Q: Many of my older women patients think they are at much higher risk for breast cancer than coronary heart disease (CHD). How can we raise women's awareness about their risks of CHD and thereby encourage them to take measures to prevent it?
A: All clinicians have to educate women about their vulnerability to CHD and recommend ways to lower their coronary risk. Almost a quarter of a million American women die of CHD each year, compared with 40,000 who die of breast cancer.1 Postmenopausal women have a 31% lifetime risk of dying of CHD, compared with a 2.8% risk each from hip fracture (as a surrogate for osteoporosis) or breast cancer. One in 3 women older than 65 years has clinical evidence of CHD.
Q: Acute myocardial infarction (MI) is underdiagnosed in women far more frequently than in men. What are the chief diagnostic pitfalls?
A: In both sexes, chest pain is by far the most prevalent presenting symptom. But an atypical presentation is much more common in women than in men. Women with MI may describe pain in the neck, arms, back, shoulder, or abdomen. A presentation that involves such diffuse pain can complicate the diagnosis. Generally, however, even such nonspecific symptoms have an acute onset and should not be discounted. A woman may experience such symptoms and not understand their potential ominous significance. If she makes an appointment to see her physician 2 or 3 days later, the acute phase may have passed and the MI may never be diagnosed. Or worse -she may not live to keep that appointment.
Furthermore, a subgroup of older patients of both sexes -many of whom are women with diabetes -may not experience any pain during an MI. They may feel extreme fatigue, shortness of breath, or a sensation of being "totally washed-out." Even in this group, however, the onset of symptoms is relatively abrupt, and patients may therefore go to the emergency department(ED). In this setting, a high index of suspicion among health care professionals is absolutely crucial.
ED physicians sometimes follow the patient's lead and take the wrong diagnostic path. Some women who do not understand the nature of their symptoms will clutch their chests and say, "I'm having indigestion."In contrast, a man with the same symptoms and presentation will say, "I'm having a heart attack," and will be managed appropriately. If we educate women to realize that they are vulnerable to CHD and MI, many more will realize that their symptoms may be far more serious than indigestion.
Q: Does underdiagnosis of MI in women account for the fact that women are also undertreated for CHD?
A: Unfortunately, yes. Women in an ED are treated less frequently than they should be with thrombolytic therapy and less often than men with ß-blockers, aspirin(Drug information on aspirin), angiotensin- converting enzyme inhibitors, and other drugs.3 This is not because physicians choose to undertreat women; it's simply that MI is often not suspected, and therefore urgent ECG and other diagnostic tests are not done. This results in omission or delay of life-saving therapies.
Also, women typically present to the hospital later than their male counterparts following symptom onset. This is true not only with a first MI, but with recurrent MI as well. Delayed hospital admission means that women may miss the window of opportunity for certain interventions, particularly coronary thrombolysis.
Q: Women have worse outcomes than men after treatment for MI. Is this a result of inherent biologic differences, of age at presentation, or other factors?
A: Women aged 60 to 70 years have higher mortality after MI than age-matched men, both during hospitalization and in the first 2 years after the event. It is not yet clear whether this is a function of biologic differences, risk factors, treatment issues, or comorbidity. Women with a first MI are likely to have a higher risk factor burden than men -that is, they tend to have concomitant diabetes, hypertension, and/or dyslipidemia. When we adjust the data for these conditions, the differences in mortality decrease, but the higher incidence of death in women does not disappear. The obvious challenge, then, becomes primary prevention: if we address risk factors earlier and more aggressively, we might significantly reduce women's cardiovascular risk.
Although the absolute risk of coronary events in both sexes increases with age and although CHD is most common in older women, younger women are at risk as well -and these younger women have worse outcomes than their male counterparts after both MI and coronary artery bypass graft (CABG>) surgery. The reasons for this are unclear. Among women younger than 50 years, post-MI mortality is more than twice as high as among men of the same age 4.Following MI, a young woman is also at very high risk for recurrence.
Mortality for men and women after MI is similar among those older than 75 years. Among the very elderly, however, women with MI tend to do slightly better than men. These differences have not been explained. One possible reason for the fact that women generally outlive men is that women seem to incur most of their serious diseases later in life, whereas men are more likely to be afflicted in middle age. Perhaps this is another reason that CHD in women has been neglected: the preponderance of CHD is in elderly women. These women are no longer at the peak of their family or career responsibilities; perhaps they're retired. Their illness is not as visible as in men with CHD, who may be stricken at the peak of their career and family obligations.
Q: Which risk factors for CHD should I be especially concerned about in my female patients?
A: Cigarette smoking and diabetes are strongly associated with an increased risk of CHD in women. Cigarette smoking seems to be a particularly important risk factor in younger women, possibly because smoking is often their major risk factor. Smoking is strongly associated with plaque erosion in premenopausal women. 5More young women take up the smoking habit than any other subgroup. This puts them at greatly increased risk.
Diabetes virtually abolishes the sex-based cardiovascular protection that is presumed in women. Women with diabetes are at much higher risk for MI than diabetic men; their risk is the same as that of women who've already had an MI. Diabetes appears to greatly magnify the adverse effects of other risk factors, such as smoking, hypercholesterolemia, and hypertension.6 Moreover, women with diabetes are more likely to have unfavorable lipid profiles and to be hypertensive and obese. The reasons and the mechanisms have yet to be completely elucidated.