The use of nuclear myocardial perfusion imaging (MPI) for the assessment of coronary artery disease (CAD) may have advantages in specific patient populations. While in asymptomatic individuals it is in general not recommended, it can be considered to detect myocardial ischaemia and CAD in specific patients at high risk such as patients with diabetes. In patients with angina but without obstructive CAD, MPI and in particular positron emission tomography (PET), is considered the reference imaging modality to evaluate the presence and extent of coronary microvascular dysfunction. Quantitation by PET, and more recently by single-photon emission computed tomography (SPECT), of myocardial blood flow and flow reserve is able to stratify the prognostic risk in this population. This is one of the reasons why SPECT and in particular PET have a specific application to recognize suspected CAD in women. In fact, even if women frequently have less anatomical obstructive disease than men, they are not necessarily protected from ischaemic cardiovascular events, possibly because of higher prevalence of diffuse endothelial/microvascular coronary dysfunction. In the growing elderly population with higher prevalence of obstructive CAD, stress nuclear MPI (with pharmacological vasodilatation in patients unable to adequately exercise) is particularly useful for its high sensitivity to diagnose significant CAD and its ability to stratify the risk and indicate possible revascularization. Similarly, nuclear MPI is particularly useful in patients with angina and chronic kidney disease who have a higher probability of obstructive CAD. On the other hand, no data exist that demonstrate a clinical benefit for screening asymptomatic patients with chronic kidney disease by MPI imaging.
Dobutamine nuclear myocardial perfusion imaging compared to dobutamine stress echocardiography as a prognostic test for coronary artery disease
