What if your doctor could swipe a wand over your neck and reveal
whether you have hidden heart disease?
That is now possible in places other than the sickbay of the
Starship Enterprise.
Miniature ultrasound machines are starting to make their way
into ordinary doctors' offices, where they may someday be as common
as stethoscopes and EKGs. A pocket-sized one weighing less than one
kilogram hit the United States market last week.
Some of these devices can make images of neck arteries, which
offer a "window" to heart arteries that cannot easily be seen. If
the neck vessels are clogged, doctors know that those around the
heart probably are, too, and that treatment or more testing is
needed.
The new ultrasound machines offer a relatively cheap, painless
way to screen people with no symptoms of heart problems for signs
of hidden trouble.
Is that a good thing?
Many doctors say yes, because for one-third of heart disease
sufferers, the first symptom is dropping dead of a heart attack.
Finding these people early and treating them could save lives. The
test may be especially good for women, who often have few
traditional signs.
Lisa Rosenstock of Madison, in the US state of Wisconsin, is an
example. At age 41, this trim, athletic mom had normal cholesterol
and blood pressure but a troubling family history of heart attacks.
Ultrasound revealed a big clog in the main artery from her heart to
her head.
Her cardiologist, Dr James Stein of the University of
Wisconsin-Madison, put her on medicines to lower her risk of a
heart attack or stroke. He also is leading a study aimed at making
ultrasound testing more common.
"There's a great need for a non-invasive and safe way to
identify people who don't have signs but have risk" of heart
disease, he said.
But there are potential downsides. The mini machines will put
this testing into the hands of a lot more people than those with
the extensive training required to do it properly. Suddenly,
small-town family doctors could be seeing scary-looking artery
buildups and may rush to treat some that may never threaten a
patient's life.
Patients, too, will see these pictures. Some may be motivated to
quit smoking, lose weight or go on cholesterol-lowering statin
drugs. But many also may be treated unnecessarily, and have side
effects from that.
Ultrasounds also are being advertised directly to consumers -
the latest "peace of mind" test like whole-body CT scans and MRIs
for those rich and worried enough to pay hundreds of dollars for
them.
Some drug makers are helping promote ultrasound testing, because
it could lead to more people taking cholesterol pills. Last year, a
group of doctors and imaging experts called for wider screening.
Their opinions were published as a supplement to the American
Journal of Cardiology paid for by Pfizer Inc, which sells the
statin Lipitor.
British-based AstraZeneca PLC is seeking federal approval to
expand marketing of its statin, Crestor, based on ultrasound
testing that showed the drug could prevent artery buildups from
getting worse.
The American Heart Association and other major cardiology groups
say that ultrasound testing with big, conventional machines can
help doctors determine heart risk in certain patients. But they do
not endorse widespread screening with the smaller devices because
evidence of benefit is lacking.
Guidelines from several groups on who should use the small
ultrasound devices and on which patients are expected next
spring.
On balance, many doctors see more promise than peril.
"It's equivalent to a mammogram of the heart," said Dr
Christopher Rembold, a cardiologist at the University of Virginia.
If doctors see something suspicious, they can refer patients to
specialists for more extensive tests before deciding whether or how
to treat it, he said.
Screening involves checking for buildups called plaque and
measuring the thickness of the wall of the main neck artery. Normal
thickness varies by age, race and sex, and charts give doctors
detailed guidance. Too-thick arteries are a sign of higher risk for
heart attack.
Until recently, only ultrasound specialists did these tests,
which were analyzed by a radiologist. That often meant patients
needed another appointment at a hospital or ultrasound center, and
a return trip to their primary doctor for results.
The new portable ultrasound devices are changing that. They
mostly are used in emergency rooms to check for problems with the
heart's valves or pumping capacity, or bulging abdominal arteries
threatening to rupture.
(Shanghai Daily November 14, 2007)