Initial Experience in GeminiOne™ Transcatheter Mitral Valve Edge-to-edge Repair Device

Transcatheter edge-to-edge repair (TEER) of the mitral valve has emerged as a standard treatment for patients with severe degenerative mitral regurgitation at high or prohibitive surgical risk. The devices approved by the Food and Drug Administration including MitraClip (Abbott Vascular, California, USA) and PASCAL (Edwards Lifesciences, California, USA) cost over $33,000 in western countries.[1] This pricing presents a significant economic burden especially in developing countries, where TEER devices are typically not covered by health insurance. The GeminiOne™ system (Peijia Medical Technology, Suzhou, China) is a Chinese-designed TEER system that has the features of fourth-generation TEER system including independent leaflet grasping as well as 4 different clamp sizes (4/6 mm in clip arm width, 10/13 clip arm length) and is strategically designed to accommodate different patients. Additionally, it has a 22-French guiding catheter and a 16-French clip delivery system. Its unique feature is the innovative sliding groove mechanism combined with a threaded central shaft structure. This design allows for automatic locking and release of the clip at any angle, thereby enabling the doctor to adjust the clipping force and balance the leaflet tension during the procedure. Additionally, because of the unique sliding groove locking mechanism, the length of the clip in closing status is shortened compared to MitraClip and therefore, requires less supravalvular height for delivery and positioning. Moreover, the maximum total clip capture length (0626 size (6 mm arm width and 13 mm arm length)) reaches 25 mm at 120° and 26 mm at 180°, which is superior to the MitraClip G4 system with XTW clip [Figure 1A]. Because all supply chain is based in China, this TEER system is cost-effective when compared to other currently imported systems.Figure 1:: Device design, key study results, and intraoperative TEE images of GeminiOne™ system. (A) Design feature of the GeminiOne™ system. (B) MR severity at baseline, post-procedure, discharge, and 30-day follow-up. (C) NYHA functional class at baseline, discharge, and 30-day follow-up. (D–H) Intraoperative TEE image: A high surgical risk patient with P3 prolapse and 4+ MR (D–E), one clip was implanted in the A3/P3 region (F–G), and MR was eliminated to 0+ (H). MR: Mitral valve; NYHA: New York Heart Association; TEE: Transesophageal echocardiogram.In this Chinese national, multicenter, single-arm, prospective, first-in-human study, we enrolled patients with degenerative mitral regurgitation with symptomatic high or prohibitive surgical risk. This registry was first approved by the ethics committee of Fuwai Yunnan Hospital (2022-049-01, June 30, 2022), and then approved by each participating center. Echocardiographic assessments were conducted at the core laboratory at baseline and the 30-day follow-up. The endpoints of this study were defined according to the Mitral Valve Academic Research Consortium. In all, 35 eligible patients with degenerative mitral regurgitation [Table 1] underwent the TEER procedure using the GeminiOne™ system. The patients' age was (71.4 ± 5.7) years and 34% were female. At baseline, all patients exhibited moderate-to-severe (29%) or severe (71%) degenerative mitral regurgitation with effective regurgitate orifice area of (0.5 ± 0.3) cm2. The Society of Thoracic Surgeons score (mitral replacement) was 8.1% ± 4.8%, and 83% (29/35) patients belonged to New York Heart Association (NYHA) class III–IV with a left ventricular ejection fraction of 58% ± 11%. Posterior leaflet lesions were present in 74% (26/35) patients, while anterior leaflet lesions were present in 26% (9/35). A2/P2 lesions were noted in 40% (14/35) of the study population, with the remainder showed non-A2/P2 lesions. Table 1 - Baseline data of the patients with degenerative mitral regurgitation included in the study cohort. Characteristics Baseline data (n = 35) Age (year) 71.4 ± 5.7 Female sex 12 Body mass index (kg/m2) 22.7 ± 2.9 Coronary artery disease 10 Atrial fibrillation 11 Hypertension 16 Diabetes 4 Chronic obstructive pulmonary disease 11 Neurologic events 3 Renal dysfunction 7 Peripheral vascular disease 6 Left ventricular ejection fraction (%) 58 ± 11 Society of Thoracic Surgeons score (mitral replacement) (%) 8.1 ± 4.8 Kansas City Cardiomyopathy Questionnaire Score 48.8 ± 12.8 Data are presented as mean ± standard deviation or n. Immediate procedure success was achieved in all 35 patients with a device time of (72.4 ± 38.8) min, number of device implanted was 1.5 ± 0.6, and 85% were of 0626 size clip. No procedure complication such as single leaflet detachment, leaflet tear, device embolism, vascular complication, severe bleeding, stroke, renal failure, or conversion to open heart surgery were noted. In the 30-day follow-up, for which data was available for all 35 patients, mitral valve was categorized as trace-to-mild (0+/1+) in 100% of study population [Figure 1B], with no 3+/4+ residual mitral valve and a pressure gradient (3.3 ± 1.2) mmHg. No procedure-induced mitral stenosis was noted in this study cohort. NYHA class showed improvement at the 30-day follow-up with 100% patients having NYHA I–II grade [Figure 1C]. No mortality or rehospitalization was noted among study population at the 30-day follow-up. This study demonstrated the initial feasibility and safety of utilizing a novel TEER device design for high-risk patients with degenerative mitral regurgitation. In this study, not only A2/P2 but also the A1/P2 and A3/P3 lesions were included with optimal 30-day results [Figure 1D–1H]. No device malfunction or device-related complication was noted. In this trial, all operators had an experience of performing at least 50 TEER procedures. The GeminiOne™ TEER system shares common features with currently available fourth-generation TEER devices that ensure its user-friendliness. Taken together, these factors ensure good results in the feasibility study. Meanwhile, the unique design of GeminiOne™ should be emphasized: given its innovative sliding groove locking mechanism, the clip could be closed and locked at any angle; this feature allows the operator to adjust the clip closing tension according to mitral valve pathology such as leaflet calcification or Barlow morphology. The length of the clip was shorter, while the clip capture length was longer, to ensure sufficient leaflet capture, than the currently available MitraClip system [Figure 1A]. Further studies are ongoing to validate these results. In conclusion, the GeminiOne™ system has the potential to offer another treatment option for patients requiring to undergo TEER. Funding This work was supported by the National Key R&D Program of China (2022YFC2503400); Major science and technology special plan project of Yunnan Province (202302AA310045); and Yunnan Provincial Clinical Research Center for Cardiovascular Diseases (202102AA310002). Author contributions Da Zhu, Shouzheng Wang, Jinping Liu, Zhenfei Fang, Mao Chen, Ben He, and Xiangbin Pan completed the procedure. Da Zhu and Shouzheng Wang drafted the submission. Xiangbin Pan conceptualized the paper and revised the submission. All authors read and approved the final manuscript. Conflicts of interest None.