A Novel KyrinTM Tricuspid Transcatheter Edge-to-edge Repair Device: A First-in-human Study

The surgical treatment of isolated tricuspid regurgitation presents a notable mortality risk, particularly in patients who are referred late. Tricuspid transcatheter edge-to-edge repair (TEER) has become a safe and effective therapeutic option for patients with tricuspid regurgitation.[1] The KyrinTM Tricuspid TEER system (Shenqi Medical, Shanghai, China) consists of a 24-French delivery catheter that is used to place one or more clips devices on the tricuspid-valve leaflets. Four clip sizes are available with a 12- or 9-mm arm length and 6- or 4-mm arm width. Herein, we report the initial result of using this tricuspid TEER system in Chinese patients with severe tricuspid regurgitation. This is a Chinese national prospective study that enrolled patients with severe tricuspid regurgitation between August 2022 and August 2023. Tricuspid regurgitation grade was assessed using the 5-grade scheme.[2] The key inclusion criteria were severe symptomatic tricuspid regurgitation despite optimal medical treatment for at least 30 d; New York Heart Association (NYHA) class Ⅱ–Ⅳ; intermediate or high risk of mortality with tricuspid valve surgery; and suitable anatomy for TEER. Patients with other valve disease that required intervention, severe pulmonary hypertension (systolic pressure >70 mmHg), and left ventricular ejection fraction ≤20% were excluded. This registry was approved by the ethics committee of Fuwai Yunnan Hospital (2022-005-01, 26 January, 2022) and then approved by each participating center (including Nanjing First Hospital, Renmin Hospital of Wuhan University, Shanghai Chest Hospital, and Fuwai Hospital). The study followed the guideline of the Tricuspid Valve Academic Research Consortium.[3] There were 34 eligible patients, with an age of (70.1 ± 7.3) years and a weight of (61.2 ± 12.9) kg; 18 (53%) were female. Demographics and comorbidities are shown in Table 1. All patients had symptomatic severe or massive tricuspid regurgitation, with an effective regurgitant orifice area of (0.5 ± 0.1) cm2, categorized as intermediate or high operation risk by the Society of Thoracic Surgeons scores >4.0%. Moreover, 30 (88%) patients had a functional etiology of tricuspid regurgitation, while 4 (12%) patients had mixed etiology. In 34 (100%) patients, the tricuspid regurgitation jet mainly originated from the anterior-septal commissure, and no patient had pacemaker lead-related tricuspid regurgitation. The right ventricular end-diastolic dimension was (36.5 ± 17.4) mm with a tricuspid annular plane systolic excursion of (17.5 ± 3.0) mm. NYHA functional class Ⅲ–Ⅳ was observed in 56% (19/34) patients, while 44% (15/34) had NYHA functional class Ⅱ. The tricuspid annular septal to lateral diameter was (39.8 ± 4.6) mm. Table 1 - Baseline data of the patients included in the study cohort. Characteristics Baseline data (n = 34) Age (years) 70.1 ± 7.3 Female sex 18 Weight (kg) 61.2 ± 12.9 Heart failure within 1 year 23 Previous coronary intervention 3 Atrial fibrillation 31 Hypertension 19 Diabetes 6 Chronic obstructive pulmonary disease 6 Neurologic events 7 Renal dysfunction 10 Liver dysfunction 5 Peripheral vascular disease 14 Left ventricular ejection fraction (%) 58.0 ± 10.6 Previous left heart surgery 5 Kansas City Cardiomyopathy Questionnaire Score 67.7 ± 16.0 6-minute walk distance (m) 321.0 ± 103.9 New York Heart Association class Ⅲ–Ⅳ 19 Tricuspid effective regurgitate orifice area (cm2) 0.5 ± 0.1 Tricuspid annular plane systolic excursion (mm) 17.5 ± 3.0 Right ventricular end-diastolic dimension (mm) 36.5 ± 17.4 Data are presented as mean ± standard deviation or n. This pioneering first-in-human study was executed through remote educational and proctorship channels in response to the COVID restrictions in China. The collaborative team comprised an adept European tricuspid TEER proctor, a local Chinese proctor with limited experience on-site, and