analyzed. Results 105 patients (58% males; 52% paroxysmal AF, 68 ± 11.3 mean age, left atrial volume index 38.6 ± 14.8 ml/m2) were included. 241/412 (58.5%) pulmonary veins were successfully isolated with a single shot (SS), with a time to isolation of 11.6 ± 8 s. Total number of radio frequency applications was 892 (mean 2.2/PV), resulting in successful isolation of 408/412 (99%) PVs at the end of the procedure. Mean electrodes’ impedance drop was significantly higher in the SS-PVI compared to the non-SS applications (21.5 ± 6.6 vs. 18.6 ± 6.5 Ohm). Concordantly, higher temperature rise was observed in the SS versus non-SS applications (10.9 ± 4.9°C vs. 9.6 ± 4.7°C). Conclusion In this multicenter real-world study, mean impedance drop and temperature rise emerged as valid predictors for SS-PVI with the novel RFB catheter. These parameters may help to guide efficient usage of the new RF balloon.

Robotic magnetic navigation-guided pulmonary vein isolation in an atrial fibrillation patient with dextrocardia situs inversus: techniques and potential advantages

BackgroundDextrocardia with situs inversus (DSI) is a very rare congenital anomaly. Catheter manipulation and ablation of atrial fibrillation (AF) in patients with this anatomical variant is challenging for the operators. This case report presents a safe and effective AF ablation guided by the robotic magnetic navigation (RMN) system in combination with intracardiac echocardiograhy (ICE) in a patient with DSI.Case presentationA 64-year-old male with DSI was referred for catheter ablation of symptomatic, drug-refractory paroxysmal AF. One transseptal access was achieved via the left femoral vein under the guidance of ICE. The three-dimensional reconstruction of the left atrium and the pulmonary veins (PVs) were performed by the magnetic catheter using the CARTO and the RMN system. Then, the electroanatomic map and pre-acquired CT images were merged. Finally, bilateral circumferential ablation lines were delivered around the ipsilateral PV ostia to achieve complete PV isolation (PVI).ConclusionsThis case demonstrates that AF catheter ablation under the guidance of the RMN system using ICE is feasible and safe in a patient with DSI. Moreover, the combination of these technologies broadly facilitates treatment of patients with complex anatomy, while reducing the risk of complications.

PO-05-133 PROLONGED NEUROMODULATION EFFECTS AFTER PULMONARY VEIN ISOLATION IN PATIENTS WITH PAROXYSMAL ATRIAL FIBRILLATION: INSIGHT FROM THE NONLINEAR HEART RATE DYNAMICS

