Transcatheter mitral valve replacement with Mi-thos system: First-in-human experience

BACKGROUND

Transcatheter mitral valve replacement (TMVR) has become an alternative for high-risk patients with severe mitral regurgitation (MR). The aim of this study was to evaluate the safety and feasibility of the Mi-thos TMVR system (NewMed Medical) for high-risk patients with severe MR.

METHODS

This was a prospective, two-center, single-arm early feasibility study. Baseline characteristics, procedural data and 30-day follow-up outcomes were collected and analyzed. The primary endpoint was intraoperative success rate of device implantation. The second endpoints were all-cause mortality and major post-procedural complications. Echocardiographic data were evaluated by an independent core laboratory. Clinical events were adjudicated by a clinical events committee.

RESULTS

Ten high-risk patients with severe MR were enrolled at two sites from August 2021 to November 2022. The median age was 70.5 years, and 60% of patients were female. The median Society of Thoracic Surgeons Predicted Risk of Mortality was 9.5%. The Mi-thos TMVR system was successfully implanted via transapical access in all patients. There was no pericedural mortality or major postpericedural complications during the 30-day follow-up. All implanted prosthetic valves had no or trace valvular or paravalvular MR, and the median mitral valve gradient at 30 days was 2.0 mmHg (IQR: 2.0-3.0 mmHg). There was one mild left ventricular outflow tract obstruction.

CONCLUSIONS

The favorable short-term outcomes of the Mi-thos TMVR system demonstrated that it might be a feasible and safe therapeutic alternative for high-risk patients with severe MR. Nevertheless, further evaluation of the Mi-thos TMVR system is warranted.

Transcatheter tricuspid valve-in-valve implantation for degenerated surgical bioprosthesis

BACKGROUND

Isolated redo surgery for degenerated tricuspid bioprosthesis is of very high risk. We aimed to evaluate the safety and efficacy of transcatheter valve-in-valve (TVIV) implantation using a novel balloon expandable Renato valve.

METHODS

A prospective multicenter study was conducted to enroll patients with degenerated tricuspid bioprostheses. A total of 12 patients underwent TVIV implantation using the Renato valve system via transfemoral, transjugular, or transatrial approaches at three institutions from May 2021 to October 2021. All-cause mortality and hemodynamic performance were evaluated up to 6 months after procedure.

RESULTS

The median age was 68.2 years, and 75.0% were female. Six patients had a history of rheumatic left-sided valve surgery and late tricuspid valve replacement. The median preoperative Society of Thoracic Surgeons score was 9.9%. The procedures were successful in all cases. Tricuspid regurgitation and paravalvular leak were none or mild in all patients. The median transvalvular gradient decreased from 7.8 mmHg preoperatively to 4.5 mmHg at 6 months after TVIV, respectively. No death occurred and all patients recovered to New York Heart Association functional class I or II during a 6-month follow-up.

CONCLUSIONS

TVIV implantation with the Renato valve was a safe and effective treatment for degenerated bioprostheses in high-risk patients.