Several Years Away
Safer heart-transplant delivery
Shipping a heart for transplant is a little like packing beer for a road trip: Doctors pack the heart on ice in an ordinary picnic cooler — just as they've done for decades — before shipping it across town or across the country. But the heart typically doesn't work as well when it's finally transplanted in a new patient, in part because the heart's function declines when it's not pumping blood. Explains Abbas Ardehali, M.D., chair of cardiothoracic transplantation at the UCLA School of Medicine: "Our organs are not meant to be on ice."
Ardehali is leading part of a large, multicenter study of a revolutionary new technology that keeps a heart beating while it's transported from donor to recipient. Called the warm blood perfusion system, it involves putting the heart on a small heart-lung machine and supplying it with the donor's blood and a nutrient-enriched solution at normal body temperature. This keeps the heart healthy and lengthens the time frame in which it can be used. In Europe, where the process has been approved and used in about 120 patients, hearts have been kept beating for more than 8 hours before transplantation, practically doubling the time an organ can be viable.
"The technology could allow organs to travel greater distances and allow us to expand the potential donor pool, making more hearts available for transplant," Ardehali says. Phase II trials are now under way, with plans to enroll 128 patients by the end of 2012. If final results are positive, the new system will take the next critical step toward FDA approval — larger phase III trials — and could debut in several years.
Stem cells for heart and arteries
Think stem cells and you probably think of the controversial embryonic variety. But autologous "adult" stem cells — those derived from a patient's own body — promise to revolutionize the treatment of some cardiac conditions, minus the tricky ethical issues. These cells are taken from a patient's bone marrow, multiplied in a lab, and injected back into the patient's bloodstream or directly into damaged heart muscle.
Stem cells could be a godsend for patients with peripheral artery disease (PAD), a severe form of vascular disease, often affecting the legs, that afflicts about 8 million Americans, 90 percent of whom are over 50. In severe cases the blood vessels of PAD patients may become so clogged that major surgery or even amputation is required. "If you get a diagnosis of PAD, your life expectancy is worse than for many types of cancer," says researcher William Marston, M.D., chief of vascular surgery at the University of North Carolina School of Medicine in Chapel Hill.
Early studies suggest that stem cell treatments may reduce the number of amputations and help wounds heal, possibly by helping generate a new network of healthy blood vessels to resupply the limbs. "We think stem cells may serve a number of functions — reduce inflammation, recruit other cells to carry out repairs, and even transform into the actual cells that populate new capillaries," Marston says.
The treatment is beginning phase III trials — the final phase before FDA approval. But researchers will need time to collect and analyze the data. "If the results continue to be positive and there are no safety issues, we would hope for approval in the next three to five years," Marston says.