Dual energy for pulmonary vein isolation using dual-energy focal ablation technology integrated with a three-dimensional mapping system: SmartfIRE 3-month results.

AIMS: Contact force (CF)-sensing radiofrequency (RF) catheters with an ablation index have shown reproducible outcomes for the treatment of atrial fibrillation (AF) in large multicentre studies. A dual-energy (DE) focal CF catheter to deliver RF and unipolar/biphasic pulsed field ablation (PFA), integrated with a three-dimensional (3D) mapping system, can provide operators with additional flexibility. The SmartfIRE study assessed the safety and efficacy of this novel technology for the treatment of drug-refractory, symptomatic paroxysmal AF. Results at 3 months post-ablation are presented here. METHODS AND RESULTS: Pulmonary vein isolation (PVI) was performed using a DE focal, irrigated CF-sensing catheter with the recommendation of PFA at posterior/inferior and RF ablation at the anterior/ridge/carina segments. Irrespective of energy, a tag size of 3 mm; an inter-tag distance ≤6 mm; a target index of 550 for anterior, roof, ridge, and carina; and a target index of 400 for posterior and inferior were recommended. Cavotricuspid isthmus ablation was permitted in patients with documented typical atrial flutter. The primary effectiveness endpoint was acute procedural success. The primary safety endpoint was the rate of primary adverse events (PAEs) within 7 days of the procedure. A prespecified patient subset underwent oesophageal endoscopy (EE; 72 h post-procedure), neurological assessment (NA; pre-procedure and discharge), and cardiac computed tomography (CT)/magnetic resonance angiogram (MRA) imaging (pre-procedure and 3 months post-procedure) for additional safety evaluation, and a mandatory remapping procedure (Day 75 ± 15) for PVI durability assessment. Of 149 patients enrolled between February and June 2023, 140 had the study catheter inserted (safety analysis set) and 137 had ablation energy delivered (per-protocol analysis set). The median (Q1/Q3) total procedure and fluoroscopy times were 108.0 (91.0/126.0) and 4.2 (2.3/7.7) min (n = 137). The acute procedural success rate was 100%. First-pass isolation was achieved in 89.1% of patients and 96.8% of veins. Cavotricuspid isthmus ablations were successfully performed in 12 patients [pulsed field (PF) only: 6, RF only: 5, and RF/PF: 1]. The PAE rate was 4.4% [6/137 patients; 2 pulmonary vein (PV) stenoses, 2 cardiac tamponades/perforations, 1 stroke, and 1 pericarditis]. No coronary artery spasm was reported. No oesophageal lesion was seen in the EE subset (0/31, 0%). In the NA subset (n = 30), microemboli lesions were identified in 2 patients (2/30, 6.7%), both of which were resolved at follow-up; only 1 was symptomatic (silent cerebral lesion, 3.3%). In the CT/MRA subset (n = 30), severe PV narrowing (of >70%) was detected in 2 patients (2/30, 6.7%; vein level 2/128, 1.6%), of whom 1 underwent dilatation and stenting and 1 was asymptomatic; both were associated with high index values and a small inter-tag distance. In the PV durability subset (n = 30), 100/115 treated PVs (87%) were durably isolated and 18/30 patients (60.0%) had all PVs durably isolated. CONCLUSION: A DE focal CF catheter with 3D mapping integration showed a 100% acute success rate with an acceptable safety profile in the treatment of paroxysmal AF. Prespecified 3-month remapping showed notable PVI durability. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05752487.

[Rhythm management in patients with heart failure].

INTRODUCTION: Arrhythmias manifest frequently in individuals with heart failure, posing a notable threat of mortality and morbidity. While the prevention of sudden cardiac death through ICD therapy remains pivotal, accurate risk stratification remains a challenging task even in 2024. Recent data underscore the early consideration of catheter ablation for ventricular tachycardias. Although antiarrhythmic drug therapy serves as an ancillary measure for symptomatic patients, it does not confer prognostic advantages. The holistic management of arrhythmias in heart failure necessitates a systematic, multidimensional approach that initiates with evidence-based medical therapy for heart failure and integrates device-based and interventional therapies. Noteworthy clinical studies have illustrated the positive prognostic impact of early rhythm control strategies, particularly catheter ablation, in individuals managing heart failure and atrial fibrillation.

