Lattice-Tip Focal Ablation Catheter That Toggles Between Radiofrequency and Pulsed Field Energy to Treat Atrial Fibrillation: A First-in-Human Trial.

BACKGROUND: The tissue selectivity of pulsed field ablation (PFA) provides safety advantages over radiofrequency ablation in treating atrial fibrillation. One-shot PFA catheters have been shown capable of performing pulmonary vein isolation, but not flexible lesion sets such as linear lesions. A novel lattice-tip ablation catheter with a compressible 9-mm nitinol tip is able to deliver either focal radiofrequency ablation or PFA lesions, each in 2 to 5 s. METHODS: In a 3-center, single-arm, first-in-human trial, the 7.5F lattice catheter was used with a custom mapping system to treat paroxysmal or persistent atrial fibrillation. Toggling between energy sources, point-by-point pulmonary vein encirclement was performed using biphasic PFA posteriorly and either temperature-controlled irrigated radiofrequency ablation or PFA anteriorly (RF/PF or PF/PF, respectively). Linear lesions were created using either PFA or radiofrequency ablation. RESULTS: The 76-patient cohort included 55 paroxysmal and 21 persistent atrial fibrillation patients undergoing either RF/PF (40 patients) or PF/PF (36 patients) ablation. The pulmonary vein isolation therapy duration time (transpiring from first to last lesion) was 22.6±8.3 min/patient, with a mean of 50.1 RF/PF lesions/patient. Linear lesions included 14 mitral (4 RF/2 RF+PF/8 PF), 34 left atrium roof (12 RF/22 PF), and 44 cavotricuspid isthmus (36 RF/8 PF) lines, with therapy duration times of 5.1±3.5, 1.8±2.3, and 2.4±2.1 min/patient, respectively. All lesion sets were acutely successful, using 4.7±3.5 minutes of fluoroscopy. There were no device-related complications, including no strokes. Postprocedure esophagogastroduodenoscopy revealed minor mucosal thermal injury in 2 of 36 RF/PF and 0 of 24 PF/PF patients. Postprocedure brain magnetic resonance imaging revealed diffusion-weighted imaging+/fluid-attenuated inversion recovery- and diffusion-weighted imaging+/fluid-attenuated inversion recovery+ asymptomatic lesions in 5 and 3 of 51 patients, respectively. CONCLUSIONS: A novel lattice-tip catheter could safely and rapidly ablate atrial fibrillation using either a combined RF/PF approach (capitalizing on the safety of PFA and the years of experience with radiofrequency energy) or an entirely PF approach. Registration: URL: https://www.clinicaltrials.gov; Unique identifiers: NCT04141007 and NCT04194307.

Impact of the Commercial Introduction of Transcatheter Mitral Valve Repair on Mitral Surgical Practice.

Background There has been uncertainty regarding the effect of transcatheter mitral valve repair (TMVr) with MitraClip on cardiac surgical practice. Our aim was to examine the impact of the commercial introduction of TMVr to a comprehensive mitral program. Methods and Results We evaluated 875 patients (aged 69±14 years; 58% men) who underwent transcatheter or mitral surgical procedures over a 6-year period at our institution. Main outcomes were changes in surgical procedural volume after TMVr introduction and short-term mortality for surgical and TMVr procedures. The numbers of patients treated with MitraClip, isolated mitral repair, and any mitral surgery were 249, 292, and 626 patients, respectively. Compared with surgery, patients with MitraClip were older (aged 82±8 versus 64±12 years; P<0.001) and had more severe morbidity. Following the introduction of MitraClip, surgical volumes steadily increased to a rate of 10 (95% CI, 3-7) procedures per year for isolated mitral procedures and 17 (95% CI, 13-20) procedures per year for all mitral surgeries. Both MitraClip and surgical volumes increased at the same rate (P=0.42). In-hospital mortality was 3.2% for MitraClip and 2.1% for all mitral surgeries (P=0.33). At 30 days, survival free of all mortality (P=0.17) and freedom from heart failure rehospitalization (P=0.75) were similar for transcatheter and surgical procedures. Conclusions The commercial introduction of TMVr may be associated with growth in cardiac surgery, without detracting from other therapies, and favorable clinical outcomes for all treated mitral regurgitation patients. These findings demonstrate the potential benefits of complementary therapies in the treatment of patients with mitral regurgitation.