Heart rate variability (HRV) reveals information undetected by direct electrocardiogram morphology evaluation. Prior research indicated that patients with paroxysmal atrial fibrillation (PAF) had altered a short-term linear HRV after pulmonary vein isolation (PVI). However, the long-term changes in the nonlinear heart rate dynamics before and after PVI remain unclear. The objective was to investigate the long-term nonlinear HRV changes before and after PVI in PAF patients. We enrolled 42 drug-refractory symptomatic PAF patients who underwent PVI. Holter monitoring were done less than 1 year before, 1∼3, and 6∼12 months after PVI, respectively. The nonlinear HRV variables, including sample entropy (SampEn), multi-scale entropy (MSE), detrended fluctuation analysis (DFA), and Poincaré Plot analysis, were analyzed. Significant reductions in SD1, SD1/SD2, MSE 1∼5, MSE 6∼20, and SampEn occurred 6∼12 months after when compared to those before PVI, respectively. SD2, MSE slope 5, DFA slope 1 decreased 1∼3 months after PVI when compared to those before PVI, respectively, whereas increased significantly 6∼12 months after PVI when compared to those 1∼3 months after PVI, respectively. DFA slope2 increased significantly after PVI when compared to that before PVI. Detailed parameters are shown in the Table 1. As measured by DFA slope2, fractal correlation properties increased significantly following PVI. Heart rate complexity (MSE 1∼5, MSE 6∼20, and SampEn) and unpredictability of an RR time series (SD1/SD2) decreased significantly after PVI, whereas long-term RR interval (SD2) and short-term complexity (MSE slope 5) decreased in the 1∼3 months after PVI and then increased in 6∼12 months after PVI. These results indicated that the neuromodulation effects from PVI was far more prolonged and extensively than expected.Tabled 1Table 1. Serial changes in the HRV parametersPatients with PAF who underwent PVI (n = 42)< 1 year pre-PVI1∼3 months post-PVI6∼12 months post-PVISD121.16 ± 8.416.31 ± 11.08∗14.19 ± 8.63∗SD2177.58 ± 44.38134.92 ± 37∗146.46 ± 37.52∗+SD1/SD20.12 ± 0.060.12 ± 0.090.1 ± 0.06∗+DFA slope11.11 ± 0.240.8 ± 0.31∗0.94 ± 0.31∗+DFA slope21.07 ± 0.11.16 ± 0.13∗1.15 ± 0.11∗MSE 1∼55.62 ± 1.824.76 ± 1.74∗4.72 ± 1.59∗MSE 6∼2019.81 ± 5.6716.01 ± 5.6∗17.3 ± 4.75∗MSE slope50.06 ± 0.07-0.01 ± 0.09∗0.03 ± 0.07+SampEn1 ± 0.321.01 ± 0.290.9 ± 0.26∗+Data are expressed as (mean ± SD); DFA slope1: Detrended fluctuation analysis slope 1; DFA slope2: Detrended fluctuation analysis slope 2; MSE 1∼5, the summation of entropy values of scales 1 to 5; MSE 6∼20, the summation of entropy values of scales 6 to 20; MSE slope 5, the linear-fitted slope of scales 1 to 5; SD1, Poincaré plot standard deviation perpendicular the line of identity; SD2, Poincaré plot standard deviation along the line of identity; SD1/SD2, SD1-to-SD2 ratio; SampEn, sample entropy; *: p < 0.05 versus < 1 year pre-PVI; +: p < 0.05 versus 1∼3 months post-PVI Open table in a new tab

670 DEXMEDETOMIDINE SEDATION FOR PULMONARY VEIN ISOLATION PROCEDURE

Abstract Background Peri-procedural anesthesia for catheter ablation of atrial fibrillation (AF) varies from conscious sedation to general anesthesia. Current guidelines do not suggest any specific strategy, thus the choice between different protocols is mainly driven by local expertise, operator and/or patient preference and availability of a dedicated anesthesiology team. Propofol is often the drug of choice despite the risk of respiratory depression. Few data have recently reported operator-directed nurse-administered dexmedetomidine (DEX) sedation as an effective and safe strategy. Aim of the study To evaluate the outcomes of operator-directed nurse-administered DEX sedation in AF ablation (pulmonary vein isolation-PVI). Method Between May 2022 and August 2022, 41 consecutive patients (male 83%, median age 64 years, IQR 57-71) with drug-refractory paroxysmal (n.27;66%) or persistent AF (n.14;34%) underwent first PVI procedure under DEX sedation. Our sedation protocol consisted of continuous intravenous administration of DEX (0.2–0,7 µg/kg/hr) titrated throughout the procedure to achieve mild to moderate sedation (Modified Observer's Assessment of Alertness and Sedation Scale 2-3). A single dose of Ondansetron (4 mg) was administered in the beginning of procedure. Adjunctive doses of fentanyl (cumulative dose 50-100 µg) were administered before the beginning of radiofrequency (RF) delivery and in case of inadequate control of the pain. A low dose propofol bolus (&amp;lt;1mg/kg) was eventually added for electrical cardioversion (ECV). Sedation-related complications were evaluated, including sustained hypoxemia (SpO2 &amp;lt;90%), need of anesthesiologist support and persistent hypotension (SBP &amp;lt; 90 mmHg). The day after the procedure, patients’ satisfaction and pain (0-100 scale) were assessed by a standardized questionnaire. Results Pulmonary vein isolation was performed either with Low Power Long Duration (LPLD, n.17;41,46%) or High-Power Short Duration (HPSD, n.24;58,54%) RF protocol. Median procedure time was 135’ (IQR 110-170’). Median DEX dose was 0,30 µg/kg/hr (IQR 0,27-0,33 µg/kg/hr). Median fentanyl dose was 75 µg (IQR 50-100 µg). In patients needing for ECV (n. 16; 39%), median propofol dose was 60 mg (IQR 47,5–105 mg). Thirteen patients (31,7%) had one or more significant risk factor (obesity, severe heart failure, pulmonary comorbidity, coronary artery disease) for anesthesia-related complications. Median pain scale value was 20 (IQR 10-50). Majority of patients (90,2%, n.37) reported mild to moderate pain (pain &amp;lt;60/100) during the procedure and satisfaction was overall high (median value 90, IQR 80-100), with a 90,2% of patients declaring a satisfaction of 60/100 or more. These results were independent from baseline characteristics (sex, age, AF type, HF, CAD, pulmonary comorbidity, obesity) and procedural aspects (LPLD vs HPSD, procedure time, need for ECV). A strong linear correlation was found between patients’ satisfaction and reported pain (r=-0,59). Only 1 (2,4%) sedation-related complication occurred, consisting in sustained post procedural hypotension treated with volume repletion. Conclusions in our experience, dexmedetomidine (DEX) sedation protocol during catheter ablation of atrial fibrillation is associated to high patients’ satisfaction and no respiratory complications. It seems to be also feasible in patients at higher risk for anesthesia-related complications (severe heart failure, BMI &amp;gt; 30 kg/m2), generally excluded from previous studies.

