Reprintented from Karl Loren
site
Part
1, PART 2
Mental Decline Is Linked to Heart Bypass Surgery
Here are the stories that appeared
in the nation's media -- taken from one
study deliberately planted in the prestigious New England Journal
Of
Medicine.
February 2001
Reprint From The New York Times
Mental Decline Is Linked to Heart
Bypass Surgery
February 8, 2001
Mental Decline Is Linked to
Heart Bypass Surgery
By DENISE GRADY
Five years after heart bypass surgery,
42 percent of patients show a significant decline on tests of
mental ability, probably from brain damage caused by the surgery,
doctors from Duke University say in a new study.
Older patients and those with a drop
in test scores soon after surgery were most likely to show declines
five years later. The report, being published today in The New England
Journal of Medicine, has evoked mixed reactions among experts.
On the one hand, they say that a lowered
test score does not necessarily mean a person is mentally impaired
and that the 42 percent figure might needlessly frighten patients
away from surgery that could save their lives. On the other hand,
researchers concede that the study was done well and that it highlights
an ugly truth that surgeons know but are not eager to discuss with
patients: some patients do wind up mentally impaired after bypass
surgery. And doctors are not sure why, though they suspect various
factors that interfere with blood flow to the brain during surgery.
The findings also seem likely to fuel
the debate about whether all of the approximately 500,000 bypass
operations done each year in the United
States are necessary, or whether more patients with blocked arteries,
particularly older people, should be treated with medication or
less invasive procedures to open clogged blood vessels.
The researchers are not the first to
link mental decline to bypass operations.
But earlier studies were shorter term, and many doctors hoped that
the cognitive losses would be temporary. The new study is the first
to show
lasting changes in so many patients so long after the surgery.
The study, based on 261 patients who
had bypass surgery at Duke from 1989 to 1993, relied on mental tests
done before surgery and then six weeks, six months and five years
later. The patients' average age was 61, with a range
of 50 to 71. Patients were considered to have declined mentally
if their test performance at five years was at least 20 percent
lower than their score
before surgery. A 20 percent drop was similar to the difference
in function between subjects at ages 40 and 60.
The drop in scores in the bypass patients
could not be attributed to aging, the authors said, because it was
more than two to three times the mental decline found in 5,888 Medicare
patients who did not have bypass surgery and whose cognitive abilities
were followed for five years in a separate study.
A doctor not associated with the study,
William A. Baumgartner, chief of
cardiac surgery at Johns Hopkins Hospital, said researchers at his
hospital
were also studying the problem but had found far fewer patients
with
significant long-term problems, perhaps 8 percent to 10 percent.
"I was shocked at the 42 percent,"
Dr. Baumgartner said. "We just haven't
seen that in our five-year follow-up. People who read this thing
are going to
be scared out of their minds that they're going to be some kind
of invalid. In
our series, that is clearly not the case. They need further work
to see how this affects the well-being of patients."
Dr. Mark F. Newman, an author of the
study and chief of cardiothoracic anesthesiology at Duke University
Medical Center, said researchers were not sure how many of the patients
were troubled by their declines or even aware
of them, since the changes might not cause problems in their daily
lives.
But Dr. Newman said he hoped the findings
would not lead patients to shun bypass surgery. "In a lot of patients,
we prolong their life," he said. "We have to continue working on
improving the quality of their life as well."
Several elements of bypass surgery
can potentially cause brain damage, Dr. Newman said. One is the
heart-lung machine, through which the patient's
blood is circulated to pick up oxygen. Doctors suspect air bubbles
produced by the machine may block blood flow through minute vessels
in the skull, killing brain cells. The machine may also pump droplets
of fat released from the surgical site to the brain, where they
can cause the same problem as air bubbles. It is also possible that
the machine does not provide enough oxygen
for some patients.
The other possible source of trouble
is fatty deposits in the patient's own
aorta, the large vessel that carries blood out of the left side
of the heart. Surgeons clamp the aorta and may sew blood vessels
to it during bypass surgery; those procedures can break off deposits,
which may then travel to
the patient's head and block blood flow.