Performance and safety of temperature- and flow-controlled radiofrequency ablation for ventricular arrhythmia.

AIMS: High-power ablation is effective for ventricular arrhythmia ablation; however, it increases the risk of steam pops. The aim of this study was to define the safety and efficacy of QMODE ablation in the ventricle and the risk of steam pop. METHODS AND RESULTS: Consecutive patients undergoing ventricular ablation using QDOT were included in a prospective single-centre registry. Procedural data, complications, and follow-up were systematically analysed and compared with a historical ventricular tachycardia (VT) and premature ventricular complexes (PVC) cohort ablated using STSF. QMODE (≤50 W) ablation was performed in 107 patients [age 62 ± 13 years; 76% male; VT (n = 41); PVC (n = 66)]. A total of 2456 applications were analysed [power: 45.9 ± 5.0 W with minimal power titration (90% > 95% max power); duration 26 ± 8 s; impedance drop 9.4 ± 4.7 Ω; ablation index: 569 ± 163; mean-max temperature 44.3 ± 2.6°C]. Ventricular tachycardia ablation was associated with shorter radiofrequency (RF) time and a trend towards shorter procedure times using QDOT (QDOT vs. STSF: 20.1 ± 14.7 vs. 31 ± 17 min; P = 0.002, 151 ± 59 vs. 172 ± 48 min; P = 0.06). Complications, VT recurrence, and mortality rates were comparable (QDOT vs. STSF: 2% vs. 2%; P = 0.9, 24% vs. 27%; P = 0.82, and 2% vs. 4%; P = 0.67). Five audible steam pops (0.02%) occurred. Premature ventricular complex ablation was associated with comparable RF and procedure times (QDOT vs. STSF: 4.8 ± 4.6 vs. 3.9 ± 3.1 min; P = 0.25 and 96.1 ± 31.9 vs. 94.6 ± 24.7 min; P = 0.75). Complication and PVC recurrence were also comparable (QDOT vs. STSF: 0% vs. 3%; P = 0.17 and 19% vs. 22%; P = 0.71). CONCLUSION: Ventricular ablation using QMODE ≤ 50 W is safe and effective for both VT and PVC ablation and is associated with a low risk for steam pop.

Eliminating transseptal sheath exchange for pulsed field ablation procedures using a direct over-the-needle transseptal access with the Faradrive sheath.

AIMS: Pulsed field ablation (PFA) for pulmonary vein isolation (PVI) combines the benefits of high procedural efficacy and safety. Transseptal puncture (TSP) to obtain left atrial (LA) access during PVI remains an important source of complications during LA procedures. For PFA procedures, TSP is generally performed using a standard transseptal sheath that is then exchanged over the wire for a dedicated PFA sheath, which might be a potential source for air embolism. We aimed to prospectively evaluate the feasibility and safety of a simplified workflow using the PFA sheath (Faradrive, Boston Scientific) directly for TSP. METHODS AND RESULTS: We prospectively enrolled 100 patients undergoing PVI using PFA at two centres. TSP was performed using the PFA sheath and a standard 98 cm transseptal needle under fluoroscopic guidance. TSP via the PFA sheath was successfully performed in all patients and no complications occurred. The median time from the first groin puncture to the completed LA access was 12 min (IQR 8-16 min). CONCLUSION: An over-the-needle TSP directly with the PFA sheath proved feasible and safe in our study. This simplified workflow has the potential to reduce the risk of air embolism, to shorten procedure time, and to reduce cost.

Long-term follow-up after the use of the as low as reasonably achievable radiation protocol in patients with symptomatic supraventricular tachycardia.

