Conventional Catheter Ablation Research Articles

History of stroke as a predictor of high left atrial fibrosis in patients with persistent atrial fibrillation-insight from the DECAAF II randomized trial.

There is a strong relationship between left atrial (LA) remodeling and ischemic stroke (IS) risk in atrial fibrillation (AF) patients. The Efficacy of Delayed Enhancement MRI-Guided Ablation vs. Conventional Catheter Ablation of Atrial Fibrillation (DECAAF-II) is the biggest MRI-based, randomized, multicenter clinical trial performed on persistent AF patients. The aim of this study is to evaluate the relationship between history of stroke and atrial fibrosis in the DECAAF II population. Persistent AF patients who underwent Late Gadolinium Enhancement Magnetic Resonance Imaging (LGE-MRI) were included in the study and divided into two different groups: those with a history of stroke and those without. Propensity score matching was performed to adjust for covariates. Atrial fibrosis was compared in both groups. Then, patients were divided into different fibrosis groups, using three different cut-offs of baseline atrial fibrosis: ≥ 15%, ≥ 20%, and ≥ 25%. Univariate logistic regression and adjusted multivariate analysis were performed to assess the effect of clinical characteristics and risk factors on baseline fibrosis. Eight-hundred forty-three patients were recruited in DECAAF II, of whom 70 (8.3%) had a history of stroke. Patients with history of stroke had a higher prevalence of hypertension (p = 0.043), diabetes (p = 0.014), and hyperlipidemia (p = 0.001). Seventy patients with no history of strokes were matched with patients with history of stroke to adjust for covariates using propensity score analysis. Patients in the stroke group had a significantly higher level of fibrosis than those without (20.2% vs. 8.1%, p = 0.017). Increased age was a significant predictor of all three baseline fibrosis classes (≥ 15%, ≥ 20%, and ≥ 25%). Additionally, history of stroke was found to be a predictor of baseline fibrosis ≥ 25% even after adjusting for other clinical characteristics and risk factors (OR = 1.98 [1.14-3.43], p = 0.01). Left atrial fibrosis level greater than 25% correlates with the history of previous stroke episodes in patients with persistent atrial fibrillation.

Real life experience with point by point pulsed field ablation for recurrent ventricular arrhythmias

Abstract Introduction The safety and effectiveness of electroporation/point by point pulsed field ablation (PP PFA) as emerging technoloy for catheter ablation (CA) of ventricular arrhythmias (VAs) has been described till now only in case reports. Purpose The aim of this observational retrospective study is to present real life data concerning the overall performance of PP PFA for CA of recurrent VA. Methods A total number of 13 consecutive patients (11 VTs and 2 PVCs), in whom recurrent VTs after RF ablation documented, were included. In all patients the substrate location was documented beforehand based on cardiac MRI or CT with myocardial thinning. For substrate mapping a high resolution multipoint mapping catheter was used. A complete success was defined as non inducibility of any arrhythmia at the end of procedure respectively lack of VA recurrence at follow – up. Results Excepting 2 patients, all other had a non ischemic cardiomyopathy as underlying heart disease (mean age 63 ± 8 y/o, mean LVEF 42 % ± 9 %). In every patient at least one conventional RF CA has been performed previously (mean 2 ± 1) and 38 % of patients had a previous epicardial RF VT ablation. The PP PFA VT ablation was performed endocardialy in 11 patients (84 %), respectively epicardialy in 2 patients. The ablation sites had a septal location in 53 % of patients and other localisation in 47 % of patients. The applied energy was 25 A. The overall acute complete success was achieved in 77 % patients. At medium 6 ± 3 months follow up a complete success was present in 46 % cases. Most frequently a VT recurrence after PP PFA ablation was encountered in patients with combined septal and nonseptal substrate distrubution. After PP PFA, the RF CA strategy due to recurrent VAs was endocardial in 2 patients, respectively epicardial 2 in cases and bipolar in 1 case. No PP PFA redos were undergone. Three major complications have been documented (1 tamponade, 1 AV block III° and 1 complete LBBB). Conclusion As bailout strategy in patients with failed conventional CA, PP PFA represents a safe strategy. Specific complications like temporary atrioventricular or intraventricular conduction disturbancies are extremely rare, reversible but not life threathening. The midterm success is satisfactory but still limited in patients with intramural substrate.

An Economic Evaluation of a Streamlined Day-Case Atrial Fibrillation Ablation Protocol and Conventional Cryoballoon Ablation versus Antiarrhythmic Drugs in a UK Paroxysmal Atrial Fibrillation Population.

