Nav: Home

Blood clots may complicate aortic valve replacements

October 05, 2015

LOS ANGELES (Oct. 5, 2015) - Heart valve replacements made from tissue (bioprosthetic valves) have long been thought to be spared the complication of blood clot formation. Researchers have now found that about 15 percent of all bioprosthetic aortic heart valve patients develop blood clots on the leaflets affecting valve opening, regardless of whether the patient received the new valve via open-heart surgery or a minimally-invasive catheter procedure, a new study from the Cedars-Sinai Heart Institute shows.

The study, published online today by the New England Journal of Medicine and scheduled for the Nov. 26 print edition, also shows that anti-coagulant medications such as Warfarin quickly resolve the clotting issue for all patients, regardless of the type of valve or procedure.

Valve replacement is a treatment for aortic stenosis, which is narrowing of the valve between the main pumping chamber of the heart and the aorta, the main artery that carries blood from the heart to the rest of the body. According to the National Institutes of Health, about two percent of people over 65 years of age develop aortic stenosis. Symptoms include chest pain, fatigue, heart palpitations and breathing problems.

"The clinical impact of blood clots on stroke will need to be studied further definitively despite some preliminary signals that clots may predispose to mini strokes," said Raj Makkar, MD, associate director of the Cedars-Sinai Heart Institute, and who is widely regarded as a world leader in performing the minimally invasive heart valve procedures. "Transcatheter and surgically implantable tissue valves are life saving devices in patients with aortic valve stenosis. These findings allow us a potentially valuable opportunity to further optimize the outcomes of these procedures. We are not recommending that all patients with these devices be on blood thinners but clearly further studies need to be done to define best medication regimens."

Said Hasan Jilaihawi, MD, director of Interventional Cardiology Imaging at the Cedars Sinai Heart Institute, "Our study also shows that the novel technique of four-dimensional high resolution CT is superior to routinely used transthoracic cardiac echocardiography for the detection of these valve leaflet clots."

Makkar began the study when a high-resolution imaging study of one of the patients in a clinical trial who had stroke showed clot formation on the aortic valve leaflets that open and close to regulate the flow of blood. "We wanted to find out if patients undergoing a tissue valve procedure are susceptible to blood clots on the leaflets and study the clinical consequences of the same. We also wanted to understand whether our aortic valve patients were more susceptible to having blood clots and whether those clots could indicate that the patient might experience a neurological complication - a mini-stroke," Makkar said.

"This brilliant work highlights a common, previously unsuspected complication of heart valve placement. Such valve replacements are becoming increasingly common as they can now be done with minimally invasive procedures," said Eduardo Marbán, MD, PhD, director of Cedars-Sinai Heart Institute. "Early recognition of clot formation on the valves could save lives and prevent stroke, as those affected could be effectively treated using blood thinners."

The study is the first systematic scientific study using four-dimensional CT angiography to assess valve performance of TAVR and surgical tissue valves in patients with aortic stenosis.

Researchers followed 187 patients who received a new valve by undergoing a transcatheter procedure or open-heart surgery to receive a new valve. All patients in the study had high-resolution imaging so researchers could detect valve problems such as clots and reduced leaflet motion. Findings include:
  • About 15 percent of all valve patients will experience blood clots on the valve's leaflets;

  • In the vast majority of patients, an anti-coagulation medicine like Warfarin, will dissolve the clots;

  • There was some suggestion that the incidence of mini-stroke - called transient ischemic attacks - but not full blown strokes, could be increased by untreated valve leaflet clots but this was inconclusive and requires further study.

The study was supported by grants from St. Jude Medical, which manufactures replacement aortic valves, and the Cedars-Sinai Heart Institute.

About the Cedars-Sinai Heart Institute

The Cedars-Sinai Heart Institute is internationally recognized for outstanding heart care built on decades of innovation and leading-edge research. From cardiac imaging and advanced diagnostics to surgical repair of complex heart problems to the training of the heart specialists of tomorrow and research that is deepening medical knowledge and practice, the Cedars-Sinai Heart Institute is known around the world for excellence and innovations.

Cedars-Sinai Medical Center

Related Stroke Articles:

How to help patients recover after a stroke
The existing approach to brain stimulation for rehabilitation after a stroke does not take into account the diversity of lesions and the individual characteristics of patients' brains.
Kids with headache after stroke might be at risk for another stroke
A new study has found a high incidence of headaches in pediatric stroke survivors and identified a possible association between post-stroke headache and stroke recurrence.
High stroke impact in low- and middle-income countries examined at 11th World Stroke Congress
Less wealthy countries struggle to meet greater need with far fewer resources.
Marijuana use might lead to higher risk of stroke, World Stroke Congress to be told
A five-year study of hospital statistics from the United States shows that the incidence of stroke has risen steadily among marijuana users even though the overall rate of stroke remained constant over the same period.
We need to talk about sexuality after stroke
Stroke survivors and their partners are not adequately supported to deal with changes to their relationships, self-identity, gender roles and intimacy following stroke, according to new research from the University of Sydney.
Standardized stroke protocol can ensure ELVO stroke patients are treated within 60 minutes
A new study shows that developing a standardized stroke protocol of having neurointerventional teams meet suspected emergent large vessel occlusion (ELVO) stroke patients upon their arrival at the hospital achieves a median door-to-recanalization time of less than 60 minutes.
Stroke affects more than just the physical
A new study looks at what problems affect people most after a stroke and it provides a broader picture than what some may usually expect to see.
Stroke journal features women's studies on how gender influences stroke risk, treatment and outcomes
Many aspects of strokes affect women and men differently, and four articles in the American Heart Association's journal Stroke highlight recent research and identify future research needs.
Too few with stroke of the eye are treated to reduce future stroke
Only one-third of 5,600 patients with retinal infarction, or stroke in the eye, underwent basic stroke work-up, and fewer than one in 10 were seen by a neurologist.
Juvenile stroke: Causes often not known
Strokes without a definitive identifiable cause account for up to 50 percent of juvenile strokes.
More Stroke News and Stroke Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#538 Nobels and Astrophysics
This week we start with this year's physics Nobel Prize awarded to Jim Peebles, Michel Mayor, and Didier Queloz and finish with a discussion of the Nobel Prizes as a way to award and highlight important science. Are they still relevant? When science breakthroughs are built on the backs of hundreds -- and sometimes thousands -- of people's hard work, how do you pick just three to highlight? Join host Rachelle Saunders and astrophysicist, author, and science communicator Ethan Siegel for their chat about astrophysics and Nobel Prizes.