Enhanced stent imaging improves the diagnosis of stent underexpansion and optimizes stent deployment

OBJECTIVES: To investigate the clinical value and diagnostic accuracy of enhanced stent imaging (ESI) as compared with quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS). BACKGROUND: ESI is an image acquisition and processing angiography-based software that improves visualization and provides measurements of deployed stents. METHODS: A total of 40 consecutive patients (42 stents) were studied. Stent deployment was evaluated sequentially and independently by angiography, ESI, and IVUS. Following each imaging modality, the operator determined the necessity of postdilation unrelated to the other modalities. Stent diameters were measured off-line by QCA, ESI, and IVUS at several sites along the deployed stent and compared. RESULTS: Following stent deployment and based solely on angiography, the operator decided to postdilate seven of the 42 stents (16.7%). This decision was not changed after reviewing the ESI images of these seven stents. Of the 35 stents not requiring postdilation based on angiography alone, ESI influenced the operator to change the decision and postdilate 10 of 35 stents (28.6%). The ESI-based measurements had better correlation with IVUS (r = 0.721, P < 0.0001) than did QCA with IVUS (r = 0.563, P < 0.0001). Bland-Altman analysis showed a trend towards better agreement between ESI and IVUS than between QCA and IVUS (mean differences = 0.038 vs. 0.121; P = 0.19, respectively). CONCLUSIONS: ESI is an easy to use modality that enhances stent visualization, helps in the decision making process whether to postdilate the stent, and provides estimation of stent expansion with better correlations than QCA when compared to IVUS.