Myocardial Perfusion Imaging in Specific Patient Populations

The clinical value of myocardial perfusion imaging is well documented for patients with known or suspected coronary artery disease. When examining specific patient cohorts, the accuracy of SPECT for diagnosis and risk stratification has been widely validated in patients with diabetes, chronic kidney disease, obesity, women, and the elderly. PET has also demonstrated substantial value in these cohorts, especially among the obese, diabetics, and women. In each subgroup, a negative test conveys a lower risk of cardiac events. However, in diabetics, only the ones with a negative perfusion study and normal coronary flow reserve have a true low cardiac risk similar to the general population. In each group, the addition of coronary flow reserve aids in the risk-stratification of patients. Of note, most patients with chronic kidney disease have an abnormal coronary flow reserve. In obese patients and women, the use of attenuation correction and alternative positioning is required to obtain the best image quality. There is a higher incidence of non-obstructive coronary disease, microvascular dysfunction, and spontaneous coronary artery dissection in women. Although age is a non-modifiable risk factor by itself, an abnormal stress perfusion study still provides information to stratify elderly patients.