INTRODUCTION: Catheter ablation is an effective treatment modality for patients with symptomatic supraventricular tachycardia (SVT), such as atrioventricular nodal re-entrant tachycardia (AVNRT) and typical atrial flutter (TAF). With increasingly invasive electrophysiological procedures and continuous development of ablation techniques, the aim is to reduce radiation doses for patients and the electrophysiological team. Modern methods that combine the "as low as reasonably achievable" (ALARA) protocol and three-dimensional mapping systems are now state-of-the-art procedures in the treatment of arrhythmia. This study aimed to compare the effectiveness and long-term success of the ALARA approach compared to those of conventional therapy, without using modern mapping systems. METHODS: Sixty-one patients with symptomatic SVT (37 with AVNRT, 19 with isthmus-dependent counter-clockwise TAF, and five with other SVTs) were randomised into two groups: the ALARA and conventional groups. All patients underwent successful SVT ablation. Clinical and remote follow-up was available for 59 patients after a mean period of 3.2 years. RESULTS: The mean fluoroscopy time was significantly shorter in the ALARA group (1.1 min vs. 8.4 min, p < 0.01). Regarding complications and recurrences, during a median follow-up period of 3.2 years, eight patients (13.5%) had recurrences, all of which occurred in the conventional group. CONCLUSION: This study confirmed a significantly lower radiation burden for patients and the entire electrophysiological team with the ALARA approach and a significantly increased risk of recurrence and complications with the conventional approach. The reduction in radiation time and high long-term success indicate the utility of the ALARA protocol in daily practice.

Evaluation and optimization of novel extraction algorithms for the automatic detection of atrial activations recorded within the pulmonary veins during atrial fibrillation.

BACKGROUND AND OBJECTIVE: The automated detection of atrial activations (AAs) recorded from intracardiac electrograms (IEGMs) during atrial fibrillation (AF) is challenging considering their various amplitudes, morphologies and cycle length. Activation time estimation is further complicated by the constant changes in the IEGM active zones in complex and/or fractionated signals. We propose a new method which provides reliable automatic extraction of intracardiac AAs recorded within the pulmonary veins during AF and an accurate estimation of their local activation times. METHODS: First, two recently developed algorithms were evaluated and optimized on 118 recordings of pulmonary vein IEGM taken from 35 patients undergoing ablation of persistent AF. The adaptive mathematical morphology algorithm (AMM) uses an adaptive structuring element to extract AAs based on their morphological features. The relative-energy algorithm (Rel-En) uses short- and long-term energies to enhance and detect the AAs in the IEGM signals. Second, following the AA extraction, the signal amplitude was weighted using statistics of the AA sequences in order to reduce over- and undersensing of the algorithms. The detection capacity of our algorithms was compared with manually annotated activations and with two previously developed algorithms based on the Teager-Kaiser energy operator and the AF cycle length iteration, respectively. Finally, a method based on the barycenter was developed to reduce artificial variations in the activation annotations of complex IEGM signals. RESULTS: The best detection was achieved using Rel-En, yielding a false negative rate of 0.76% and a false positive rate of only 0.12% (total error rate 0.88%) against expert annotation. The post-processing further reduced the total error rate of the Rel-En algorithm by 70% (yielding to a final total error rate of 0.28%). CONCLUSION: The proposed method shows reliable detection and robust temporal annotation of AAs recorded within pulmonary veins in AF. The method has low computational cost and high robustness for automatic detection of AAs, which makes it a suitable approach for online use in a procedural context.

Reduction of MANTA-associated vascular complications after implementation of key insights on failure mechanisms.

OBJECTIVES: Report MANTA-associated vascular complications after implementation of key insights on failure mechanisms. BACKGROUND: The MANTA vascular closure device is utilized to close large-bore arterial access sites. We have previously identified and published the mechanisms and predictors of MANTA-associated vascular complications. We identified three distinct mechanisms leading to MANTA-associated vascular complications, predictors were a common femoral artery (CFA) diameter <6 mm and clinically established peripheral artery disease (PAD). METHODS: We compared 100 consecutive patients of the initial cohort (first n = 100) with consecutive patients in which the key insights acquired in the initial cohort were implemented (second n = 100). RESULTS: The initial cohort (n = 100 patients) had a MANTA-related vascular complication rate of 11% (7% major and 4% minor), and 14% MANTA-related bleeding complications. In a subsequent cohort of n = 100 patients, we applied the abovementioned findings: we did not use the MANTA device if the CFA was <6 mm and in patients with PAD. In addition, femoral puncture was ultrasound guided. This strategy led to a decline in MANTA-related vascular complication rates: 2% (1% major and 1% minor) p = .03, as well as a reduction in MANTA-related bleeding complications to 5% p = .01. To the best of our knowledge, this is the lowest rate of MANTA-related vascular complication reported thus far. CONCLUSIONS: Our strategy achieves low MANTA-related vascular and bleeding complication rates. Careful and critical examination of complications can lead to rapid identification of complication mechanism and its predictors. In turn, rapid implementation of these insights can lead to a decline in complication rates.