Comparison of Radiofrequency and Cryoballoon Pulmonary Vein Ablation for the Early and Late Recurrence of Atrial Fibrillation.

Objective Early recurrence (ER) after pulmonary vein isolation (PVI) for atrial fibrillation (AF) is expected to resolve within the recommended 3-month blanking period, irrespective of the ablation device used. To compare the occurrence and relationship of AF within the blanking period and subsequent late recurrence (LR) with radiofrequency (RF) and cryoballoon (CB) ablation. Methods A retrospective analysis of 294 patients (mean age=62±9, 70.0% male) undergoing PVI for drug-refractory paroxysmal AF was done. After categorizing the patients into the RF group (n=152) and the CB group (n=142), a group-wise comparison was done to investigate the impact of ER on LR throughout a 2-year follow-up. Results The groups were similar regarding the occurrence of ER (RF=22.4%, CB=24.6%, p=0.62), while LR was significantly higher in the RF group (p=0.003). ER was associated with LR in the RF group (p<0.01) but not in the CB group (p=0.08), while a significant independent association with an increased LR risk was observed [hazard ratio (HR) 6.12; 95% confidence interval (CI) 3.56-10.51, p<0.01]. RF ablation also significantly increased the risk of LR (HR=2.93; 95% CI=1.64-5.23, p<0.01). Conclusion A recurrence of atrial arrhythmia is more frequent with RF-PVI than with CB-PVI for patients with paroxysmal AF. ER and RF-ablation are strong predictors for LR after the 3-month blanking period.

Predictive value of HMGB1 for atrial fibrillation recurrence after cryoballoon ablation in paroxysmal atrial fibrillation patients.

Cryoballoon ablation (CBA) is recommended for patients with symptomatic drug refractory paroxysmal atrial fibrillation (pAF). However, substantial atrial fibrillation (AF) recurrence is common during follow-up. Searching for a potential biomarker representing both myocardial injury and inflammation to identify patients at high risk of AF recurrence after CBA is very meaningful for postoperative management of AF patients. To evaluate the clinical efficacy of high-mobility group box 1 (HMGB1) protein released from the left atrium to predict AF recurrence in pAF patients after CBA at 1-year follow-up. We included 72 pAF patients who underwent CBA. To determine the expression levels of HMGB1, left atrial blood samples were collected from the patients before CBA and after the procedure through the transseptal sheath. Patients were followed up for AF recurrence for 1 year. A total of 19 patients of the 72 experienced AF recurrence. The level of postoperative HMGB1 (HMGB1post) was higher in the AF recurrence group than in the AF non recurrence group (p = .03). However, no differences were noted in the levels of other biomarkers such as preoperative high-sensitivity C-reactive protein (hs-CRP), postoperativehs-CRP, and preoperative HMGB1 between the two groups. Multiple logistic regression analysis revealed that a higher level of serum HMGB1post was associated with AF recurrence (odds ratio: 5.29 [1.17-23.92], p = .04). Receiver operating characteristic analysis revealed that HMGB1post had a moderate predictive power for AF recurrence (area under the curve: 0.68; sensitivity: 72%; and specificity: 68%). The 1-year AF-free survival was significantly lower in patients with a high HMGB1post level than in those with a low HMGB1post level (hazard ratio: 3.81 [1.49-9.75], p = .005). In pAF patients who under went CBA, the level of HMGB1 after CBA was associated with AF recurrence and demonstrated a moderate predictive power. Thus, we offer a potential biomarker to identify pAF patients at high risk of AF recurrence.

