Assessment of Myocardial Perfusion in Patients After CABG: An Update and Clinical Implications

Abstract

Stress radionuclide myocardial perfusion imaging (MPI) has been well-established as a useful modality for assessing the status of the coronary circulation in post-coronary artery bypass graft (CABG) patients. CABG by itself escalates progression of atherosclerosis or thrombosis in bypassed native coronary arteries. In most cases MPI will be employed in post-CABG patients who are experiencing symptoms. The major clinical question is whether there is myocardial ischemia, and if so, what is the extent and severity, and are there high-risk markers that would encourage diagnostic coronary and graft angiography. Recent important advances in MPI, including introduction of routine attenuation correction, CZT instrumentation, PET MPI, and PET quantitative blood flow have further enhanced the value of MPI for this population. The purpose of this review is to provide information on these advances relevant to the post-CABG patient, to describe common image findings, and to explore the diagnostic and prognostic significance of different findings in this unique population.