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Background: This prospective trial sought to phenotype persistent atrial fibrillation (AF) based on AF mechanisms using electrocardiographic imaging (ECGI) mapping to determine whether this would predict long-term freedom from arrhythmia after pulmonary vein isolation (PVI)., Methods: Patients with persistent AF of <2 years duration underwent cryoballoon PVI. ECGI mapping was performed before PVI to determine potential drivers (PDs) defined as rotational activations completing ≥1.5 revolutions or focal activations. The coprimary endpoint was the association between (1) PD burden (defined as the number of PD occurrences) and (2) PD distribution (defined as the number of segments on an 18-segment model of the atria harboring PDs) with freedom from arrhythmia at 1-year follow up., Results: Of 100 patients, 97 completed follow up and 52 (53.6%) remained in sinus rhythm off antiarrhythmic drugs. Neither PD burden nor PD distribution predicted freedom from arrhythmia (hazard ratio [HR]: 1.01, 95% confidence interval [CI]: 0.99-1.03, p = .164; and HR: 1.04, 95% CI: 0.91-1.17, p = .591, respectively). Otherwise, the burden of rotational PDs, rotational stability, and the burden of PDs occurring at the pulmonary veins and posterior wall all failed to predict arrhythmia recurrence (all p > .10)., Conclusions: AF mechanisms as determined using ECGI mapping do not predict outcomes after PVI for persistent AF. Further studies using different methodologies to characterize AF mechanisms are warranted (NCT03394404)., (© 2022 Wiley Periodicals LLC.)

Introduction: The optimal ablation approach for persistent atrial fibrillation (AF) remains unclear., Methods and Results: Objective was to compare the long-term rates of freedom from AF/AT in patients that underwent STAR mapping guided ablation against outcomes of patients undergoing conventional ablation procedures. Patients undergoing ablation for persistent AF as part of the Stochastic Trajectory Analysis of Ranked signals (STAR) mapping study were included. Outcomes following 'pulmonary vein isolation (PVI) plus STAR mapping guided ablation (STAR mapping cohort) were compared to patients undergoing PVI alone ablation during the same time period and also a propensity-matched cohort undergoing PVI plus the addition of complex fractionated electrogram (CFAE) and/or linear ablation ("conventional ablation"). Rates of procedural AF termination and freedom from AF/AT during follow-up were compared. Sixty-five patients were included in both the STAR cohort and propensity matched conventional ablation cohort. AF termination rates were significantly higher in the STAR cohort (51/65, 78.5%) than conventional ablation cohort (10/65, 15.4%) and PVI alone ablation cohort (13/50, 26.0%; STAR cohort vs. other 2 cohorts both p < .001). There was no significant difference in procedure time between the three cohorts. During ≥20 months follow-up a lower proportion of patients had AF/AT recurrence in the STAR cohort (20.0%) compared with the conventional ablation cohort (50.8%) or the PVI alone ablation cohort (50.0%; both p < .05 compared to STAR cohort)., Conclusions: Outcomes of PVI plus STAR mapping guided ablation was superior to PVI alone or in combination with linear/CFAE ablation. A multicenter randomized controlled trial is planned to confirm these findings., (© 2020 The Authors. Journal of Cardiovascular Electrophysiology published by Wiley Periodicals LLC.)

Aims: We sought out to make comparisons between all atrial fibrillation (AF) catheter ablation technologies using randomized controlled trial data. Our comparisons were freedom from AF, procedural duration, and fluoroscopy duration., Methods: Searches were made of EMBASE, MEDLINE, and CENTRAL databases, and studies were selected which had cryoballoon, conventional radiofrequency (RF), multipolar RF catheters, and laser technology as an arm in the study and were identified as randomized controlled trials (RCTs). These studies were analyzed for direct comparisons using conventional meta-analysis and a combination of indirect and direct comparisons via a network meta-analysis (NMA)., Results: With respect to freedom from AF both direct comparisons and NMA did not demonstrate any significant difference. However in analysis of procedural and fluoroscopy duration (minutes) for the pulmonary vein ablation catheter (PVAC), both conventional analysis and NMA revealed significantly shorter procedure times, RF vs PVAC (conventional: 61.99 [38.03-85.94], P <.00001; NMA: 54.76 [36.64-72.88], P < .0001) and fluoroscopy times, RF vs PVAC (conventional: 12.96 [6.40-19.53], P = .0001; NMA: 8.89 [3.27-14.51], P < .01). The procedural duration was also shorter for the cryoballoon with NMA, RF vs CRYO (20.56 [3.47-37.65], P = .02)., Discussion: Our analysis demonstrated that while there was no difference in the efficacy of the individual catheter technologies, there are significant differences in the procedural duration for the PVAC and the cryoballoon. While they may seem an attractive solution for high-volume centers, further RCTs of next-generation technologies should be examined., (© 2020 The Authors. Journal of Cardiovascular Electrophysiology published by Wiley Periodicals LLC.)