Symptom control for atrial fibrillation can be achieved by catheter ablation or drug therapy. We assessed the cost effectiveness of a novel streamlined atrial fibrillation cryoballoon ablation protocol (AVATAR) compared with optimised antiarrhythmic drug (AAD) therapy and a conventional catheter ablation protocol, from a UK National Health Service (NHS) perspective. Data from the AVATAR study were assessed to determine the cost effectiveness of the three protocols in a two-step process. In the first stage, statistical analysis of clinical efficacy outcomes was conducted considering either a three-way comparison (AVATAR vs. conventional ablation vs. optimised AAD therapies) or a two-way comparison (pooled ablation protocol data vs. optimised AAD therapies). In the second stage, models assessed the cost effectiveness of the protocols. Costs and some of the clinical inputs in the models were derived from within-trial cost analysis and published literature. The remaining inputs were derived from clinical experts. No significant differences between the ablation protocols were found for any of the clinical outcomes used in the model. Results of a within-trial cost analysis show that AVATAR is cost-saving (£1279 per patient) compared with the conventional ablation protocol. When compared with optimised AAD therapies, AVATAR (pooled conventional and AVATAR ablation protocols efficacy) was found to be more costly while offering improved clinical benefits. Over a lifetime time horizon, the incremental cost-effectiveness ratio of AVATAR was estimated as £21,046 per quality-adjusted life-year gained (95% credible interval £7086-£71,718). The AVATAR streamlined protocol is likely to be a cost-effective option versus both conventional ablation and optimised AAD therapy in the UK NHS healthcare setting.

Dipole Density Guided Catheter Ablation versus Conventional Substrate Modification for Repeat Catheter Ablation of Persistent Atrial Fibrillation.

The optimal ablation strategy for recurrent persistent atrial fibrillation (persAF) after initially successful catheter ablation (CA) remains debatable. Dipole density (DD) guided CA using the AcQMap system has been proven to be feasible and effective in patients with persAF. So far, long-term outcome data for DD-guided CA in patients with recurrence of persAF are sparse. This study sought to assess long-term outcome data in patients undergoing a DD-guided CA for recurrence of persAF after previous CA in comparison to conventional repeat CA. Patients undergoing DD-guided CA for recurrence of persAF after previous ablation were compared to patients undergoing conventional substrate modification (CSM). A total of 64 patients (32 DD-guided and 32 CSM) were included in this analysis. Procedure duration (DD: 236 ± 61 min; CSM: 198 ± 59 min; p = 0.004) and fluoroscopy time (DD: 36 ± 15 min; CSM: 20 ± 11 min; p = 0.0001) were significantly longer in the DD group. After a long-term median follow-up (FU) of 27 months (interquartile range 12.8-34.3), DD-guided CA was inferior to CSM regarding overall arrhythmia-free survival (DD: 6 patients (19%), CSM: 11 patients (34%); HR 1.47; p = 0.04). Freedom from AF did not differ between both groups (DD: 16 patients (50%); CSM: 18 patients (56%), HR 0.99, p = 0.47). During FU, more patients underwent repeat CA after DD-guided ablation (DD: 16 patients (50%), CSM: 7 patients (22%), p = 0.04). No major complications occurred overall. Dipole density-guided CA is equally safe but associated with longer procedure duration compared to conventional substrate modification for treatment of recurrent persAF after previous CA. Of note, long-term arrhythmia-free survival is significantly worse after DD-guided ablation, and more patients undergo redo procedures.

Empirical Marshall vein ethanol infusion as the first-line strategy in patients with persistent atrial fibrillation undergoing mitral isthmus ablation

Abstract Background Marshall vein ethanol infusion (MVEI) as an additional therapy to conventional catheter ablation (CA) has been proved to be efficacious in patients with persistent atrial fibrillation (PeAF). However, whether empirical MVEI could be the first-line strategy in mitral isthmus (MI) ablation has seldomly been investigated. Objective To compare the efficacy, safety and long-term outcomes between provisional and empirical MVEI in PeAF patients undergoing their index MI ablation. Methods We enrolled 133 propensity-score matched patients with PeAF at a ratio of 1:2.5 either into the provisional group (n=38, MVEI was performed when conventional endocardial and/or epicardial ablations were inadequate to achieve bidirectional MI block) or the empirical group (n=95, MVEI was applied empirically before MI CA). Baseline characteristics, procedure results and long-term outcomes were compared between groups. Results All of the baseline characteristics were comparable. Less spontaneous or inducible atrial tachycardias (ATs) including MI-dependent ones were encountered in the empirical group (P<0.001). More epicardial ablations were applied (26.3% vs 9.5%, P=0.016) and higher incidence of CA-facilitated restoration of sinus rhythm was recorded (86.8% vs 11.7%, P<0.001) in the provisional group. Although more fluoroscopy time (6.4[4.2, 9.3] vs 9.5[5.9, 11.6] min, P=0.019) and radiation exposure (69.0[25.3, 160.2] vs 122.0[62.5, 234.1] mGy, P=0.010) were documented in the empirical group with comparable procedure time, less time was consumed to achieve bidirectional MI block during endocardial ablation in the empirical group (455.9±192.2 vs 366.5±161.3 sec, P=0.038). Incidences of procedure-related complications were similar between groups. During a 16.5±4.4-month follow-up, the empirical group showed significantly higher freedom from AT recurrence (81.6% vs 95.8%, log-rank P=0.003), while the freedoms from AF recurrence were similar. Both univariate (HR 0.19, 95%CI 0.05-0.64, P=0.008) and multivariate (HR 0.25, 95%CI 0.07-0.92, P=0.037) Cox regression analyses indicated that empirical MVEI was independently associated with lower long-term AT recurrence. Conclusion Among patients with PeAF underwent their index MI ablations, empirical MVEI could reduce the endocardial MI ablation time and improve the long-term freedom from AT recurrence.Flowchart of the study.Freedoms from AF and AT recurrence

