On World Heart Day today, a look at the cardiac risks women face too
Three decades ago, while I was undergoing cardiology training, rarely did a case of a woman with a heart attack present itself. Various studies showed that the ratio of men and women affected was 5:1. However, the situation is changing and that gap seems to be narrowing.
That women are protected from heart attacks and require higher risk factor burden for disease development is a myth from the past. It may be true that the overall prevalence of heart attacks is lower in women than in men and the age of presentation is later. However, women above 70 with heart disease outnumber men. This may be due to increased general longevity, with the absolute number of elderly women with heart attacks being higher as a consequence. Risk factors
The usual risk factors such as diabetes mellitus, hypertension, abdominal obesity, high cholesterol levels and psycho-social stress are common to men and women. However, lack of exercise and premature menopause, either natural or surgically caused, have a bearing on the development of heart attacks in women. Fortunately, smoking is not a major risk factor in women as yet in India.
Diabetes takes away the so-called ‘female advantage’, or the natural protection present in women of child bearing age. High blood pressure affects men and women equally. The Inter Heart study showed that abdominal obesity, increased waist-hip ratio and high levels of cholesterol are more common in women with heart disease. A family history of premature heart attacks also has a high preponderance among those with heart disease in both sexes.
It has been observed that women have fewer obstructive blocks in blood vessels supplying the heart (coronary arteries) and that the caliber of vessels is smaller compared to men of the same age. This makes it difficult to manage heart attacks in women by means of balloon angioplasty or coronary artery bypass graft surgery. It has also been shown that diabetic women with major vessel block (Left Anterior Descending artery) are at a high risk of recurrence of blocks (restenosis) after angioplasty. Women have more procoagulant (clotting) potential than men, as per a Scottish study.Symptoms
Women fail to recognise symptoms, and being usually busy with their daily chores or caregiver duties, delay seeking medical help. Women do not exercise regularly and are less compliant with preventive medications such as aspirin and cholesterol lowering statins.
Research from the last decade has revealed gender specific differences in the presentation, manifestation and diagnosis of heart attacks. Sixty four per cent of women who die suddenly of heart attack did not have the classic warning symptoms, as against only 50 per cent of men with such presentation.Limitations
Exertional symptoms have lower predictive value in women than in men. Women have poor effort tolerance and are apprehensive and anxious and do not reach the expected target heart rate during a stress test of the heart. This affects the diagnostic accuracy of the stress test and leads to higher rates of false positive (>30 per cent) test results.
Epidemiological data have established a link between menopause and higher heart attack incidence. Female hormones like oestrogen appear to play a protective role in premenopausal women as compared to age matched men. Observational studies showed the benefit of hormone replacement therapy (HRT) in preventing cardiac events in postmenopausal women (primary prevention).
However, two mega studies (Women’s Health Initiative and Million Women Study) showed an increased risk of breast, uterine and ovarian cancers with HRT, without any significant benefit of heart attack prevention. The use of HRT for a short period in the management of menopausal symptoms is, however, approved. None of the major studies with HRT showed any benefit for the prevention of major adverse cardiovascular events even in those already diagnosed with heart disease (secondary prevention). Currently HRT is not recommended for either primary or secondary prevention of ischemic heart disease (IHD).Post-menopausal symptoms
A study presented at the American Heart Association’s cardiovascular disease, epidemiology and prevention conference in Colorado concluded that severe menopausal symptoms may be associated with increased risk of IHD. Data were collected among 5,600 women between the age of 46 and 57 regarding high blood pressure and cholesterol levels. Women with a history of flushing and night sweats had higher levels of blood pressure and cholesterol and higher incidence of heart attacks in a 10-year follow up. This risk of heart disease was attributed to declining oestrogen levels during menopause.
The conclusions are the following: There is a gender bias in diagnosing and investigating heart attacks. One should not underestimate IHD risk in women. There is no reason for gender specific treatment once heart attack is diagnosed. Women with heart disease must be treated as aggressively as men. Women should strictly adhere to lifestyle modifications and be compliant with medications. And, HRT is not recommended for the primary or secondary prevention of heart attacks.
Dr. I. Sathyamurthy is an interventional cardiologist and Director, Department of Cardiology, Apollo Hospitals, Chennai. He received the Padma Shri in 2000 and the Dr. B.C Roy National award in 2001
7 months ago