ASE: Stress Echo Helps Find Women with Suspected Coronary Disease

SEATTLE, June 18 -- Stress echocardiography can help spot women suspected to be at a high risk for coronary artery disease, investigators reported here.
Among women with a high pretest probability of coronary disease, an abnormal stress echo test helped identify patients with the highest risk of clinical events, they said at the American Society of Echocardiography.
Stress echocardiography added significantly to the prognostic information provided by clinical variables and stress electrocardiography data, they added.
"For women with a high pretest probability of coronary artery disease, stress echocardiography is an effective method for risk stratification because it provides incremental prognostic value beyond that of clinical, stress ECG, and resting echo," said Sabrina Sawhney, M.D., of St. Luke's-Roosevelt Hospital Center and Columbia University in New York.
She pointed out that coronary disease is more difficult to diagnose in women because they often have atypical symptoms, more diffuse disease, and more small-vessel disease. Stress echo already is widely used to risk-stratify patients with known or suspected coronary disease, but a relative paucity of data exists on the prognostic value of stress echo in high-risk women.
The investigators evaluated 447 consecutive women referred for stress echo studies. All the patients had a more than 85% probability for coronary disease on the basis of computerized analysis of clinical history and coronary risk factors. Patients with known coronary disease were considered high risk regardless of clinical findings.
Those who could exercise underwent a maximal symptom-limited treadmill test, using a standard Bruce protocol. Patients who could not exercise were evaluated by dobutamine stress echo.
On the basis of the stress echo images, Dr. Sawhney and colleagues assigned left-ventricular wall-motion segment scores ranging from 1 (normal) to 5 (dyskinesia). An abnormal stress response was defined by one or more of::
Lack of increase in thickness and excursion in a ventricular wall segment (fixed defect)
Deterioration of ventricular segment thickness and excursion in response to stress
Biphasic response
The patients' mean age was 65, and they were followed for an average of 2.6 years. Three fourths of the patients had dobutamine stress tests. Dr. Sawhney said that 69 patients died during follow-up and 44 had clinical events--20 MIs and 24 cardiac deaths.
The stress echo results included 207 abnormal tests, which occurred more often in patients with diabetes, typical angina, a history of MI or coronary bypass surgery, or heart failure.
Comparison of wall-motion scores and event rates showed that the risk of a hard clinical event or overall mortality increased with the extent of ischemia, as reflected by a patient's stress echo test. Patients with a normal stress echo test had an annual event rate of 1.8%, whereas the event rate jumped to 6.1% a year with an abnormal test.
For both hard events and overall mortality, the addition of stress echo significantly improved prognostic accuracy compared with the combination of clinical variables, ECG evaluation, and rest echocardiography (P<0.0001).
"The greatest increase in incremental prognostic value occurred when stress echo was added to the other three factors," said Dr. Sawhney.