Efficacy and feasibility of vein of Marshall ethanol infusion during persistent atrial fibrillation ablation: A systematic review and meta-analysis.

Catheter ablation (CA) is currently used to treat persistent atrial fibrillation (PeAF). However, its effectiveness is limited. This study aimed to estimate the effectiveness of the vein of Marshall absolute ethanol injection (VOM-EI) for PeAF ablation. Adjunctive vein of Marshall ethanol injection (VOM-EI) strategies are more effective than conventional catheter ablation (CA) and have similar safety outcomes. We extensively searched the literature for studies evaluating the effectiveness and safety of VOM-EI + CA compared with CA alone. The primary endpoint was the rate of acute bidirectional block of the isthmus of the mitral annulus (MIBB). The secondary endpoints were atrial fibrillation (AF) or atrial tachycardia (AT) recurrence over 30seconds after a 3-month blanking period. Weighted pooled risk ratios (RRs) and corresponding 95% confidence intervals (CIs) were calculated using a random effects model. Based on the selection criteria, nine studies were included in this systematic review, including patients with AF (n = 2508), persistent AF (n = 1829), perimitral flutter (n = 103), and perimitral AT (n = 165). There were 1028 patients in the VOM-EI + CA group and 1605 in the CA alone group. The VOM-EI + CA group showed a lower rate of AF/AT relapse (RR = 0.70; 95% CI = 0.53-0.91; p = .008) and a higher rate of acute MIBB (RR = 1.29; 95% CI = 1.11-1.50; p = .0007) than the CA alone group. Our meta-analysis revealed that adjunctive VOM-EI strategies are more effective than conventional CA and have similar safety outcomes.

Smartphone AF Burden During the Blanking Period Predicts Catheter Ablation Outcomes: Insights From DECAAF II

BackgroundAtrial fibrillation (AF) recurrence during the blanking period is under investigated. With the rise of smartphone-based electrocardiogram (ECG) monitoring, there's potential for better prediction and understanding of AF recurrence trends. ObjectivesIn this study the authors hypothesize that AF burden derived from a single-lead Smartphone ECG during the blanking period predicts recurrence of atrial arrhythmias after ablation. Methods630 patients with persistent AF undergoing ablation were included from the DECAAF II (Effect of MRI-Guided Fibrosis Ablation vs Conventional Catheter Ablation on Atrial Arrhythmia Recurrence in Patients With Persistent Atrial Fibrillation) trial. Patients recorded daily ECG strips using a smartphone device. AF burden was defined as the ratio of ECG strips with AF to the total number of strips submitted. The primary outcome was the recurrence of atrial arrhythmia. ResultsRecurrence occurred in 301 patients during the 18-month follow-up period. In patients who developed recurrent arrhythmia after 90 days of follow-up, AF burden during the blanking period was significantly higher when compared with patients who remained in sinus rhythm (31.3% vs 7.5%; P < 0.001). AF burden during the blanking period was an independent predictor of arrhythmia recurrence (HR: 1.41; 95% CI: 1.36-1.47; P < 0.001). Through grid searching, an AF burden of 18% best discriminates between recurrence and no-recurrence groups, yielding a C-index of 0.748. After a follow-up period of 18 months, recurrence occurred in 33.7% of patients (147 of 436) with an AF burden <18% and in 79.4% of patients (154 of 194) with an AF burden >18% (HR: 4.57; 95% CI: 3.63-5.75; P < 0.001). ConclusionsA high AF burden derived from a smartphone ECG during the blanking period is a strong predictor of atrial arrhythmia recurrences after ablation.

Efficacy and safety of visually guided laser balloon versus cryoballoon ablation for paroxysmal atrial fibrillation: a systematic review and meta-analysis.

