Minnesota medical device giant Medtronic (NYSE:MDT) today unveiled highly anticipated results from the U.S. pivotal trial of its CoreValve transcatheter aortic valve implantation system, touting strong 1-year outcomes in treatment of high-risk patients suffering from aortic valve disease.
The company reported low rates of major stroke and all-cause mortality at 1 month and at 1 year following implantation, with nearly 75% of patient participants alive and stroke-free at 12 months, said co-principal investigator Dr. Jeffrey Popma, who presented the results during a late-breaking session of this year’s Transcatheter Cardiovascular Therapeutics symposium in San Francisco.
The data could lead to approval as soon as the 1st half of next year, skipping the FDA’s usual advisory panel review, according to a Medtronic statement.
"The FDA has determined it has sufficient information to evaluate the safety and efficacy of the Medtronic CoreValve System for this patient group without the need for an external expert panel," the company said.
The pivotal study enrolled nearly 500 patients from 40 U.S. sites that each had no prior experience with the CoreValve system. Most of the patients enrolled had "extreme" co-morbidities in addition to their aortic valve disease, including diabetes and prior stroke.
"With this desperate population, nearly 75% of them are alive and without stroke after a year," Dr. Popma reported.
Researchers posted 1-month and 1-year stroke rates that were among the lowest reported for a TAVI system, reported at 2.4% and 4.1% respectively. Strokes rates were even lower among the approximately 800 additional patients enrolled in the continuing access arm of the trial, with a 1.8% major stroke rate at 1 month.
Rates of paravalvular leakage were also encouraging, with outcomes actually improving over time. About 11.5% of patients were reported with leakage at 1 month, improving to 4.1% at 1 year, an outcome that surprised other members of the morning’s panel. Dr. Popma explained that the decreasing leakage may have to do with the valve size selected for the patients and the positioning of the valves in the heart.
The new study continued to show higher rates of permanent pacemaker implantation for CoreValve than has been reported for some rival devices, with 22.2% of patients requiring an implant within the 1st month, an outcome that was unsurprising.
"The pacemaker rates are predictable," Dr. Leon said during the panel discussion. "I think it’s a byproduct of the specific device. The importance of that is debatable, but it’s not really a concern, it was anticipated."
"22.2% is on the lower side of pacemaker implantation for CoreValve," Dr. Popma added. "We were very satisfied with that."
Pacemaker implantation was also not associate with late mortality, Dr. Popma noted, and the pacemaker rate isn’t reported as a safety issue for TAVI systems.
Other presenters during this week’s TCT conference have been more concerned about the pacemaker implantation rate, citing it as the only difference between CoreValve and rival Edwards Lifesciences’ (NYSE:EW) Sapien device. During a presentation earlier this week San Raffaele Scientific Institute’s Dr. Alaide Chieffo presented results form a retrospective analysis of TAVI patients, reporting a statistically significant difference in patients requiring permanent pacemaker implants, with 22.5% of CoreValve patients requiring pacemakers compared with only 5.9% of Sapien patients. No other statistical differences cropped up between the 2 devices, Dr. Chieffo said.
"Importantly, there is no association between pacemaker implants and increased mortality, while other complications – such as stroke, PVL, rupture, and vascular complications – are much more worrisome because they can be dangerous and even life-threatening for patients," Medtronic told MassDevice.com.