Impact of contact force sensing technology on outcome of catheter ablation of idiopathic pre-mature ventricular contractions originating from the outflow tracts.

AIMS: Catheter ablation of frequent idiopathic pre-mature ventricular contractions (PVC) is increasingly performed. While potential benefits of contact force (CF)-sensing technology for atrial fibrillation ablation have been assessed in several studies, the impact of CF-sensing on ventricular arrhythmia ablation remains unknown. This study aimed to compare outcomes of idiopathic outflow tract PVC ablation when using standard ablation catheters as opposed to CF-sensing catheters. METHODS AND RESULTS: In a retrospective multi-centre study, unselected patients undergoing catheter ablation of idiopathic outflow tract PVCs between 2013 and 2016 were enrolled. All procedures were performed using irrigated-tip ablation catheters and a 3D electro-anatomical mapping system. Sustained ablation success was defined as a ≥80% reduction of pre-procedural PVC burden determined by 24 h Holter ECG during follow-up. Overall, 218 patients were enrolled (median age 52 years, 51% males). Baseline and procedural data were similar in the standard ablation (24%) and the CF-sensing group (76%). Overall, the median PVC burden decreased from 21% (IQR 10-30%) before ablation to 0.2% (IQR 0-3.0%) after a median follow-up of 2.3 months (IQR 1.4-3.9 months). The rates of both acute (91% vs. 91%, P = 0.94) and sustained success (79% vs. 74%, P = 0.44) were similar in the standard ablation and the CF-sensing groups. No differences were observed in subgroups according to arrhythmia origin from the RVOT (65%) or LVOT (35%). Complications were rare (1.8%) and evenly distributed between the two groups. CONCLUSION: The use of CF-sensing technology is not associated with increased success rate nor decreased complication rate in idiopathic outflow tract PVC ablation.

Simplifying transfemoral ACURATE neo implantation using the TrueFlow nonocclusive balloon catheter.

OBJECTIVES: This study aimed to investigate the safety and efficacy of ACURATE neo transcatheter aortic valve replacement (TAVR) facilitated by predilatation with the nonocclusive TrueFlow balloon catheter. BACKGROUND: Now that TAVR is moving forward, physicians have attempted to simplify and streamline the procedure and the so-called minimalist approach has become more popular. METHODS: We enrolled 142 patients (mean age: 82 ± 5 years, 61% female) in a prospective registry. Patients at low risk for intraprocedural third-degree atrioventricular block (AVB) underwent TAVR with the TrueFlow balloon without rapid pacing and without insertion of a provisional pacemaker (n = 121). The remaining 21 patients were predilated with rapid pacing using a provisional pacemaker and a standard balloon. RESULTS: Predilatation with the TrueFlow balloon was successful in all 121 patients. Postdilatation was less frequently required after predilatation with the TrueFlow (25% vs. 57%, p = .003). Moreover, median procedural duration with the TrueFlow was significantly shorter (42 [interquartile range, IQR: 34-53] vs. 55 [IQR: 46-61] min, p = .004). In-hospital outcomes were similar. At 30 days, there was no mortality, two (1%) patients had suffered a stroke and only four (3%) had required implantation of a new pacemaker. CONCLUSION: Among patients with a low risk for intraprocedural third-degree AVB, the TrueFlow nonocclusive balloon catheter facilitates implantation of the ACURATE neo without the necessity of rapid pacing and a provisional pacemaker.

Pulmonary vein isolation using ablation index vs. CLOSE protocol with a surround flow ablation catheter.