Newly developed catheter ablation (CA) techniques, such as laser balloon ablation (LBA) and cryoballoon ablation (CBA), have been introduced in recent years and emerged as valuable alternatives to conventional radiofrequency CA strategies for paroxysmal atrial fibrillation (PAF) patients. However, evidence comparing LBA and CBA remain controversial. Thus, we conducted this meta-analysis to assess the efficacy and safety between these two techniques. Scientific databases (PubMed, Embase) and relevant websites (the Cochrane Library, ClinicalTrials.gov) were systematically searched from inception to March 2023. The primary outcomes of interest were the AF recurrence and the procedure-related complications. Secondary outcomes included procedural time, fluoroscopy time, and left atrial (LA) dwell time. Seven clinical trials with a total of 637 patients were finally enrolled. No significant differences were found between LBA and CBA in terms of AF recurrence [16.3% vs. 22.7%, odds ratio (OR) = 0.66, 95% confidence interval (CI): 0.42-1.05, p = 0.078] or total procedural-related complications (8.4% vs. 6.4%, OR = 1.33, 95% CI: 0.71-2.51, p = 0.371). LBA had a significantly longer procedural time [weighted mean difference (WMD) = 38.03 min, 95% CI: 13.48-62.58 min, p = 0.002] and LA dwell time (WMD = 46.67 min, 95% CI: 14.63-78.72 min, p = 0.004) than CBA, but tended to have shorter fluoroscopy time. LBA and CBA treatment have comparable efficacy and safety for PAF patients. LBA was associated with longer procedural and LA dwell times compared with CBA. Further large-scale studies are warranted to compare these two techniques with the newest generations.Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=426513, identifier (CRD42023426513).

The impact of empirical Marshall vein ethanol infusion as a first-choice intraoperative strategy on the long-term outcomes in patients with persistent atrial fibrillation undergoing mitral isthmus ablation.

Marshall vein ethanol infusion (MVEI) as an additional therapy to conventional catheter ablation (CA) has been proved to be efficacious in patients with persistent atrial fibrillation (PeAF). However, whether empirical MVEI could be the first-line strategy in mitral isthmus (MI) ablation has seldom been investigated. Here, we aim to compare the efficacy, safety, and long-term outcomes between provisional and empirical MVEI in PeAF patients undergoing the index MI ablation procedure. We enrolled 133 patients with PeAF either in the provisional group (n = 38, MVEI was performed when conventional endocardial and/or epicardial ablation procedures were inadequate to achieve bidirectional MI block) or in the empirical group (n = 95, MVEI was performed empirically before MI CA). All of the baseline characteristics were comparable. Less spontaneous or inducible atrial tachycardias (ATs) were encountered in the empirical group of patients (P < 0.001). More epicardial ablations were applied (26.3% vs. 9.5%, P = 0.016) and a higher incidence of CA-facilitated restoration of sinus rhythm was recorded (86.8% vs. 11.7%, P < 0.001) in the provisional group of patients. Although more fluoroscopy time (6.4[4.2, 9.3] vs. 9.5[5.9, 11.6] min, P = 0.019) and radiation exposure (69.0[25.3, 160.2] vs. 122.0[62.5, 234.1] mGy, P = 0.010) were documented in the empirical group with comparable procedure time, less time (455.9 ± 192.2 vs. 366.5 ± 161.3 s, P = 0.038) was consumed to achieve bidirectional MI block during endocardial ablation in the provisional group. Incidences of procedure-related complications were similar between the two groups. During a 16.5 ± 4.4-month follow-up, the empirical group of patients showed a significantly higher rate of freedom from AT recurrence (95.8% vs. 81.6%, log-rank P = 0.003), while the rate of freedom from AF or atrial tachyarrhythmias (combining AF and AT) was similar. Both univariate (HR 0.19, 95% CI 0.05-0.64, P = 0.008) and multivariate (HR 0.25, 95% CI 0.07-0.92, P = 0.037) Cox regression analyses indicated that empirical MVEI was independently associated with lower long-term AT recurrence. Among patients with PeAF who underwent the index MI ablation procedure, empirical MVEI could reduce endocardial MI ablation time and provide greater long-term freedom from AT recurrence.

Value of Electrocardiogram Algorithms Predicting Right Ventricular Outflow Tract Origin in the Era of Catheter Mapping

Background: The 12-lead electrocardiogram (ECG) is an extremely useful tool for analyzing cardiac arrhythmias and numerous ECG algorithms have been developed to predict the origin of right ventricular outflow tract (RVOT) arrhythmias. Aim: To determine if using complex, time-consuming analysis, and difficult-to-memorize ECG algorithms is feasible and preferable before the ablation procedure when compared with the use of multipolar mapping catheter use during the ablation procedure. Methods: 47 consecutive patients admitted for radiofrequency catheter ablation of idiopathic PVC were included prospectively in this study. Of the algorithms selected for comparison, three have a memorable design and easy applicability (Dixit, Joshi, Pytkowski) and the fourth has a complex, detailed design and is more difficult to memorize (Zhang). Results: The greatest accuracy was observed for the algorithms proposed by Dixit and Pytkowski – 92. 3%. However, when the algorithms were compared for their accuracy, specificity, and sensitivity, no significant differences were found (p=0. 96). Conclusions: 3-D guided mapping using a conventional ablation catheter in a narrower, precise area of interest in the RVOT, based on ECG algorithms is not inferior compared to the multielectrode catheter mapping in the whole RVOT, in terms of mapping time, total procedural time, and radiofrequency application time.