Novel Strategy for Predicting Conduction Abnormalities During Transcatheter Closure of Perimembranous Ventricular Septal Defect in Adults.

BACKGROUND: In this study we evaluated the feasibility and efficacy of predicting conduction system abnormalities under 3-dimensional (3D) electroanatomic mapping guidance during transcatheter closure of perimembranous ventricular septal defects (pmVSDs) in adults.Methods and Results:The distribution of the His-Purkinje system (HPS) close to the margins of pmVSDs in the left ventricle was identified using 3D electroanatomic mapping and near-field HPS was further confirmed by different pacing protocols. Of the 20 patients in the study, 17 (85%) were successfully treated by transcatheter intervention. The minimum distance between the margins of the pmVSD and near-field HPS, as measured by 3D electroanatomic mapping, ranged from 1.3 to 3.9 mm (mean [± SD] 2.5±0.7 mm). Five patients with a minimum distance <2 mm had a higher risk (3/5; 60%) for adverse arrhythmic events, whereas patients with a distance >2 mm were at a much lower risk (1/15; 6.7%) of procedure-related conduction block (P=0.032). No other adverse events were recorded during the follow-up period (median 30 months). CONCLUSIONS: A minimum distance between the pmVSD and near-field HPS <2 mm was associated with a relatively high risk of closure-related conduction block. 3D electroanatomic mapping may be helpful in guiding decision making for transcatheter closure and reduce the incidence of adverse arrhythmic events.

Catheter ablation of ventricular arrhythmia guided by a high-density grid catheter.

INTRODUCTION: Minimal data exist on the Advisor HD Grid (HDG) catheter and the Precision electroanatomic mapping (EAM) system for ventricular arrhythmia (VA) procedures. Using the HDG catheter, the EAM uses the high-density (HD) wave mapping and best duplicate software to compare the maximum peak-to-peak bipolar voltages within a small zone independent of wavefront direction and catheter orientation. This study aimed to summarize the procedural experience for VAs using the HDG catheter. METHODS: Clinical and procedural characteristics of VA ablation procedures were retrospectively reviewed that used the HDG catheter and the Precision EAM over a 12-month period. RESULTS: A total of 22 patients, 18 with sustained ventricular tachycardia and 4 with premature ventricular contractions were included. Clinically indicated left and/or right ventricular (LV, RV, respectively), and aortic maps were created. LV substrate maps (n = 13) used a median 1700 points (interquartile range [IQR]25%-75% , 1427-2412) out of a median 18 573 (IQR25%-75% , 15 713-41 067) total points collected. RV substrate maps (n = 11) used a median 1435 points (IQR25%-75% , 1114-1871) out of a median 16 005 (IQR25%-75% , 11 063-21 405) total points collected. Total point utilization, used vs collected, was 9%. Mean mapping time was 43 ± 17 minutes (substrate, 34 ± 18 minutes; activation/pace mapping, 9 ± 13 minutes). Acute success was achieved in 56 (86%) and short-term success achieved in 16 patients (73%) at a median follow-up of 145 days (IQR25%-75% , 62-273 days). There were no procedural complications. CONCLUSION: HD wave mapping using the novel HDG catheter integrated with the Precision EAM is safe and feasible in VA procedures in the LV, RV, and aorta. Mapping times are consistent with other multielectrode mapping catheters.

Left atrial voltage mapping with a direction-independent grid catheter: Comparison with a conventional circular mapping catheter.

