A new look at heart disease in women
If a “standard approach” to identifying and diagnosing
heart disease exists, it goes something like this: You notice pain
or tightness in your chest. Your doctor sends you for an exercise stress
test. As you walk on the treadmill, the electrocardiogram shows that
part of your heart isn’t getting enough oxygenated blood. Next
stop: angiography. This special x-ray shows that cholesterol-filled
plaque has narrowed one of your coronary arteries by 75% or more. Treatment
This sequence, it turns out, doesn’t work nearly as well in women
as it does in men. Many women don’t have the strength or endurance
to complete an exercise stress test. And a whopping half or more of women
who have alarming stress tests have what look to be clear coronary arteries
on an angiogram.
In the past, such women were told not to worry; this wasn’t really
dangerous heart disease. Ongoing work from a study of women with chest
pain is replacing this with a more urgent message: There’s
a stealth form of heart disease that doesn’t show up on angiograms,
and it might be just as bad for you as the traditional type.
Doctors have traditionally used a one-size-fits-all approach to identifying
and diagnosing heart disease. In this view, women often lack the “classic” signs
of reduced blood flow to part of the heart, a condition known as ischemia.
They have “false-positive” stress tests nearly five times
as often as men.
This is gradually giving way to the realization that ischemia can have
different causes and different effects in women and men.
Inside arteries, LDL (bad) cholesterol particles work their way into
the inner lining of an artery. White blood cells migrate to these deposits
and gorge on LDL particles. Over time, as the cycle is repeated, the
mixture of LDL and dead white blood cells expands and bulges into the
artery. Cardiologists call this bulge a plaque. The more a plaque pushes
into the blood vessel, the less room there is for blood flow.
But chest pain or pressure can’t always be traced to a bulging
plaque. Between 50% and 60% of women, and about 20% of men, have chest
pain or other symptoms when they are active or stressed even though an
angiogram shows no plaques big enough to limit blood flow through the
This condition has been attributed to spasms of the coronary arteries,
heightened sensitivity to pain in and around the heart, or problems with
small arteries that can’t be seen on an angiogram.
To get a better handle on the origins and effects of chest pain, researchers
started the WISE study back in 1996. They are tracking nearly 1,000 women
who had chest pain or other symptoms of a blocked coronary artery but
whose angiograms showed no plaques large enough to limit blood flow.
Here are some eye-opening results:
Greater hazard. Data from studies show that women with
coronary microvascular syndrome continue to have symptoms that disrupt
their lives and are at greater risk for a subsequent heart attack or
stroke, and have a poorer quality of life.
Outward expansion. In many women and some men, plaque
expands outward, away from blood flow. Seen from the inside, the artery
looks bulge-free and fine.
Size matters. Plaque can build up in coronary arteries
that are too small to be seen on an angiogram. Problems in these smaller
arteries could limit blood flow to the heart.
Endothelial function. In some women with coronary microvascular
syndrome, a malfunction in the endothelium prevents coronary arteries
from opening up and delivering more blood to the heart when needed, which
can cause ischemia.
Beyond the stress test. Some women don’t have
the strength to do a full exercise stress test. An incomplete one doesn’t
yield useful results. The researchers show that answering simple questions
about the ability to climb stairs, do housework, have sex, can help determine
who is a good candidate for an exercise stress test and who might be
better off with other tests.
Early warning. In the WISE study, the early onset of
high systolic or pulse pressure was linked with higher chances of having
significant coronary artery disease.
Anemia. Women with anemia were more likely to have
had a heart attack or stroke or to develop heart failure.
This research has raised many questions, but one message is crystal
clear: If you have chest pain or other worrisome symptoms when you exercise
or are under stress, clean arteries don’t necessarily mean your
heart and arteries are fine. If your doctor dismisses you or your symptoms,
it may be time to dismiss your doctor.
July 2006 update
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