Illustration by Maria Rendon
|
Scalpel-Free Heart Treatments of the Future
By Melissa Hendricks, March-April 2004
|
Doctors have made great strides in detecting and preventing heart disease.
But their flashiest advances are still in the pipeline: treatments to make
open-heart surgery a thing of the past. Though in rudimentary testing today,
these therapies could transform cardiac care within five to 10 years:
Gene therapy
To bypass a clogged artery, the doctor would snake a plastic tube to the
blockage and deliver a gene that stimulates the growth of new vessels. Young
vessels would, over a period of weeks, sprout and grow around the blockage.
NIH-funded researchers are now testing the technique in patients.
Genetically engineered drugs
A powerful synthetic version of HDL (the "good" cholesterol) would
sweep through the bloodstream, whisking away the LDL ("bad")
cholesterol molecules in its path. Plaque would diminish. Early results with a
small group of patients at the Cleveland Clinic are promising. Researchers must
now repeat these results safely in a larger test group.
Blood stem cells
Certain cells in bone marrow can mature into muscle cells, to rebuild
damaged cardiovascular tissue. To replace a section of heart muscle destroyed
by a heart attack, for example, your doctor would remove some of your bone
marrow, isolate its blood stem cells, and inject them into the damaged region
of the heart. These cells would mature into healthy heart muscle and blood
vessels. At the Texas Heart Institute in Houston, the therapy increased blood
flow to the heart and improved endurance in 11 patients with severe heart
failure. The next step will be a placebo-controlled trial to confirm that the
cells are what caused the change.
Lab-grown patches
Your medical team would replace a scarred section of your heart with a
healthy new piece of tissue the team custom-made for you. The team would first
remove a small sample of your healthy heart tissue and use these cells to grow
a larger patch of heart muscle on a dissolvable piece of scaffolding. Surgeons
would then remove the scar tissue left from your heart attack and replace it
with the healthy new patch of lab-grown heart. This tissue-engineering
technique could be ready for clinical trials in about four years, predicts
Buddy Ratner, a professor of bioengineering at the University of Washington in
Seattle.
Replacement hearts
One day, scientists could grow an entire heart in the lab. Patients would no
longer have to rely on organ donors. But such marvels more likely await our
grandchildren than ourselves, says Ratner: a lab-grown heart "is a very
far-reaching goal."
|