Background: Noninvasive mapping identifies potential drivers (PDs) in atrial fibrillation (AF). We analyzed the impact of pulmonary vein isolation (PVI) on PDs and whether baseline PD pattern predicted termination of AF., Methods: Patients with persistent AF less than 2 years underwent electrocardiographic imaging mapping before and after cryoballoon PVI. We recorded the number of PD occurrences, characteristics (rotational wavefronts ≥ 1.5 revolutions or focal activations), and distribution using an 18-segment atrial model., Results: Of 100 patients recruited, PVI terminated AF in 15 patients; 21.3% ± 9.1% (8.7 ± 4.8) of PDs occurred at the pulmonary veins (PVs) and posterior wall. PVI had no impact on PD occurrences outside the PVs and posterior wall (33.2 ± 12.9 vs 31.6 ± 12.5; P = .164), distribution over the remaining 13 segments (9 [8-11] vs 9 [8-10]; P = .634), the proportion of PDs that was rotational (82.9% ± 9.7% vs 83.6% ± 10.1%; P = .496), or temporal stability (2.4 ± 0.4 vs 2.4 ± 0.5 rotations; P = .541). Fewer focal PDs (area under the curve, 0.683; 95% CI, 0.528-0.839; P = .024) but not rotational PDs (P = .626) predicted AF termination with PVI., Conclusions: PVI did not have a global impact on PDs outside the PVs and posterior wall. Although fewer focal PDs predicted termination of AF with PVI, the burden of rotational PDs did not. It is accepted though not all PDs are necessarily real or important. Outcome data are needed to confirm whether noninvasive mapping can predict patients likely to respond to PVI., (© 2020 Wiley Periodicals, Inc.)

Introduction: Implantable loop recorders (ILR) are predominantly implanted by cardiologists in the catheter laboratory. We developed a nurse-delivered service for the implantation of LINQ (Medtronic; Minnesota) ILRs in the outpatient setting. This study compared the safety and cost-effectiveness of the introduction of this nurse-delivered ILR service with contemporaneous physician-led procedures., Methods: Consecutive patients undergoing an ILR at our institution between 1st July 2016 and 4th June 2018 were included. Data were prospectively entered into a computerized database, which was retrospectively analyzed., Results: A total of 475 patients underwent ILR implantation, 271 (57%) of these were implanted by physicians in the catheter laboratory and 204 (43%) by nurses in the outpatient setting. Six complications occurred in physician-implants and two in nurse-implants (P = .3). Procedural time for physician-implants (13.4 ± 8.0 minutes) and nurse-implants (14.2 ± 10.1 minutes) were comparable (P = .98). The procedural cost was estimated as £576.02 for physician-implants against £279.95 with nurse-implants, equating to a 57.3% cost reduction. In our center, the total cost of ILR implantation in the catheter laboratory by physicians was £10 513.13 p.a. vs £6661.55 p.a. with a nurse-delivered model. When overheads for running, cleaning, and maintaining were accounted for, we estimated a saving of £68 685.75 was performed by moving to a nurse-delivered model for ILR implants. Over 133 catheter laboratory and implanting physician hours were saved and utilized for other more complex procedures., Conclusion: ILR implantation in the outpatient setting by suitably trained nurses is safe and leads to significant financial savings., (© 2019 Wiley Periodicals, Inc.)

