Diagnostic testing strategies for coronary artery disease: Special issues related to gender

Abstract

Early reports of the prevalence, diagnosis, and outcomes of coronary artery disease (CAD) in women have led to the acceptance of several myths concerning noninvasive diagnostic studies in women. Many of the myths can be explained by age-related differences in prevalence, methodological errors that exclude women from enrollment, worse clinical baseline risk profiles, comorbid diseases at the time of interventions, and smaller coronary vessels. Awareness of these age-related prevalence factors in women and the potential for delaying the onset of CAD by estrogen treatment in postmenopausal women must be considered in assessing the accuracy of diagnostic studies. The critical role of noninvasive testing in women is to diagnose CAD accurately in a population with a lower prevalence of disease prior to the development of more severe clinical manifestations when therapeutic interventions have a higher risk and a poor outcome. Exercise radionuclide ventriculography has lower specificity in women, which may be due to gender differences in the response to excercise. Radionuclide perfusion imaging for the detection of CAD is accurate, there is extensive published literature, and it is used widely. High-dose dipyridamole in combination with echocardiography is not widespread in the United States; most pharmacologic echocardiographic studies are performed using dobutamine, and there are no reports on gender differences using dobutamine echocardiography. At this time, however, there is a paucity of published data on accuracy and no information on the prognostic value of this method. Both perfusion imaging and echocardiography have a better diagnostic accuracy than electrocardiographic stress testing. Myocardial perfusion imaging with thallium-201 or Tc-99m sestamibi identifies not just the presence or absence of CAD, it also prognostically identifies those patients with more severe disease who may benefit from invasive diagnostic testing and possible therapeutic interventions. Technetium-99m perfusion agents offer several advantages over thallium-201 : less attenuation, the ability to measure first-pass ejection fraction, and gated image acquisition. All 3 of these characteristics are expected to improve both sensitivity and specificity in women. Early reports of the prevalence, diagnosis, and outcomes of coronary artery disease (CAD) in women have led to the acceptance of several myths concerning noninvasive diagnostic studies in women. Many of the myths can be explained by age-related differences in prevalence, methodological errors that exclude women from enrollment, worse clinical baseline risk profiles, comorbid diseases at the time of interventions, and smaller coronary vessels. Awareness of these age-related prevalence factors in women and the potential for delaying the onset of CAD by estrogen treatment in postmenopausal women must be considered in assessing the accuracy of diagnostic studies. The critical role of noninvasive testing in women is to diagnose CAD accurately in a population with a lower prevalence of disease prior to the development of more severe clinical manifestations when therapeutic interventions have a higher risk and a poor outcome. Exercise radionuclide ventriculography has lower specificity in women, which may be due to gender differences in the response to excercise. Radionuclide perfusion imaging for the detection of CAD is accurate, there is extensive published literature, and it is used widely. High-dose dipyridamole in combination with echocardiography is not widespread in the United States; most pharmacologic echocardiographic studies are performed using dobutamine, and there are no reports on gender differences using dobutamine echocardiography. At this time, however, there is a paucity of published data on accuracy and no information on the prognostic value of this method. Both perfusion imaging and echocardiography have a better diagnostic accuracy than electrocardiographic stress testing. Myocardial perfusion imaging with thallium-201 or Tc-99m sestamibi identifies not just the presence or absence of CAD, it also prognostically identifies those patients with more severe disease who may benefit from invasive diagnostic testing and possible therapeutic interventions. Technetium-99m perfusion agents offer several advantages over thallium-201 : less attenuation, the ability to measure first-pass ejection fraction, and gated image acquisition. All 3 of these characteristics are expected to improve both sensitivity and specificity in women.