Daily Camera: BCH cardiovascular surgeon leads international study on longevity of structural heart valve

Photo courtesy of the Daily Camera

Today's edition of the Daily Camera (12/29/22) features a front-page story on Boulder Heart cardiovascular surgeon, Daniel O'Hair, MD, and his groundbreaking international study regarding the longevity of heart valves, which was recently published in the Journal of the American Medical Association (JAMA). Read the abstract of the study here. 

Continue reading the full article below:

Boulder cardiovascular surgeon leads international study on longevity of structural heart valve

Study shows catheter valve has longer lifespan than surgically implanted valve

By ANNIE MEHL | amehl@dailycamera.com | Boulder Daily Camera

PUBLISHED: December 28, 2022, at 6:02 p.m. | UPDATED: December 28, 2022, at 6:03 p.m.

A first-of-its-kind study led by a Boulder Community Health cardiovascular surgeon found that a specific type of heart valve that is implanted using a catheter rather than by open-heart surgery has a slower rate of deterioration  — an exciting discovery as the catheter method has become the most common form of aortic valve replacement.

Over the past decade, many hospitals have shifted away from surgical aortic valve replacements, which are done through cutting open a patient’s chest, and now prefer transcatheter aortic valve replacements. Transcatheter valves use a catheter that’s fed through a patient’s leg and replaces the patient’s valve with a sophisticated bio-prosthetic valve. The replacement valve widens the valve opening and takes over aortic valve’s job of regulating blood flow.

“There are more valves implanted (by catheter) than with open surgery because the results have been so good,” said Daniel O’Hair, cardiovascular surgery program chair at BCH and lead scientist for the study, which was published this month.

“What’s different is we never knew how long those valves were going to last. Patients want to know, (and) that’s a very important question, ‘Am I going to have to have this done (again) in two more years or five more years or 10 more years?'”

The international study gave researchers the answers they were seeking and produced promising findings — revealing that deterioration is almost three times higher for surgical valves than for a specific transcatheter aortic valve made by medical device company Medtronic.

“What data is showing for the very first time is structural valve deterioration is significantly less common in transcatheter valves, which just means … better outcomes for the patients, longer durability, (and) it keeps them out of the hospital more,” O’Hair said.

The study was published Dec. 14 in Journal of the American Medical Association. It documented outcomes for 4,700 patients, collected from December 2010 to June 2016 and analyzed from December 2021 to October 2022 to determine the frequency of structural valve deterioration at five years for those who underwent transcatheter aortic valve replacement and those who underwent surgical aortic valve replacement, the study said.

An aortic valve is the most common valve that surgeons replace, O’Hair said. The valve opens to let blood flow from the left ventricle — a large chamber at the bottom of the heart — to the aorta. It also closes to prevent blood from flowing in the wrong direction. The closed valve keeps blood from leaking from the aorta back into the heart.

“This valve wears out with age, so there is an aging phenomenon and then there are some people who are born with a minor irregularity in the shape of that valve or the way it’s put together, which doesn’t cause a problem for many, many years, and then in their 60s or so, the valve starts to wear out,” O’Hair said.

During the study, researchers examined Medtronic’s transcatheter aortic valve, which was favored when compared with one other implant in a separate study, O’Hair said. He added that Medtronic’s aortic valve is the first catheter implant that has been found to be superior to the surgical valves.

A spokesperson with Medtronic, who declined to be named for this article, added that this finding will have a major impact on patient choice. This valve, which started as an option for a niche patient population who couldn’t undergo surgery, will become the norm for patients needing a heart valve replacement.

“That’s being driven by the data but also by patient choice,”  the spokesperson said. “It’s a much less invasive surgery for patients.”

Most of the valves implanted through open-heart surgery are similar to each other, but this specific valve made by Medtronic is designed differently, O’Hair said. For one, its leaflets — the parts that open and close — are situated higher than they are on other valves, allowing for a larger opening and more blood flow. They are also made out of a very thin pig tissue. Additionally, the frame that contains the leaflets is made of nitinol, which comprises nickel and titanium. This material is unique for its strength and moldable characteristics. When the frame is cold, it can be bent, but when warmed, it immediately returns to its original shape. This allows it to be made small, inserted into the body, then resume its original shape.

A commonly used surgical valve also has leaflets, which are made of bovine tissue, but unlike Medtronic’s valve, its shape cannot be altered, O’Hair said.

Since O’Hair began using transcatheter aortic valves in 2010, he has implanted about 2,000, he said. This type of valve is generally given to someone 65 or older, but O’Hair said he has used this approach on a patient as young as 46.

“If we can get 15 years out of these things, I think that’ll be a huge step forward for many patients, and I do think that the age of implant will continue to come down,” he said.

O’Hair said the oldest data recorded on this specific valve looks at its durability about nine years after implementation. He added more studies are to come as hospitals continue using this method of aortic valve replacement.

“I think what we’ve learned from the design of this transcatheter valve is going to translate into better systems and better valves for open (heart) surgery as well because the transcatheter valve is so unique and this data is so unique,” O’Hair said.

“I think there’s a lot of lessons that can be learned to improve the other valves that we use for implants.”

Photo caption: Dr. Daniel O’Hair, a cardiovascular surgeon at Boulder Community Health, led a study that showed a heart valve implanted using a catheter rather than by open-heart surgery has a slower rate of deterioration. (Cliff Grassmick / Staff Photographer)

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About Dr. O'Hair: 

With over 25 years of experience, Dr. Daniel O’Hair is one of the nation’s leading experts in robotic-assisted mitral valve repair and Colorado’s most experienced surgeon for that procedure. He is also the most experienced surgeon in a multi-state region offering robotic mitral valve repair.

Dr. O’Hair, Director of Cardiovascular Surgery at BCH and board-certified cardiovascular surgeon, successfully created one of the largest, high-performing heart valve programs in the U.S. and served as a medical community leader in Wisconsin for two decades, performing the first-robotic assisted mitral valve repair, TAVR, and mitral valve replacement (TMVR) procedures in the state.

Dr. O’Hair’s case experience in the U.S. and internationally is over 6,000. In Oct. 2021, Dr. O’Hair completed his 500th robotics case – a rare surgical milestone.