Efficacy of culprit plaque assessment by 64-slice multidetector computed tomography to predict transient no-reflow phenomenon during percutaneous coronary intervention

Background: It has been reported that multidetector spiral computed tomography (MDCT) allows the classification of coronary plaques by measuring computed tomography (CT) density values. However, the impact of CT density values in culprit lesions on the occurrence of transient no-reflow during percutaneous coronary intervention (PCI) has not been investigated. Methods: The study population consisted of 51 consecutive patients who were diagnosed as having coronary artery disease by 64-slice MDCT before PCI. The CT density values were measured in multiple cross-sectional images along the plaque by 5-pixel regions of interest at multiple sites in the culprit plaque. The measurements were performed by 2 physicians who were unaware of the outcome of PCI. In addition, we describe a new observation noted on MDCT: from the formal resemblance to a ring, we dubbed these images as showing a "signet ring-like appearance.". Results: Of the total 51 patients, 9 had transient no-reflow during the procedure. There was a significant difference in CT density of the culprit plaque between patients with transient no-reflow and those without (67.0 ± 10.1 vs 97.8 ± 37.2 Hounsfield units, P = .018). In addition, a signet ring-like appearance was observed more frequently in patients with transient no-reflow (55.6% vs 16.7%, P = .013). By multivariate analysis, low CT density value and ejection fraction were identified as independent predictors of transient no-reflow. Conclusions: The assessment of plaque characteristics by MDCT might be useful for the prediction of transient no-reflow during PCI.