Dr. Newman said newer techniques in
which the surgery was done without
the machine, and with little or no manipulation of the aorta, might
help to protect the brain. But not all patients are candidates for
the new techniques.
In the United States, about 20 percent of bypass operations are
done without the heart-lung machine. The machine will always be
needed for some types of cases, Dr. Newman said, and for that reason
researchers are trying to develop drugs that patients can be given
during surgery to help brain cells tolerate declines in blood pressure
and oxygen level that cannot always be avoided during surgery.
But other researchers say it is not
clear that the heart-lung machine should
take all the blame. Dr. Ola A. Selnes, a neuropsychologist at Johns
Hopkins,
who wrote an editorial in the same issue, said other studies had
shown cognitive declines in elderly patients who had operations
not involving the heart; the stress of anesthesia and major surgery
may have been too much for them.
Dr. Selnes noted that cognitive problems
in bypass patients might be partly
due to their underlying vascular disease, which affects blood vessels
all over the body.
A weakness of the study, and of earlier
ones, is the lack of a control group a set of patients who do
not have bypass surgery but who have vascular disease similar to
that in the surgical patients and who match them in age, sex, race,
education level, lifestyle and so on. Only by comparing two such
groups over time could researchers find out how much mental decline
is due to bypass surgery and how much to vascular disease. Dr. Selnes
said such a study was under way.
When answers do become available, Dr.
Selnes said, it might be possible to identify patients who are particularly
at risk for cognitive problems, and to suggest alternative treatments
to bypass surgery. "Not everyone has to have bypass," Dr. Selnes
said. "There are choices. Of these 600,000 being done
very year, only a subset really require what you might call emergency
surgery."
Other patients, he said, could be offered
medical treatment or less invasive procedures like balloon angioplasty
to open clogged vessels.
"There has been a kind of blind faith
that bypass is the ultimate answer to any kind of heart disease,
and I think that has to be rethought," Dr. Selnes said.
Saving the Heart Can Sometimes
Mean Losing the Memory
By SANDEEP JAUHAR
James Haneman believes his surgeons sacrificed
his mind in saving his heart.
In 1989, Mr. Haneman had a law practice
in New Orleans, earned a six-figure
salary and sat on several important state and federal law committees.
Then he
had a heart attack and surgery to bypass blockages in his coronary
arteries.
He came through the surgery fine physically.
But since then, Mr. Haneman says, he has had memory problems and
even simple tasks, like writing letters, elude
him. His doctors told him the problems would be only temporary.
"They told me
not to make any important decisions for a month," he recalled.
But when he returned to work, he recalled,
"I could study something and not be ready to say it the next day,
particularly in the order it had to be presented." The doctors told
him to wait another month.
Frustrated, he turned to self-help tapes
and books on memory enhancement. He tried computer exercises and
reading nonfiction. But his problems persisted and after two years
he quit practicing law. "When you can't remember anything, you can't
practice law," he said. "I was doing my clients an injustice."
Though Mr. Haneman is an extreme example,
heart surgeons say he is not alone. Doctors say evidence is mounting
that a small but significant number of bypass patients suffer some
degree of cognitive impairment, like memory and attention deficits
and language problems, particularly if they spend time on heart-lung
machines.
These patients are apart from the approximately
2 percent to 5 percent of
patients who suffer strokes after bypass surgery, a procedure 600,000
Americans undergo each year.
It is unknown how many patients suffer
the less catastrophic, but nevertheless debilitating, cognitive
problems. Depending on how the problem is defined,
studies suggest that anywhere from 10 percent to 50 percent or more
of bypass patients do poorly on tests of memory, language and spatial
orientation six
months after surgery. These changes can persist years after surgery,
and in many cases are probably irreversible.
A significant number of these patients
will have recognizable problems in their
day-to-day lives. It is estimated that the total cost of these problems
exceeds $1 billion a year.
In part, experts say, the incidence of
the problem is increasing because older, sicker patients are now
being offered bypass operations. In the early 1980's, the average
age of bypass patients was about 58, according to Dr. John Murkin,
director of cardiac anesthesia at the University of Western Ontario
in Canada.
Now, it is 66.
