Comparison of Iodixanol and Ioxaglate for Coronary Optical Coherence Tomography Imaging

Background. The impact of contrast type on coronary imaging using optical coherence tomography (OCT) has received limited study. We compared OCT imaging obtained using the non-ionic, iso-osmolar iodixanol with the ionic, low-osmolar ioxaglate. Methods. Twenty-two vessels in 20 patients were imaged twice using manual injection of iodixanol and ioxaglate in random order. OCT images were analyzed at 1 mm intervals to determine lumen area, artifact diameter and area, as well as stent strut coverage and malapposition in OCT pullbacks that included stents. Results. There were no complications related to OCT imaging or to contrast administration. A total of 2184 cross-sections (1092 with iodixanol and 1092 with ioxaglate) were analyzed. Compared with iodixanol, imaging using ioxaglate provided similar mean lumen area (6.21 +/- 2.83 mm(2) vs 6.27 +/- 2.83 mm(2); Spearman's rho, 0.982), mean minimum lumen diameter (2.47 +/- 0.59 mm vs 2.50 +/- 0.58 mm; Spearman's rho, 0.939), and mean maximum lumen diameter (2.99 +/- 0.71 mm vs 3.01 +/- 0.70 mm; Spearman's rho, 0.964), but lower mean artifact area per cross-section (0.099 +/- 0.325 mm(2) vs 0.068 +/- 0.329 mm(2); P<.001). Analyses of 3303 stent struts in 388 cross-sections (194 with iodixanol and 194 with ioxaglate) demonstrated similar strut malapposition rates (11.82% vs 13.90%; P=.10) and strut coverage (41.92% vs 40.33%; P=.35). Conclusions. Compared with iodixanol, OCT imaging using ioxaglate provided similar lumen and diameter measurements and stent strut characterization, but smaller area of artifact.