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.
There are a few aspects of heart failure that pertain especially to
women. These include the causes of heart failure in women, the age of
women who develop heart failure, the symptoms caused by the heart
failure, and how doctors treat heart failure in women. If you’re a woman
who has heart failure, you should make sure you know these 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.