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Heart disease is the leading cause of death among American women.
Yet recent surveys indicate that many women continue to underestimate
the threat of heart disease, and continue to hold misconceptions
regarding which lifestyle interventions are most beneficial. In
part to amend this situation, the American Heart Association recently
released updated guidelines for the prevention and treatment of
heart disease in women. Sean Henahan talked to the director
of the group that formulated the new AHA guidelines, Lori Mosca
MD, MPH, PhD, about how and why they were created and what role
they might play in improving public health. Dr Mosca is the Chair
of Preventive Cardiology at New York Presbyterian Hospital.
Q: Would you give us some background about the new AHA guidelines
for the prevention and treatment of heart disease in women? What
was the rationale for preparing them?
A: Cardiovascular disease claims the lives of more than half a
million women in this country every year, more than all types of
cancers combined. That is one death every minute. And yet our surveys
tell us that few women are aware of the degree of risk posed by
heart disease.
There have been a lot of important advances in the treatment of
heart disease in recent years. Previous guidelines for the prevention
and treatment of cardiovascular disease have been based primarily
on studies that involved men. We wanted to have a set of guidelines
that we could be confident would offer the best current information
on women in particular. Moreover, it has become clear from studies
conducted in past five years that women are not getting the same
preventive and therapeutic cardiovascular care that men are. We
wanted to close that treatment gap. We wanted to make sure that
we used reliable data to support preventive intervention in women.
Another rationale for creating the guidelines is exemplified in
the recent Women's Health Initiative (WHI) study findings regarding
hormone therapy. The study was just halted by the National Institutes
of Health following the finding that hormone replacement therapy
was not, as had been believed, preventing heart disease in post-menopausal
women. This was a huge surprise because thousands and thousands
of women had been receiving hormones to prevent heart disease, when
we really didn't have quality of evidence to support that approach.
This showed how some preventive interventions in women had became
standard of care before we really had the scientific proof that
we needed to make such strong recommendations.
Shutting down the estrogen-only arm of the WHI was the final nail
in the coffin for hormone therapy. But there is good news as well.
We now have a set of guidelines that are clear about what experts
have documented will prevent heart disease and what will not. The
guidelines assign a class III recommendations to hormone therapy,
that is considered to be not useful or effective and potentially
harmful.
Q: Could you tell us something about the guidelines were developed?
A: Under the auspices of the American Heart Association, we formed
a team of 27 recognized authorities in different areas of heart
disease. The researchers searched the world literature of the past
100 years, and systematically analysed the data from general studies,
also looking at subgroup analysis of women. The team identified
more than 7000 articles. They graded the articles as to quality
of evidence that would used to support any subsequent recommendations.
The team also developed a generalizability index, to determine likelihood
that research done in men would apply to women. This formed the
basis for a series of recommendation graded as Class I, Class II
or Class III <see table>. The end result is hat physicians
now have a tool for calculating a woman's ten-year risk of having
a heart attack or stroke, along with a series of recommendations
for individualized treatment.
Q: Let's talk about prevention. We are always hearing about
the growing obesity epidemic in this country. Many people seem to
realize the importance of losing weight, but it seems that lot more
of them are going for the high protein, high fat Atkins diet approach,
than the low fat heart health diet recommended by the AHA. Are you
concerned by this?
A: Yes, I'm very concerned. Even though it may be associated with
temporary weight loss, there is absolutely no evidence that the
Atkins diet would prevent heart disease. I think a person that follows
the Atkin's diet is likely to end up as a thin corpse. There is
just no way that eating that amount of fat is going to be good for
your coronary arteries. There will probably never be a randomised
trial of the Atkins diet versus the AHA diet because it would be
unethical to feed people a high fat diet. We have known for decades
that societies that eat high fat die at higher rates of heart disease.
We also know that following the basic guidelines of the AHA diet
is a good step towards a heart healthy lifestyle.
Q: We've known since the 1960s that lowering blood pressure
in hypertensive patients reduced the risk of heart attack and stroke.
We've also learned that lowering cholesterol has similar effects.
Are these interventions equally useful for men and women?
A: There is not a gender difference in the treatment of high blood
pressure or high cholesterol. There is ample data to support treatment
of both men and women. The trends we saw when we looked at the benefits
of cholesterol and blood pressure lowering therapy indicated that
they provided equal or potentially greater benefit in women.
Q: The new guidelines do differ somewhat from the men's guidelines
when it comes to the use of long-term aspirin therapy to reduce
the risk of heart attack. Tell us about that.
A: Aspirin is a situation where, in some cases, aspirin therapy
may be more harmful for women than for men. That may be because
women are more likely to have a hemorrhagic or bleeding type of
stroke. Women are also more likely to have uncontrolled hypertension,
which also puts them at risk for a hemorrhagic stroke. We are more
conservative in women because the risk/benefit ratio differs from
what we see in men. The aspirin recommendations are the best example
of how the guidelines take a more personalized approach to treatment.
We recommend that women be stratified in high risk, intermediate
risk, and lower risk categories. Depending on their risk level,
we then make a recommendation about how aggressive to be with preventive
therapy. High-risk women, all should use aspirin therapy unless
otherwise contraindicated, at lowest dose possible, one 80 mg baby
aspirin per day. The data are quite good for that approach. In the
lower risk category, we make the opposite recommendation. We suggest
that women in that group do not use aspirin therapy for prevention
of heart disease, because the potential for side effects might outweigh
any benefit, which is still unproven at this point. For women at
intermediate risk, we suggest, the physicians individualize the
treatment based on the woman's risk for heart disease and stroke,
including the risk of bleeding from hemorrhagic stroke, or bleeding
from the gastrointestinal tract.
Q: Your own research suggests that women continue to hold some
unusual ideas about lowering their risk for heart disease, don't
they?
A: We did a national survey of women's awareness of heart disease.
We were happy to see that most of the women surveyed appreciated
the value of exercise, weight loss and stress reduction for reducing
heart disease risk. However, we also saw that many women believed
that complementary and alternative medicine approaches such as antioxidant
vitamin supplementation and aromatherapy could also lower risk.
There are a lot of myths out there. However, our review found no
evidence to support the value of antioxidant vitamin supplements,
and there have been no reliable clinical trials with aromatherapy.
Again, this was the rationale for creating the guidelines- we wanted
to make sure that we were very clear about the available evidence
to support different preventive strategies.
Q: By now most people should be at least somewhat aware that
lifestyle modification, such as quitting smoking, moderating alcohol
consumption and maintaining a health weight all contribute to a
longer, healthier life. Yet it doesn't seem like a lot of busy doctors
take the time to counsel their patients about this. What are your
thoughts?
A: Lifestyle modification has been, is and always will be the primary
method for prevention of heart disease. Our panel gave this a class
I recommendation, our strongest recommendation. It has importance
for prevention of heart disease regardless of how it affects your
blood pressure or cholesterol level. There are so many good things
about diet and exercise that you can't measure in terms of risk
factors. If I were to write a prescription for the perfect drug,
one that improves blood reactivity, lowers blood pressure, cholesterol,
and heart rate, all with minimal side effects, that perfect drug
would be exercise. The problem now is that less than 20% of doctors
counsel women about lifestyle maneuvers in primary care practice.
Women need to be proactive about their own lifestyles and they need
to talk to their physicians about what the risk factors are, what
their goals are and how they are going to reach those goals.
This interview was conducted on March 2nd, 2004.
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