PARIS – Early highly preliminary results from the first-in-human study of percutaneous repair of a failing tricuspid valve indicate that the transcatheter procedure appears safe, durable, and effective – at least through the first 6 months.
“Even though the one-grade reduction of tricuspid regurgitation on color Doppler flow imaging is modest, the impact in terms of clinical improvement seems very encouraging and warrants pursuing this innovative technique,” Dr. Jean-Michel Juliard said in presenting the early findings at the annual congress of the European Association of Percutaneous Cardiovascular Interventions.
The three-country, prospective, single-arm study is aimed at winning European regulatory approval for 4tech Cardio’s TriCinch System. The study includes 24 patients with severe functional tricuspid regurgitation. Dr. Juliard, a cardiologist at Bichat Hospital in Paris, presented 6-month follow-up data on two patients and 3-month follow-up for a third.
First, a bit about the procedure. It’s conducted under general anesthesia and relies upon transesophageal and intracardiac echocardiographic guidance. The objectives are to reduce the effective cross-sectional valve area by diminishing the septo-lateral dimension of the tricuspid annulus diameter, restore tricuspid valve leaflet coaptation, and relieve symptoms.
The 4tech delivery system consists of two parts. To begin, a guidewire is placed in the right coronary artery, a 24-French sheath is introduced via the right femoral vein, and an exchange guidewire is positioned in the right ventricular apex. The first part of the delivery system is then inserted in order to place an anchor on the tricuspid valve annulus in the vicinity of the antero-posterior commissure.
“This is probably the most difficult part of the whole procedure,” according to Dr. Juliard. “It is done using intracoronary and transesophageal echo guidance.”
Once the anchor is well positioned, the second part of the system is advanced, locked into the first part, and tension is applied under echocardiographic control in order to implant a nitinol self-expanding stent in the inferior vena cava. As soon as traction is applied, the tricuspid regurgitation decreases. Once the correction process is completed, the TriCinch delivery system and venous introducers are removed. For study purposes, dosing of diuretics remained unchanged post procedure.
In the first 6 months, the tricuspid septo-lateral distance improved from 52 to 42 mm in one patient and from 45 to 40 mm in another. A third patient had improvement from 43 to 34 mm at 3 months of follow-up.
In terms of clinical improvement, two patients went from New York Heart Association functional class III to class II, and another went from class III to class I. Six-minute walk distance increased from a baseline of 320 m to 367 m at 6 months of follow-up in one patient and from 400 m to 750 m in another, with a 3-month improvement from 160 to 280 m in the third patient.
Serial imaging studies showed device stability over time, with no migration and no stent thrombosis.
In response to an audience question, Dr. Juliard conceded that at this early stage in the development of the procedure, the placebo effect can’t be ruled out as a possible explanation for the observed strong clinical improvement despite what he conceded was “very modest” reduction in tricuspid regurgitation. Time will tell.
“I hope it is not a placebo effect, but as we maintain the same dose of diuretics, it does seem that the patients feel better,” he added.
The rationale for developing a transcatheter solution to functional tricuspid regurgitation, especially one that’s compatible with concomitant transcatheter mitral valve procedures, as the TriCinch System is intended to be, lies in the wealth of evidence that tricuspid regurgitation is associated with increased mortality, substantial morbidity, and severely impaired quality of life due to the need for repeated hospitalizations. Surgery for patients with tricuspid regurgitation is often extremely high risk because affected patients typically have right ventricular dysfunction, pulmonary hypertension, and/or previous valve surgery.
The ongoing study is funded by 4tech Cardio. Dr. Juliard reported having no financial conflicts.