Optical coherence tomography versus intravascular ultrasound in the evaluation of observer variability and reliability in the assessment of stent deployment: the OCTIVUS study.

Abstract

To compare the variability in the assessment of coronary stents among interventional cardiologists (readers) using optical coherence tomography (OCT) and intravascular ultrasound (IVUS). IVUS is established and validated in the evaluation of coronary stent. For cardiologists without core lab expertise, the utility of IVUS is limited by image quality. OCT yields higher image resolution; however, the consistency with which these readers interpret OCT images has not been fully evaluated or compared with IVUS. OCT and IVUS image sets (five pairs) obtained after stent placement were reviewed by readers with clinical experience in both modalities. Parameters assessed included stent expansion and symmetry, reference vessel and in-stent cross-sectional area (CSA) and diameter, and stent strut apposition as well as Multicenter Ultrasound Stenting in Coronaries criteria. These interpretations were compared with core lab readings and examined for interobserver variability. The interobserver variability for measurement of in-stent CSA was 1.34 mm(2) using IVUS compared with 0.85 mm(2) using OCT (P = 0.024). Variation in the deviation from core lab measurement of in-stent CSA for IVUS was 1.48 mm(2) compared with 0.87 mm(2) for OCT (P = 0.042). The interobserver agreement for obtaining the Multicenter Ultrasound Stenting in Coronaries criteria using IVUS was 80.4% compared with 81.1% using OCT (P = 0.78). Compared with the corelab measurement, the readers obtained an agreement of 72.7% using IVUS vs. 67.3% using OCT (P = 0.43). In the assessment of deployed coronary stents by practicing cardiologists, OCT images are interpreted more consistently compared with IVUS and can be used to assess stent deployment using IVUS-validated metrics.