Study shows ventricular assist devices allow diseased hearts to regenerate muscle

HeartWare's Ventricular Assist System--Courtesy of HeartWare International

Researchers at the University of Texas Southwestern Medical Center in Dallas found that heart disease patients on a left ventricular assist device were able to regenerate heart muscles, a sign of recovery that does not typically occur.

LVADs help patients' weakened hearts by pumping blood throughout the body. They are often used as bridge to transplantation for those waiting for a heart transplant.

The team concluded that 6 months after the use of an LVAD, patients' hearts had a 60% decrease in mitochondrial content and 45% decrease in cardiomyocyte (cardiac muscle cell) size.

By helping the heart to do its job and enabling what the researchers call "mechanical unloading," LVADs reduce the amount of oxidative damage to the heart. That damage stops cell regeneration in normal adults.

But the DNA damage response was lower in patients on LVAD for more than 6 months, and as a result, cell regeneration could occur, said Dr. Hesham Sadek, a professor at the medical center and one the study's lead authors.

"This result shows that patients with mechanical assist devices have the ability to make their muscle cells divide," he said in a statement. "And the obvious question now is, 'Are these hearts regenerating? Could LVADs be used as a cure for heart failure?' "

More details are available in the team's recently published study in Journal of the American College of Cardiology.

"Dr. Sadek's findings raise the prospect of reawakening otherwise quiescent cardiac muscle cells, coaxing them into regenerating new and healthy cells. This has been an over-arching objective of the field for many years. The next step will be to leverage these exciting results to rebuild the failing heart," said University of Texas medical professor Dr. Joseph Hill in a statement.

Thoratec and HeartWare ($HTWR) are the leading producers of LVADs. Last year Thoratec was plagued by an article in the New England Journal of Medicine, which linked its HeartMate II LVAD to an increased rate of pump thrombosis. To address the study findings head-on, Thoratec said it would kick off a new clinical trial to improve pump implantation and minimize pump thrombosis with its HeartMate II device.

- read the release
- here's the study abstract