Ruth Pavelko lies in an operating suite that looks like the mission
center for a rocket launch. Interventional cardiologist Emerson Perin is
to inject stem cells into Pavelko’s weakened heart. Pavelko, a diabetic,
four heart attacks by the time she was 55. Blockage in major heart
vessels, despite 13 attempts to keep them open, has left much of her
muscle almost dead.
Patients with extremely advanced heart failure are eligible for some sort
assistive device, an artificial heart, or a transplant. Clinical trials at the
Heart Institute and several other sites now offer another option:
stem cells derived from her own bone marrow. Stem cells can
other cell types, including those that form blood vessels.
Images on color monitors and real-time X-rays are part of a technology
developed by Perin to distinguish living heart muscle from dead scar
inside the left ventricle of the heart. The left ventricle does most of the
of the heart, and most heart attacks and cases of heart failure involve
to the left ventricle. Perin has now identified about 70 spots inside the
Pavelko’s left ventricle that are not contracting well, but still seem to be
viable. By the end of the surgery, about 1 million of her own stem cells
have been injected into those spots in her heart. She is one of 16
the first U.S. trial using stem cells derived from adult bone marrow to
advanced heart failure.
In 2000, the first trial of adult stem cells for the heart involved
stem calls from thigh muscle, not bone marrow. While early results
improvements, but many patients eventually developed arrhythmias
(dangerous abnormalities in heart rhythm), presumably because thigh
contracts differently than heart muscle. A year later, Donald Orlick, a
scientist at the National Institutes of Health reported that stem cells
from bone marrow and injected into mouse hearts improved function by
Important questions include whether injected stem cells actually change
heart muscle cells, whether they work by secreting powerful growth
or whether they change into new blood vessels.
Some scientists thought that clinical trials might be premature. Some
suggested that stem cells could create scar tissue, thereby making
worse, not better. Other work showed that stem cells, if injected into
bloodstream, could clog small blood vessels, again possibly making
worse. Perin says that it’s easier to be cautious as a scientist than as a
physician. “They don’t have patients dying; I do.” After deciding that
injection into scarless heart muscle was the best approach, Perin had
tuned his technology and was ready to go by the end of 2001.
The trial was risky. There were no published studies involving stem
multiple heart attack patients. His patients were very ill. One patient
ill, he was gray in color, couldn’t breathe, and was starving. You can’t
you can’t breathe. His ejection fraction (a measure of the heart’s
ability) was 10%. Normal is 55%. A few viable areas of heart muscle
identified, but much of the left ventricle was dead. Another worry in
like this; an early death during the study would end the trial. Perin took
chance and injected him. “I was really worried.” Five months later he
jogging on the beach. Before long, 13 of 14 patients had shown
Perin is not the only one doing stem cell research in heart patients.
Patel, a cardiac surgeon from the University of Pittsburgh has completed
three clinical trials in Asia and South America. He has seen an oveerall
increase in pumping ability from 26% to 46%, almost normal. Results he
describes as “unbelievable.”” Two publications are in the works. Johns
Hopkins is also starting clinical trials using stem cells in heart attack
The journal Circulation published Perin’s work in July.
Ruth Pavelko doesn’t read cardiac journals, but she knows something is
different in her heart. Before she received her stem cell injections, she
couldn’t walk to her mailbox. Today she climbs stairs many times a
once a week she makes the quarter-mile trip to a nearby park.