"As we operate on older and older patients,
because of the accumulated burden
of disease in their blood vessels, we're seeing more neurological
injury," Dr.
Murkin said.
In part, experts say, the cognitive impairment
itself is the result of stroke, particularly "ministrokes" that
patients can suffer when fatty material is dislodged from the aorta,
the body's largest blood vessel, when it is clamped in order to
shunt blood into a heart-lung machine.
The acts of clamping and unclamping can
break the hardened fat coating the wall
of the aorta into tiny pieces, like pliers squeezing an eggshell,
which can then
lodge in the brain. "On video it looks like a snowstorm," said Denise
Barbut,
former director of stroke research at the Weill Medical College
of Cornell
University, who has used ultrasound to study the flow of these particles
during bypass surgery.
Experts say there are probably several
other contributing factors, including tiny blood clots or bubbles
from the heart-lung machine, inadequate blood flow to the brain
during surgery and brain inflammation.
Whatever the cause, the syndrome is so
pervasive that heart surgeons and cardiologists have coined a term
for it: pump head. Some even go so far as to encourage some patients
to seek other remedies for their heart disease.
"A high-functioning 75-year-old who I
might normally be very aggressive about bypassing, I might try to
manage medically or with angioplasty," said Dr. Richard Fuchs, a
cardiologist in private practice in Manhattan, referring to powerful
heart drugs and balloon procedures that open up blocked arteries
without surgery.
Other experts say they save this advice for patients who already
have some
sort of cognitive impairment.
Some experts say some of the cognitive
problems after bypass surgery may actually result from depression,
which for reasons that are unclear develops in many patients after
the surgery.
In any event, the cognitive impairment
occurs in a minority of patients. "I have a fairly large cadre of
patients who tell me they've never been better," said Dr.
Jeffrey Gold, chairman of cardiothoracic surgery at the Albert Einstein
College of Medicine and Montefiore Medical Center in the Bronx.
"Many will tell you they're much more creative and prolific, that
they haven't suffered any cognitive decline whatsoever."
Dr. Gold points out that some research
shows that knee-replacement surgery can result in similar cognitive
impairment and that bypass surgery done off a heart
-lung pump results in stroke rates similar to those when conventional
bypass surgery is done on pump. "I think pump head is a misnomer,"
he said. "The implication is that the cognitive decline is due to
the pump, and that if you avoid it you're safe, but that doesn't
appear to be the case."
When patients have cognitive changes
after surgery, the effects are often subtle. They may think a little
slower or feel "clouded." They may forget appointments or where
they put things. They may become irritable or depressed.
"The defects can be subtle and patients
can often compensate for them," said Dr. Mehmet Oz, a professor
of cardiothoracic surgery at Columbia-Presbyterian
Medical Center in Manhattan. "On the other hand, if their functioning
is already
low, the results can be debilitating."
Sometimes the changes can be a bit bizarre.
"Suddenly the type of food or the
type of restaurant they like changes," said Dr. Mani Subramanian,
chief of cardiothoracic surgery at Lenox Hill Hospital in Manhattan.
Dr. Gold of Montefiore said one of his patients recently had called
after bypass surgery to say he was feeling well and was back at
work. "But he told me, `I can't stand the taste of lettuce anymore.'
He used to eat a lot of salad, but that changed after surgery."
For Paul Wechsler, a 60-year-old former
architect who lives in New Jersey, the changes were not subtle or
bizarre, just painful. "The bypass surgery knocked
out a lot of my memory," he said from his home, where he spends
most of his
days. "It changed my whole life around mentally."
The memory problems started immediately
after his bypass surgery in 1996. He
told his doctor about them, and was assured they would be temporary.
But in the following months he did not improve. He found himself
asking his fiancιe to calculate the tip at restaurants. "I couldn't
understand jokes that she would tell me," he said. "Even now, she'll
say something to me and I'll say, `What do you mean by that?' "
He had been running his own construction
business and working as a salesman before the surgery, but he had
to quit. "I used to enjoy the challenge of building things up from
nothing," he said, but it gave him fits. Though he believes his
mental functioning may now be starting to improve, he remains on
permanent disability. "I still have to read a paragraph three times
to get the meaning," he said.