AIMS: Pulmonary vein isolation (PVI) using ablation index (AI) incorporates stability, contact force (CF), time, and power. The CLOSE protocol combines AI and ≤6 mm interlesion distance. Safety concerns are raised about surround flow ablation catheters (STSF). To compare safety and effectiveness of an atrial fibrillation (AF) ablation strategy using AI vs. CLOSE protocol using STSF. METHODS AND RESULTS: First cluster was treated using AI and second cluster using CLOSE. Procedural data, safety, and recurrence of any atrial tachycardia (AT) or AF >30 s were collected prospectively. All Classes 1c and III anti-arrhythmic drugs (AAD) were stopped after the blanking period. In total, all 215 consecutive patients [AI: 121 (paroxysmal: n = 97), CLOSE: n = 94 (paroxysmal: n = 74)] were included. Pulmonary vein isolation was reached in all in similar procedure duration (CLOSE: 107 ± 25 vs. AI: 102 ± 24 min; P = 0.1) and similar radiofrequency time (CLOSE: 36 ± 11 vs. AI: 37 ± 8 min; P = 0.4) but first pass isolation was higher in CLOSE vs. AI [left veins: 90% vs. 80%; P < 0.05 and right veins: 84% vs. 73%; P < 0.05]. Twelve-month off-AAD freedom of AF/AT was higher in CLOSE vs. AI [79% (paroxysmal: 85%) vs. 64% (paroxysmal: 68%); P < 0.05]. Only four patients (2%) without recurrence were on AAD during follow-up. Major complications were similar (CLOSE: 2.1% vs. AI: 2.5%; P = 0.87). CONCLUSION: The CLOSE protocol is more effective than a PVI approach solely using AI, especially in paroxysmal AF. In this off-AAD study, 79% of patients were free from AF/AT during 12-month follow-up. The STSF catheter appears to be safe using conventional CLOSE targets.

Standardized pulmonary vein isolation workflow to enclose veins with contiguous lesions: the multicentre VISTAX trial.

AIMS: To evaluate the safety and effectiveness of pulmonary vein isolation in paroxysmal atrial fibrillation (PAF) using a standardized workflow aiming to enclose the veins with contiguous and optimized radiofrequency lesions. METHODS AND RESULTS: This multicentre, prospective, non-randomized study was conducted at 17 European sites. Pulmonary vein isolation was guided by VISITAG SURPOINT (VS target ≥550 on the anterior wall; ≥400 on the posterior wall) and intertag distance (≤6 mm). Atrial arrhythmia recurrence was stringently monitored with weekly and symptom-driven transtelephonic monitoring on top of standard-of-care monitoring (24-h Holter and 12-lead electrocardiogram at 3, 6, and 12 months follow-up). Three hundred and forty participants with drug refractory PAF were enrolled. Acute effectiveness (first-pass isolation proof to a 30-min wait period and adenosine challenge) was 82.4% [95% confidence interval (CI) 77.4-86.7%]. At 12-month follow-up, the rate of freedom from any documented atrial arrhythmia was 78.3% (95% CI 73.8-82.8%), while freedom from atrial arrhythmia by standard-of-care monitoring was 89.4% (95% CI 78.8-87.0%). Freedom fromrepeat ablations by the Kaplan-Meier analysis was 90.4% during 12 months of follow-up. Of the 34 patients with repeat ablations, 14 (41.2%) demonstrated full isolation of all pulmonary vein circles. Primary adverse event (PAE) rate was 3.6% (95% CI 1.9-6.3%). CONCLUSIONS: The VISTAX trial demonstrated that a standardized PAF ablation workflow aiming for contiguous lesions leads to low rates of PAEs, high acute first-pass isolation rates, and 12-month freedom from arrhythmias approaching 80%. Further research is needed to improve the reproducibility of the outcomes across a wider range of centres.Clinical trial registration: ClinicalTrials.gov, number NCT03062046, https://clinicaltrials.gov/ct2/show/NCT03062046.

Evaluation of comprehensive geriatric assessment in older patients undergoing pacemaker implantation.

