|
Mayo Clinic discovery
could mean better access to
more donor hearts and
improved transplant outcomes
(DUBAI)
-
A discovery by
Mayo Clinic researchers
could mean more donor hearts
are available for heart
transplant, giving more
people a second chance at
life. In findings published
in Nature Cardiovascular
Research, a team led by
Mayo
Clinic cardiac surgeon Paul
Tang, M.D., Ph.D.,
identified a biological
process that contributes to
donor heart injury during
cold storage. The
researchers found that a
drug already used to treat
heart conditions can prevent
this damage.
Heart
transplantation is the most
effective treatment for
end-stage heart failure, yet
fewer than half of donor
hearts are ultimately used.
One major reason is the
relatively short window for
transplanting a donated
heart into a patient, due to
concerns over low donor
heart function that comes
from leaving a heart in cold
storage too long.
Why
donor hearts deteriorate in
cold storage
Although
cold storage slows
metabolism and helps
preserve tissue, prolonged
exposure to cold storage
conditions can lead to
molecular changes that
compromise the heart's
performance after
transplant. One complication
is called primary graft
dysfunction, in which the
transplanted heart cannot
pump blood effectively after
surgery. This may affect up
to 20% of recipients to
varying degrees.
To
investigate why this damage
occurs, the researchers
focused on a protein inside
heart cells called the
mineralocorticoid receptor,
which plays a role in how
cells respond to stress.
During cold storage, they
found that this protein
undergoes a process in which
it clumps together in a way
that harms heart cells, a
phenomenon known as
liquid-liquid phase
separation. This process
promotes cardiac damage from
increased inflammation and
cell death, making the heart
less likely to function well
after transplant.
Preventing damage with a
common drug
To test
whether the process could be
prevented, the researchers
treated donor hearts with a
drug called canrenone, which
blocks mineralocorticoid
receptor activity. In human
donor hearts stored beyond
the typical timeframe,
treatment with the drug
nearly tripled their pumping
strength compared to hearts
stored without it. The
hearts also showed better
blood flow and fewer signs
of cell injury. The findings
suggest canrenone may help
extend the safe storage
period for donor hearts by
improving the heart’s
pumping strength to increase
chances of a successful
transplant.
"As a
cardiovascular surgeon, I’ve
personally experienced in
the operating room how every
additional hour of
preservation can impact the
likelihood of whether a
donor heart can return to
normal function after
transplantation," Dr. Tang
says. "This discovery may
give us a new tool to
preserve heart function for
longer during storage,
improve transplant outcomes,
and enhance patient access
to lifesaving transplants."
The study's findings
also have the potential to
improve the preservation of
other transplantable organs.
Similar protein clustering
was observed in donor
kidneys, lungs, and livers
during cold storage. This
suggests that the same
strategy may help expand
transplant options across
multiple organ systems.
PRINT
THIS ARTICLE
|
