OBJECTIVES: To investigate the impact of branching angle (BA) on neointimal coverage of drug-eluting stents (DESs) in bifurcation lesions.
BACKGROUND: Previous experimental studies indicated that BA influences the local flow turbulence and wall shear stress, which are associated with neointimal coverage of DESs.
METHODS: Fifty-five bifurcation lesions in 47 patients were evaluated by serial optical coherence tomography (OCT) before DES implantation and at follow-up. Neointimal coverage was assessed in cross-sectional OCT images containing the side branch; regions including the side branch ostium (SO) and vessel wall (VW) were assessed separately. BA was measured using angiography (Angio-BA) and longitudinal OCT imaging (OCT-BA).
RESULTS: In the SO region, a significant negative correlation was found between the uncovered strut percentage and Angio-BA or OCT-BA (r=-0.41, P=0.0024; r=-0.33, P=0.0167, respectively) and a significant positive correlation was found between Angio-BA and average neointimal thickness (r=0.31, P=0.025), whereas no correlation was observed between OCT-BA and average neointimal thickness (r=0.20, P=0.158). In the VW region, no correlation was found between Angio-BA or OCT-BA and the uncovered strut percentage or average neointimal thickness.
CONCLUSIONS: BA influence the neointimal coverage over DES struts in the SO at coronary bifurcation lesions, but not in those attached to the VW.