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Background: Left ventricular outflow tract (LVOT) obstruction is a common, often fatal complication of transcatheter mitral valve replacement (TMVR). Laceration of the anterior mitral leaflet to prevent outflow obstruction (LAMPOON) was safe and effective at preventing LVOT obstruction at 30 days in the National Heart, Lung, and Blood Institute LAMPOON trial., Objectives: The authors report the 5-year outcomes of intentional anterior mitral leaflet laceration before SAPIEN 3 TMVR, in patients at risk of LVOT obstruction., Methods: The National Heart, Lung, and Blood Institute LAMPOON trial was a prospective, multicenter, single-arm safety and feasibility study of LAMPOON and transseptal SAPIEN 3 TMVR in annuloplasty rings (valve-in-ring) or native mitral annular calcification (MAC) (valve-in-MAC). All subjects had high predicted risk for LVOT obstruction. Subjects were not excluded for excessive frailty or comorbidity. The primary endpoints were technical success and safety at 30 days. Secondary clinical and echocardiographic endpoints were assessed at 1 year and clinical follow-up at 5 years., Results: Thirty subjects were enrolled between June 2017 and June 2018, equally between the valve-in-MAC and valve-in-ring arms. At 30 days, LAMPOON was successful in all 30 subjects, with no strokes, 1 (3%) death, and 1 (3%) moderate LVOT obstruction. Eighteen (65%) survived to 1 year, and 7 (25%) survived to 5 years. Six (20%) were hospitalized for heart failure in the first year. From baseline to 1 year, there was a 24-point improvement in Kansas City Cardiomyopathy Questionnaire score and a 60-m improvement in 6-minute walk distance. There was no significant change in N-terminal pro-brain natriuretic peptide. At 1 year, LVOT gradients remained low., Conclusions: LAMPOON enabled TMVR despite the risk for LVOT obstruction. There were no long-term complications associated with LAMPOON. The selection of inoperable patients limited assessment of long-term survival following TMVR. (NHLBI DIR LAMPOON Study: Intentional Laceration of the Anterior Mitral Leaflet to Prevent Left Ventricular Outflow Tract Obstruction During Transcatheter Mitral Valve Implantation; NCT03015194)., Competing Interests: Funding Support and Author Disclosures This work was supported by the Division of Intramural Research, NHLBI, National Institutes of Health (Z01-HL006040), and by the intramural programs of the participating centers. The NHLBI and Edwards Lifesciences have a collaborative research and development agreement on transcatheter modification of mitral valve leaflets, including joint financial support of this study. Drs Khan, Rogers, and Lederman are coinventors on patents, assigned to the National Institutes of Health, for catheter devices to lacerate valve leaflets. Dr Khan is a proctor for Edwards Lifesciences and Medtronic; and has equity in Transmural Systems. Dr Greenbaum is a proctor for Edwards Lifesciences, Medtronic, and Abbott Vascular; and has equity in Transmural Systems and Excision Medical. Dr Babaliaros is a consultant for Edwards Lifesciences, Abbott Vascular, and Transmural Systems; and his employer has research contracts for clinical investigation of transcatheter aortic and mitral devices from Edwards Lifesciences, Abbott Vascular, Medtronic, St. Jude Medical, and Boston Scientific. Dr Rogers is a consultant for Edwards Lifesciences, Boston Scientific, Abbott, Anteris, and Medtronic; serves on advisory boards for Medtronic and Boston Scientific; and has equity in Transmural Systems. Dr Eng is on the Speakers Bureau for Edwards Lifesciences and Medtronic. Dr Foerst is a proctor for Edwards Lifesciences and Medtronic. Dr Paone is proctor for Edwards Lifesciences and has equity in Medtronic. Dr Lederman is the principal investigator on a cooperative research and development agreement between the National Institutes of Health and Edwards Lifesciences for transcatheter modification of the mitral valve. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Published by Elsevier Inc.)