Introduction: Identifying drivers in persistent atrial fibrillation (AF) remains challenging. We sought to validate an automated system for detection of focal activation using basket and PentaRay catheters in AF., Methods: Patients having ablation for atrial tachycardia (AT) and persistent AF were mapped. Thirty-second unipolar basket and PentaRay recordings were analyzed using CARTOFINDER. Focal activation or "region of interest" (ROI) was defined as more than or equal to 2 consecutive focal activations with one electrode leading relative to its neighbors with QS morphology on the unipolar electrogram. ROI was validated in AT. AF patients were mapped to (1) look for evidence of focal activations on wavefront maps, (2) evaluate whether these were detected as ROI on basket recordings, and (3) whether these sites could be identified on sequential PentaRay recordings., Results: ROIs were identified in five focal ATs but none of 16 reentrant ATs. Twenty-eight AF patients had 35 focal drivers identified from basket wavefront maps with an ablation response in all (16 cycle length slowing and 19 AF termination). Thirty focal activations were detected on basket ROI maps (86%). Twenty-three of 28 patients had sequential PentaRay mapping and 22 of 30 focal drivers in these patients (73%) were identified as ROI. These drivers had greater temporal stability (3.6 ± 0.6 vs 2.7 ± 0.6; P < 0.001), higher recurrence rate (12.4 ± 2.7 vs 7.2 ± 0.9; P < 0.001), and more frequently were associated with AF termination ( P < 0.001) compared with those not identified as ROI., Conclusions: Focal activations can be detected in AF using sequential recordings. The ablation response at focal sources suggests they may be viable therapeutic targets., (© 2018 The Authors. Journal of Cardiovascular Electrophysiology Published by Wiley Periodicals, Inc.)

Introduction: This study sought to validate a novel wavefront mapping system utilizing whole-chamber basket catheters (CARTOFINDER, Biosense Webster). The system was validated in terms of (1) mapping atrial-paced beats and (2) mapping complex wavefront patterns in atrial tachycardia (AT)., Methods and Results: Patients undergoing catheter ablation for AT and persistent AF were included. A 64-pole-basket catheter was used to acquire unipolar signals that were processed by CARTOFINDER mapping system to generate dynamic wavefront propagation maps. The left atrium was paced from four sites to demonstrate focal activation. ATs were mapped with the mechanism confirmed by conventional mapping, entrainment, and response to ablation. Twenty-two patients were included in the study (16 with AT and 6 with AF initially who terminated to AT during ablation). In total, 172 maps were created with the mapping system. It correctly identified atrial-pacing sites in all paced maps. It accurately mapped 9 focal/microreentrant and 18 macroreentrant ATs both in the left and right atrium. A third and fourth observer independently identified the sites of atrial pacing and the AT mechanism from the CARTOFINDER maps, while being blinded to the conventional activation maps., Conclusions: This novel mapping system was effectively validated by mapping focal activation patterns from atrial-paced beats. The system was also effective in mapping complex wavefront patterns in a range of ATs in patients with scarred atria. The system may therefore be of practical use in the mapping and ablation of AT and could have potential for mapping wavefront activations in AF., (© 2018 Wiley Periodicals, Inc.)

Background: Technology and clinical practice surrounding the use of the primary prevention implantable cardioverter defibrillator (ICD) are in a state of constant evolution. The purpose of the study was to test the hypothesis of significant temporal trends in characteristics and outcomes over a decade of ICD therapy., Methods: Between 2002 and 2012, 5,539 consecutive patients (age 62.5 ± 11 years, 84.9% male), with ischemic or nonischemic cardiomyopathy, implanted with a primary prevention ICD from 12 centers in France were included. Information on characteristics and outcomes (including causes of death) were evaluated over a median follow-up of 994 days (466-1,667)., Results: In addition to a shift in the type of devices implanted with a significant increase in cardiac resynchronization therapy-defibrillator (CRT-D) over time (43.6 to 60.4%, P = 0.0001), an increase in mean age (from 61.5 ± 11.6 to 63.2 ± 10.9 years, P = 0.0016), proportion of nonischemic cardiomyopathy (31.0 to 44.7%, P <0.0001) and women recipients (11.4 to 15.8%, P = 0.004) was observed. A total of 1,181 patients (22.3%) received ≥1 appropriate therapy, inappropriate therapies occurred in 355 patients (6.7%) and 826 patients (15.2%) died, mainly from cardiovascular causes (49.3%). Annual mortality incidence (5.4% to 4.3%, P = 0.05), as well as incidence of appropriate therapy (10.4% to 7.1%, P = 0.0004), significantly decreased over the decade. By contrast, incidence of ICD-related late (>30 days after implant) complications significantly increased (4.6 to 7.6%, P = 0.003)., Conclusion: Our findings demonstrate significant changes in patterns of use and outcomes in primary prevention ICD over the last decade with reductions in mortality and appropriate therapies, counterbalanced by an increase in complications., (© 2017 Wiley Periodicals, Inc.)