institutional operators, forming the 3 interactive components. State-of-the-art instruments integrated with monitoring capabilities such as cameras, fluoroscopy, echocardiography, and hemodynamics were employed. The incorporation of microphones via 5-generation speed facilitated simultaneous maneuvers and real-time feedback. In 32 patients, 54 KyrinTM devices (1.6 ± 0.8 per patient) were implanted, as the procedure failed in one patient owing to septal hugger, and in another, clip implantation was not successful because of a large coaptation gap despite volume management during the procedure. Acute procedural success (defined as implantation of at least one device with post-procedural tricuspid regurgitation grade less than 2+, with no mortality or conversion to surgery) was achieved in 31 patients (91%) with a procedure time of (168 ± 59) min. In one patient, residual 3+ tricuspid regurgitation was noted after the procedure. The tricuspid inflow pressure gradient before and after implantation of the KyrinTM devices was (1.0 ± 0.5) mmHg and (1.1 ± 0.5) mmHg, respectively, which was not statistically significant (P > 0.05). Clip single-leaflet device attachment was not observed in the entire study cohort during the hospital stay. There were no other in-hospital complications. At follow-up, there were no reported deaths or major adverse events. NYHA class was improved after the TEER procedure with the incidence of class Ⅲ reducing from 56% (19/34) before procedure, to 13% (4/32) at the 30-day follow-up (P < 0.05). Echocardiography revealed sustained tricuspid regurgitation reduction at the 30-day follow-up [Figure 1]. The presence of a tricuspid regurgitation grade ≥3+ was reduced from 100% (34/34) before the procedure to 3% (1/32) at the 30-day follow-up (P < 0.05). Worsening of right ventricular function was not observed after the procedure (tricuspid annular plane systolic excursion: (17.5 ± 3.0) mm at baseline vs. (17.0 ± 3.2) mm at the 30-day follow-up, P > 0.05). There was no statistically significant in right ventricular remodeling (tricuspid annular diameter: (39.8 ± 4.6) mm at baseline vs. (37.2 ± 4.6) mm at the 30-day follow-up, P > 0.05).Figure 1: Key study results, device design, and intraoperative echocardiogram images of the KyrinTM system. KyrinTM repair system showed significant TR reduction (A) and NYHA class improvement (B) at the 30-day follow-up. (C) KyrinTM clip design. (D) Preoperative 3-dimensional transesophageal echocardiogram reveal 4+ TR from the anterior-septal commissure. (E and F) One clip was implanted in the anterior-septal commissure, (G) TR was reduced to trace (1+). TR: Tricuspid regurgitation; NYHA: New York Heart Association.This first-in-human experience evaluating a novel KyrinTM system transcatheter tricuspid repair demonstrated high procedural success rate, optimal safety outcome, and significant clinical improvement in patients with severe tricuspid regurgitation. The incorporation of a 5-generation-enabled remote proctor played a pivotal role in achieving these outcomes, demonstrating its feasibility in procedural guidance. Larger studies with long-term follow-up are required to validate these preliminary results and further define the impact of KyrinTM repair on clinical outcomes. Funding This work was supported by the National Key R&D Program of China (2022YFC2503400) and the Major Science and Technology Special Plan Project of Yunnan Province (202302AA310045). Author contributions Da Zhu, Shouzheng Wang, Junjie Zhang, Jing Chen, Ben He, and Xiangbin Pan completed the procedure. Da Zhu, Mi Chen, 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 Mi Chen received grant from Boston Scientific and she is a consultant for Jenscare Scientific. The remaining authors have nothing to disclose. Editor notes: Ben He is an Editorial Board Member of Cardiology Discovery. The article was subject to the journal’s standard procedures, with peer review handled independently of this editors and his research groups.