BACKGROUND: This study evaluated the use of comprehensive geriatric assessment (CGA) in older patients undergoing pacemaker implantation. METHODS: In this prospective cohort, CGA was performed in 197 patients ≥75 years at pacemaker implantation and yearly thereafter. CGA embraced the following domains: cognition, mobility, nutrition, activities of daily living (ADLs), and falls (with or without loss of consciousness). Based on comorbidities, the Charlson comorbidity index (CCI) was calculated. For predictive analysis, logistic regression was used. RESULTS: During a mean follow-up duration of 2.4 years, the incidence rates of syncope decreased from 0.46 to 0.04 events per year (p < 0.001), and that of falls without loss of consciousness from 0.27 to 0.15 (p < 0.001) before vs. after implantation. Sixty-three patients (32.0%) died. Impaired mobility (OR 2.60, 95%CI 1.22-5.54, p = 0.013), malnutrition (OR 3.26, 95%CI 1.52-7.01, p = 0.002), and a higher CCI (OR per point increase 1.25, 95%CI 1.04-1.50, p = 0.019) at baseline were significant predictors of mortality. Among 169 patients who survived for more than 1 year and thus underwent follow-up CGA, CGA domains did not deteriorate during follow-up, except for ADLs. This decline in ADLs during follow-up was the strongest predictor of later nursing home admission (OR 9.29, 95%CI 1.82-47.49, p = 0.007). Higher baseline age (OR per year increase 1.10, 95%CI 1.02-1.20, p = 0.018) and a higher baseline CCI (OR per point increase 1.32, 95%CI 1.05-1.65, p = 0.017) were associated with a decline in ADLs during follow-up. CONCLUSIONS: CGA is useful to detect functional deficits, which are associated with mortality or nursing home admission after pacemaker implantation. The present study seems to support the use of CGA in older patients undergoing pacemaker implantation as functional deficits and falls are amenable to geriatric interventions.

Pulmonary vein isolation using a higher power shorter duration CLOSE protocol with a surround flow ablation catheter.

INTRODUCTION: The CLOSE protocol combines ablation index (AI) and ≤6 mm interlesion distance using standard power settings for the treatment of atrial fibrillation (AF). The purpose was to compare the safety and efficacy of a conventional CLOSE and a higher power shorter duration (HPSD)-CLOSE pulmonary vein isolation (PVI) strategy. METHODS AND RESULTS: All consecutive patients referred for PVI were included after informed consent was obtained from them. Group 1 was treated with a standard CLOSE protocol and group 2 with a HPSD-CLOSE protocol (45 W anterior and 35 W posterior). Procedural parameters and 6-month follow-up were analyzed. In total, 174 patients (group 1: n = 94 [paroxysmal: n = 74]; group 2: n = 80 [paroxysmal: n = 65], similar baseline characteristics) were included. PVI was reached in all, but procedure duration (82 ± 18 minutes vs 100 ± 22 minutes; P < .0001) and radiofrequency (RF) time (23 ± 5 minutes vs 36 ± 11 minutes; P < .0001) was shorter in group 2. First pass isolation was similar in groups 2 and 1 (left veins: 94% vs 90%; P = .42 and right veins: 83% vs 84%; P = .79, respectively). Six-month off- antiarrhythmic drugs freedom of AF/AT was similar in groups 2 and 1 (82% [paroxysmal: 86%] vs 83% [paroxysmal: 88%]; P = .93, respectively). Major complications were similar (group 2: 1% vs group 1: 3%; P = .39). CONCLUSION: A higher-power short duration approach can shorten a CLOSE procedure and reduce ablation time without having a negative impact on safety or efficiency.

Atrial tachycardias: Cause or effect with ablation of persistent atrial fibrillation?

INTRODUCTION: It is largely believed that atrial tachycardias (ATs) encountered during ablation of persistent atrial fibrillation (PsAF) are a byproduct of ablative lesions. We aimed to explore the alternative hypothesis that they may be a priori drivers of AF remaining masked until other AF sources are reduced or eliminated. METHODS AND RESULTS: Radiofrequency ablation of fibrillatory drivers mapped by electrocardiographic imaging (ECGI; ECVUE™, Cardioinsight Technologies, Cleveland, OH, USA) terminated PsAF in 198 (73%) out of 270 patients (61 ± 10 years, 9 ± 9 m). Two hundred and six ATs in 158 patients were subsequently mapped. Their anatomic relationship to the fibrillatory drivers prospectively identified by ECGI was then established. There were 26 (13%), 52 (25%), and 128 (62%) focal, localized, and macrore-entrant ATs, respectively. In focal/localized re-entrant ATs, 64 (82%) were terminated within an AF-driver region, in which 26 (81%) among 32 focal/localized ATs analyzed with 3-D-mapping system merged to driver map occurred from AF-driver regions in 1.0 ± 1.0 cm distance from the driver core. Importantly, there was no attempt at ablation of the associated AF-driver region in 25 of 64 (39%) of focal/localized re-entrant ATs. The sites of ATs origin generally had low-voltage, fractionated, and long-duration electrograms in AF. All but two focal/localized re-entrant ATs were successfully ablated. CONCLUSION: The majority of post-AF-ablation focal and localized re-entrant ATs originate from the region of prospectively established AF-driver regions. A third of these are localized to regions not subsequently submitted to ablation. These data suggest that many ATs exist, although not necessarily manifest independently, prior to ablation. They may have a role in the maintenance of PsAF in these individuals.

