Women with Heart Disease Could Benefit from Simple Echocardiography Test

Heart disease is the leading killer of women in the United States, but echocardiography testing methods being developed by researchers at the St. Louis University School of Medicine are giving doctors new tools in predicting life-threatening heart problems in women between the ages of 49 and 75.

"Our research is extremely important because women in this age group are historically underdiagnosed, and by detecting problems earlier, we can help prevent heart attack or death and extend these women's lives," says Melda S. Dolan, M.D., associate professor in the division of cardiology at Saint Louis University School of Medicine.

In conducting their research, the St. Louis team worked with 421 diabetic women in the target age group. The women underwent dobutamine stress echocardiography, a type of stress test that the researchers found to provide valuable information that could help doctors predict future fatal heart problems.

What makes dobutamine stress echocardiography tests different is that they are done without exercise. In traditional echocardiography tests, patients run on a treadmill to increase their heart rate.

The dobutamine stress echocardiography tests use ultrasound technology to scan the hearts of patients who have been injected with a drug that makes the heart beat faster. The tests determine if the patients have abnormalities of the heart wall.
"Women with diabetes and other clinical risk factors, such as smoking, obesity and a family history, are more likely to have heart disease or die from it," says Dolan. "Dobutamine stress echo tests serve an important role in predicting heart attacks or cardiac death in these higher-risk women."

Dolan said that although history of congestive heart failure and previous heart attacks were clinical predictors for the patients, the dobutamine stress echo tests were also beneficial in predicting cardiac events. When the research team followed up with patients two years after the initial tests, they found that 23 had died from cardiac events and 54 had experienced heart attacks.
"The rate at which the patients experienced cardiac death or heart attacks was higher in patients with positive stress tests for ischemia - a decreased supply of blood to the heart - than in those who had negative tests," Dolan says.
Dolan and her team also conducted a study of 1,404 patients who underwent preoperative dobutamine stress echocardiography to determine if they had ischemia.

"In the medical community, it is common to believe the heart rate must be at least 85 percent of the maximal heart rate," Dolan said. "However, we found that a negative dobutamine stress test without abnormalities has a very strong negative predictive value - that is, that patients test negative for ischemia - whether the heart rate is maximal or not."

The implications for such results are that doctors ordering stress echocardiography can have more confidence in tests returning negative for ischemia than they had previously thought, effectively broadening the parameters normally used to rule out ischemia - meaning some patients will not have to undergo additional heart scans to rule out the condition before they undergo surgery.

Swathy Kolli, M.D.; Michelle Bierig, RDCS; Jeannette A. St. Vrain, RDCS; Bernard Chaitman, M.D.; and Arthur Labovitz, M.D., director of the division of cardiology at Saint Louis University School of Medicine, were co-authors of the study.