What Every Woman Should Know About Heart Failure
Heart failure is a major cause of
disability and death in both men and women. Over the last few decades,
significant resources have been dedicated to understanding what causes
it, and to developing better treatments for it. And significant strides
have been made.
One thing that we have discovered is that
many aspects of heart failure differ between men and women. For both
sexes, heart failure comes about as a result of coronary artery disease,
or chronic hypertension (high blood pressure). Usually, the symptoms of
heart failure, and the treatment of it, are similar in men and women,
but there are some differences.
Causes of Heart Failure That Are Especially
Important in Women
Hypertension
The most common medical problems that lead to heart failure are
hypertension and coronary artery disease (CAD). Of these, hypertension
is the leading cause in both sexes. However, hypertension is
substantially more likely to cause heart failure in women than in men.
Hypertension increases the risk of developing heart failure by 300% in
women, but “only” 200% in men. Among women with heart failure,
hypertension is the underlying cause in 59% of cases in women, compared
to 39% in men. So while it’s important for anyone with hypertension to
be treated adequately, it’s even more so for women.
Diastolic Heart Failure
In diastolic heart failure, cardiac function deteriorates because the
heart muscle becomes stiff, and the heart has difficulty filling with
blood. As a result, the amount of blood that is pumped around the body
with each beat is significantly reduced (making you tired and exercise
intolerant), and the blood that is unable to fill the heart “backs up”
into the lungs (producing pulmonary congestion). While this condition
can occur in anyone, it’s more prominent in women than men.
Diabetes
Diabetes by itself doesn’t cause heart failure, but people with diabetes
have a high incidence of conditions that do, such as CAD and
hypertension. Furthermore, for reasons that are not understood, women
with diabetes are twice as likely to develop heart failure than men with
diabetes.
Obesity
Women who are obese have a high risk of developing heart failure that is
50% higher than women who are normal weight. Obese men also have a
higher risk of heart failure, but the excess risk from obesity is not
thought to be as high in men as it is in women.
Chemotherapy
Certain drugs used for chemotherapy can cause cardiac toxicity that can
lead to heart failure. Women tend to be exposed to these chemotherapy
agents a lot more often than men, in particular, for the treatment of
breast cancer.
Stress Cardiomyopathy
Stress cardiomyopathy, also known as “broken heart syndrome,” is a form
of sudden, severe heart failure that is triggered by extreme emotional
trauma. While this condition can be found in either sex, it’s far more
common in women, and may be related to microvascular angina – a
condition that is more common in women.
Age of Women with Heart Failure
Women who develop heart failure usually do so at an older age than men
who develop heart failure. Unfortunately, as past clinical trials tended
to exclude people over the age of 65, this means that relatively little
data has been collected from clinical trials showing how older women
with heart disease respond to treatment. Recently, researchers have been
including a sufficient number of elderly women in their clinical
trials, and this shortcoming is slowly being rectified.
Symptoms of Heart Failure in Women
As mentioned previously, the symptoms of heart failure in men and women
are largely the same – gradually worsening fatigue, dyspnea, exercise
intolerance, and edema. However, some scientific studies suggest that
women with heart failure are more likely to experience significant
dyspnea and edema than men.
Response to Treatment in Women
As stated, clinical trials evaluating the treatment of heart failure
have tested considerably more men than women. Nevertheless, the data
that is available strongly suggests that women with heart failure
respond to treatment just as favorably as men.
Differences in How the Hearts of Men and Women Respond to Cardiac Stress
In studies with animals and in clinical trials, evidence is accumulating
to suggest that the heart muscles of men and women react differently to
various kinds of physiologic stress. Several animal studies have looked
at how the hearts of males and females react to experimental conditions
that have been designed to produce heart failure. These studies have
consistently shown that female cardiac muscle tends to respond by making
various adaptions that help to prevent heart failure, whereas male
cardiac muscle fails more quickly.
Clinical trials on people have shown the same thing. In those with
aortic stenosis (a narrowing of the aortic valve, which greatly
increases the pressure and stress in the left ventricle), premenopausal
women develop cardiac hypertrophy (thickening of the heart muscle) more
readily than men. This hypertrophy reduces wall stress, delays the onset
of dilated cardiomyopathy and thus, reduces the risk of heart failure.
Interestingly, postmenopausal women do not show this same adaption, and
they develop heart failure at the same rate as men, suggesting that
female hormones may play a part. However, clinical trials evaluating
this have given contradictory results.
These findings may help to explain why women develop heart failure later
than men, and why women who have heart failure tend more often to have
diastolic heart failure than men.
Still, having said this, all we can say
with confidence at the moment is that the hearts of men and women
respond somewhat differently to various kinds of physiological stress.
Outcome of Heart Failure in Women
Evidence suggests that, even though they usually develop heart failure
at a later age than men, women with heart failure tend to survive longer
than men.
This relatively good news for women who have heart failure is
counter-balanced by some clinical evidence that suggests that doctors
tend to be less aggressive when treating women with heart failure when
compared with men. One reason for this may be that women may tend to
minimize their cardiac symptoms when talking to their doctors. Those
doctors who do not push their patients for a full accounting of symptoms
may not be aware of just how sick their female patients actually are.
Therefore, it’s very important for anyone, male or female, who has
symptoms of heart failure – especially worsening fatigue or dyspnea – to
make sure their doctors are aware of it. But, maybe women need a little
extra reminding of how important it is.