Head to head comparison between the conventional balloon occlusion method and the non-occlusion method for optical coherence tomography.

BACKGROUND Optical coherence tomography (OCT) has been introduced as a high-resolution imaging modality for the coronary arteries. The current OCT system, however, has a serious limitation in that the image acquisition method requires a soft balloon occlusion to avoid signal scattering from red blood cells. PURPOSE The purpose of this study was to compare OCT images from the conventional balloon occlusion method and a non-occlusion image acquisition method, the continuous-flushing method, in the clinical setting. METHODS OCT was performed with the conventional balloon occlusion method and the continuous-flushing method sequentially in 23 patients with stable angina. The image quality and quantitative measurements of OCT images were directly compared between the two methods. RESULTS There were no adverse events related to the OCT procedure in any patients. There were no changes in systolic blood pressure and heart rate during the OCT procedure. ST-segment elevation (>2 mm) was recorded in 22 of 23 (96%) patients with the balloon occlusion method, but it was only observed in 1 of 23 (4%) patients with the continuous-flushing method (p<0.01). There were no differences in the visible length (the balloon occlusion method 28.6±2.3 mm vs. the continuous-flushing method 29.2±1.6 mm, p=0.49), image quality, or quantitative measurements between the two methods. CONCLUSIONS OCT imaging with the continuous-flushing method could be performed safely and obtained similar quality images compared with the balloon occlusion method. OCT can be used to observe the proximal site of coronary arteries with this new technique.