To avoid the potentially deleterious
effects of heart-lung machines, surgeons
have developed off-pump, or beating-heart, bypass surgery. Here,
surgeons
insert a clamp through a small incision in the chest wall to immobilize
a small
section of the beating heart. A new vessel is then stitched, while
the heart continues to pump blood to the brain and the rest of the
body. Aortic clamping
and a heart-lung machine can be avoided. The surgery is relatively
new, however, and most bypass surgery is still done on pump.
But studies of whether off-pump surgery
protects against pump head have not produced clear results. Dr.
Oz of Columbia is now conducting a study, the largest
to date, in which 600 bypass patients will be randomly treated with
on- or
off-pump surgery and studied for cognitive decline. "If we're going
to make decisions affecting the lives of 600,000 people a year,
we don't want to base that on the results of a small trial," he
said.
Other treatments for pump head are being
developed. Embolex, a Northern California company founded
by Dr. Barbut, the neurologist, has designed a filter
to catch debris from the aorta during surgery. Another company,
Cardeon, has developed a balloon device that opens up inside
the aorta during surgery,
shutting off blood flow and obviating the need for a clamp.
Some experts believe that more attention
is being paid to pump head today because more catastrophic results,
like strokes and deaths, have sharply decreased as anesthesia and
surgical techniques have improved. The mortality
rate for bypass surgery is now less than 1 percent. "The nice thing
is that today
we can worry about the subtle changes," said Dr. Mark Newman, chairman
of anesthesiology at Duke University Medical Center.
Dr. Gold of Montefiore said the decision
about whether to perform bypass surgery on or off pump can be made
in the operating room. He recently had a 52-year-old patient who
expressed concern before surgery about intellectual decline. After
opening up the patient's chest in the operating room and discovering
by ultrasound that his aorta was lined with a large amount of plaque,
Dr. Gold decided to do the bypass surgery off pump.
"The most important thing, in my humble
opinion, is to be flexible," Dr. Gold said. "The goal is to fit
to the patient's needs, not artificially choose a surgical modality."
He added that for the majority of patients, on-pump surgery the
most studied was their best option.
Copyright 2001 The
New York Times Company
Study
Sees Post-Surgical Mental Loss
Los Angeles Times -- February 8, 2001
By JANET MCCONNAUGHEY,
Associated Press Writer
Many
patients who undergo heart bypass surgery suffer a significant
and, it turns out, long-lasting loss of brain power, a study suggests.
Doctors have known that people often
lose some of their mental sharpness immediately after a heart
operation, but many seemed to recover fairly
quickly. The new study, however, found that this recovery is short-lived.
The study looked at 261 patients
who were on a heart-lung machine
during bypass surgery. It found that five years after the operation,
40 percent showed a 20 percent drop in mental ability. That loss
is similar to what a
person normally goes through between the ages of 40 and 60.
Doctors do not know for sure why
this mental loss happens, or even
whether the operation causes it. For example, it might be that
people whose arteries need to be replaced already have damaged
blood vessels in their
brains as well. The loss might also have something to do with
being put on a heart-lung machine, which circulates blood through
the patient's body during surgery.
An estimated 400,000 people a year
are put on heart-lung machines for a bypass operation in the United
States. The findings suggest that 160,000 of them risk losing
some of their mental ability.
Dr. Mark F. Newman, who led the
study published in Thursday's New
England Journal of Medicine, noted that many patients in the Duke
University study might not have lived five years without the operation.
"Now it's a matter of fine-tuning"
the operation "to improve the quality of life as well as the length
of life," he said.
Moreover, the people who lost mental
ground in this study might have lost brain power faster anyway,
said Dr. Irving L. Kron, chief of cardiac and thoracic surgery
at the University of Virginia School of Medicine.
"It may be that the stress of the
operation brings things out or pushes
things along that were there to start with," Kron said.
Newman said other research appears
to indicate that there are fewer problems with the brain after
bypass operations done without the heart-lung machine.
Participants in the latest study
took tests in memory, attention,
concentration and manual dexterity five times: before the operation,
when
they left the hospital, and six weeks, six months and five years
later.
