New Trial to Study Ability of Cold to Improve Outcomes of Resuscitated Cardiac Arrest Patients
DURHAM, N.C. -- Neurologists have a saying that when the
heart stops, "time is brain." Now they may have a new cool way
of bettering the odds of preserving brain cells in patients
whose hearts have stopped beating.
Duke University Medical Center researchers are testing the
ability of cold, or hypothermia, to protect the delicate brain
tissue of resuscitated cardiac arrest patients and hope to
improve the often dismal outcomes for these patients.
For 32-year-old Durham resident Talario Jenkins, the new
approach now being evaluated in a clinical trial shows great
When Jenkins checked in at an urgent care clinic complaining
of a rapidly beating heart, the doctors realized that they
couldn't control it, so they called an ambulance to take him to
the emergency department at Duke University Hospital. While en
route, he went into cardiac arrest. Paramedics shocked his
heart back into action, but he went about 10 minutes without
blood flow to his brain. He arrived at Duke in a coma.
Waiting for him at Duke was neurologist Dr. Carmelo
Graffagnino, who organized and leads the four-site trial, which
will find out if rapid cooling can prevent brain damage after
"Dr. Graffagnino explained the system to me -- why he felt
it could help, its benefits and risks -- and I decided to do
it," recalled Jenkins' wife, Danisha, who consented to her
unconscious husband's participation in the trial. "It seemed
like the best chance he had of surviving."
Within minutes, Graffagnino threaded a triple lumen catheter
through a vessel in Jenkins' leg to his vena cava -- the body's
largest blood vessel and began circulating cool saline
throughout the catheter. Within several hours, Jenkins' body
had cooled from its normal temperature of 37 C to as low as 32
C (98.6 F to about 90 F).
After spending 24 hours in the neurological intensive care
unit in this cooled state, he was slowly rewarmed back to
normal body temperature. Days later he received a operation to
correct his Wolff-Parkinson-White syndrome, a congenital
condition which can cause sudden episodes of extremely fast
heart rates. He was discharged the next day, less than a week
after the cardiac arrest.
"While every patient is different, someone like Mr. Jenkins
would likely have suffered some mental decline as a result of
no blood flow for 10 minutes," Graffagnino said. "Had he been
out for 20 to 30 minutes, there would have been only a 10 to 20
percent chance he would have survived. He is now back at work
and seems perfectly normal. We hope that the cooling played a
role in that, but we won't know for sure until the study is
After promising results from small clinical trials in Europe
and additional animal studies showing that hypothermia can
protect brain cells, Graffagnino organized the multi-center
trial to test the hypothesis. If the results of this
FDA-approved PhaseI/II trial are promising, the researchers
plan to launch a much larger study.
Acting quickly to protect the brain is important, the
researchers say, because four out of five patients who are
unconscious after being resuscitated after their heart has
stopped beating suffer serious brain damage or die.
"When the brain is deprived of oxygen, as it is in cardiac
arrest, a whole cascade of biochemical events occurs, which
lead to brain cells literally 'exciting' themselves to death,"
Graffagnino explained. "Furthermore, when these patients are
resuscitated and blood flow is restored to the brain, another
cascade of events wreaks havoc on brain cells.
"We know from previous studies that hypothermia can stop or
slow down these biochemical reactions," Graffagnino continued.
"During the time of cold, we're offering the brain protection
and allowing the healing process to occur."
While European trials cooled cardiac arrest patients from
the outside using special cooling blankets, the new trial will
cool people from the inside-out. During this period of
coldness, participants will be given medications that will
sedate and "paralyze" them, so they won't shiver, he added.
"I remember lying there in bed -- I could hear things and
people talking, but I couldn't move or open my eyes," Jenkins
recalled of his recovery period. "It was very strange."
It is common for cardiac arrest patients not to remember the
event, and in many cases, the event can cause patients to lose
memories formed days before the arrest.
In order to be considered for the trial, a patient's heart
must have stopped beating, and then have been restarted --
usually by cardiopulmonary resuscitation (CPR) -- but still be
unconscious. The hypothermia procedure must begin within an
hour of the cardiac arrest. Researchers plan to test patients
twice after the therapy -- 30 days and 90 days later.
"It is sort of a Catch-22 in that we want everyone to know
how to perform CPR, but the reality is that it only works in
one out of five cases," Graffagnino said. "With hypothermia,
maybe we can improve those outcomes.
"We only have one hour to start cooling the patient down, so
the biggest challenge we face is finding next-of-kin and
explaining the procedure to them," Graffagnino said. "So much
needs to happen in a short period of time."
Researchers hope to enroll 10 patients within six months at
the four sites: Duke University Hospital, the University of
Houston, the Oschner Clinic in New Orleans, and the Henry Ford
Medical Center in Detroit.
Graffagnino said that about 300,000 Americans suffer from a
cardiac arrest each year.