New data suggests that the risk of stroke related to the emerging therapy of transcatheter aortic value replacement is not as high as previously thought.
At the American College of Cardiology meeting in Chicago earlier this week, both Edwards Lifesciences (NYSE:EW) and Medtronic (NYSE:MDT) reported a lower risk for stroke for this therapy. It is considered a good alternative for patients with acute stenosis who cannot endure open heart surgery. Edwards is the only company in the U.S. to have an approved transcatheter aortic valve implant (TAVI) system (Sapien), and Medtronic is expected to introduce its CoreValve TAVI system in 2014 domestically.
Wall Street took notice, but the good news needs to be parsed.
Dr. Axel Linke, who presented Medtronic’s CoreValve results at the ACC meeting, said that while he couldn’t say exactly what led to fewer strokes, the study could have benefited from physicians and medical centers who had prior experience in TAVI procedures, according to MassDevice.
The familiarity aspect seems to be consistent with the results of a study that Mayo Clinic did with respect to TAVI procedures. Mayo found that the doctors performing TAVI have a steep learning curve; they may require as many as 30 procedures before they reach proficiency in using TAVI. The study was part of Edwards Lifesciences’ Partner Trial and was based on observing 44 patients who underwent transcatheter aortic valve replacement at the Mayo Clinic in Rochester, Minnesota between November 2008 and May 2011.
The study published online Dec. 21 in the Journal of the American College of Cardiology: CardiovascularInterventions found that physicians “significantly improved their average procedure duration and some safety measures from the first to the 44th transcatheter aortic-valve implantation,” according to Heart.org.
The editor of the journal, Dr. Peter Block,has expressed concern over the roll out of Edwards’ Sapien and underscored the significance of how much time it takes doctors to get comfortable with the new device.
How all this will play out over the next year should concern every center and operator contemplating the addition of TAVI to their list of available therapies. [I]t may take more than a full year for an operator to become procedure “proficient,” [and] the question of maintenance of proficiency is totally unanswered at present.
If Linke’s thesis proves to be true that as medical centers and physicians become more familiar with the procedure, potential for strokes following TAVI go down, then it would make sense for a conservative rollout and close monitoring of the technology as Block seems to be advocating.
Of course, that would mean return on investment for these multimillion-dollar products is years away, at least in the U.S. (Both Sapien and CoreValve are approved in the European Union). Medtronic spent $700 million to acquire CoreValve in 2009.
[Photo Credit: chrisroll]