INTRODUCTION: A recently introduced grid mapping catheter (GMC) is designed for better electrode-tissue contact and can collect bipolar signals both along and across the splines, which may allow more efficient voltage map generation independent of propagation direction. We compared the GMC with a conventional circular mapping catheter (CMC) for left atrial (LA) voltage mapping. METHODS: This study included 20 consecutive patients undergoing repeat ablation for recurrent atrial fibrillation who had demonstrated LA low-voltage areas (LVAs, <0.10 mV). Following pulmonary vein isolation, LA voltage mapping was performed twice, once using the GMC and once using the CMC. RESULTS: Voltage mapping was more efficient using the GMC than the CMC in terms of mapping time (459 [404, 543] vs 602 [496, 814] seconds; P = .014) and the number of mapping points (2446 [2099, 3104] vs 1841 [1494, 2314]; P = .002). The incidence of catheter-induced ectopies was lower (44 [28, 62] vs 114 [74, 188]; P < .0001) using the GMC. The GMC utilizing all bipoles detected LVAs in 85% of patients with LVAs detected by CMC. LVA measurements were significantly smaller on maps generated by the GMC using bipoles along or across the splines than those measured with the CMC (11.1 [4.6, 17.2] or 9.7 [2.5, 16.0] vs 16.4 [6.8, 26.8] cm2 ; P = .008 and P = .001, respectively), and were even smaller when using all bipoles (7.9 [1.1, 13.5] cm2 , P = .0001). CONCLUSION: The GMC allowed a more efficient mapping procedure and enabled more selective identification of LVAs with smaller LVA size.

[TAVI simplification: A focus]. / Simplification des procédures TAVI : mise au point.

After a first procedure carried out in 2002 by Pr Cribier's, Transcatheter Aortic Valve Replacement or TAVR revolutionized the management of aortic stenosis with a constant increase in the number of procedures performed worldwide. Experience of operators and teams and evolution of the technique has been accompanied by a drastic reduction in complications in patients at lower surgical risk. In parallel, the procedure was considerably simplified, carried out more and more under local anesthesia, with percutaneous femoral approach, secondary radial approach, prosthesis implantation without predilatation, rapid pacing on left ventricle wire and early discharge. Thus, the "simplified" TAVR adopted in most centers nowadays is a real revolution of the technique. However, simplified TAVR must be accompanied upstream by a rigorous selection of patients who can benefit from a minimalist procedure in order to guarantee its safety.

Identification of repetitive atrial activation patterns in persistent atrial fibrillation by direct contact high-density electrogram mapping.

INTRODUCTION: Recent studies have characterized drivers in persistent atrial fibrillation using automated algorithm detection with panoramic endocardial mapping by means of basket catheters. We aimed to identify repetitive atrial activation patterns (RAAPs) during ongoing atrial fibrillation (AF) based upon automated annotation of unipolar electrograms (EGMs) recorded with a high-density regional endocardial contact mapping catheter. METHODS: In 14 persistent AF patients, high-resolution EGMs were recorded for 30 seconds at sequential PentaRay (Biosense Inc) positions covering the entire biatrial surface. All recordings were reviewed off-line with dedicated software allowing automated annotation of the local activation time of the unipolar fibrillatory EGMs (CARTOFINDER; Biosense Inc). RAAPs were defined as a consistent activation pattern (for ≥3 consecutive beats) of either focal activity with centrifugal spread (RAAPfocal ) or rotational activity across the PentaRay splines spanning the AF cycle length (RAAProtational ). RESULTS: A total of 498 PentaRay recordings were analyzed (35.6 ± 7.6 per patient). The number of PentaRay recordings displaying RAAP was 9.8 ± 3.1 per patient (range = 3-15), of which 2.4 ± 2.4 RAAProtational (range = 0-7), and 7.4 ± 4.4 RAAPfocal (range = 1-13). 77% of RAAPs portrayed focal firing. The median number of repetitions per 30 second recording was 11 (range = 3-225) per recording. RAAPs were observed both in the right atrium (RA) (35%) and left atrium (LA) (65%), with the majority being near the left PVs/appendage (35% of all RAAPs) and the superior vena cava/right appendage (23% of all RAAPs). CONCLUSION: High-resolution, sequential endocardial EGM-based mapping allows identification of RAAPs in persistent AF. In our series, focal firing was the most frequently observed pattern.

Global multielectrode contact-mapping plus ablation with a single catheter in patients with atrial fibrillation: Global AF study.

