(College Station)—For John Criscione, seeing patients with congestive heart failure and not knowing the cause or a solution was unacceptable.
Criscione, an assistant professor in the Department of Biomedical Engineering at Texas A&M University, has both a Ph.D. in engineering and an M.D. Fueled by a desire to help people, Criscione focused his attention on studying how mechanics––the study of force and motion in matter––applies to the biology of the heart.
John
Criscione, left, who is both an engineer and a medical doctor,
believes that physical therapy can rehabilitate a heart after a heart attack.
Criscione said he believes the heart can be rehabilitated after a heart attack to ward off congestive heart failure. In the absence of disease, the body grows to meet the demands placed on it, said Criscione. The same is true of the heart, Criscione said.
"Bones, tendons and muscles clearly respond to mechanical loads," Criscione said. "If you start an exercise program, you'll get bigger muscles. If you run, your leg bones get bigger to handle that load.
"The heart does a different kind of work than muscles––not locomotion, but pumping. You have to do work in the heart to get blood from arteries to veins, and that's mechanics."
With congestive heart failure, a progressive deterioration of the heart, Criscione said the heart grows and changes shape in a way that makes the heart worse at pumping. Patients with congestive heart failure can't climb stairs without feeling winded or tired and have trouble walking or even getting out of bed.
These failing hearts, Criscione said, show drastically different strain patterns than healthy hearts.
"After a heart attack, the heart's mechanics are changed, so the ideal treatment for heart failure is to restore the heart's regular strain pattern."
Currently, the only real cure for congestive heart failure is a heart transplant, but most people with congestive heart failure aren't eligible to be on a transplant list. Mechanical assist devices called left ventricular assist devices (LVAD), invented by heart pioneer Michael DeBakey, may help to change the mechanical load on the heart.
Many of those hearts even manage to repair themselves, a process known as ventricular recovery. But doctors cannot attain ventricular recovery in every patient, and current assist devices only help the heart pump blood.
Criscione said he thinks it may be possible to rehabilitate the heart after a heart attack –– a kind of cardiac physical therapy.
"When something goes wrong with joints and muscles, we need mechanics to get back into shape," Criscione said. "After a car accident or surgery, physical therapy can help repair the joint to become more functional. I think we can do the same for the heart."
If
all goes well, trials on humans may begin as early as 2008.
Criscione said such cardiac physical therapy would change the load on the heart, thereby changing the heart's abnormal mechanics to guide good heart growth and operation.
And that’s where his invention comes in.
CorInnova’s device, called a direct cardiac compression device, fits around the heart. Pumping air into the chamber around the heart squeezes the heart and pushes blood out. Letting the air out of the chamber allows the heart to expand and fill with blood.
Implanted just after a heart attack, the device could restore proper motion to the heart when motion becomes abnormal. Criscione’s invention modulates the growth of the heart, but doesn’t replace the heart or its action.
Criscione and CorInnova co-founder Dennis Robbins are currently conducting one-day animal trials on sheep with help from Teresa Fossum and Dave Nelson in the College of Veterinary Medicine’s Michael DeBakey Institute of Biomedical Devices at Texas A&M. Results from these trials so far show that the device does restore motion to the heart.
“Now the question is,” he said, “if we do this for four weeks, do we reduce tissue death?"
To test this, Criscione will begin 18 months of long-term efficacy trials in sheep this summer, studying the heart’s performance during the time the device is implanted. He said the efficacy trials will tell if the device can be operated for several weeks without being rejected and if the longer implantation time reduces tissue death in the heart.
Depending on the results of the efficacy trials, Criscione said he and Robbins will either head back to the drawing board or proceed to safety studies before clinical trials. If all goes well, he said they could begin clinical human trials in 2008.
"Everyone has their own heart," Criscione said. "We want
to get theirs to work right." 