, relief of mitral regurgitation, and increases in cardiac hemodynamics and quality of life sustained at 1 year.
Further, patients with severe mitral annular calcification (MAC) showed improvements in hemodynamics, functional status, and quality of life after the procedure.
With 70 centers participating in the Tendyne SUMMIT trial, the first 100 trial roll-in patients accrued from the first one or two patients from each site without previous Tendyne TMVR experience.
“For this new procedure, with new operators, there was no intraprocedural mortality, and procedural survival was 100%,” co-primary investigator Jason Rogers, MD, of the University of California Davis Medical Center, Sacramento, told attendees at a Late-Breaking Clinical Science session at the Transcatheter Cardiovascular Therapeutics annual meeting.
“The survival was 74% at 12 months. The valve was very effective at eliminating much regurgitation, and 96.5% of patients had either zero or 1+ at a year, and 97% at 30 days had no mitral regurgitation,” he reported. As follow-up was during the COVID-19 pandemic, several of the deaths were attributed to COVID.
Device and trial designs
The Tendyne TMVR is placed through the cardiac apex. It has an outer frame contoured to comport with the shape of the native mitral valve. Inside is a circular, self-expanding, tri-leaflet bioprosthetic valve.
A unique aspect of the design is a tether attached to the outflow side of the valve to allow positioning and control of the valve. At the end of the tether is an apical pad that is placed over the apical access site to control bleeding. The device is currently limited to investigational use in the United States.
The trial enrolled patients with grade III/IV MR or severe MAC if valve anatomy was deemed amenable to transcatheter repair or met MitraClip indications and if these treatments were considered more appropriate than surgery.
Dr. Rogers reported on the first 100 roll-in (early experimental) patients who received Tendyne TMVR. There was a separate severe MAC cohort receiving Tendyne implantation (N = 103). A further 1:1 randomized study of 382 patients compared Tendyne investigational treatment with a MitraClip control group.
At baseline, the 100 roll-in patients had an average age of 75 years, 54% were men, 46% had a frailty score of 2 or greater, and 41% had been hospitalized in the prior 12 months for heart failure. Left ventricular ejection fraction (LVEF) was 48.6% ± 10.3%.
Improved cardiac function
Procedural survival was 100%, technical success 94%, and valve implantation occurred in 97%. Of the first 100 patients, 26 had died by 1 year, and two withdrew consent, leaving 72 for evaluation.
Immediate post-procedure survival was 98%, 87.9% at 3 months, 83.7% at 6 months, and 74.3% at 1 year. MR severity decreased from 29% 3+ and 69% 4+ at baseline to 96.5% 0/1+ and 3.5% 2+ at 1 year.
Cumulative adverse outcomes at 1 year were 27% all-cause mortality, 21.6% cardiovascular mortality, 5.4% all-cause stroke, 2.3% myocardial infarction (MI), 2.2% post-operative mitral reintervention, no major but 2.3% minor device thrombosis, and 32.4% major bleeding.
Most adverse events occurred peri-procedurally or within the first month, representing, “I think, a new procedure with new operators and a high real risk population,” Dr. Rogers said.
Echocardiography at 1 year compared with baseline showed significant changes with decreases in left ventricular end diastolic volume (LVEDV), increases in cardiac output (CO) and forward stroke volume, and no change in mitral valve gradient or left ventricular outflow tract (LVOT) gradient. New York Heart Association (NYHA) classification decreased from 69% class III/IV at baseline to 20% at 1 year, at which point 80% of patients were in class I/II.
“There was a consistent and steady improvement in KCCQ [Kansas City Cardiomyopathy Questionnaire] score, as expected, as patients recovered from this invasive procedure,” Dr. Rogers said. The 1-year score was 68.7, representing fair to good quality of life.