Efficacy of Catheter Ablation Using the Electroanatomical System without the Use of Fluoroscopy in Patients with Ventricular Extrasystolic Beats.

Catheter ablation (CA) has become safe and efficient for the treatment of patients with ventricular extrasystolic beats (VEBs). The three-dimensional electroanatomic mapping (EAM) system allows the elimination of fluoroscopy time during CA procedures. Non-fluoroscopy CA is a challenging procedure requiring intimate knowledge of cardiac anatomy in patients with VEBs. The study aimed to evaluate the efficacy and safety of the non-fluoroscopy CA using the EAM system in patients with VEBs. Completely fluoroless CA of VEBs guided by EAM was performed in 86% (94 out of 109) of consecutive patients with VEBs. The remaining 15 patients underwent conventional fluoroscopy-guided CA. Demographic and clinical baseline characteristics, procedure parameters, and following complications were obtained from the medical records. Primary outcomes were the acute procedural success rate, the permanent success rate (6-month follow-up), complications, and procedure time. There were no significant differences between groups regarding baseline characteristics. Acute procedural success was achieved in 85 patients (90%) in the non-fluoroscopy group and in 14 patients (93%) in the fluoroscopy group (ns). A long-term success rate was achieved in 82 patients (87%) in the non-fluoroscopy group and in 14 (82%) patients in the fluoroscopy group (ns). The median procedure time was 85 min in the non-fluoroscopy group and 120 min in the fluoroscopy group (p = 0.029). There was only one major complication in the non-fluoroscopy group (ns). Completely fluoroless CA of VEBs guided by EAM is a feasible, safe, and efficient procedure.

Midterm results of bipolar ablation in patients with intramural substrate and recurrent VTs based on a single center experience

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Catheter ablation of VTs and intramyocardial substrate (IS) remains a challenge that may require alternative mapping and ablation strategies such as bipolar ablation (BA) to achieve VT non inducibility. However, the long-term success of these alternative strategies is still uncertain. Purpose The aim of this study was to report the midterm center experience success of BA RF ablation of VT in patients with documented intramyocardial scar in cardiac imaging. Methods 19 patients with documented intramyocardial substrate on cardiac imaging (cardiac MRI or cardio CT with delayed enhancement) and VT recurrences after at least one conventional catheter ablation were retrospectively included. The intraprocedural success (i.e. VT non inducibility at the end of procedure) respectively midterm success (i.e VT recurrence after 6 months from BA) were investigated. The ablation was performed using a special RF generator which permits bipolar RF ablation between 2 irrigated catheters. Results A total number of 19 patients were included (100 % men, mean age 66,7 ± 9,16 y/o). The mean LVEF was 39,5 ± 5,7. The distribution of underlying structural heart disease was as follow: 21 % ischemic cardiomyopathy (4 out of 19 patients), 52 % dilative cardiomyopathy (10 out of 19 patients) respectively 26 % other etiologies (5 out of 19 patients). A mean number of 2 ± 1 conventional VT ablation were previously performed. In almost all patients (94 %, 18 out of 19 patients) the clinical VT was induced before the BA (mean CL 342 ± 91ms). The BA was performed predominantly septal (84%, 16 out of 19 patients). In 3 patients an endo/epicardial BA was performed. No VT was inducible any more at the end of procedure in 15 patients (79 %). At a mean follow up of 1 ± 0,5 years no recurrence of clinical VT was noted but non-clinical VT recurrence was seen in 9 patients (47 %) exclusively in patients with septal substrate. Conclusion BA represents a good alternative strategy for CA in patients with IS and failed conventional VT ablation with good acute success but high VT recurrence rate in patients with septal IS.

