Comparison of Intravascular Ultrasound, Quantitative Coronary Angiography, and Dual-Source 64-Slice Computed Tomography in the Preprocedural Assessment of Significant Saphenous Vein Graft Lesions

The correlation between cardiac computed tomographic (CT) and intravascular ultrasound (IVUS) assessment of saphenous vein graft (SVG) lesions has not been studied. The aim of this study was to evaluate the accuracy of dual-source computed tomography in quantitative assessment of significant SVG lesions scheduled for percutaneous coronary intervention (PCI). Preintervention dual-source CT (DSCT) scans were performed in consecutive patients before PCI of the SVG lesion. All subjects underwent IVUS examination of the target lesion before stent implantation. Lesion characteristics were described using dual-source computed tomography, quantitative coronary angiography, IVUS, and visual estimation. Luminal areas and diameters, lesion lengths, and DSCT suggested stent dimensions were compared. Twenty-two SVG lesions were assessed in 22 patients. Minimal lumen area measured by IVUS was larger than by dual-source computed tomography (3.5 ± 1.2 vs 3.0 ± 1.2 mm2, p = 0.04), although there was close correlation between measurements (R = 0.7, p = 0.007). Proximal and distal reference lumen diameters by IVUS and dual-source computed tomography were similar (3.3 ± 0.4 vs 3.4 ± 0.6 mm, p = 0.5, and 3.4 ± 0.6 vs 3.5 ± 0.6 mm, p = 0.4, respectively) and were well correlated (R = 0.85, p <0.0001, and R = 0.81, p <0.0001, respectively). Lesion length by IVUS averaged 18.3 ± 6.1 versus 17.6 ± 5.3 mm by dual-source computed tomography (p = 0.1). There was good correlation between mean reference lumen diameter by dual-source computed tomography and diameter of the implanted stent (R = 0.84, p = 0.0009) and a very good correlation between stent length and lesion length as assessed by dual-source computed tomography (R = 0.9, p <0.0001). In conclusion, DSCT measurements in SVGs correlate with IVUS so that DSCT scan data before PCI of an SVG lesion may be helpful in stent size selection.