Molecular Imaging News
February 2, 2005
Cardiac Imaging is Underused in Women to Diagnose Disease
American Heart Association
Cardiac imaging methods such as stress SPECT and stress echocardiography work as well in women as in men to accurately diagnose coronary artery disease (CAD). Women at risk for CAD, however, are less often referred for the right tests, according to a consensus statement from the American Heart Association.
The statement was published in the February 1, 2005, special women’s themed issue of Circulation: Journal of the American Heart Association, and presented that day at The State Of The Heart: Go Red For Women news conference in New York City.
The statement also says that current approaches to diagnostic testing may need to be varied when applied to female patients. An ongoing investigation is needed to fully appreciate how women’s hormones affect the vascular system and test results.
Jennifer H. Mieres, MD, chair of the committee that wrote the new statement and an SNM member, said that women should not be assessed with a "what’s good for the goose is good for gander" approach to noninvasive testing. The latest data from heart studies indicate that there are some important gender differences, she said.
"For example, exercise electrocardiogram (ECG), which has been around for a long time, is not as accurate in all women. In women who are able to exercise, it is still useful, but its utility is dependent upon the woman’s exercise capacity."
Mieres is director of nuclear cardiology at Northshore University Hospital in Manhasset, NY, and is an assistant professor at New York University School of Medicine. She is vice-chair of the American Heart Association’s Cardiac Imaging Committee.
"Heart disease continues to be the leading cause of death in women, and when we look at all types of heart disease, coronary heart disease (CHD) is the largest subset of this mortality, claiming the lives of an estimated 240,000 American women each year," Mieres said. Yet, women who are at risk for CHD—sometimes referred to as CAD—often are not referred for appropriate diagnostic testing, perhaps because physicians are more familiar with using imaging studies to evaluate men, she said. The aim of the new statement is to give physicians an easy roadmap for referrals.
Women who have chest pains or other symptoms that suggest CHD but have a normal resting ECG should be referred for exercise treadmill testing—if they are capable of exercise, Mieres said. For women with abnormal resting ECG, or women who are unable to exercise, the referral should be for SPECT imaging or stress echocardiography.
The committee also concluded that women with diabetes "merit special consideration and are included in the current statement as candidates for cardiac imaging because they have an increased risk of cardiovascular death that is up to eight-fold higher than that of non-diabetic women." The committee also noted that women with polycystic ovary syndrome or metabolic syndrome also may be candidates for cardiac imaging. Mieres said that imaging can be done in a number of ways, including stress echocardiography or gated SPECT myocardial perfusion imaging. Computed tomography (CT), magnetic resonance (MR) imaging and carotid intima-media thickness measurements are all listed as new and rapidly developing imaging technologies.
The committee made no recommendation about using CT measurements of coronary calcium—the so-called calcium score. But Mieres said the committee agreed that women with calcium scores of 400 or higher have the same increased risk as men with high calcium scores. They felt there was not enough data to assess the value of adding coronary calcium screening to conventional risk factor assessment. The committee also felt there is not enough gender-specific data to make a recommendation on cardiac MR imaging but felt available data suggest some future role of this technology in diagnosing and assessing risk in women with heart disease symptoms and an intermediate risk of coronary artery disease.
Co-authors of the study include Leslee J. Shaw, PhD; Andrew Arai, MD; Matthew J. Budoff, MD; Scott D. Flamm, MD; W. Gregory Hundley, MD; Thomas H. Marwick, MD, PhD; Lori Mosca, MD, PhD; Ayan R. Patel, MD; Miguel A. Quinones, MD; Rita F. Redberg, MD, MSc; Kathryn A. Taubert, PhD; Allen J. Taylor, MD; Gregory S. Thomas, MD, MPH; and Nanette K Wenger, MD.