Long-term follow-up after left atrial appendage occlusion with comparison of transesophageal echocardiography versus computed tomography to guide medical therapy and data about postclosure cardioversion.

AIMS: The use of left atrial appendage (LAA) occluders in atrial fibrillation is increasing. There are few data on the comparison between transesophageal echocardiography (TEE) and computed tomography (MDCT) assessing peridevice flow and outcome of electrical cardioversion (ECV) in these patients. METHODS AND RESULTS: Single-center prospective registry from 2009 to 2015 including all LAA occluders to analyze success and complications during implantation and follow-up. Patients having ≥1 ECV were further analyzed. TEE was performed during implantation and at 6 weeks. In a subgroup of 77 patients, we compared MDCT with TEE at 6 weeks. Overall, 135 patients (69 ± 9 years; 70% male; CHA2 DS2 -VASc score: 3.6 ± 1.4; HAS-BLED score: 2.5 ± 0.6) received a LAA occluder (Watchman, n = 73; ACP-1, n = 59; Amulet, n = 3; PVI + LAA occluder, n = 91; and LAA occluder only, n = 44). Device implantation was successful in 131 (97%). Eight patients (5.9%) had major periprocedural complications (ischemic stroke/transient ischemic attacks, n = 4, tamponade, n = 2, device thrombosis, n = 2, Dressler syndrome, n = 1). The periprocedural complication rate was similar between concomitant procedure and LAA occluder only (8/91 vs. 5/44; P = 0.6). Twelve patients (9%) died (procedure-related, n = 2; 1%) during follow-up of 44 months (IQR: 43). MDCT (n = 77) at 6 weeks showed similar peridevice flow compared to TEE (TEE: 1.5 ± 1.9 mm vs. MDCT: 1.1 ± 2.2 mm, P = 0.25). Thromboembolic events occurred in 3 patients (CVA, n = 1; TIA, n = 2) during follow-up. In total, 41 ECV were performed in 26 patients (1.6 ± 0.9/patient), 13 months (IQR: 24) after implantation (<1 month: n = 8). No ECV-related clinical complications were observed. CONCLUSION: LAA occlusion is feasible with an acceptable safety profile and few events during long-term follow-up. ECV after LAA occlusion is feasible. MDCT could help to evaluate peridevice flow.

A new cryoenergy for ventricular tachycardia ablation: a proof-of-concept study.

INTRODUCTION: Lack of transmural lesion formation during radiofrequency (RF) ablation for ventricular tachycardia (VT) is an important determinant of arrhythmia recurrence. The aim of this proof-of-concept study was to evaluate safety and efficacy of a new and more powerful cryoablation system for ventricular ablation. METHODS AND RESULTS: Five healthy female sheep (59 ± 6 kg) underwent a surgical sternotomy for epicardial and endocardial access [endocardial access via right atrial appendage and left ventricular (LV) apex]. A cryoablation system with liquid nitrogen (IceCure) was used to create 3 min freezes at the right ventricle (RV). Left ventricular cryoablation was performed with either a 6 min or 2 × 4 min freezes. To assess safety, ablation was also performed on the mid left anterior descending artery and the proximal coronary sinus. A total of 45 lesions were created (RV epicardial, n = 12; LV epicardial, n = 18; RV endocardial, n = 7; LV endocardial, n = 8; LAD, n = 4; and CS, n = 4). The mean lesion volume was 5055 ± 92 mm3 (length: 32 ± 4.6 mm, width: 16.0 ± 6.4 mm, and depth: 11.2 ± 4.4 mm). Lesions were transmural in 28/45 (62%) and >10 mm in depth in 35/45 (78%). Of the endocardial lesions, 12/15 were transmural (80%). There was no benefit of the bonus freeze in LV lesions (6 vs. 2 × 4 min: 6790 ± 44 vs. 5595 ± 63 mm3; P = 0.44). All ablated vascular structures appeared macroscopically normal without acute stenosis. One animal died due to incessant Ventricular fibrillation (VF). CONCLUSION: Our results indicate that a more powerful cryoablation system is able to create large, transmural ventricular lesions from both the endocardium and the epicardium. The technology may hold potential for both surgical and catheter-based VT ablation in humans.