Fifty-six percent did significantly
worse when they were released from the hospital than when they
were admitted.
Nearly half of those people were
back up to pre-operation levels when tested six months after the
operation. But at the five-year mark, most were back down to the
levels measured when they were leaving the hospital.
Older people and those with the
least education were the most likely to
have lower scores five years later.
People who did not show any losses
just after the operation were in
equally good shape five years later.
The bypass operations took place
from 1989 through 1993, and the last five-year tests were given
in 1998.
Doctors are more aware of problems
which can cause brain damage than they were when those bypasses
were done, and improved techniques "will reduce or have reduced
neurocognitive dysfunction," Newman said.
"I think our technology is continuing
to improve," he said.
- - -
On the Net:
Duke University Medical Center:
http://www.mc.duke.edu/
New England Journal of Medicine:
http://www.nejm.org/
American Heart Association: http://www.americanheart.org/
University of Virginia Medical School:
http://www.med.virginia.edu/schools/medschl.html
Search
the archives of the Los Angeles Times for similar stories.
You will not be charged to look for stories, only to retrieve
one.
Copyright 2001 Los Angeles Times
February 8, 2001
Health
Research Suggests
Bypass Patients Face Higher Risk of Memory Loss
By RON WINSLOW
Staff Reporter of THE WALL STREET JOURNAL
A new study suggests that a significant
number of patients undergoing coronary-artery bypass surgery suffer
sustained memory loss and other cognitive problems as a result
of the operation.
The findings reflect growing awareness
that the widely used procedure
carries with it the risk of a variety of neurological problems,
ranging from stroke to much less severe side effects such as confusion,
difficulty concentrating or paying attention. The report is among
the first to indicate
that such cognitive deficits can recur as many as five years after
surgery.
"We have thought of this problem
as a transient or temporary injury that occurred but we were unsure
of what the long-term consequences were,"
said Mark F. Newman, a cardiac anesthesiologist at Duke University
Medical Center, Durham, N.C., and lead author of the study. The
results, published in Thursday's New England Journal of Medicine,
indicate people who suffer an immediate cognitive decline after
the operation typically recover, but are at high risk of experiencing
the deficit again.
More than 500,000 bypass operations
are performed in the U.S. annually, and researchers have made
important strides reducing death rates and the incidence of stroke,
among other complications. But the more-subtle emotional and cognitive
changes have gotten much less attention.
"My hope is that we can provide as
much quality of life as we do quantity of life," Dr. Newman said.
"The way to do that is to preserve cognitive function."
Investigators at Duke and elsewhere
are studying the operation to determine possible causes and ways
to avoid such deficits. Research by David Stump, a neuropsychiatrist
and his colleagues at Wake Forest University Baptist
Medical Center, for instance, indicates that debris that breaks
off from a diseased aorta during the operation can end up in the
brain, causing strokes
or cognitive problems. The practice of returning to the patient
any blood that collects in the chest cavity during the operation
as well as how quickly body
temperature, especially in the brain, is restored postoperatively
also may
play a role in cognitive deficits, he has found.
The new study, based on 261 patients
who had bypass surgery at Duke from 1989 to 1993, found that 53%
had at least a 20% decline in brain function, based on a battery
of neurocognitive tests shortly after the operation. Scores, on
average, returned to presurgery levels within six months, but
among those with an initial decline, about two-thirds, in effect,
had relapsed when they
were tested again five years after the operation.
A weakness in the study is that the
patients weren't compared with a control group who didn't have
the surgery. Thus, it isn't possible to determine for sure how
much of the effect resulted from the operation and how much might
relate to such factors as a patient's condition prior to the surgery,
or to declines associated with aging. Still, Dr. Newman believes
the findings indicate bypass surgery can accelerate any cognitive
decline linked to getting older.
Irving Kron, chief of thoracic and
cardiovascular surgery at University of Virginia, Charlottesville,
said he thinks the study suggests that if a patient already has
a "tendency toward cognitive dysfunction," certain elements of
bypass surgery could precipitate it.
Write to Ron Winslow at ron.winslow@wsj.com
Part
1, Part 2
|
