By Bill Berkrot
SAN FRANCISCO (Reuters) - Patients who received the original version of Edwards Lifesciences Corp's non-invasive heart valve replacement system had a nearly identical death rate after three years as those who had open-heart surgery, with no increased risk of stroke, according to results from a clinical trial.
The data, presented on Monday at the American College of Cardiology (ACC) scientific meeting in San Francisco, should provide doctors some reassurance about the durability of the Edwards transcatheter aortic valve replacement (TAVR), known as Sapien.
Three years after implantation, the death rates for any reason in high-risk patients deemed eligible for surgery was nearly identical at 44.2 percent for Sapien and 44.8 percent for those who got new valves via standard open-heart surgery.
Heart related death rates also mirrored each other at three years - 30.1 percent for Sapien versus 30.2 percent for surgery.
"It gives me a level of comfort that ... the late mortality is largely associated not with the device implanted, but with the intrinsic patient co-morbidities," said Dr. Martin Leon, a co-lead investigator of the trial.
TAVR allows surgeons to replace diseased heart valves by threading the new valve into place through an artery, sparing patients the chest cracking, open-heart surgery.
"These valves are showing to be durable," said Dr. Miguel Quinones, chairman of the 2013 ACC meeting, who was not involved in the study. "There is no question TAVR is here to stay."
The Sapien and newer generations of the valve system is widely considered to be Edwards' most important product line. Edwards' shares were off 2.4 percent at $88.14 in afternoon trading on the New York Stock Exchange.
Because it is relatively new and there were concerns about a high number of strokes seen shortly after the procedure in the 699-patient study, the big unanswered questions around Sapien were how it would hold up long after implantation and whether a higher stroke rate would persist after 30 days.
The three-year follow-up data should help to answer those questions.
"There seems to be no structural deterioration thus far," said Dr. Vinod Thourani, co-lead researcher of the Partner study, who presented the findings at the meeting.
STROKE DATA IS POSITIVE
The stroke data was also encouraging. At three years, the Sapien stroke rate was 8.2 percent compared with 9.3 percent for the surgical group.
The stroke rate with Sapien had been higher up to two years. But between two and three years there were nine strokes in the surgical arm and only one in the Sapien arm.
"So whatever early tendency that was observed that indicated a higher stroke frequency with TAVR has been more than negated with the late follow-up," Leon, director of the Center for Interventional Vascular Therapy at Columbia University Medical Center in New York, said in an interview.
"The main message is there really is no constant hazard related to TAVR that suggests that stroke rates will be higher over time," said Leon, who earlier at the meeting presented data that compared a newer, smaller and easier-to-use version of the Sapien already available in Europe with the original.
A problem of blood leakage around the valve persisted and was overwhelmingly higher with Sapien, researchers said. Thourani, from Emory University School of Medicine in Atlanta, said even mild leakage is associated with higher death rates after valve replacement.
However, Leon said, "If you look at sub group of patients who had none or trace valvular leak, they had an extraordinarily low mortality - half that of surgery."
Edwards is attempting to address the problem with newer valves in its developmental pipeline that include a skirt or cuff around the valve designed to prevent leakage.
The Sapien, which has been supplanted in Europe and elsewhere by the newer Sapien XT, was first approved in the United States in late 2011, only for patients considered too frail to survive open-heart surgery. That was expanded last autumn for a wider group of high-risk patients of the type included in this study.
Dr. Patrick O'Gara, the incoming the ACC president who hosted a panel that discussed the data, said concerns about high death rates must be put into perspective.
"Let's remember that we're dealing with a group of patients that are 84 years of age on average and our expectations for these outcomes need to be tempered," O'Gara said. "We have durability information in the octogenarian group over three years of time."
For U.S. approval to be expanded into younger and lower-risk patients, Edwards must continue to demonstrate the long-term safety and durability of the system. The U.S. Food and Drug Administration has asked for five years of follow-up data.
Of the latest findings, Leon said: "From as much as you can determine from an additional year of follow-up, these are all encouraging signs."
(Reporting by Bill Berkrot; Editing by Maureen Bavdek)