Heart Disease in Women

Happening Issue 65 Jul, 2010

Cardiovascular death rate in developed nations is decreasing due to advanced treatment technology.  However, the same cannot be said for women.  Due to an aging population, the death rate is in fact increasing in them. Coronary heart disease and stroke are the two most common causes of death in women in most developed countries.  Cardiovascular death claims almost 55% of all death in women which is more than all forms of cancer deaths combined or simply one in two women would die of heart disease compared to one in twenty five who would die of breast cancer.  The media often erroneously reports breast cancer as being the leading cause of death in women.  This misconception has to be addressed as breast cancer claims only one tenth of lives compared to heart disease in women.

It’s of paramount importance to bring increased awareness of heart disease in women because almost 65% of deaths occur in those with no previous symptoms.  Women during fertile age have a lower risk of cardiac events but this protection fades away after menopause. The response to therapy may also differ in women because of endogenous hormone levels, lower body weight and higher fat proportions.  There have been reports where aspirin tends to have protective effects for stroke in women but not for heart attacks.

The major risk factors for coronary heart disease in women are smoking, hypertension, diabetes, obesity, sedentary lifestyle, poor nutrition and dyslipidemia.  Among these risk factors, gender differences have been noted in diabetes and dyslipidemia.  Age is an important risk factor for both men and women but women are on average ten years older when they develop coronary heart disease.  Smoking is the leading risk factor with more than 50% of heart attacks being attributed to tobacco.  We have to realize that cessation of smoking brings risk of heart disease to the non-smokers level within 3-5 years.  It’s distressing to know that the demographic pattern shows increase in younger women smoking worldwide when the male counterparts show a decline.  Moreover, the use of oral contraceptives in young women who smoke, further increases the risk.

More women than men develop hypertension as they get older and we know that control of hypertension reduces the risk of both stroke and heart disease.  Data reveals that more than 50% of women after the age of 55 have high cholesterol levels and that there are significant treatment benefits for post-menopausal women with dyslipidemia.

Risk of coronary heart disease mortality associated with diabetes is again higher in women than men.  This gender based difference may be due to a particular deleterious effect of diabetes on lipids and blood pressure.  Obesity and sedentary lifestyle are parallel risk factors for both men and women.

Oral contraceptives raise blood pressure and pose additional risk in women who smoke.  They do not increase the risk of heart attack on women who do not have other risk factors associated with heart disease.  There is a threefold increase in stroke for those taking pills, which increases to tenfold for smokers.  It has been found that low dose pills containing less than 50ug estrogens are safe except in smokers.  Also, lifetime costs are significantly higher for women than for men of the same age group (over 65) when the majority of strokes occur. Women also have greater tendency to suffer from atypical chest pain or to complain of abdominal pain, nausea, fatigue and shortness of breath.  As women tend to have heart attacks later in life than men, they often have other diseases that mask cardiac symptoms.  Coronary heart disease is more often of the silent type in women.  Also, some of the diagnostic tests used to diagnose heart diseases like the TMT (treadmill test) are less accurate in women. Moreover, HRT (hormone replacement therapy) may induce false positive results.  There is also an increased chance of SVD (single vessel disease) being missed out in women. Similarly, breast tissue may result in false positive results with even recent diagnostic investigations like myocardial perfusion thallium test. However, SPECT (computed CT), calcium scoring and exercise ECHO are valuable diagnostic tools in women.  Thus, women with heart disease tend to be both under investigated and under treated when actually the female gender is strongly associated with increased risk for heart disease.  The one-year post heart attack mortality risk is 41% in women compared to 27% for men.  Similarly, in hospitals, mortality rate is 13% for women compared to 7% for men.  By and large, women have smaller coronary blood vessels and intervention procedures like angioplasty and by-pass surgery show higher adverse effects like local bleeding and vessel dissection during and immediate post procedures in women.  Thus, women with coronary heart disease have most to gain from using risk reduction strategies.

HRT (hormone replacement therapy) is controversial to say the least.  Uniil recently, affluent women used to be prescribed hormones routinely at menopause for symptom relief, osteoporosis and cardiac protection.  However, the latest research data has not shown any remarkable benefit for the heart.  Thus, HRT is not solely prescribed for cardiac protection.  Women who elected to take hormones were educated and thus had favorable levels of blood pressure, cholesterol, insulin, body weight, alcohol intake and physical activity.  Thus, the amount of estrogen protection could be exaggerated.  It has also been shown that most risk factors associated with HRT increases with therapy duration.  Some are of the view that short term relief of menopausal symptoms with HRT will be worth the small absolute increase in risk for breast cancer, emboli and heart disease for many women provided the therapy is used for the shortest period of time necessary to successfully treat menopausal symptoms.  However, until more definitive data is available, HRT should be based on a woman’s baseline risk for heart disease, weighing the potential net benefit on overall health.

In conclusion, all female groups should acknowledge the gender difference in heart disease.  Medication has a role in primary prevention in selected groups.  However, major emphasis should be placed on lifestyle modifications, smoking, diabetes, obesity, diet and physical activity.  Also, awareness of heart disease in women including the delayed onset on them needs to be emphasized at different forum levels of education/seminar programs.  As I write this article, international trials such as WTH (women take heart) & WISE (women with ischaemia syndrome evaluation) have just been released in March where they have emphatically concluded that women must aggressively manage their risk factors if they are to live a longer, healthier life.

Dr. Baral is the consultant cardiologist at Ganga Lal Heart Institute & NORVIC Hospital. Ph: 4436612/4437610, Mobile: 98510-53577