Eccentric morphology of jailed side-branch ostium after stent crossover in coronary bifurcation lesions: a three-dimensional optical coherence tomographic analysis.

BACKGROUND: Angiographic stenosis of a jailed side-branch ostium is usually observed after a single-stent crossover at coronary bifurcation lesions. However, the stenosis severity is typically overestimated due to the limited information obtained from two-dimensional morphology by angiography. We evaluated the actual stenosis of jailed side-branch ostium using three-dimensional (3D) optical coherence tomography (OCT).

METHODS: Using 3D reconstructions of OCT data, we analyzed minimal lumen area (MLA) and eccentricity of the jailed side-branch ostium in 41 patients who were treated with single stent crossover at coronary bifurcation lesions and subsequently underwent serial OCT follow-up.

RESULTS: The MLA of jailed side-branch ostium calculated from quantitative coronary angiography (QCA) assuming a circular lumen markedly decreased after stent implantation (1.73±1.22mm(2) pre-intervention to 0.84±0.91mm(2) post-intervention, p<0.001). However, the MLA of jailed side-branch ostium measured at post-intervention by 3D-OCT (2.67±1.75mm(2)) was significantly larger than that measured by QCA (p<0.001). There were no statistically significant changes in MLA of jailed side-branch ostium based on 3D-OCT measurements during the follow-up (2.35±1.50mm(2) at 3-6 months post-intervention; 2.44±1.27mm(2) at 1-2 years post-intervention, p=0.098). The shapes of the jailed side-branch ostium were nearly elliptical (mean eccentricity index: 2.97±1.27 post-intervention; 2.79±1.17 at 3-6 months post-intervention; 2.59±1.02 at 1-2 years post-intervention).

CONCLUSIONS: Compared to 3D-OCT measurements, QCA measurements overestimated the jailed side-branch ostial stenosis after single stent crossover due to eccentric morphology from orthogonal projection in coronary angiography. Significant changes in the MLA of jailed side-branch ostium by 3D-OCT were not observed during the follow-up.