Three-dimensional anatomical assessment of coronary artery lesions using optical coherence tomography

Background: The first and, thereby, decisive criterion for making a decision on myocardial revascularization is an anatomical severity of the coronary artery stenosis assessed by the decrease of lumen diameter ≥50 % (i.e., one-dimensionally). Intravascular imaging (IVI) enables to assess the stenosis by the decrease of the lumen area (twodimensionally) that is a more accurate anatomical assessment of the extent of lesions since it takes into account possible lumen deformations. Moreover, IVI provides ordered series of two-dimensional images and enables volumetric assessment of the degree of stenosis, considering both transverse and longitudinal lumen deformation, i.e., an even more accurate assessment of the stenosis severity. However, this capability of IVI is currently not fully utilized. Objective: The study was aimed at testing the hypothesis on the superiority of volumetric three-dimensional characteristics of stenoses obtained using simplified analysis of optical coherence tomography (OCT) data over standard two-dimensional and one-dimensional anatomical assessments for determining the severity of coronary lesions. Methods: This prospective clinical study included patients with chronic coronary artery disease (CAD) and a high risk of percutaneous coronary intervention (PCI) due to complex coronary lesions. Volumetric characteristics of the lesions were assessed by simplified analysis of serial OCT images; the degree of the stenosis by area and diameter was measured in standard way. The significance of the obtained anatomical data was compared by their relationship with the validated indicator of the risk of major adverse cardiovascular events (MACE) in patients with coronary artery disease undergoing PCI – SYNTAX score. The relationship was assessed using Pearson correlation analysis; the significance of the coefficients was assessed by Student’s t-criterion; p-value < 0.05 was considered statistically significant. Results: The study included 33 patients, of whom 5 were excluded due to the inability to perform OCT without predilation. A significant positive relationship was found between the volumetric degree of stenosis and the SYNTAX score (r = 0.339, p = 0.042) whereas the two-and onedimensional parameters, including the decrease of lumen area, failed to demonstrate such relationship (r = –0.067, p = 0.74). Conclusion: Volumetric stenosis assessments, in particular the volumetric stenosis degree, obtained using simplified OCT data analysis are superior in assessing lesion severity and the risk of adverse PCI outcomes compared to existing standard area and diameter assessments, i.e., 2- and 1-dimensional assessments.