Comparison of two different sampling intervals for optical coherence tomography evaluation of neointimal healing response after coronary stent implantation

Abstract

Background/objectivesOptical coherence tomography (OCT) is widely used for evaluation of healing response to stent implantation. We sought to test the agreement between the 1-mm and 0.6-mm sampling intervals for assessment of the percentage of uncovered and malapposed struts by OCT. MethodsThirty­eight patients presenting with acute coronary syndrome were randomized to receive either a titanium­nitride­oxide­coated stent (n=19) or an everolimus­eluting stent (n=19). Neointimal strut coverage and strut apposition were evaluated by OCT at 2­month follow­up. Two independent investigators performed offline OCT image analysis at 1­mm intervals. One investigator repeated the measurements at 0.6­mm intervals and measurements were compared between the two sampling intervals. ResultsAt a median follow­up of 60 [8] days, 694 cross­sections (7603 struts) and 1138 cross­sections (12,331 struts) were analysed at 1­mm and at 0.6­mm intervals, respectively. The median [IQR] percentage of uncovered struts was 3.27% [11.1] versus 3.38% [9.76] (p=0.001), and the mean (±SD) percentage was 7.69±9.99% versus 6.27±8.14% (p=0.004), for the 1­mm sampling interval versus the 0.6­mm sampling interval analysis, respectively; the median percentage of malapposed struts was 0.42% [2.04] versus 0.12% [1.63], respectively, (p=0.003). The intraclass correlation coefficient between the two observers for the percentage of uncovered struts was 0.95. ConclusionsThe OCT-evaluated strut-level measurements of neointimal healing after stent implantation differ significantly between the 1-mm and the 0.6-mm sampling intervals.