Purpose: To introduce alternating current-controlled, conductive ink-printed marker that could be implemented with both custom and commercial interventional devices for device tracking under MRI using gradient echo, balanced SSFP, and turbo spin-echo sequences., Methods: Tracking markers were designed as solenoid coils and printed on heat shrink tubes using conductive ink. These markers were then placed on three MR-compatible test samples that are typically challenging to visualize during MRI scans. MRI visibility of markers was tested by applying alternating and direct current to the markers, and the effects of applied current parameters (amplitude, frequency) on marker artifacts were tested for three sequences (gradient echo, turbo spin echo, and balanced SSFP) in a gel phantom, using 0.55T and 1.5T MRI scanners. Furthermore, an MR-compatible current supply circuit was designed, and the performance of the current-controlled markers was tested in one postmortem animal experiment using the current supply circuit., Results: Direction and parameters of the applied current were determined to provide the highest conspicuity for all three sequences. Marker artifact size was controlled by adjusting the current amplitude, successfully. Visibility of a custom-designed, 20-gauge nitinol needle was increased in both in vitro and postmortem animal experiments using the current supply circuit., Conclusion: Current-controlled conductive ink-printed markers can be placed on custom or commercial MR-compatible interventional tools and can provide an easy and effective solution to device tracking under MRI for three sequences by adjusting the applied current parameters with respect to pulse sequence parameters using the current supply circuit., (© 2024 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)

Background: Deep intramural ventricular tachycardia substrate targets are difficult to access, map, and ablate from endocardial and epicardial surfaces, resulting in high recurrence rates., Objectives: In this study, the authors introduce a novel approach called ventricular intramyocardial navigation for tachycardia ablation guided by electrograms (VINTAGE) to access and ablate anatomically challenging ventricular tachycardia from within the myocardium., Methods: Guidewire/microcatheter combinations were navigated deep throughout the extravascular myocardium, accessed directly from the right ventricle cavity, in Yorkshire swine (6 naive, 1 infarcted). Devices were steered to various intramyocardial targets including the left ventricle summit, guided by fluoroscopy, unipolar electrograms, and/or electroanatomic mapping. Radiofrequency ablations were performed to characterize ablation parameters and reproducibility. Intramyocardial saline irrigation began 1 minute before ablation and continued throughout. Lesions were analyzed on cardiac magnetic resonance and necropsy., Results: VINTAGE was feasible in all animals within naive and infarcted myocardium. Forty-three lesions were created, using various guidewires and power settings. Forty-one (95%) lesions were detected on cardiac magnetic resonance and 38 (88%) on necropsy; all undetected lesions resulted from intentionally subtherapeutic ablation energy (10 W). Larger-diameter guidewires yielded larger size lesions. Lesion volumes on necropsy were significantly larger at 20 W than 10 W (178 mm 3 [Q1-Q3: 104-382 mm 3 ] vs 49 mm 3 [Q1-Q3: 35-93 mm 3 ]; P = 0.02). Higher power (30 W) did not create larger lesions. Median impedance dropped with preablation irrigation by 12 Ω (Q1-Q3: 8-17 Ω), followed by a further 15-Ω (Q1-Q3: 11-19 Ω) drop during ablation. Intramyocardial navigation, ablation, and irrigation were not associated with any complications., Conclusions: VINTAGE was safe and effective at creating intramural ablation lesions in targets traditionally considered inaccessible from the endocardium and epicardium, both naive and infarcted. Intramyocardial guidewire irrigation and ablation at 20 W creates reproducibly large intramural lesions., Competing Interests: Funding Support and Author Disclosures Supported by the Division of Intramural Research, National Heart Lung and Blood Institute, National Institutes of Health (NIH), grant Z01-HL006040 (to Dr Lederman). Dr Halaby is a coinventor on applicable patent applications assigned to the NIH. Dr Bruce is a coinventor on applicable patent applications assigned to the NIH. Dr Kolandaivelu is a coinventor on applicable patent applications assigned to the NIH. Dr Rogers has performed consulting for Edwards Lifesciences, Medtronic, Boston Scientific, and Transmural Systems; has served on the Advisory Board for Medtronic and Boston Scientific; holds equity interest in Transmural Systems; and is a coinventor on patents, assigned to the NIH, for transcatheter electrosurgery devices. Dr Khan is a coinventor on applicable patent applications assigned to the NIH; has served as a proctor for Edwards Lifesciences and Medtronic; and holds equity in Transmural Systems. Dr Yildirim is a coinventor on applicable patent applications assigned to the NIH. Dr Lederman is a coinventor on applicable patent applications assigned to the NIH. Dr Babaliaros has served as a consultant for Edwards Lifesciences, Abbott Vascular, and Transmural Systems, and his employer has research contracts for the clinical investigation of transcatheter aortic and mitral devices from Edwards Lifesciences, Abbott Vascular, Medtronic, St Jude Medical, and Boston Scientific. Dr Greenbaum has served as a proctor for Edwards Lifesciences, Medtronic, and Abbott Vascular and holds equity in Transmural Systems and Excision Medical. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Published by Elsevier Inc.)