Incremental value of low-voltage area ablation in persistent atrial fibrillation: a systematic review and meta-analysis

Abstract Funding Acknowledgements Type of funding sources: None. Background/Introduction The optimal ablation approach for patients with persistent atrial fibrillation (AF) is a topic of high controversy. The efficacy of adjunctive ablation strategy beyond conventional pulmonary vein isolation remains uncertain. Purpose We sought to investigate the effectiveness of individualized low-voltage area (LVA) substrate modification in patients with persistent AF receiving conventional catheter ablation. Methods We systematically searched PubMed, Cochrane Library, and grey literature sources including clinicaltrials.gov, from inception to 1st November 2022, to identify relevant randomized controlled trials (RCTs). Patients with persistent AF undergoing conventional catheter ablation vs. ablation with additional LVA substrate modification were compared. Freedom from arrhythmia was set as the primary efficacy outcome and total procedure time as the secondary efficacy outcome. A prespecified subgroup analysis was performed for patients with presence of LVAs. We did not impose any filter regarding the study setting, sample size, study duration, or publication language. All analyses were performed using R version 4.1.0 and a two-sided p-value&amp;lt;0.05 was considered statistically significant. Results We pooled data from 5 RCTs with a total of 989 participants (31% female) with persistent AF. Ablation with additional LVA substrate modification resulted in a significantly increased likelihood for freedom from arrhythmia by 60%, compared to conventional AF ablation (odds ratio 1.60; 95% confidence interval 1.13-2.28; I2=39%; p=0.009). No difference in the total procedure time was identified between the two approaches (mean difference -28.94 min; 95% confidence interval -69.39 to 11.51 min; I2 = 98%, p=0.16). In patients with LVAs (n=240), additional LVA substrate modification yielded a higher probability for freedom from arrhythmia than conventional AF ablation (odds ratio 1.73; 95% confidence interval 1.03-2.90; I2=0%; p=0.04). Conclusion This meta-analysis demonstrates that an individualized ablation approach with low-voltage area substrate modification is associated with improved outcomes in patients with persistent AF.

The outcomes of cryoballoon, high-power short-duration, and conventional radiofrequency atrial fibrillation catheter ablation: a propensity score weighted study

Abstract Funding Acknowledgements Type of funding sources: None. Purpose We compared the efficacy, safety, and heart rate variability (HRV) after cryo-balloon (Cryo-PVI), high-power short-duration (HPSD-PVI) or conventional radiofrequency pulmonary vein isolation (conventional-PVI) in patients with atrial fibrillation (AF). Methods In this retrospective analysis of single-center cohort, we included 2,975 patients who underwent AF catheter ablation (74.1% male, median 60 years old, 74.1% paroxysmal AF). We compared the procedural factors, rhythm outcomes, complication rates, and post-procedural heart rate variability (HRV) between the Cryo-PVI (n=493), HPSD-PVI (n=638), and conventional-PVI (n=1,844). Results In spite of significantly shorter procedural time in the Cryo-PVI group (73 min for Cryo-PVI vs 110 min for HPSD-PVI vs 153 min for conventional-PVI, p&amp;lt;0.001), major complication (2.8% for Cryo-PVI vs 2.4% for HPSD-PVI vs 2.5% for conventional-PVI, p=0.875) or freedom from late recurrence (log-rank, p=0.357) did not differ among the three ablation groups. Cryo-PVI showed significantly lower risk for AF recurrence in patients with paroxysmal AF (weighted hazard ratio [WHR] 0.62, 95% confidence interval [CI] 0.41-0.93), but worse rhythm outcome in those with non-paroxysmal AF (WHR 1.47, 95% CI 1.06-2.05, p for interaction=0.002) as compared with conventional-PVI. In the subgroup analysis for HRV (n=1,429), Cryo-PVI group showed significantly higher low-frequency to high-frequency ratio at post-procedure 3 month (p&amp;lt;0.001), 1-year (p&amp;lt;0.001), and 2-year (p=0.023). Conclusion Cryo-PVI showed better rhythm outcome in patients with paroxysmal AF, but worse outcome in those with non-paroxysmal AF with higher long-term post-procedural sympathetic nervous activity as compared with conventional-PVI.

Quantification of Mechanical Characteristics of Conventional Steerable Ablation Catheters for Treatment of Atrial Fibrillation Using a Heart Phantom.

Accurate and reliable catheter navigation is important in formation of adequate lesions during radiofrequency cardiac catheter ablation. To inform future device design efforts and to characterize the limitations of conventional devices, the focus of this study is to assess and quantify the mechanical performance of manual ablation catheters for pulmonary vein isolation procedures within a phantom heart model. We measured three important metrics: accuracy of catheter tip navigation to target anatomical landmarks at the pulmonary veins (PVs), orientation of the catheter relative to the tissue at the targets, and the delivered force values and their stability and variations at those targets. A stereovision system was used for navigational guidance and to measure the catheter's tip position and orientation relative to the targets. To measure force, piezoelectric sensors were used which were integrated at the targets, whereby operators were instructed to stabilize the catheter to achieve a chosen reference force value. An overall positioning accuracy of 1.57 ± 1.71mm was achieved for all targets. No statistical significance was observed in position accuracy between the right and left PVs (p = 0.5138). The orientation of the catheter relative to tissue surface was 41° ± 21° with no statistical significance between targets. The overall force stability was 41 ± 6g with higher difficulty in force stabilization in the right compared to the left PV (40 ± 8 vs. 43 ± 2g, p < 0.0001). Based on our results, future improvements to manual catheter navigation for ablation should focus on improving device performance in orientation control and improved force stability.

