Diagnostic performance of adenosine-stress dynamic CT myocardial perfusion imaging in detecting myocardial ischemia in patients with intermediate coronary stenosis

Abstract Objective: This study aimed to investigate the diagnostic performance of CT myocardial perfusion imaging (CT-MPI) in detecting myocardial ischemia in patients with intermediate coronary stenosis (50%–70%) using fractional flow reserve (FFR) as the reference standards. Methods: Consecutive patients with suspected coronary artery disease (CAD) diagnosed using coronary computed tomography angiography (CCTA) were prospectively enrolled and scanned with adenosine-stress dynamic CT-MPI and referred to invasive coronary angiography (ICA) and FFR within 10 days. The inclusion criteria were as follows: intermediate coronary artery stenosis confirmed using quantitative ICA, and the FFR was measured to assess its hemodynamic significance. Results: In 31 patients, intermediate stenosis was confirmed using ICA in 31 vessels, and FFR was measured in these vessels. Based on the FFR results, 24 vessels were assessed as causing ischemia in 24 patients (FFR £ 0.80). On a per-vessel basis, the sensitivity, specificity, positive predictive values (PPV) and negative predictive values (NPV) and diagnostic accuracy of absolute myocardial blood flow (MBF) and relative MBF were 79.17%, 85.71%, 54.54%, 95%, and 80.65% and 95.83%, 85.71%, 85.71%, 95.83%, and 93.55%, respectively. With FFR £ 0.8 as a positive event, the area under the curve (AUC) values for the qualitative (visual) assessment, absolute MBF, and relative MBF were found to be 0.601, 0.792, and 0.899, respectively. The relative MBF was higher than the qualitative assessment (P < 0.05). The AUC of the relative MBF value was higher than the absolute MBF value, but the difference was not statistically significant (P = 0.0649). The absolute MBF cutoff value was 116.275 mL·100 mL -1 ·min -1 , and the relative MBF cutoff value was 0.736. Conclusion: The CT-MPI is feasible in detecting myocardial ischemia in patients with intermediate coronary stenosis.