Background: Acute aortic regurgitation is life-threatening with few nonsurgical options for immediate stabilization. We propose Trans-Aortic Balloon to Ease Regurgitation Applying Counter-Pulsation (TABERNACL), a simple, on-table temporary valve using commercially available equipment to temporize acute severe aortic regurgitation., Methods: We hypothesize that an appropriately sized commercial balloon dilatation catheter-straddling the aortic annulus and connected to a counterpulsation console-can serve as a temporizing valve to restore hemodynamic stability in acute aortic regurgitation. We performed benchtop testing of valvuloplasty, angioplasty, and sizing balloons as counterpulsation balloons. TABERNACL was assessed in vivo in a porcine model of acute aortic regurgitation (n=8). We also tested a static undersized, continuously inflated transvalvular balloon as a spacer intended physically to obstruct the regurgitant orifice., Results: Benchtop testing identified that Tyshak II and PTS sizing (NuMed Braun) balloon catheters performed adequately as temporary valves (ie, complete inflation and deflation with each cycle) and resisted fatigue, in contrast to others. When TABERNACL was used in the acute severe regurgitation animals, there was immediate hemodynamic improvement, with a significant 35% increase in diastolic aortic pressure by 16 mm Hg ([95% CI, 7-25] P =0.0056), 34% reduction in left ventricular end-diastolic pressure by -7 mm Hg ([95% CI, -10 to -5] P =0.0006), improvement in the aortic diastolic index by 0.28 ([95% CI, 0.18-0.39] P =0.0009), and reversal of electrocardiographic myocardial ischemia. As an alternative, static balloon inflation across the aortic valve stabilized regurgitation hemodynamics at the expense of a new aortic gradient and caused excessive ectopy from balloon movement in the left ventricular outflow tract., Conclusions: TABERNACL improves hemodynamics and reduces coronary ischemia by electrocardiography in animals with acute severe aortic regurgitation. TABERNACL valves obstruct the diastolic regurgitant orifice without systolic obstruction. This may prove a lifesaving bridge to definitive valve replacement therapy., Competing Interests: Disclosures Dr Rogers reports consulting from Edwards Lifesciences, Medtronic, Boston Scientific, and Transmural Systems; is on the advisory board at Medtronic and Boston Scientific; reports equity interest in Transmural Systems; and reports intellectual property (coinventor on patents), assigned to the National Institutes of Health (NIH), for transcatheter electrosurgery devices. Dr Khan reports educational grants from Abbott, Boston Scientific, Edwards Lifesciences, and Philips; is a proctor at Edwards Lifesciences and Medtronic; reports equity interest in Transmural Systems; and reports intellectual property (coinventor on patents), assigned to NIH, for transcatheter electrosurgery devices. The other authors report no conflicts.