Background: Chronic kidney disease (CKD) is a risk factor for arrhythmias in patients with heart failure (HF). However, the effects of CKD on ventricular arrhythmia (VA) burden in patients with cardiac resynchronization therapy and defibrillator (CRT-D) devices in a primary prevention setting are unknown., Objective: To determine whether baseline CKD is associated with increased risk of VA in patients implanted with primary prevention CRT-D devices., Methods and Results: In this retrospective study, 199 consecutive primary prevention CRT-D recipients (2005-2010) were stratified by estimated glomerular filtration rate (eGFR) levels prior to device implantation with 106 (53.2%) ≥CKD III (eGFR < 60 mL/min/1.73 m 2 ) (CKD group). CKD group patients were significantly older (70.0 ± 10 years vs. 61.3 ± 12 years, P < 0.05) with higher prevalence of ischemic cardiomyopathy (56.2% vs. 40.2%, P < 0.05). Detected ventricular tachycardia (VT)/ventricular fibrillation (VF) episodes resulting in device therapy occurred significantly more frequently in the CKD group [40/106(37.8%)] than controls [24/93(25.8%)], (odd ratio [OR] = 1.74, 95% confidence interval [CI] = 1.01-3.2, P = 0.05). At 5-year follow-up, interval censored data analysis showed 41% VT/VF incidence in the CKD group compared to 24% incidence in controls (P < 0.05). Cox proportional hazards model identified CKD > III as the only predictor of sustained VA in this group (adjusted hazard ratio [HR] 2.92, CI = 1.39-6.1, P = 0.004)., Conclusion: Baseline CKD is a strong independent risk factor for VA in primary prevention CRT-D recipients. Further understanding of the underlying arrhythmogenic mechanisms relating to CKD may be of interest to allow appropriate correction and prevention. Device programming in this cohort may need to reflect this increased risk., (© 2016 Wiley Periodicals, Inc.)

Introduction: The additional benefit of contact force (CF) technology during pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF) to improve mid-term clinical outcome is unclear., Methods and Results: Eligible patients with symptomatic paroxysmal AF were enrolled in this prospective trial, comparing circular antral catheter ablation (guided by Carto 3 System, Biosense Webster) using either a new open-irrigated CF catheter (SmartTouch Thermocool, Biosense Webster) (CF group) or a non-CF open-irrigated catheter (EZ Steer Thermocool, Biosense Webster) (control group). Overall, 30 patients were enrolled in each group, with a standardized 12-month follow-up, free of antiarrhythmic therapy. Demographic, cardiovascular and anatomic characteristics were similar in both groups. Though complete PVI was eventually achieved in all cases in both groups, success using an exclusive anatomic approach was 80.0% in CF group versus 36.7% in control group (P < 0.0001). CF use was associated with significant reductions in fluoroscopy exposure (P < 0.01) and radiofrequency time (P = 0.01). The incidence rates of AF recurrence were 10.5% (95% CI, 1.38-22.4) in the CF group, and 35.9% (95% CI, 12.4-59.4) in the control group (log rank test, P = 0.04). After adjustment on potential confounders, the use of CF catheter was found to be associated with a lower AF recurrence (OR 0.18, 95% CI 0.04-0.94, P = 0.04)., Conclusion: Our findings suggest a potential benefit of real-time CF sensing technology, in reducing AF recurrence during the first year after PVI., (© 2013 Wiley Periodicals, Inc.)