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Amanda Jekowsky , American College of
Cardiology, 202-375-6645, ajekowsk@acc.org
January
12, 2009
Making the Link: Contraceptive Hormone
Use and Cardiovascular Disease
Newer formulations may lower risks, more research
is needed
Over 80 percent of women use hormonal contraception at some
point in their lifetime. However, the use of contraceptive
hormone therapies to prevent pregnancy—birth control
pills, patches and vaginal rings—may heighten the risk
of heart problems or stroke in certain women, particularly
those who smoke, are over 35 years old or have existing cardiovascular
risk factors.
As with all medicines, contraceptive hormones must be selected
and initiated upon evaluating the risks and benefits for each
patient, according to a review article published in the January
20, 2009, issue of the Journal of the American College
of Cardiology (JACC).
“As women use these therapies more frequently, and
for longer periods of time, there is an urgent need to better
understand and minimize associated cardiovascular risks,”
says C. Noel Bairey Merz, M.D., F.A.C.C., F.A.H.A., director
of the Women's Heart Center, Cedars-Sinai Heart Institute
and co-author of the study. “Women at high risk for
cardiovascular problems, especially those who smoke, should
consider alternative forms of contraception. Those with other
cardiac risk factors such as hypertension or elevated cholesterol
can consider use with monitoring under the advisement of their
health care provider.”
The impact of reproductive hormones on cardiovascular health
is complex. Low estrogen levels and irregular menstrual cycles
have been found to elevate the risk of coronary atherosclerosis
(the thickening and hardening of the inside walls of the arteries)
and adverse cardiac events (e.g., heart attacks, strokes or
deaths due to heart disease). At the same time, supplemental
estrogen can increase the risk of blood clots, which can lead
to stroke.
According to the authors, while older formulations of contraceptive
hormones can slightly increase blood pressure, newer generation
contraceptive hormone formulations appear to carry lower cardiovascular
risks and are as safe and effective in preventing pregnancy.
However, further study is needed.
“The newer formulations have lower doses of estrogen,
which is safer in terms of lowering the risk of blood clots,”
says Dr. Merz. “They also tend to use a progestagen—hormones
that produce effects similar to those of progesterone—which
are expected not to raise and may even slightly lower blood
pressure.”
Recent data reveal that since 2000 the death rate from cardiovascular
disease has increased in women between the ages of 35 and
44 years compared with decreases in all other age groups.
Research points to higher rates of obesity and smoking and
declines in physical activity, as well as a concomitant increased
use of oral contraceptives among this group of women (from
4 percent to 17 percent) during the same timeframe.
The article provides an overview of clinical studies of risk
and cardiac events in women using contraceptive hormones,
as well as guidelines for prescribing these therapies in women
with existing cardiovascular risk factors (e.g., high blood
pressure, high cholesterol, diabetes). The report also discusses
the impact of hormonal contraception on specific mechanisms
underlying cardiovascular disease, including atherosclerosis,
thrombosis (formation of a clot inside a blood vessel), vasomotion
(blood vessel constriction) and arrhythmogenesis (irregularities
in the heart beat).
“Health care providers must evaluate each woman’s
risk factors, especially those related to cardiovascular health,
prior to starting any contraceptive therapy,” says Chrisandra
Shufelt, M.D., M.S., assistant director, Women's Heart Center,
Cedars-Sinai Heart Institute and co-author of the study. “Although
pre-menopausal women have a much lower risk of cardiovascular
disease, routine screening for potential problems and follow
up is important.”
Drs. Merz and Shufelt report no conflicts of interest.
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The American College of Cardiology is leading the way to optimal
cardiovascular care and disease prevention. The College is
a 36,000-member nonprofit medical society and bestows the
credential Fellow of the American College of Cardiology upon
physicians who meet its stringent qualifications. The College
is a leader in the formulation of health policy, standards
and guidelines, and is a staunch supporter of cardiovascular
research. The ACC provides professional education and operates
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quality care. More information about the association is available
online at www.acc.org .
The American College of Cardiology (ACC) provides these news
reports of clinical studies published in the Journal of
the American College of Cardiology as a service to physicians,
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