Frequency‐domain optical coherence tomography assessment of unprotected left main coronary artery disease—a comparison with intravascular ultrasound

Abstract

Objectives To investigate safety and feasibility of imaging unprotected left main (ULM) using frequency‐domain optical coherence tomography (FD‐OCT) compared with intravascular ultrasound (IVUS). Background IVUS has been used to assess and guide percutaneous coronary intervention (PCI) of ULM disease. FD‐OCT offers 10‐fold higher axial resolution than IVUS and its high‐speed image acquisition obviates the need for proximal balloon occlusion. Methods We prospectively enrolled 35 consecutive patients with ULM disease. FD‐OCT and IVUS assessments were attempted pre‐ and post‐PCI and compared in regards to safety, ability to image the region of interest (ROI), number of pullbacks, volume of contrast and ability to detect malapposition, dissection, and thrombus. Results Patients were followed for 1 year when FD‐OCT imaging was repeated. FD‐OCT required more repeated pullbacks to image the ROI compared to IVUS. Mean lumen and stent areas were similar between FD‐OCT and IVUS (11.24 ± 2.66 vs. 10.85 ± 2.47 mm², P = 0.13 and 10.44 ± 2.33 vs. 10.49 ± 2.32 mm², P = 0.82, respectively), whereas imaged stent length was shorter with FD‐OCT. Malapposition areas and volumes were larger and more edge dissections were detected by FD‐OCT. There were no clinical adverse events and no complications associated with FD‐OCT at baseline and 1‐year follow‐up. All dissections were healed, whereas stent malapposition was still detected at follow‐up. Conclusions FD‐OCT assessment of ULM is feasible and safe. Direct comparisons with IVUS reveal that FD‐OCT achieved imaging completeness less often, whereas it was more sensitive in detecting malapposition and edge dissections, and similar to IVUS in the assessment of lumen and stent dimensions.