Alternative to left ventricular lead implantation through the coronary sinus: 1-year experience with a minimally invasive and robotically guided approach.

AIMS: Left ventricular (LV) lead implantation through the coronary sinus (CS) can be limited and sometimes not possible-alternative approaches are needed. Minimally invasive, robotically guided LV lead implantation has major advantages, but there are little published data about the short- and long-term follow-ups, in terms of feasibility, safety, electrical performance, and impact on clinical outcome. METHODS AND RESULTS: A total of 21 heart failure patients underwent robotically guided LV lead implantation using the Da Vinci Robotic System. Indications were failed implant with conventional approach through the CS (n = 16) and non-response to conventional cardiac resynchronization therapy (n = 5). During the procedure, the entire LV free wall was exposed through 3 transthoracic ports (10 mm diameter each) allowing ample choice of stimulation site and the ability to implant 2 LV leads via a Y connector. Patients were prospectively followed up for 1 year. The two LV leads were successfully implanted in all patients. No peri-procedural complications were observed. After a mean stay in the intensive care unit of 1.2 ± 4 days, the 21 patients were hospitalized in the EP department for 6.7 ± 2.9 days. Acute LV thresholds were excellent (1.0 V ± 0.6/0.4 ms) and stayed stable at 1-year follow-up (1.5 V ± 0.6/0.4 ms, P = 0.21). Four patients demonstrated an increased threshold (>2 V/0.4 ms). There was no phrenic nerve stimulation. After 12 months, in the failed implant group, 69% of the patients were echocardiographic and clinical responders. CONCLUSION: The robotic approach was feasible, safe, and minimally invasive. Accordingly, robotically guided LV lead implantation seems to offer a new alternative when conventional approaches are not suitable.

Image Integration to Guide Catheter Ablation in Scar-Related Ventricular Tachycardia.

BACKGROUND: Although multi-detector computed tomography (MDCT) and cardiac magnetic resonance (CMR) can assess the structural substrate of ventricular tachycardia (VT) in ischemic cardiomyopathy (ICM), non-ICM (NICM), and arrhythmogenic right ventricular cardiomyopathy (ARVC), the usefulness of systematic image integration during VT ablation remains undetermined. METHODS AND RESULTS: A total of 116 consecutive patients (67 ICM; 30 NICM; 19 ARVC) underwent VT ablation with image integration (MDCT 91%; CMR 30%; both 22%). Substrate was defined as wall thinning on MDCT and late gadolinium-enhancement on CMR in ICM/NICM, and as myocardial hypo-attenuation on MDCT in ARVC. This substrate was compared to mapping and ablation results with the endpoint of complete elimination of local abnormal ventricular activity (LAVA), and the impact of image integration on procedural management was analyzed. Imaging-derived substrate identified 89% of critical VT isthmuses and 85% of LAVA, and was more efficient in identifying LAVA in ICM and ARVC than in NICM (90% and 90% vs. 72%, P < 0.0001), and when defined from CMR than MDCT (ICM: 92% vs. 88%, P = 0.026, NICM: 88% vs. 72%, P < 0.001). Image integration motivated additional mapping and epicardial access in 57% and 33% of patients. Coronary and phrenic nerve integration modified epicardial ablation strategy in 43% of patients. The impact of image integration on procedural management was higher in ARVC/NICM than in ICM (P < 0.01), and higher in case of epicardial approach (P < 0.0001). CONCLUSIONS: Image integration is feasible in large series of patients, provides information on VT substrate, and impacts procedural management, particularly in ARVC/NICM, and in case of epicardial approach.