Table 3

Factors Affecting the Accuracy of Diagnostic Testing in Women

1) Menopausal status
 Premenopausal women: endogenous estrogen may elicit a digoxin-like effect and provoke ST-segment changes resulting in a false positive exercise electrocardiogram.
  In the premenopausal woman, angina and ischemia have been shown to vary by the menstrual cycle. In the luteal/menstrual phase, where estradiol levels are low, a greater prevalence of ischemia and reduced time to ischemia onset has been noted.
 Postmenopausal women: the prevalence of coronary disease is increased resulting in a higher predictive accuracy.
  Menopausal symptom therapy (previously called hormone replacement therapy): these agents promote peripheral vasoreactivity with evidence noting an increase in exercise time, a decrease in myocardial ischemia in postmenopausal women with coronary disease (note: there has been a decrease in the prevalence of electrocardiographic (but not perfusion) ischemia.
2) Functional capacity
 There is a diminished ability to elicit ischemia if adequate heart rate and estimated metabolic equivalents (METs) have not been achieved. Women incapable of performing 5 METs on exercising testing should be re-tested with pharmacologic stress imaging.
3) Disease prevalence
 In women with a lower prevalence of disease and a greater prevalence of single-vessel disease, the overall predictive accuracy of stress testing with or without imaging is diminished when compared to a male population.
4) Electrocardiographic changes
 Resting ST-T-wave changes: the presence of significant resting ST-T-wave changes on a 12-lead electrocardiogram diminishes the accuracy of identifying peak exertional changes. Current American College of Cardiology/American Heart Association guidelines recommend cardiac imaging in women and men with significant ST-T-wave changes on their resting electrocardiogram.
 Lower electrocardiogram voltage: population-based studies have noted a lower QRS voltage that may affect the test’s diagnostic accuracy in women.