Coronary heart disease (CHD) is the number one killer of women in the United States. Each year, more than 250,000 women die from CHD. But many more live with it. Around the world, 6,400,000 women alive today have a history of heart attack or angina.

The risk factors that predict the onset of CHD in healthy women are well established. But the risk factors for coronary events in women who have CHD are not as well known.

Despite this knowledge gap, effective therapies exist for the secondary prevention of heart disease in women. (The goal of secondary prevention is to prevent a heart attack or worse in women with established heart disease.) And yet, previous studies have suggested that secondary prevention treatments are underprescribed in women.

In a study published in the January 21, 2003 Annals of Internal Medicine , researchers identified eleven factors that increase the risk of heart attack or death from CHD in women with established heart disease. They also found that women with heart disease—particularly those at highest risk for a coronary event—were being undertreated for secondary prevention.

About the Study

The researchers analyzed data from 2763 participants of the Heart and Estrogen/Progestin Replacement Study (HERS).

HERS participants were postmenopausal women, aged 80 years or younger, who had an established history of coronary artery disease (CAD). CAD was defined as having had a heart attack , coronary artery bypass surgery , coronary angioplasty , or evidence that a major coronary artery had narrowed by at least 50%. The women had been randomized to receive hormone replacement therapy or a placebo.

Upon entering the study, all participants reported behavioral risk factors and medical history for CHD. At that time, they underwent physical exams in which physicians measured their blood pressure, cholesterol levels, evidence of heart failure, and other factors.

Over the course of the HERS study, researchers had recorded nonfatal heart attacks and death due to coronary heart disease.

The Findings

Risk Factors

The eleven risk factors for heart attack or death from CHD in women with established CHD included:

Women with five or more of these risk factors were six times more likely to suffer a coronary event each year than women with none of these risk factors (8.7% vs. 1.3%).

Secondary Prevention

Even though all of the participants in the study had established coronary artery disease, half or fewer were taking drugs that have been proven effective for secondary prevention in women. For example, only half of the women who met the National Cholesterol Education Program criteria for lipid-lowering therapy were taking cholesterol-lowering drugs. And only one-third of the women in the trial were treated with beta-blockers . Use of angiotensin-converting enzyme (ACE) inhibitors and aspirin was also lower than it should have been.

Strikingly, the women with the highest risk for recurrent coronary events were the least likely to be treated with aspirin or cholesterol-lowering medications.

How Does This Affect You?

The reasons for the suboptimal management of women with CHD in this study are not clear, and without a direct comparison to men, the researchers cannot say whether men would have been managed differently. Historically, however, women with symptoms or risk factors of CHD have not been managed as aggressively as their male counterparts.

This study identifies eleven factors that, particularly in combination, significantly increase the risk of coronary events in women with known heart disease. It also highlights the inadequate use of treatments that have been shown to reduce the risk of subsequent coronary events in women. Based on these results, physicians should identify these risk factors and promote greater use of these treatments. If you are a woman with a history of CHD, ask your physician whether one or more secondary prevention treatments may be appropriate for you.