Journal of Invasive Cardiology

Abstract: Objectives. This study sought to assess the effectiveness and safety of the second-generation frequency-domain optical coherence tomography (FD-OCT) system. Background. The second-generation FD-OCT was recently developed, with simplified imaging technique and faster acquisition time compared to the first-generation time-domain OCT. However, the safety and effectiveness of the FD-OCT has not been evaluated, and this study was conceived as a pre-approval study for Food and Drug Administration clearance for clinical use in the United States. Methods. A total of 50 patients were enrolled from 3 institutions. Following stent implantation, the FD-OCT was performed with contrast injection through the guiding catheter to acquire pullback images with the pressure-triggered automatic pullback device. The primary endpoint was to achieve a median clear image length of more than 24 mm. Serious procedure-related or postprocedural adverse events (death, myocardial infarction, or ventricular arrhythmia) were recorded to assess safety of the device. Results. The primary endpoint of obtaining >24 mm of median clear image length (CIL) was achieved in 94% of the subjects (47 out of 50), with measured CIL of 43.2 mm. In 5 patients (10.6 %), a second attempt was necessary due to suboptimal image quality of the first pullback. In 36 patients (76.6%), a full stent length was obtained during the first attempt. There were no serious procedure-related or postprocedural adverse events. Conclusions. The new second-generation FD-OCT system provides fast and reliable resolution images of the coronary artery. The pullback can be safely performed over long segments of the artery without serious adverse events.

J INVASIVE CARDIOL 2012;24(5):206-209

Key words: frequency domain OCT, FD-OCT, feasibility, safety

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Intracoronary optical coherence tomography (OCT) is a high-resolution imaging modality that uses near-infrared light to visualize coronary artery structures and geometry. Since its first use for in vivo coronary artery evaluation in 2002,¹ it has been widely accepted as a reliable tool for assessing the structures of coronary arteries. With OCT, it is possible to visualize pathologic changes in microstructures of the coronary artery, as well as evaluate the adequacy of stent deployment due to its higher resolution (10 µm) compared to intravascular ultrasound (IVUS; resolution, 100 µm).¹

One limitation of OCT compared to IVUS is the requirement for blood to be displaced in order to obtain images of the artery wall. The techniques for blood displacement in the conventional time-domain OCT (TD-OCT) require either the combined use of a small imaging catheter and a compliant occlusion balloon (occlusive technique) or an infusion of an iso-osmolar viscous solution through the guiding catheter (non-occlusive technique).² These techniques have been proven to be safe, but require extra time to perform and may not be feasible in clinically unstable patients.^3,4 Additionally, the TD-OCT has a slow pullback rate of about 0.5-3 mm/s, with 10-30 seconds of occlusion or flush to image a 30-mm long coronary artery, which may lead to myocardial ischemia.⁴