Detection of left main stem and three-vessel coronary artery disease by myocardial perfusion SPECT imaging

Stress radionuclide myocardial perfusion single-photon emission computed tomography (SPECT) imaging (MPI) is a well-validated diagnostic procedure for the assessment of patients with suspected coronary artery disease (CAD). It has a high sensitivity for the detection of flow-limiting coronary stenosis and provides incremental prognostic information that contributes to risk stratification and guides clinical-decision making with regard to management and therapeutic interventions. The diagnostic accuracy and predictive value of MPI in patients with three-vessel and left main stem (LMS) disease is less well-documented. There is evidence suggesting that assessment of myocardial perfusion on MPI is less effective at identifying significant three-vessel CAD as well as LMS disease. This limitation can be overcome, to a certain extent, by incorporating other imaging findings as well as clinical and stress testing parameters that help identify individuals at an increased risk of adverse cardiac events and hence those with severe and extensive coronary disease. Quantification of myocardial perfusion reserve using currently available radiotracers as well as simultaneous non-invasive assessment of coronary anatomy and atheromatous plaque may enhance the diagnostic performance of MPI in this subset of high-risk patients.