Greenbaum AB, Ueyama HA, Gleason PT, Khan JM, Bruce CG, Halaby RN, Rogers T, Hanzel GS, Xie JX, Byku I, Guyton RA, Grubb KJ, Lisko JC, Shekiladze N, Inci EK, Grier EA, Paone G, McCabe JM, Lederman RJ, and Babaliaros VC
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.)