Discordance between the morphological and physiological information of 64-slice MSCT coronary angiography and myocardial perfusion imaging in patients with intermediate to high probability of coronary artery disease.

BACKGROUND The aim of this study was to determine the relationship between the morphological and physiological information of coronary CT angiography (CCTA) and stress myocardial perfusion imaging (S-MPI) from the standpoint of risk stratification of patients with intermediate to high probability of coronary artery disease (CAD). METHODS AND RESULTS In total, 51 patients underwent both CCTA and S-MPI as sequential examinations. In each patient, the severity of coronary plaque and stenosis (>50%) and the presence of myocardial perfusion abnormalities were assessed and the prognostic information from the CCTA and S-MPI results was compared. In 30 patients with normal S-MPI, 3 (10%) had only completely normal coronaries and another 3 (10%) had non-obstructive CAD as observed on CCTA. The remaining 24 patients (80%) with normal S-MPI and all 21 patients with abnormal S-MPI study had obstructive CAD. High-risk CAD (defined as obstructive left main trunk (LMT) lesion or 3-vessel disease) was seen in 10 (33%) of 30 patients with normal S-MPI, although it was less frequent than in the 14 (67%) of 21 patients with abnormal S-MPI. CONCLUSIONS A normal S-MPI result can reflect a wide range of coronary atherosclerosis types and severities and, to some extent, involves severe coronary atherosclerosis such as LMT lesion and 3-vessel disease in patients with an intermediate to high probability of CAD.