Empire Health Services and Spokane Cardiology PS are participating in a national study to compare two methods of diagnosing coronary-artery disease in women.
Dr. Janice Christensen, a cardiologist with Spokane Cardiology and lead investigator in the study here, says the goal of the trial is to identify the better of the two ways to detect heart disease in women and ultimately to lower the mortality rate for women from the disease.
Over the past 20 years, the mortality rate for women with coronary-artery disease hasnt declined as quickly as it has for men, she says.
Both of the diagnostic tests being studied put stress on the heart through physical activitytypically by having women walk briskly or run on a treadmillthen gauge how the heart responds to the increased activity.
One method is the electrocardiogram, which records electrical activity in the heart and is considered the standard test used currently to detect coronary-artery disease.
The second method, an alternative to the electrocardiogram, is whats known as single photon emission computerized tomography, or SPECT. Vicki Shumaker, clinical research coordinator at Empire Health, says that with the SPECT test, a small dose of radiation is injected into a patients bloodstream before the patient exercises, and scans of the patients heart are taken before and after exercise. If heart disease is present, Shumaker says, the test will show a different blood flow pattern in the heart when its stressed, compared with when its beating normally.
The trial is being called the WOMEN study, with the acronym standing for What is the Optimal Method of ischemia Evaluation in womeN, and is being commissioned by a group of hospitals and medical schools, including Emory University and the Mayo Clinic. The study isnt sponsored by a drug company, so the pursuit is more academic in nature, Christensen says.
Deaconess Medical Center, which is owned by Empire Health, is one of 50 sites nationwide participating in the study, in which a total of about 1,000 women will be enrolled over a one-year span that started last fall. Deaconess enrolled its first patient in the study in September and has enrolled four patients to date. At least 15 women are expected to be enrolled here, Christensen says. Those women will be followed for two years after the time they enroll, she says.
Shumaker says women who havent suffered a heart attack or stroke, but are experiencing chest pain and are considered to have an intermediate or high likelihood of coronary-artery disease, are eligible for the study.
The SPECT test has been available for a number of years, but is more expensive to perform than an electrocardiogram, which is the test screening recommended by the American Medical Association for heart disease in both men and women, Christensen says.
Some physicians, however, believe the SPECT test is more effective at identifying heart disease in women.
Studies have shown that up to 40 percent of women who take an electrocardiogram cant get their heart rate high enough to record a desirable reading, which can cause the test to be inconclusive or misleading, Christensen says. This occurs because women who have heart disease often show their first symptoms later in life than male victims of the disease and often are obese or have orthopedic problems, which limit their physical abilities, she says.
Also, estrogen can alter the results of an electrocardiogram, causing readings that suggest heart disease when none exists, she says. Studies have shown a wide range in false-positive rates for electrocardiograms in women, with one study finding as high as 60 percent of readings were erroneous, Christensen says.
The SPECT procedure has false-positive rates of between 20 percent and 30 percent due to shadows on heart scans caused by breast tissue, Christensen says.
Both technologies, however, have improved in recent years, and false positives are on the decline, she says.
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