UA Cardiologist’s Work to Reduce Blood Clots with VAD Rotor Recognized by NIH

UA professor of medicine and biomedical engineering Marvin J. Slepian, MD, of the Sarver Heart Center, was featured (along with a short video) in an article from the National Institute of Biomedical Imaging & Bioengineering on the National Institutes of Health (NIH) website:

Dr. Slepian discusses use of vascular assist rotors engineered to reduce platelet activation. Such devices are implanted in end-stage heart failure patients to help pump blood in place of the heart.

NIH News & Events

October 7, 2015

Bioengineers Work to Head-off Dangerous Blood Clots in Patients with Ventricular Assist Devices

Work with “mechanoceuticals” could have even further-ranging applications in future

A team of NIBIB-supported bioengineers, aerospace scientists, and cardiovascular clinicians are improving the function of thousands of life-saving ventricular assist devices (VADs) implanted in advanced heart failure patients each year. VADs are mechanical pumps with a small rotor that spins at high speeds to circulate blood. However, these life-saving pumps can create pockets of turbulence that increase risk of platelet activation, which results in unwanted, dangerous blood clots and stroke.

Previously, the team re-engineered the VADs to remove these pockets of turbulence, which reduced more than 90 percent of platelet activation and clotting. In the current study, to further reduce risk, the team examined the role of platelet stiffness in the activation of clotting with the goal of developing treatments that would increase platelet pliability and further reduce platelet activation and clotting.

Heart failure occurs when the heart can’t pump enough blood and oxygen to support organs of the body. According to the American Heart Association, about 5.1 million people in the United States have heart failure with an estimated 75,000 to 150,000 patients with end-stage heart failure, where VADs are used as a bridge while awaiting a heart transplant. More recently, these devices are providing an alternative to transplant, allowing a near normal quality of life.

The approach of redesigning VADs in previous work to reduce unwanted clotting was a huge improvement, but the reengineered state-of-the-art VADs continue to carry an approximately 1-10% risk of initiating dangerous clotting events.

Marvin J. Slepian, MD, a professor of medicine and biomedical engineering at the University of Arizona’s Sarver Heart Center and a senior member of the research group, says, “As we reach the physical limitations of optimizing VAD design, we are now turning to the study of the biomechanical properties of platelet activation to further reduce dangerous clotting. We are moving from the engineering domain, where we altered the device, to the biological, where we try to alter the platelets so they become more flexible and therefore, less reactive as they flow through the VAD.”

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Release Date: 
10/12/2015 - 8:00am
Original Story: