Gender Disparities in Women's Cardiovascular Disease Care

Introduction: Cardiovascular Disease as a Women's Health Issue

One in three women in the United States suffers from cardiovascular disease, also known as coronary artery disease (CAD). This fact has prompted both the lay and scientific communities to recognize coronary artery disease as a significant health issue for women. Progress has been made in defining the incidence of heart disease in women and describing gender-specific differences related to cardiac anatomy and physiology. In addition, both traditional and gender-specific coronary risk factors have been studied, along with the reliability of conventional cardiac diagnostic tests in women. However, a great deal remains unknown because women have largely been excluded from past research on the diagnosis and treatment of heart disease. In particular, women's cardiac symptoms may differ from the classic presentation seen in men.

Coronary artery disease kills more women than all cancers combined, yet their diagnosis can be missed or delayed. Detection of CAD at an earlier stage in women may result in earlier recognition and treatment, and subsequently lower associated morbidity and mortality rates. The purpose of this evidentiary review is to examine the effect of gender on the recognition, treatment, and outcomes of coronary artery disease in women. For example, women experience shortness of breath on exertion, abdominal pain, and back pain, while men more often present with classic midsternal chest pain. Clinical outcomes of women receiving standard medical and surgical treatments remain another area of uncertainty (Shirato & Swan, 2010).

The development of evidence-based medicine has led to daily clinical practice being increasingly based on the results of large, randomized, multicentre studies aimed at improving the prevention and treatment of disease in both sexes. However, given the differences between the two sexes regarding the incidence of cardiovascular disease, as well as the effectiveness of preventive and therapeutic measures, the lesser representation of women in large studies creates a significant problem. It is telling that in clinical studies of coronary artery disease or stroke published between 1997 and 2006, women made up only 27% of the study population, and in many of those studies results were not reported separately by sex. This represents a significant gap in data concerning cardiovascular diseases in women.

Synthesis of the Literature

Additionally, numerous studies have shown suboptimal rates of coronary heart disease (CHD) therapies among women. Once women enter the health care system, they are likely to receive fewer medical and interventional procedures, such as thrombolytic therapy or rescue coronary angioplasty. Treating women and men differently may be explained, in part, by difficulties in diagnosis that arise in women with CHD — particularly because chest pain in women may often be considered benign. However, treating women differently when there is no clinical reason to do so, such as in the setting of acute myocardial infarction (MI), represents an apparently unjustified sex-dependent approach (Pyrgakis, 2010).

Randomized trials have shown that low-dose aspirin decreases the risk of a first myocardial infarction in men, with little effect on the risk of ischemic stroke. Because similar data in women were scarce, a randomized controlled trial with low-dose aspirin was conducted in a female population (Ridker et al., 2005). The study randomly assigned 39,876 initially healthy women aged 45 years or older to receive 100 mg of aspirin on alternate days or placebo, and then monitored them for 10 years for a first major cardiovascular event — defined as nonfatal myocardial infarction, nonfatal stroke, or death from cardiovascular causes.

During follow-up, 477 major cardiovascular events were confirmed in the aspirin group, compared with 522 in the placebo group, for a nonsignificant reduction in risk of 9%. There was a 17% reduction in the risk of stroke in the aspirin group compared with the placebo group, owing to a 24% reduction in the risk of ischemic stroke and a nonsignificant increase in the risk of hemorrhagic stroke. Compared with placebo, aspirin had no significant effect on the risk of fatal or nonfatal myocardial infarction or death from cardiovascular causes. In this large primary-prevention trial among women, aspirin lowered the risk of stroke without affecting the risk of myocardial infarction or death from cardiovascular causes, resulting in a nonsignificant finding with respect to the primary end point.

Psychological Factors and CAD in Women

The Women's Ischemia Syndrome Evaluation (WISE) study provided an opportunity to determine possible relationships among hostility, angiographic CAD, and anginal symptoms in a large sample of women. A previous report from the WISE study showed that hostility and anger are positively related to CAD risk factors and that hostility was a positive predictor of CAD events in this sample. To determine the relationship of psychological characteristics to initial CAD diagnosis, the study compared (1) anger and hostility in symptomatic women with and without angiographic CAD, and (2) the relationship of measures of anger and hostility to anginal and cardiac-related symptom reports and functional status in the WISE sample.

Data were collected from 636 women with suspected CAD referred for diagnostic angiography in the WISE Study. CAD was assessed as the angiographic presence or absence of disease (defined as 50% stenosis in any epicardial coronary artery). Hostility, anger, angina, symptoms, and functional status were assessed using the Cook-Medley Hostility Inventory, the Spielberger Anger Expression Scale, cardiovascular symptom history, and the Duke Activity Status Index.

Logistic regression revealed that anger-out — that is, aggressive behavior expressed in response to angry feelings — was independently associated with the presence or absence of angiographic CAD. Among women with suspected CAD, anger-out scores were associated with the presence of angiographic CAD. Anger and hostility traits were also associated with increased symptoms, particularly nonanginal chest pain in women without angiographic CAD. The relationships among psychosocial factors, cardiac symptoms, and angiographic CAD are potentially important in the management of women with suspected CAD (Krantz et al., 2006).