Artificial intelligence-adjudicated spatiotemporal dispersion: A patient-unique fingerprint of persistent atrial fibrillation.

BACKGROUND: Spatiotemporal dispersion-guided ablation is a tailored approach for patients in persistent atrial fibrillation (PsAF). The characterization of dispersion extent and distribution and its association with common clinical descriptors of PsAF patients has not been studied. OBJECTIVES: Artificial intelligence-adjudicated dispersion extent and distribution (AI-DED) was obtained with a machine/deep learning classifier (VX1 Software, Volta Medical) in PsAF patients undergoing ablation. The purpose of this study was to test the hypothesis that AI-DED is unique to each patient and independent of common procedural and clinical parameters. METHODS: In a subanalysis of the Ev-AIFib study (NCT03434964), spatiotemporal dispersion maps were built with VX1 software in 78 consecutive persistent and long-standing PsAF patients. AI-DED was quantified using 2 distinct approaches (visual regional characterization or automated global quantification of AI-DED). RESULTS: AI-DED paired-subregion Euclidean distance measurements between 78 patients (average distance 5.07 ± 0.60; min 2.23; max 9.75) demonstrate that AI-DED is a patient-unique characteristic of PsAF. Importantly, both AF type and AF history do not correlate with AI-DED levels (R2 = 0.006, P = .53; and R2 = 0.03, P = .25, respectively). The most extensive AI-DED levels are not associated with poorer procedural (83%, 81%, and 83% of AF termination in low, medium, and high dispersion groups, respectively; P = .954) and long-term (88%, 75%, and 91% of freedom from AF/atrial tachycardia after multiple procedures; P = .517) outcomes. CONCLUSION: The atrial distribution and extent of multipolar electrogram spatiotemporal dispersion follow a nonrandom, albeit patient-unique, distribution in PsAF patients. AI-DED may represent a procedure-implementable fingerprint of the PsAF substrate.

Subcutaneous Implantable Cardioverter-Defibrillators in Patients With Congenital Heart Disease.

BACKGROUND: Very few data have been published on the use of subcutaneous implantable cardioverter-defibrillators (S-ICDs) in patients with congenital heart disease (CHD). OBJECTIVES: The aim of this study was to analyze outcomes associated with S-ICDs in patients with CHD. METHODS: This nationwide French cohort including all patients with an S-ICD was initiated in 2020 by the French Institute of Health and Medical Research. Characteristics at implantation and outcomes were analyzed in patients with CHD. RESULTS: From October 12, 2012, to December 31, 2019, among 4,924 patients receiving an S-ICD implant in 150 centers, 101 (2.1%) had CHD. Tetralogy of Fallot, univentricular heart, and dextro-transposition of the great arteries represented almost one-half of the population. Patients with CHD were significantly younger (age 37.1 ± 15.4 years vs 50.1 ± 14.9 years; P < 0.001), more frequently female (37.6% vs 23.0%; P < 0.001), more likely to receive an S-ICD for secondary prevention (72.3% vs 35.9%; P < 0.001), and less likely to have severe systolic dysfunction of the systemic ventricle (28.1% vs 53.1%; P < 0.001). Over a mean follow-up period of 1.9 years, 16 (15.8%) patients with CHD received at least 1 appropriate shock, with all shocks successfully terminating the ventricular arrhythmia. The crude risk of appropriate S-ICD shock was twice as high in patients with CHD compared with non-CHD patients (annual incidences of 9.0% vs 4.4%; HR: 2.1; 95% CI: 1.3-3.4); however, this association was no longer significant after propensity matching (especially considering S-ICD indication, P = 0.12). The burden of all complications (HR: 1.2; 95% CI: 0.7-2.1; P = 0.4) and inappropriate shocks (HR: 0.9; 95% CI: 0.4-2.0; P = 0.9) was comparable in both groups. CONCLUSIONS: In this nationwide study, patients with CHD represented 2% of all S-ICD implantations. Our findings emphasize the effectiveness and safety of S-ICD in this particularly high-risk population. (S-ICD French Cohort Study [HONEST]; NCT05302115).

Right atrial appendage firing in atrial fibrillation.

