UPDATED March 31, 2014, with comment from Medtronic
Edwards Lifesciences (NYSE:EW) shares gained today after a small study showed that its Sapien XT replacement heart valve tops the CoreValve device made by Medtronic (NYSE:MDT) in terms of overall "device success."
The 241-patient Choice trial of the 2 transcatheter aortic valve implants showed device success in 95.9% of patients implanted with the Sapien XT device, compared with 77.5% of patients in the CoreValve arm. "Device success was defined as "successful vascular access and deployment of the device and retrieval of the delivery system, correct position of the device, intended performance of the heart valve without moderate or severe regurgitation, and only 1 valve implanted in the proper anatomical location."
Secondary end points included cardiovascular mortality, bleeding and vascular complications, post-procedural pacemaker placement, and a combined safety endpoint at 30 days including all-cause mortality, major stroke or other serious complications. Results from the trial, presented yesterday at the American College of Cardiology’s annual conference in Washington, were also published in the Journal of the American Medical Assn.
Medtronic also presented data at the conference from another study of the CoreValve implant, showing for the 1st time that a TAVI device is superior to open heart surgery in high-risk patients. The positive results prompted the FDA to allow Medtronic to skip an advisory panel meeting on the high-risk indication.
The researchers behind the head-to-head study pitting Sapien XT against CoreValve attributed the difference in device success to "a significantly lower frequency of residual more-than-mild aortic regurgitation," with a 4.1% rate for the Sapien cohort and an 18.3% rate for the CoreValve group. The difference was also due to "the less frequent need for implanting more than 1 valve," they wrote, citing a 0.8% rate for the Sapien arm versus a 5.8% rate for the CoreValve arm. There was no significant difference in the mortality rate at 30 days, according to the study.
But the study was limited by the use of angiography instead of echocardiography during implantation, the authors said. The CoreValve device continues to expand after implantation, which may have skewed the regurgitation results against it. More study is needed to elaborate on the differences between the devices, they said.
"We decided to choose the angiography to evaluate aortic regurgitation because it is an established tool for qualitative and semi-quantitative assessment of aortic regurgitation, is readily available during the procedure, and can provide essential information to initiate further management," the authors wrote. "With an accumulating body of evidence linking more-than-mild aortic regurgitation and consequently device failure with a worse clinical outcome after [TAVI], the findings of the Choice trial may have important clinical implications. Notably, at short-term follow-up, improvement of heart failure symptoms was more frequently observed with the [Sapien XT] valve, whereas minor stroke rates were numerically higher. Nevertheless, long-term follow-up of the Choice population should be awaited to determine whether differences in device success will translate into a clinically relevant overall benefit for the balloon-expandable valve."
"The Choice study is a small head-to-head study that focuses on a ‘device success’ composite endpoint versus harder clinical outcomes like death and stroke," Medtronic said today in an email to MassDevice.com. "Other hard clinical endpoints, such as bleeding, vascular complications and [New York Heart Assn.] class improvement, also showed similar outcomes. As a result, Medtronic believes that physicians will look to more rigorous trials with hard clinical endpoints when evaluating these valves – including the Partner and CoreValve U.S. piivotal trials – to provide reliable guidance on [TAVI] device selection."
EW shares were trading at $74.63 apiece as of about 11:10 a.m. today, up 4.9%. MDT shares were up 1.4% to $61.26 each.
