Diagnostic strategy in ischemic heart disease at the era of multimodality cardiac imaging.

or more than 2 decades, myocardial perfusion imaging (MPI) has been one of the best clinical tools for guiding clinicians in the management of patients with suspected or known coronary artery disease (CAD). MPI has been considered the best noninvasive imaging modality for measuring myocardial blood flow. The presence of significant ischemia on MPI usually necessitates further evaluation with coronary angiography (CAG), whereas a normal or mildly abnormal finding is not followed by further evaluation, because the outcome is usually benign. Thus, the MPI-guided strategy has an established role in the screening, diagnosis, risk stratification and prognosis of patients with stable chronic chest pain syndrome. However, because MPI is a modality that demonstrates ischemia, but not the true extent of coronary atherosclerosis, it is limited to some extent in predicting future events. Approximately half of the patients with normal MPI have subclinical CAD on CAG, which explains why despite the evidence of normal myocardial perfusion patients with subclinical CAD are at relatively high risk of coronary events. Even though a normal MPI result generally indicates a benign prognosis, the warranty period of such a result could be substantially shorter in patients with high coronary risk factors.