Background: The role of atrial fibrillation (AF) drivers located at the left atrium, superior vena cava, crista terminalis and coronary sinus (CS) is well established. While these regions are classically targeted during catheter ablation, the role of right atrial appendage (RAA) drivers has been incompletely investigated. Objective: To determine the prevalence and electrophysiological characteristics of AF driver's arising from the RAA. Materials and methods: We conducted a retrospective analysis of clinical and procedural data of 317 consecutive patients who underwent an AF ablation procedure after bi-atrial mapping (multipolar catheter). We selected patients who presented with a per-procedural RAA firing (RAAF). RAAF was defined as the recording of a sustained RAA EGM with a cycle length shorter than 120 ms or 120 < RAAF CL ≤ 130 ms and ratio RAA CL/CS CL ≤ 0.75. Results: Right atrial/atrium appendage firing was found in 22 patients. The prevalence was estimated at 7% (95% CI, 4-10). These patients were mostly men (72%), median age: 66 yo ± 8 without structural heart disease (77%). RAAFs were predominantly found in paroxysmal AF patients (63%, 32%, and 5% for paroxysmal, short standing and long-standing AF, respectively, p > 0.05). RAAF median cycle length was 117 ms ± 7 while CS cycle length was 180 ms ± 10 (p < 0.01). Conclusion: In 317 consecutive AF ablation patients (22 patients, 7%) the presence of a high-voltage short-cycle-length right atrial appendage driver (RAAF) may conclusively be associated with AF termination. This case series exemplifies the not-so-uncommon role of the RAA in the perpetuation of AF.

Artificial intelligence software standardizes electrogram-based ablation outcome for persistent atrial fibrillation.

INTRODUCTION: Multiple groups have reported on the usefulness of ablating in atrial regions exhibiting abnormal electrograms during atrial fibrillation (AF). Still, previous studies have suggested that ablation outcomes are highly operator- and center-dependent. This study sought to evaluate a novel machine learning software algorithm named VX1 (Volta Medical), trained to adjudicate multipolar electrogram dispersion. METHODS: This study was a prospective, multicentric, nonrandomized study conducted to assess the feasibility of generating VX1 dispersion maps. In 85 patients, 8 centers, and 17 operators, we compared the acute and long-term outcomes after ablation in regions exhibiting dispersion between primary and satellite centers. We also compared outcomes to a control group in which dispersion-guided ablation was performed visually by trained operators. RESULTS: The study population included 29% of long-standing persistent AF. AF termination occurred in 92% and 83% of the patients in primary and satellite centers, respectively, p = 0.31. The average rate of freedom from documented AF, with or without antiarrhythmic drugs (AADs), was 86% after a single procedure, and 89% after an average of 1.3 procedures per patient (p = 0.4). The rate of freedom from any documented atrial arrhythmia, with or without AADs, was 54% and 73% after a single or an average of 1.3 procedures per patient, respectively (p < 0.001). No statistically significant differences between outcomes of the primary versus satellite centers were observed for one (p = 0.8) or multiple procedures (p = 0.4), or between outcomes of the entire study population versus the control group (p > 0.2). Interestingly, intraprocedural AF termination and type of recurrent arrhythmia (i.e., AF vs. AT) appear to be predictors of the subsequent clinical course. CONCLUSION: VX1, an expertise-based artificial intelligence software solution, allowed for robust center-to-center standardization of acute and long-term ablation outcomes after electrogram-based ablation.

Localized Atrial Tachycardia and Dispersion Regions in Atrial Fibrillation: Evidence of Spatial Concordance.

INTRODUCTION: During atrial fibrillation (AF) ablation, it is generally considered that atrial tachycardia (AT) episodes are a consequence of ablation. Objective: To investigate the spatial relationship between localized AT episodes and dispersion/ablation regions during persistent AF ablation procedures. Methods: We analyzed 72 consecutive patients who presented for an index persistent AF ablation procedure guided by the presence of spatiotemporal dispersion of multipolar electrograms. We characterized spontaneous or post-ablation ATs' mechanism and location in regard to dispersion regions and ablation lesions. RESULTS: In 72 consecutive patients admitted for persistent AF ablation, 128 ATs occurred in 62 patients (1.9 ± 1.1/patient). Seventeen ATs were recorded before any ablation. In a total of 100 ATs with elucidated mechanism, there were 58 localized sources and 42 macro-reentries. A large number of localized ATs arose from regions exhibiting dispersion during AF (n = 49, 84%). Importantly, these ATs' locations were generally remote from the closest ablation lesion (n = 42, 72%). CONCLUSIONS: In patients undergoing a persistent AF ablation procedure guided by the presence of spatiotemporal dispersion of multipolar electrograms, localized ATs originate within dispersion regions but remotely from the closest ablation lesion. These results suggest that ATs represent a stabilized manifestation of co-existing AF drivers rather than ablation-induced arrhythmias.

Cardiac Implantable Electronic Device Infection: Detailed Analysis of Cost Implications.