Thoracoscopic epicardial ablation of atrial fibrillation: Safety, efficacy, single center experience.

Atrial fibrillation (AF) is associated with reduced quality of life and increased risk of ischaemic cerebrovascular events. The left atrial epicardial ablation procedures have evolved towards a successful and safe rhythm control strategy for patients with symptomatic drug-refractory paroxysmal, persistent or post-ablation AF or with a high risk of catheter ablation failure. The aim was to evaluate the efficacy and safety of thoracoscopic ablation at our instituiton. We observed 81 patients undergoing thoracoscopic ablation from January 2015 to December 2019. The mean age was 61.3±8.5 years and the average duration of AF was 3.1±2.6 years. The cohort consisted of 16.5% of paroxysmal AF, 36.7% persistent, and 46.8% of long-standing AF. The procedure was completed in 79 patients; during follow-up, 15 patients (19%) received radiofrequency ablation. Freedom from atrial arrhythmia recurrence was 55.7% after a follow-up (FUP) period of 3.1 ± 1.4 years. At the follow-up visit, sinus rhythm was present in 81% of patients. No relationships between arrhythmia recurrence and BMI, LVEF, left atrial dimension, gender, and AF duration were found. Major complications were noticed in 4 patients (5.0%); 2 had peripheral embolisation, 2 patients were converted to a sternotomy. At the time of the FUP visit, 25.3% of patients were using antiarrhythmic and 74.7% were still using anticoagulants. In the majority of patients, sinus rhythm remained despite a considerable atrial tachycardia recurrence rate, with a relatively low percentage of patients on antiarrythmic drugs.

Alteration of Skin Sympathetic Nerve Activity after Pulmonary Vein Isolation in Patients with Paroxysmal Atrial Fibrillation.

Autonomic system plays a pivotal role in the pathogenesis of paroxysmal atrial fibrillation (AF). Skin sympathetic nerve activity (SKNA) is a noninvasive tool for assessing sympathetic tone. However, data on changes in SKNA after ablation are limited. Here, we retrospectively enrolled 37 patients with symptomatic drug-refractory paroxysmal AF who underwent pulmonary vein isolation (PVI) with radiofrequency ablation (RFA) or cryoablation (CBA). SKNA was measured from the chest and right arm 1 day prior to ablation, as well as 1 day and 3 months after ablation. One day after ablation, the SKNA-Arm increased from 517.1 µV (first and third quartiles, 396.0 and 728.0, respectively) to 1226.2 µV (first and third quartiles, 555.2 and 2281.0), with an increase of 179.8% (125% and 376.0%) (p < 0.001); the SKNA-Chest increased from 538.2 µV (first and third quartiles, 432.9 and 663.9) to 640.0 µV (first and third quartiles, 474.2 and 925.6), with an increase of 108.3% (95.6% and 167.9%) (p = 0.004), respectively. In those without recurrence, there was a significant increase in SKNA 1 day after ablation as compared with those before ablation. Twelve patients received SKNA measurement 3 months after ablation; both SKNA-Arm (p = 0.31) and SKNA-Chest (p = 0.27) were similar to those before ablation, respectively. Among patients with symptomatic drug-refractory paroxysmal AF receiving PVI, increased SKNA was observed 1 day after ablation and returned to the baseline 3 months after ablation. Elevation of SKNA was associated with lower early and late recurrences following ablation.