Ablation versus anti-arrhythmic therapy for reducing all hospital episodes from recurrent atrial fibrillation: a prospective, randomized, multi-centre, open label trial.

There is rising healthcare utilization related to the increasing incidence and prevalence of atrial fibrillation (AF) worldwide. Simplifying therapy and reducing hospital episodes would be a valuable development. The efficacy of a streamlined AF ablation approach was compared to drug therapy and a conventional catheter ablation technique for symptom control in paroxysmal AF. We recruited 321 patients with symptomatic paroxysmal AF to a prospective randomized, multi-centre, open label trial at 13 UK hospitals. Patients were randomized 1:1:1 to cryo-balloon ablation without electrical mapping with patients discharged same day [Ablation Versus Anti-arrhythmic Therapy for Reducing All Hospital Episodes from Recurrent (AVATAR) protocol]; optimization of drug therapy; or cryo-balloon ablation with confirmation of pulmonary vein isolation and overnight hospitalization. The primary endpoint was time to any hospital episode related to treatment for atrial arrhythmia. Secondary endpoints included complications of treatment and quality-of-life measures. The hazard ratio (HR) for a primary endpoint event occurring when comparing AVATAR protocol arm to drug therapy was 0.156 (95% CI, 0.097-0.250; P < 0.0001 by Cox regression). Twenty-three patients (21%) recorded an endpoint event in the AVATAR arm compared to 76 patients (74%) within the drug therapy arm. Comparing AVATAR and conventional ablation arms resulted in a non-significant HR of 1.173 (95% CI, 0.639-2.154; P = 0.61 by Cox regression) with 23 patients (21%) and 19 patients (18%), respectively, recording primary endpoint events (P = 0.61 by log-rank test). The AVATAR protocol was superior to drug therapy for avoiding hospital episodes related to AF treatment, but conventional cryoablation was not superior to the AVATAR protocol. This could have wide-ranging implications on how demand for AF symptom control is met. Clinical Trials Registration: NCT02459574.

Safety profile and long-term efficacy of very high-power short-duration (60-70 W) catheter ablation for atrial fibrillation: results of a large comparative analysis.

This retrospective study sought to compare complication rates and efficacy of power-controlled very high-power short-duration (vHPSD) and conventional catheter ablation in a large cohort of patients with atrial fibrillation (AF). We analyzed 1115 consecutive patients with AF (38.7% paroxysmal, 61.3% persistent) who received first-time catheter ablation at our centre from 2015 to 2021. Circumferential pulmonary vein isolation ± additional substrate ablation using an irrigated-tip catheter was performed with vHPSD (70 W/5-7 s or 60 W/7-10 s) in 574 patients and with conventional power (30-35 W/15-30 s) in 541 patients. Baseline characteristics were well-balanced between groups (mean age 65.1 ± 11.2 years, 63.4% male). The 30-day incidence of cardiac tamponade [2/574 (0.35%) vs. 1/541 (0.18%), P = 0.598], pericardial effusion ≥ 10 mm [2/574 (0.35%) vs. 1/541 (0.18%), P = 0.598] and transient ischaemic attack [1/574 (0.17%) vs. 2/541 (0.37%), P = 0.529] was not significantly different between vHPSD and conventional ablation. No stroke, atrio-esophageal fistula, cardiac arrest or death occurred. Procedure (122.2 ± 46.8 min vs. 155.0 ± 50.5 min, P < 0.001), radiofrequency (22.4 ± 19.3 min vs. 52.9 ± 22.0 min, P < 0.001), and fluoroscopy (8.1 ± 7.2 vs. 9.2 ± 7.4, P = 0.016) duration were significantly shorter in the vHPSD group. At 12 months follow-up, freedom of any atrial arrhythmia was 44.1% vs. 34.2% (P = 0.010) in persistent AF and 78.1% vs. 70.2% in paroxysmal AF (P = 0.068). vHPSD ablation is as safe as conventional ablation and is associated with an improved long-term efficacy in persistent AF.

