(Adds study details, background, analyst, doctor comment)
By Bill Berkrot and Ransdell Pierson
WASHINGTON, March 29 Medtronic Inc's
minimally invasive CoreValve system for replacing diseased
aortic heart valves led to a significantly higher survival rate
after one year than traditional open heart surgery in patients
deemed at high risk of death during surgery, according to data
from a study presented on Saturday.
One year after receiving the CoreValve in the 795-patient
Phase III trial, the rate of death was 14.2 percent compared
with a 19.1 percent death rate in the surgery group, researchers
said. The result, presented at the American College of
Cardiology scientific meeting in Washington, was deemed to be
There was also no increased risk of stroke seen with
CoreValve compared with surgery, which had been one of the main
concerns of transcatheter aortic valve replacement (TAVR) early
on in clinical testing.
"I think the results were outstanding," said Dr. David
Adams, a co-principal investigator of the CoreValve trial.
TAVR systems use a catheter threaded through an artery to
the heart to put the new valve in place, sparing patients
chest-cracking open-heart surgery and typically longer hospital
stays associated with the invasive surgical procedure.
Early on, Adams explained, the question was could TAVR be an
alternative as good as surgery. "Now, it might be better," he
said. "We're making continual progress. It's not only an
alternative but may be a preferable alternative."
CoreValve won U.S. approval in January, three months earlier
than expected, to treat patients deemed too frail to endure open
heart surgery, known as extreme-risk patients.
The latest results in high-risk, or less ill, patients
should help expand the approval to treat a larger group as
Medtronic competes with Edwards Lifesciences Corp's
Sapien valve replacement, the first to gain U.S. approval.
Both have been available for several years in Europe, where
medical devices tend to get approved far more quickly.
"A positive outcome in the CoreValve high-risk trial should
lead to approval in this patient population in the U.S. by the
end of 2014," Wells Fargo analyst Larry Biegelsen said in a
research note prior to release of the data.
The U.S. Food and Drug Administration has determined that
data from the study would be sufficient to make an expanded
approval decision without first convening an expert advisory
panel to discuss it, Medtronic said.
In addition to the survival result, the rate of major
adverse cardiovascular and cerebrovascular events was
significantly lower with CoreValve - 20.4 percent versus 27.3
percent for surgery. That was a combination of death from any
cause, heart attack, stroke or need for another procedure.
More than twice as many patients in the surgery group went
on to develop atrial fibrillation, a potentially dangerous
irregular heart beat, researchers reported.
More than 100,000 people in the United States have severe
aortic stenosis with about one-third too ill or frail for
open-heart surgery, making them potential TAVR candidates.
Patients are typically older than 80 years old.
Glenn Novarro, an analyst with RBC Capital Markets,
estimated the U.S. TAVR market to be worth about $450 million in
2014. As positive clinical trial results mount in less extreme
risk patients and physician acceptance increases, sales of the
systems could provide important growth drivers for Medtronic and
"I think TAVR is going to have broader acceptance for
increased risk patients," said Adams, chairman of cardiothoracic
surgery at Mt Sinai Hospital in New York.
The primary difference between the two systems is that
Sapien uses a balloon, such as those employed in angioplasty
procedures, to expand the valve once it is in place. The
Medtronic system uses a special alloy that self expands as it
reacts to body heat once the valve is in place. CoreValve also
uses a smaller catheter than the currently approved Sapien. But
the next generation Sapien XT device with a smaller catheter is
expected to gain U.S. approval in the coming months.
Doctors and investors may get a glimpse of how the
competition will shape up later at the ACC meeting, when German
researchers present results of a head-to-head study comparing
CoreValve with the Sapien XT.
Quality of life measures with those who received CoreValve
were deemed to be non-inferior, or about as good, as those whose
valves were surgically replaced.
There were some disadvantages reported in the CoreValve
patients, including a low but significantly higher rate of valve
leakage and a higher rate of need for permanent implantation of
Adams said those issues were minor given the survival
advantage demonstrated in the trial.
"The message is very clear," he said. "It was a superior
(Reporting by Bill Berkrot and Ransdell Pierson; Editing by
Elaine Hardcastle and James Dalgleish)