NEW YORK (Reuters Health) – In low-risk women, exercise treadmill testing (ETT) gives similar results to exercise myocardial perfusion imaging (MPI) and is less expensive, researchers report in an August 15th on-line paper in Circulation.
As Dr. Leslee J. Shaw told Reuters Health by email, “The test of choice for low risk women, including those younger women or those with few cardiac risk factors, is an exercise test without imaging.”
Dr. Shaw of Emory University, Atlanta, Georgia and colleagues note that guidelines cite ETT as the preferred procedure for the initial evaluation of women with suspected myocardial ischemia. However, current practice may include higher-cost procedures, such as MPI.
To gain more solid evidence of the relative utility of these approaches, the researchers studied 824 exercise-capable women with suspected coronary artery disease. They were randomized to ETT or exercise MPI. Exertional chest pain occurred was seen in 13% of the ETT group and 12% of MPI patients.
In the ETT group ECG results were normal in 64%, indeterminate in 16%, and abnormal in 20%. The MPI results were normal in 91%, mildly abnormal in 3%, and moderate to severely abnormal in 6% of women.
Over 2 years, in evaluated women, there were 3 nonfatal MIs, 1 heart failure hospitalization, 12 acute coronary syndrome hospitalizations, and only 1 sudden cardiac death.
At two years, 98% in both groups were major cardiac event-free. The 2-year rate of hospitalization for chest pain symptoms was 3% for ETT women and 4% in the MPI arm.
Overall, diagnostic costs were significantly lower (48%) for the ETT compared with the exercise MPI group.
“Among women who are capable of exercise at the time of planned diagnostic testing,” the investigators conclude, “our data support an initial ETT-alone testing strategy compared with an initial exercise MPI testing strategy.”
Dr. Shaw added that “For higher risk women, including older women and those with multiple cardiac risk factors, who are incapable of at least moderate physical functioning or with disabling comorbidity, a stress myocardial perfusion scan is effective at diagnosing heart disease and for providing an estimate of long term prognosis.”
Comparative Effectiveness of Exercise Electrocardiography With or Without Myocardial Perfusion Single Photon Emission Computed Tomography in Women With Suspected Coronary Artery Disease