INTRODUCTION: The critical question for technological advancement of catheter ablation of atrial fibrillation (AF) is whether a creative new concept can combine and even improve the options of single-tip catheters with the simplicity of the use of balloon catheters. Herein are described the results from the first clinical study of a new multielectrode contact-mapping plus ablation array (Globe) offering such a complete solution. METHODS AND RESULTS: The multielectrode Globe array consists of 16 flat ribs with 122 gold-plated electrodes. Each electrode can record electrograms, ablate, pace, and can measure tissue contact and temperature. Single-shot pulmonary vein isolation (PVI) is possible with temperature-guided ablation of up to 24 electrodes simultaneously with automatic, individual power control of every electrode. Sixty patients with symptomatic AF underwent PVI using the Globe. In all sixty patients, acute PVI was achieved in 232 of 234 attempted PVs (99.1%). In 34 patients treated with "single-hot-shot" ablation, PVI was achieved in 136 of 136 PVs (100%). Single-procedure 12-month freedom from AF off antiarrhythmic drugs in the "single-hot-shot" group was 75.5% and freedom from AF/atrial tachycardia 72.3%. In two patients, pericardial tamponade was observed, one after a transseptal puncture, and one during array insertion with an over-advanced sheath. There were no other device-related serious adverse events, including stroke, PV stenosis, esophageal perforation, or phrenic nerve palsy. CONCLUSIONS: In this first clinical series, the Globe catheter was found to be an easy-to-use system for single-shot PVI. The continuously updated multielectrode voltage and activation mapping data indicate future options for mapping and ablation beyond PVI.

Larger and deeper ventricular lesions using a novel expandable spherical monopolar irrigated radiofrequency ablation catheter.

BACKGROUND: Radiofrequency (RF) ablation is an established treatment for ventricular tachycardia (VT). However, the inability of current RF catheters to address deep or large substrate may explain most of the clinical failures. OBJECTIVES: The aim of this study is to assess the efficacy and safety of ablation in the left ventricle (LV) in sheep using a novel 8-Fr deflectable ablation catheter (Sphere-9; Affera, Inc) with a 9-mm expandable spherical monopolar irrigated RF tip vs a standard RF irrigated catheter (Biosense Webster, Diamond Bar, CA). The impact on tissue was assessed on local bipolar electrograms (from nine uniformly distributed mini surface electrodes and an internal central reference electrode), as well as on direct lesion measurement post mortem. METHODS AND RESULTS: Eleven sheep underwent LV endocardial ablation in healthy tissue using the Sphere-9 catheter (n = 6), or a conventional irrigated RF catheter (n = 5). Twenty lesions were created with the Sphere-9 (current limit: 2.7 A; temp. limit: 60°C; irrigation: 30 mL/min; and duration: 60-120 seconds). Local bipolar electrograms at the surface of the catheter disappeared during RF delivery in 17 of 20 (85%) lesions. The mean lesion volume was 1707 ± 771 mm 3 (length: 15.8 ± 3.3 mm; width: 11.6 ± 4.2 mm; and depth: 10.3 ± 2.9 mm). Twenty-five lesions were created with a standard RF irrigated catheter (power control 35 W; irrigation: 30 mL/min; duration: 60 seconds; volume 537 ± 398 mm 3 ; length: 8.2 ± 2.3 mm; width: 5.2 ± 1.8 mm; and depth: 5.5 ± 2.4 mm). The novel spherical RF catheter created significantly larger lesions ( P < .001 for measurements in all dimensions). There were no steam pops with the novel ablation catheter vs one with the conventional catheter. CONCLUSIONS: This novel spherical monopolar irrigated RF catheter creates lesions that are twice as large and deep as a standard irrigated RF catheter.

Locating Atrial Fibrillation Rotor and Focal Sources Using Iterative Navigation of Multipole Diagnostic Catheters.

PURPOSE: Multi-polar diagnostic catheters are used to construct the 3D electro-anatomic mapping of the atrium during atrial fibrillation (AF) ablation procedures; however, it remains unclear how to use the electrograms recorded by these catheters to locate AF-driving sites known as focal and rotor source types. The purpose of this study is to present the first algorithm to iteratively navigate a circular multi-polar catheter to locate AF focal and rotor sources without the need to map the entire atria. METHODS: Starting from an initial location, the algorithm, which was blinded to the location and type of the AF source, iteratively advanced a Lasso catheter based on its electrogram characteristics. The algorithm stopped the catheter when it located of an AF source and identified the type. The efficiency of the algorithm is validated using a set of simulated focal and rotor-driven arrhythmias in fibrotic human 2D and 3D atrial tissue. RESULTS: Our study shows the feasibility of locating AF sources with a success rate of greater than 95.25% within average 7.56 ± 2.28 placements independently of the initial position of the catheter and the source type. CONCLUSIONS: The algorithm could play a critical role in clinical electrophysiology laboratories for mapping patient-specific ablation of AF sources located outside the pulmonary veins and improving the procedure success.

