Three-Dimensional Optical Coherence Tomographic Analysis of Eccentric Morphology of the Jailed Side-Branch Ostium in Coronary Bifurcation Lesions.

BACKGROUND: The severity of angiographic diameter stenosis of the jailed side-branch ostium is usually overestimated over the 3-D optical coherence tomography (OCT)-measured actual stenosis. Using 3-D OCT, morphologic changes in the jailed side-branch ostium were evaluated before and after a single stent crossover at coronary bifurcation lesions.

METHODS: In 109 patients who received a single stent crossover at coronary bifurcation lesions, the minimal lumen area (MLA) before and after intervention and the eccentricity of the jailed side-branch ostium were measured with 3-D OCT. The eccentricity index was defined as the ratio of maximal diameter/minimal diameter of the jailed side-branch ostium. When the eccentricity index was < 1.5, the shape of the jailed side-branch ostium was defined as circular. The MLA of the jailed side-branch ostium was also calculated from the quantitative coronary angiography (QCA) minimal lumen diameter assuming a circular lumen.

RESULTS: The 3-D OCT-measured MLA of the jailed side-branch ostium decreased from 2.91 ± 1.65 mm(2) before intervention to 2.37 ± 1.48 mm(2) after intervention (P < 0.01). The QCA-derived MLA also decreased from 2.35 ± 1.71 mm(2) before intervention to 1.68 ± 1.56 mm(2) after intervention (P < 0.01). However, the 3-D OCT-measured MLA was significantly larger than the QCA-derived MLA (P < 0.01). The shape of the jailed side-branch ostium changed from circular to elliptical after the stent implantation (eccentricity index: 1.40 ± 0.33 before intervention; 1.71 ± 0.60 after intervention; P < 0.01).

CONCLUSIONS: Compared with QCA measurements, 3-D OCT analysis could be useful to guide decisions regarding additional intervention after stent implantation across coronary bifurcation lesions.