TORONTO – In a multicenter European study, 30-day mortality and 1-year mortality after implantation of the stentless Freedom Solo aortic bioprosthetic valve were 1.4% and 4.4%, respectively. Patients in the study experienced "remarkable" functional status improvement at 1 year, reported principal investigator Dr. Markus Thalmann at the annual meeting of the American Association for Thoracic Surgery.
"Our trial showed excellent results in terms of morbidity and mortality and low rates of valve-related adverse events in a 12-month follow-up period," said Dr. Thalmann during his late-breaking clinical trials presentation. "It also demonstrated good hemodynamics leading to a remarkable functional status improvement."
The Sorin Freedom Solo aortic bioprosthesis is made of two layers of bovine pericardium, with no synthetic material added. The valve is implanted with a single running suture line technique in a strict supra-annular position and has no contact with the native annulus. The bioprosthesis is not approved in the United States.
Dr. Thalmann, of Krankenhaus Hietzing, Vienna, noted the importance of performing a careful decalcification of the annulus during implantation. "You should do it as properly as you’d do it when implanting a stented valve, even if you don’t put your stitches through the annulus," he said.
In response to a question, he said that the trial was requested by the Food and Drug Administration to provide more information on the single-line suture technique used to implant the valve.
The researchers conducted a prospective, nonrandomized, multicenter trial at 18 clinical centers in eight European countries. All patients with an indication for prosthetic aortic valve replacement were included, except those with a preexisting valve prosthesis in the mitral, pulmonary, or tricuspid positions. Patients needing double or triple valve replacement were also excluded, as were those with active endocarditis and congenital bicuspid valves.
A total of 616 patients received the valve. Patients had a mean age of 74.5 years, 45.9% were female, and the mean logistic EuroSCORE was 10.1%. Concomitant cardiac procedures, including coronary artery bypass grafting, were performed in 43.2% of patients.
Early (30-day) mortality was 1.4%, rising to 4.4% at 1 year. Valve-related mortality at 30 days and 1 year was 0.3% and 1.1%, respectively.
Overall morbidity was low. At 30 days, 4.5% of patients required reintervention for bleeding, 0.3% for perivalvular leakage. No structural valve dysfunction or valve thrombosis was noted at 30 days, with one case of each seen at 1 year (0.2% and 0.2%).
Preoperatively, 49.3% of patients were in New York Heart Association class III or IV heart failure. At 1 year, 97.0% were in NYHA class I or II heart failure.
"We found good hemodynamics after 1 year," said Dr. Thalmann. The overall mean gradient was 7.2 mm Hg, and the effective orifice area was 1.5 cm2.
Patients will be followed for up to 5 years.
The Freedom Solo valve is currently being tested in an investigational device exemption (IDE) study in the United States. The Sorin Solo Smart valve, the evolution of the Freedom Solo valve, received a European CE mark approval in November 2013.
Dr. Thalmann is a consultant for the Sorin Group, which funded the study.