Feasibility of complex transfemoral electrophysiology procedures in patients with inferior vena cava filters.

BACKGROUND: The presence of inferior vena cava filters (IVCFs) has been considered a relative contraindication to electrophysiology (EP) procedures that require transfemoral venous placement of multiple catheters and/or long sheaths. There are inadequate data related to complex EP procedures in this population. OBJECTIVE: The purpose of this study was to describe the experience of a single high-volume center with respect to complex EP procedures in patients with IVCFs. METHODS: Patients with IVCFs undergoing complex EP procedures between 2004 and 2018 were identified. Clinical characteristics, IVCF type, procedural findings, and complications were analyzed. RESULTS: Fifty complex ablation procedures were performed in 40 patients (mean age 63.8 ± 10.9 years; 68% men). The mean IVCF dwell time was 69.1 ± 19.1 months, and 48 patients (96%) were on chronic oral anticoagulation. Procedures included ablation of atrial fibrillation (n = 21), ventricular tachycardia (n = 20), supraventricular tachycardia (n = 3), cavotricuspid isthmus flutter (n = 3), supraventricular tachycardia and cavotricuspid isthmus flutter (n = 1), and transvenous lead extraction (n = 3). Twenty procedures included quadripolar catheters (mean 1.4 ± 0.75), and 33 procedures involved deflectable decapolar catheters (mean 1.7 ± 0.47). Long sheaths were used in 35 cases (mean 1.63 ± 0.49) and intracardiac echocardiography in 38. In 4 cases (involving 3 patients), the IVCF was occluded and could not be crossed. There were no procedural complications related to the IVCF. CONCLUSION: The substantial majority of IVCFs in patients presenting for complex EP procedures were patent and easily crossed under fluoroscopic guidance. The presence of an IVCF should not discourage operators from performing procedures that require transfemoral deployment of multiple catheters and/or sheaths.

Procedural and long-term outcome after catheter ablation of idiopathic outflow tract ventricular arrhythmias: comparing manual, contact force, and magnetic navigated ablation.

Aims: Currently, comparative data on procedural and long-term clinical outcome of outflow tract (OT) idiopathic ventricular arrhythmia (IVA) ablation with manual (MAN), contact force (CF), and magnetic navigation system (MNS) ablation are lacking. The aim of this study was to compare the procedural and long-term clinical outcome of MAN, CF, and MNS ablation of OT IVAs. Methods and results: Seventy-three patients (31 MAN, 17 CF, and 25 MNS patients; consecutive per group) with OT IVA, who underwent catheter ablation in our centre were analysed. Procedural success rates (success at the end of the procedure), procedural data and long-term follow-up data were compared. Baseline patient demographics were comparable. Procedural success rates were similar (MAN 81%, 71% CF, and MNS 92%; P = 0.20). Median fluoroscopy time was shorter in the MNS group: MAN 29 (16-38), CF 37 (21-46), and MNS 13 (10-20) min (P = 0.002 for MNS vs. CF and MAN). The overall complication rate was: MAN 10%, CF 0%, and MNS 0% (P = 0.12). Median follow-up was: MAN 2184 (1672-2802), CF 1721 (1404-1913), and MNS 3031 (2524-3286) days (P <0.001). Recurrences occurred in MAN 46%, CF 50%, and MNS 46% (P = 0.97). Repeat procedures were performed in MAN 20%, CF 40%, and MNS 33% (P = 0.32). Conclusion: Procedural and long-term clinical outcome of OT IVA ablation are equal for MAN, CF, and MNS. MNS has a favourable procedural safety profile due to the shorter fluoroscopy time compared with MAN and CF.