Background: Left ventricular outflow tract (LVOT) obstruction is a source of morbidity in hypertrophic cardiomyopathy (HCM) and a life-threatening complication of transcatheter mitral valve replacement (TMVR) and transcatheter aortic valve replacement (TAVR). Available surgical and transcatheter approaches are limited by high surgical risk, unsuitable septal perforators, and heart block requiring permanent pacemakers., Objectives: The authors report the initial experience of a novel transcatheter electrosurgical procedure developed to mimic surgical myotomy., Methods: We used septal scoring along midline endocardium (SESAME) to treat patients, on a compassionate basis, with symptomatic LVOT obstruction or to create space to facilitate TMVR or TAVR., Results: In this single-center retrospective study between 2021 and 2023, 76 patients underwent SESAME. In total, 11 (14%) had classic HCM, and the remainder underwent SESAME to facilitate TMVR or TAVR. All had technically successful SESAME myocardial laceration. Measures to predict post-TMVR LVOT significantly improved (neo-LVOT 42 mm 2 [Q1-Q3: 7-117 mm 2 ] to 170 mm 2 [Q1-Q3: 95-265 mm 2 ]; P < 0.001; skirt-neo-LVOT 169 mm 2 [Q1-Q3: 153-193 mm 2 ] to 214 mm 2 [Q1-Q3: 180-262 mm 2 ]; P < 0.001). Among patients with HCM, SESAME significantly decreased invasive LVOT gradients (resting: 54 mm Hg [Q1-Q3: 40-70 mm Hg] to 29 mm Hg [Q1-Q3: 12-36 mm Hg]; P = 0.023; provoked 146 mm Hg [Q1-Q3: 100-180 mm Hg] to 85 mm Hg [Q1-Q3: 40-120 mm Hg]; P = 0.076). A total of 74 (97.4%) survived the procedure. Five experienced 3 of 76 (3.9%) iatrogenic ventricular septal defects that did not require repair and 3 of 76 (3.9%) ventricular free wall perforations. Neither occurred in patients treated for HCM. Permanent pacemakers were required in 4 of 76 (5.3%), including 2 after concomitant TAVR. Lacerations were stable and did not propagate after SESAME (remaining septum: 5.9 ± 3.3 mm to 6.1 ± 3.2 mm; P = 0.8)., Conclusions: With further experience, SESAME may benefit patients requiring septal reduction therapy for obstructive hypertrophic cardiomyopathy as well as those with LVOT obstruction after heart valve replacement, and/or can help facilitate transcatheter valve implantation., Competing Interests: Funding Support and Author Disclosures This work was supported by intramural funds in the Emory Structural Heart and Valve Center, Emory University Hospital Midtown; and by Z01-HL006040, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health. Drs Greenbaum, Ueyama, Gleason, Hanzel, Xie, Byku, Guyton, Grubb, Lisko, Shekiladze, Inci, Grier, Paone, and Babaliaros have received institutional research support from Abbott Vascular, Ancora Heart, Edwards Lifesciences, Gore Medical, JenaValve, Medtronic, Polares Medical, Transmural Systems, and 4C Medical. Dr Greenbaum has served as a consultant to Abbott Vascular, Edwards Lifesciences, Excision Medical, and Medtronic; and has equity interests in Transmural Systems and Excision Medical. Dr Khan has served as a proctor for Edwards Lifesciences and Medtronic; and has equity interest in Transmural Systems. Drs Khan, Rogers, and Lederman are coinventors on patent applications, assigned to the National Institutes of Health, for transcatheter electrosurgical devices. Dr Rogers has served as a consultant and proctor for Edwards Lifesciences; has served as a consultant, proctor, and advisory board member for Medtronic and Boston Scientific; and has equity interest in Transmural Systems. Dr Hanzel has served as a consultant for Medtronic. Dr Byku has served as a consultant for Edwards Lifesciences and Shockwave Medical. Dr Grubb has served on the Advisory Board of, served as a consultant for, or received honorarium from Medtronic, Boston Scientific, Abbott, 4C Medical, Ancora, and OpSens. Dr Paone has served as a consultant and proctor for Edwards Lifesciences; and has equity interest in Medtronic. Dr McCabe has served as a consultant for Edwards, Abbott, Medtronic, and Shockwave Medical; and has equity interest in Excision Medical. Dr Babaliaros has served as a consultant to Abbott Vascular, Edwards Lifesciences, and Medtronic; and has equity interest in Transmural Systems. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Published by Elsevier Inc.)