The Use of Cardiac Stereotactic Radiation Therapy (SBRT) to Manage Ventricular Tachycardia: A Case Report, Review of the Literature and Technical Notes

among cardiac arrhythmias, ventricular tachycardia (VT) is one that can lead to cardiac death, although significant progress has been made in its treatment, including the use of implantable cardioverter-defibrillators (ICD) and radiofrequency catheter ablation. Nevertheless, long-term recurrence rates remain in about half of patients and drastically impact the patient's quality of life. Moreover, recurrent ICD shocks are painful and are associated with higher mortality and worsening of heart failure. Recently, more and more experiences are demonstrating potential efficacy in the use of stereotactic body radiotherapy (SBRT) (also called cardiac radio-ablation) to treat this condition. In this paper, we report our experience in the use of cardiac radio-ablation for the treatment of refractory ventricular tachycardia with a focus on the technique used, along with a review of the literature and technical notes. an 81-year-old male patient with a long history of non-ischemic dilated cardiomyopathy and mechanical mitral prosthesis underwent a biventricular cardioverter defibrillator implant after atrial ventricular node ablation. At the end of 2021, the number of tachycardias increased significantly to about 10 episodes per day. After failure of medical treatment and conventional RT catheter ablation, the patient was treated with SBRT for a total dose of 25 Gy in a single session at the site of the ectopic focus. No acute toxicity was recorded. After SBRT (follow-up 7 months) no other VT episodes were recorded. SBRT appears to be safe and leads to a rapid reduction in arrhythmic storms as treatment for VT without acute toxicity, representing one of the most promising methods for treating VT storms.

Cardiac radioablation does not worsen cardiac function: preliminary safety results of the prospective STARNL-1 trial

Abstract Background Cardiac radioablation for ventricular tachycardia (VT) appears to be highly effective and safe in patients with recurrent VT despite anti-arrhythmic therapy and catheter ablation(s), although global experience is currently very limited. Detailed echocardiographic strain analysis could provide important insights in (subclinical) functional safety. Importantly, current stereotactic cardiac radioablation techniques includes irradiation of the VT substrate but, inherently, also includes irradiation of the VT border zone and some healthy cardiac tissue. The latter particularly may result in detoriation of cardiac function after cardiac radioablation. Purpose To evaluate functional echocardiographic safety of cardiac radioablation. Methods The STARNL-1 trial is a prospective, monocenter, single-arm, pre-post intervention study. Six patients with recurrent VT despite high dose anti-arrhythmic drugs, after (single or multiple) conventional catheter ablation and deemed unsuited for repeat catheter ablation, were treated with a single fraction 25 Gy radiotherapy dose. Per protocol, patients underwent echocardiograms at baseline, 24 hours after treatment, and 3 months after treatment. Echocardiograms were analysed using 2D-speckle tracking. Mean radiotherapy dose per segment was calculated according to the AHA 17-segment model. Echocardiographic parameters were compared between baseline, 24 hours and 3 months, and correlated to radiotherapy dose. Results Patients were all male (age 55–83 years), all suffered from ischaemic cardiomyopathy, and all completed 3 month follow-up. At baseline, median left ventricle ejection fraction (LVEF) was 38% [30; 47] and median global longitudinal strain (GLS) −8% [−12; −5]. Interestingly, LVEF significantly improved 24 hours after treatment (42% [36; 49], p=0.046) but GLS did not change (−7% [−12; −5], p=0.833). At 3 months, both LVEF and GLS were unchanged compared to baseline (LVEF 39% [33; 49%], p=0.463; GLS −6% [−12; −5], p=0.893). The difference in longitudinal strain per segment before and after treatment did not correlate with the mean radiotherapy dose per segment, both 24 hours after treatment (Pearson coefficient −0.082, p=0.410) and 3 months after treatment (Pearson coefficient −0.005, p=0.957). In Figure 1 an illustrative case is presented. Conclusion(s) Cardiac radioablation for VT does not worsen (subclinical) cardiac function within the first 3 months after treatment. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): Dutch Heart Foundation

Magnetic resonance imaging-guided conventional catheter ablation of isthmus-dependent atrial flutter using active catheter imaging.

Interventional cardiac magnetic resonance (iCMR) has been established as a radiation-free alternative compared to standard fluoroscopy-guided catheter ablation for cavotricuspid isthmus (CTI)-dependent atrial flutter to image anatomy, structural alterations, and further catheter guidance. The purpose of this study was to explore the safety, feasibility, and efficacy of CTI ablations performed completely in the iCMR suite using active catheter imaging. Consecutive patients underwent iCMR-guided catheter ablation for CTI-dependent atrial flutter. Procedures were performed in a 1.5-T magnetic resonance (MR) imaging unit with MR-conditional ablation catheters. Catheter guidance was achieved using active catheter imaging via integrated MR receive tip coils. Acute success, periprocedural complications, and short-term follow-up were collected for further analysis. All patients (N = 15; 73% male; median age 70 years; interquartile range [67-82]) achieved acute procedural success without any complication. Median procedural time was 43 minutes [33-58] with median radiofrequency delivery time of 18 minutes [12-26]. Postprocedural lesion visualization scanning was completed in a median of 32 minutes [10-42]. None of the patients with 6-month follow-up had atrial flutter recurrence. In the iCMR suite, CTI-dependent atrial flutter ablation could be achieved safely using active catheter imaging without any complication. It further allows detailed anatomic visualization of the CTI, intraprocedural lesion visualization, and exclusion of pericardial effusion.