SAN FRANCISCO – A mean aortic valve pressure gradient of 11.5 mm Hg 30 days after transcatheter aortic valve replacement with the investigational repositionable Lotus valve in 120 patients was significantly better than the performance goal of 18 mm Hg, a study showed.
Approximately 4% of patients in the prospective registry study died within the 30 days and 2% had a disabling stroke, both of which could be considered low rates, Dr. Ian T. Meredith said at the Transcatheter Cardiovascular Therapeutics annual meeting. Another 4% of patients developed nondisabling strokes by the 30-day follow-up in an intent-to-treat analysis.
Aortic regurgitation rates were "negligible" after the procedure, said Dr. Meredith of Monash Medical Centre, Clayton, Australia, and professor of cardiology at Monash University, Melbourne.
Before valve replacement, 15% of patients had moderate or severe aortic regurgitation. Thirty days later, none had severe and 1% had moderate aortic regurgitation in the REPRISE II study (Repositionable Percutaneous Replacement of Stenotic Aortic Valve Through Implantation of Lotus Valve System – Evaluation of Safety and Performance).
Mild aortic regurgitation rates went from 44% at baseline to 17% at 30 days. Trace regurgitation was seen in 21% at baseline and at 30 days of follow-up.
The primary endpoints in the study were mean aortic valve pressure gradient at 30 days and 30-day all-cause mortality. The mean aortic gradient decreased from 46 mm Hg at baseline to 12.1 mm Hg at discharge and 11.5 mm Hg at 30 days. The mean effective orifice area increased from 0.7 cm2 at baseline to 1.6 cm2 at discharge and 1.7 cm2 at 30 days. Clinical event rates were similar to those reported in other valve trials, he said.
The 14-center study enrolled patients between October 2012 and April 2013 who were aged at least 70 years and rated New York Heart Association class II or greater. They had an aortic valve area less than 1 cm2, an aortic annulus measuring 19-27 mm, and a mean pressure gradient greater than 40 mm Hg or a jet velocity greater than 4 m/sec. Patients also had a Society of Thoracic Surgeons score of at least 8% and/or high surgical risk due to frailty or comorbidities.
The Lotus valve can be assessed in position before release, shortened or expanded mechanically, and, if desired, repositioned or fully resheathed and retrieved. It includes patented adaptive seal technology on the outside surfaces of the valve to fill up irregular surfaces of the fractured native aortic valve and reduce paravalvular leakage, Dr. Meredith said. The study used two valve sizes, 23 mm and 27 mm.
All 120 Lotus valves were successfully placed. Repositionings of 31 valves were all successful, and attempted retrievals of 6 valves were all successful. "As a consequence of this, there was no valve migration, no embolization, no ectopic valve deployment, and absolutely no need to put a second valve inside a valve for incorrect positioning or aortic regurgitation," he said at the meeting, cosponsored by the American College of Cardiology.
New pacemakers were needed in 29% (34 patients), mainly for third-degree atrioventricular block in 30 patients. "Perhaps the most important determinant of new pacemaker insertion was oversizing of the left ventricular outflow tract or the annulus due to the fact that only two valve sizes were available for this study," Dr. Meredith said. He predicted that this high rate of pacemaker implantation could be halved when more Lotus valve sizes and a more flexible catheter are available for future trials.
"We use the Lotus valve. The beauty of the valve is it can be repositioned and retrieved," Dr. A. Pieter Kappetein said at a press briefing. "You can plant the valve with a lot of confidence for the operator. At every stage of the procedure, you can control. I think that is the beauty of this valve," said Dr. Kappetein, professor of thoracic surgery at Erasmus University, Rotterdam, the Netherlands.
The Lotus valve system is available at selected centers in Europe and is not yet approved in the United States or Japan. The investigators plan to conduct a 130-patient extension of REPRISE II and a 1,000-patient pivotal trial (REPRISE III) to seek Food and Drug Administration approval.
Boston Scientific, which makes the Lotus valve system, funded the study. Dr. Meredith reported financial associations with Boston Scientific and Medtronic.
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