Background: Intramyocardial guidewire navigation is a novel technique that allows free transcatheter movement within ventricular muscle. Guidewire radial depth, between endocardial and epicardial surfaces, is ambiguous by x-ray and echocardiography., Objectives: The aim of this study was to develop a simple tool, EDEN (Electrocardiographic Radial Depth Navigation), to indicate radial depth during intramyocardial guidewire navigation. Combined with routine imaging, EDEN facilitates a new family of intramyocardial catheter procedures to slice, reshape, pace, and ablate the heart., Methods: We mapped intramyocardial electrograms of left and right ventricular walls and septum during open- and closed-chest swine procedures (N = 53), including MIRTH (Myocardial Intramural Remodeling by Transvenous Tether) ventriculoplasty. We identified radial depth-dependent features on unipolar electrograms. We developed a machine learning-based classifier to indicate categorical position, and modeled the findings in silico to test understanding of the physiology., Results: EDEN signatures distinguished 5 depth zones throughout left and right ventricular free walls and interventricular septum. Relative ST-segment elevation magnitude best discriminated position and was maximum (40.1 ± 6.5 mV) in the midmyocardium. Subendocardial positions exhibited dominant Q waves with lower-amplitude ST segments (16.8 ± 5.8 mV), whereas subepicardial positions exhibited dominant R waves with lower-amplitude ST segments (15.7 ± 4.8 mV). EDEN was unaffected by pacing-induced left bundle branch block. ST-segment elevation declined over minutes and reappeared after submillimeter guidewire manipulation. Modeling recapitulated EDEN features. The machine learning-based classifier was 97% accurate. EDEN successfully guided MIRTH ventriculoplasty., Conclusions: EDEN provides a simple and reproducible real-time reflection of categorical guidewire-tip radial depth during intramyocardial guidewire navigation. Used in tandem with x-ray, EDEN enables novel, transcatheter, intramyocardial therapies such as MIRTH, SESAME (Septal Surfing Along Midline Endocardium), and cerclage ventriculoplasty., Competing Interests: Funding Support and Author Disclosures Supported by the Division of Intramural Research, National Heart Lung and Blood Institute, National Institutes of Health (NIH), grant Z01-HL006040 (Dr Lederman). Drs Bruce, Yildirim, Kolandaivelu, and Lederman are coinventors of patents, assigned to the NIH, for EDEN related devices. Dr Rogers is a consultant and physician proctor to Edwards Lifesciences, Medtronic, and Boston Scientific; is an advisory board member for Medtronic; and holds equity interest in Transmural Systems. Drs Babaliaros and Greenbaum receive institutional research support from Abbott Vascular, Ancora Heart, Edwards Lifesciences, Gore Medical, Jena Valve, Medtronic, Polares Medical, Transmural Systems, and 4C Medical; receive consulting fees from Abbott Vascular, Edwards Lifesciences, and Medtronic; and have equity interest in Transmural Systems. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Published by Elsevier Inc.)

Background: Obstructive sleep apnea (OSA) is associated with atrial remodeling, atrial fibrillation (AF), and increased incidence of arrhythmia recurrence after pulmonary vein (PV) isolation. We aimed to characterize the atrial substrate, including AF triggers in patients with paroxysmal AF and OSA., Methods and Results: In 86 patients with paroxysmal AF (43 with ≥moderate OSA [apnea-hypopnea index ≥15] and 43 without OSA [apnea-hypopnea index <5]), right atrial and left atrial voltage distribution, conduction velocities, and electrogram characteristics were analyzed during atrial pacing. AF triggers were examined before and after PV isolation and targeted for ablation. Patients with OSA had lower atrial voltage amplitude (right atrial, P =0.0005; left atrial, P =0.0001), slower conduction velocities (right atrial, P =0.02; left atrial, P =0.0002), and higher prevalence of electrogram fractionation ( P =0.0001). The areas of atrial abnormality were consistent among patients, most commonly involving the left atrial septum (32/43; 74.4%). At baseline, the PVs were the most frequent triggers for AF in both groups; however, after PV isolation patients with OSA had increased incidence of additional extra-PV triggers (41.8% versus 11.6%; P =0.003). The 1-year arrhythmia-free survival was similar between patients with and without OSA (83.7% and 81.4%, respectively; P =0.59). In comparison, control patients with paroxysmal AF and OSA who underwent PV isolation alone without ablation on extra-PV triggers had increased risk of arrhythmia recurrence (83.7% versus 64.0%; P =0.003)., Conclusions: OSA is associated with structural and functional atrial remodeling and increased incidence of extra-PV triggers. Elimination of these triggers resulted in improved arrhythmia-free survival., (© 2017 American Heart Association, Inc.)