Optimal cutoff value for minimal lumen cross sectional area of coronary stents on 64-MDCT coronary angiography compared with intravascular ultrasound

Abstract

In this study, we aimed to prospectively assess an optimal cutoff value for the minimal lumen cross sectional area (CSA) of coronary stents on 64-MDCT coronary angiography compared with intravascular ultrasound (IVUS). We performed 64-MDCT in 39 patients with 43 stents. Stenosis of more than 75% of the CSA was selected as the cutoff criterion for in-stent restenosis (ISR). The minimal lumen CSA and minimal stent CSA were measured independently on the CT images. Correlation analyses were performed between 64-MDCT and IVUS. Receiver operating characteristic (ROC) curves were calculated for the minimal lumen CSA on 64-MDCT using IVUS (significant ISR defined as minimal lumen CSA < 4mm2 on IVUS) as the gold standard. Sensitivity, specificity, positive predictive value, and negative predictive value to detect ISR using 64-MDCT were 60%, 100%, 100%, and 95%, respectively. For the assessment of minimal lumen CSA and minimal stent CSA, 64-MDCT showed a good correlation with IVUS (r = 0.73 and 0.63, p < 0.0001). However, the correlation for the area of stenosis between 64-MDCT and IVUS was weak, with a correlation coefficient of 0.29. The area under the ROC curve was 0.82 (p < 0.0001) for per-stent analysis, indicating a high degree of agreement between 64-MDCT and IVUS for significant ISR. Optimal cutoff value on 64-MDCT is 6.2mm2 using IVUS minimal CSA 4mm2 as the golden standard with sensitivity 83.33% and specificity 72%.