WASHINGTON – A novel transcatheter mitral valve replacement with a transseptally introduced docking mechanism that secures the valve with native mitral valve leaflets was found feasible and effective in an initial series of 10 patients, according to a first-in-man report at CRT 2018 sponsored by the Cardiovascular Research Institute at Washington Hospital Center.
“All patients remained hemodynamically stable throughout the procedure, and the valve was successfully implanted in all patients,” reported John G. Webb, MD, McLeod Professor of Heart Valve Intervention at the University of British Columbia, Vancouver.
The experimental Sapien M3 valve evaluated in this study has a novel design with docking and valve components. The Sapien M3 dock is comprised of a shape-memory nitinol dock that is guided to encircle the native leaflets, which is the first step in securing the system. Subsequent functional turns around the leaflets then provide a rigid landing space for placement of the M3 valve. A final atrial turn on the docking mechanism suspends the device against the mitral annulus to maintain position for valve deployment.The docking system “is retrievable up until the point of the final release,” Dr. Webb explained. A knitted polyethylene terephthalate skirt is employed to aid in creating a seal between the leaflets and the dock. Once the docking system is in place, the procedure “then becomes a relatively standard transcatheter transseptal valve-in-valve–type procedure” that is a “fairly easy part of the procedure at centers with transcatheter valve implantation experience.”
The very first case was performed in a 75-year-old woman with severe mitral valve insufficiency. Frail with multiple comorbidities and a left ventricular ejection fraction of 30%, the patient was not a candidate for surgery. Although Dr. Webb acknowledged that the first case “was a learning process,” he reported that the patient was discharged after a 1-night hospital stay with reassuring valve placement and function based on imaging studies.
Data was available from 10 patients from five participating centers in Canada and the United States. The mean age was 74 years, and all were New York Heart Association class III or higher. The mean left ventricular ejection fraction was 37.5%. Although the average Society of Thoracic Surgery risk score was only 4.9%, Dr. Webb noted that this underestimated the vulnerability of a population in which most had compromised renal function. Half of the 10 had severe mitral valve regurgitation prior to valve replacement, and the remainder had moderate to severe regurgitation.
“At the end of 30 days, all had mild or less insufficiency,” Dr. Webb reported. Although one patient did develop significant mitral insufficiency after discharge because of a small tear attributed to probing, it was repaired with a plug. The one technical failure occurred in a patient who required a plug during the course of valve replacement; again, the plug proved effective for preventing significant valve insufficiency.