Transapical off-pump echo-guided mitral valve repair with neochordae implantation mid-term outcomes

Abstract

Background: The NeoChord echo-guided transapical beating heart repair is a promising early-stage minimally invasive surgical procedure for degenerative mitral valve (MV) regurgitation (DMR) correction. The technique has been improved since its inception following procedure standardization, patient selection optimization, and learning curve stabilization. We hereby present the mid-term clinical results through three years of our large single center experience. Methods: All consecutive patients with severe symptomatic DMR due to prolapse or flail of one or both mitral leaflets that underwent the NeoChord procedure between November 2013 and June 2019 were included. Patients were categorized according to MV anatomy; Type A isolated central posterior leaflet prolapse and/or flail, Type B posterior multi-segment prolapse and/or flail, Type C anterior and/or bi-leaflet prolapse or flail, Type D paracommissural prolapse and/or flail and/or significant leaflet and/or annular calcifications. Patients underwent clinical and echocardiographic follow-up at one, three, six, twelve months and yearly thereafter. Clinical outcomes and the composite primary endpoint (patient success) were defined according to Mitral Valve Academic Research Consortium (MVARC) criteria. Mitral regurgitation (MR) severity was graded as absent, mild, moderate and severe according to American Society of Echocardiography (ASE) and European Society of Cardiology (ESC) guidelines. Results: Two hundred and three patients were included; median follow-up was 24 months [interquartile range (IQR), 9-36]. Median age was 64 years (IQR, 54-74 years), median Society of Thoracic Surgeons (STS) Predicted Risk of Mortality (PROM) was 0.60% (IQR, 0.32-1.44%). There were 106 Type A patients (52.2%), 68 Type B (33.5%), 16 Type C (7.9%), and 13 Type D (6.4%). Kaplan-Meier estimate of survival was 99.0%±0.7% at one and two years and 94.0%±2.9% at three years. At one-year follow-up patient success was 91.2%±2.0% and 111 patients (74%) presented a residual MR mild or less (1+). At three-year follow-up patient success was 81.2%±3.8% and 32 patients (64%) had a residual MR mild or less (1+). Patient success was significantly different according to anatomical type (P=0.001). Echocardiographic analysis showed a significant acute left ventricle and left atrial reverse remodeling that was maintained up to three years. Conclusions: The NeoChord echo-guided transapical beating heart repair procedure demonstrated good clinical outcomes and echocardiographic results up to three-year follow-up.

Initial experiences of transapical beating‐heart mitral valve repair with a novel artificial chordal implantation device

“…The advantage of this therapy is that the length of the ePTFE sutures can be adjusted on the beating heart to maximize leaflet coaptation and to minimize MR, to ensure optimal repair quality finally, according to the real‐time TEE assessment. Up to now, two other transapical artificial chordal implantation devices, Neochord (Neochord, Inc.) and Harpoon (Harpoon, Inc.), have been reported with good safety and effectiveness and stable MR reduction during early‐term and midterm follow‐up 10–16 …”

“…Gammie et al 14 reported outcomes in 30 patients with isolated posterior leaflet prolapse using Harpoon system. Colli et al invented a new mitral vavle anatomical classification and concluded that patients with isolated central posterior leaflet and posterior multisegment prolapse benefited more from transapical mitral valve repair by Neochord system 15,16 . Different mitral valve morphologies were included in this initial study to identify optimal mitral valve morphology for further studies.…”

“…Up to now, two other transapical artificial chordal implantation devices, Neochord (Neochord, Inc.) and Harpoon (Harpoon, Inc.), have been reported with good safety and effectiveness and stable MR reduction during early-term and midterm follow-up. [10][11][12][13][14][15][16] MitralStitch TM system is a novel transapical artificial chordae implantation system with three distinguished characteristics. First, this system has a unique designed retractable arm made by a Nitinol frame as the positioner, which could be clearly identified in TEE imaging and effectively facilitate grasping of the target prolapsing leaflet.…”

“…Although the number of patients enrolled in this study was limited, 1-year follow-up results showed a trend that patients with isolated central posterior leaflet prolapse and multisegment prolapse but dominated by central segment had more stable MR improvement, which was consistent with other reports. 15,16 Four patients had recurrence of moderate or more MR during 1-year follow-up. The possible reasons included untreated leaflet prolapse (one patient), implanted artificial chordae relative elongation (two patients), implanted artificial chordae rupture (one patient).…”

“…Other studies also concluded that one chorda was possibly related to higher risk of relative elongation after ventricle reverse remodeling and rupture due to more stress on it. Therefore, they recommended that the ideal number of implanted chordae is 1 or 2 chords more than the number required to reduce regurgitation 16,18 . Whether the different joint of artificial chordae on the leaflet will improve MR correction in the patients with marginal posterior leaflet prolapse or anterior leaflet prolapse need to be validated by long‐term outcomes.…”