BACKGROUND: Infections of cardiac implantable electronic devices (CIED) are associated with significant morbidity and mortality. Despite many preventive measures, this condition is associated with significant costs for the health care system. METHODS: We retrospectively analyzed all infection cases referred for lead extraction at a single university hospital over 1 year (2015-2016). We then calculated all costs related to the infection episode per patient using hospital databases and charts review. RESULTS: Thirty-eight patients with CIED infections (29% women-mean age 71 ± 14 years) were referred for lead extraction (27 pocket infections, 11 endocarditis). Devices were mainly pacemakers (60%). When the pathogen was identified, Staphylococcus aureus methicillin sensitive was the main cause. Extraction was performed in all but 3 cases (92%). One death occurred in the nonextracted group. Respective durations of hospitalization and intravenous and antibiotic administration for patients undergoing extraction were 21 and 36 days. The calculated mean total cost for CIED infection management was CAD$29,907 (median: 26,879; range: CAD$4,827-$62,585). Mean hospital charges were CAD$12,291, accounting for 41% of the total costs. CONCLUSIONS: This study represents the first analysis of the direct costs associated with lead extraction in Canada. Device infections are associated with significant costs and increased morbidity. Any preventive measure will have a significant impact on the economic burden of the health care system and patient outcome after lead extraction.

Outcomes and costs associated with two different lead-extraction approaches: a single-centre study.

AIMS: We sought to compare outcomes and costs of a stepwise approach to transvenous lead extraction (TLE) involving laser-assisted sheaths or mechanical polypropylene sheaths, with/without crossover. METHODS AND RESULTS: We prospectively included patients who underwent TLE (between August 2013 and December 2014) as part of a stepwise approach involving simple traction, lead snaring, and sheath-assisted dissection; all of these patients underwent a first-line polypropylene-sheath-extraction approach (Group A). The comparison group (Group B) was consecutive patients who had undergone TLE before August 2013, during which laser-assisted sheath extraction was the first-line approach. The number of patients in Group B was adjusted to match the number who eventually needed sheaths in Group A. Procedural data, outcomes, and costs were compared between groups (comparison of approaches) and in patients who needed sheath-assisted extraction (comparison of techniques). Overall, 521 leads were extracted (131 patients in Group A, 104 in Group B). Radiological and clinical success rates were similar; crossover from polypropylene to laser sheaths was needed in 10 patients in Group A (vs. none in Group B). Radiological (P< 0.001) and clinical (P= 0.01) success rates were higher and were achieved with a lower radiation exposure (P= 0.03) with laser sheaths in patients (60 in each group) who needed sheath-assisted extraction. Complication rates were similar in both groups (P= 0.66) but two deaths occurred in Group B. The laser approach had higher material cost (P= 0.002). CONCLUSIONS: Although laser-assisted TLE was more effective than polypropylene sheath-assisted TLE, the latter was associated with fewer complications and was more cost-effective.

Contact-Force Catheters: Efficacy Versus Safety? Case Report of 2 Atrioesophageal Fistulae.

Contact-force (CF) catheters appear to be more effective compared to standard ablation catheters for complex radiofrequency ablation including atrial fibrillation (AF) ablation when optimal CF >10 g is achieved. Some have suggested that this technology could also improve procedural safety. We report 2 cases of atrioesophageal fistulae (AEF), a rare but catastrophic complication of AF ablation. These are to our knowledge the first cases of AEF described after using CF catheters.

Electromyographic monitoring for prevention of phrenic nerve palsy in second-generation cryoballoon procedures.

BACKGROUND: Electromyography-guided phrenic nerve (PN) monitoring using a catheter positioned in a hepatic vein can aid in preventing phrenic nerve palsy (PNP) during cryoballoon ablation for atrial fibrillation. We wanted to evaluate the feasibility and efficacy of PN monitoring during procedures using second-generation cryoballoons. METHODS AND RESULTS: This study included 140 patients (43 women) in whom pulmonary vein isolation was performed using a second-generation cryoballoon. Electromyography-guided PN monitoring was performed by pacing the right PN at 60 per minute and recording diaphragmatic compound motor action potential (CMAP) via a quadripolar catheter positioned in a hepatic vein. If a 30% decrease in CMAP amplitude was observed, cryoapplication was discontinued with forced deflation to avoid a PNP. Monitoring was unfeasible in 8 of 140 patients (5.7%), PNP occurred in 1. Stable CMAP amplitudes were achieved before ablation in 132 of 140 patients (94.3%). In 18 of 132 patients (13.6%), a 30% decrease in CMAP amplitude occurred and cryoablation was discontinued. Each time, recovery of CMAP amplitude took <60 s. In 9 of 18 cases, a second cryoapplication in the same pulmonary vein was safely performed. We observed no PNP or complication related to electromyography-guided PN monitoring. CONCLUSIONS: Electromyography-guided PN monitoring using a catheter positioned in a hepatic vein seems feasible and effective to prevent PNP during cryoballoon ablation using second-generation cryoballoon.

Challenges of treatment of aortic obstruction in Takayasu disease.

Diffuse aortitis, as seen in Takayasu disease, is characterised by extreme wall fragility, associated with a high risk of complications such as dissection and aneurysm formation, following endovascular treatment. We report a patient with Takayasu disease who presented with a very difficult clinical course associated with several unfavourable outcomes of stent insertion.