Accuracy of dynamic stress CT myocardial perfusion in patients with suspected non-ST elevation myocardial infarction

Coronary CT angiography (CCTA) and dynamic stress CT myocardial perfusion (CT-MPI) are established modalities in the analysis of patients with chronic coronary syndromes. Their role in patients with suspected non-ST elevation myocardial infarction (NSTEMI) is unknown. CCTA with CT-MPI might assist in the triage of NSTEMI patients to the Cath lab. We investigated the correlation of significant epicardial lesions by CT-MPI in addition to CCTA compared to invasive coronary angiography (ICA) with fractional flow reserve (FFR) in patients with NSTEMI. Twenty NSTEMI patients scheduled for ICA were enrolled in this study with planned ICA. CCTA and CT-MPI was performed pre-ICA. For each coronary artery, the presence or absence of significant lesions was interpreted by CCTA with CT-MPI, using an FFR of ≤ 0.8 or angiographic culprit (stenosis > 90%, suspected plaque rupture) as reference. The main outcome was the per-vessel correlation. Sixteen out of 20 patients had a culprit lesion that required immediate revascularization. CCTA with ≥ 50% stenosis demonstrated a per vessel sensitivity and specificity for the detection of significant stenosis of respectively 100% (95% CI: 86-100%) and 75% (95% CI: 58-88%). CCTA with CT-MPI showed a lower sensitivity 90% (95% CI: 70-99%) but higher specificity of 100% (95% CI: 90-100%). CCTA with CT-MPI exhibits a strong correlation for identifying significant CAD in patients with NSTEMI. Thereby, it might assist in the triage of ICA in NSTEMI patients.