Novel predictors of late lumen enlargement in distal reference segments after successful recanalization of coronary chronic total occlusion.

OBJECTIVES: Although successful recanalization of coronary chronic total occlusion (CTO) can induce subsequent positive vascular remodeling in the distal segment, the predictors are not fully understood. The aim of this study was to investigate the extent and predictors related to luminal gain after successful CTO recanalization. METHODS: A total of 134 patients who underwent intravascular ultrasound (IVUS)-guided percutaneous coronary intervention (PCI) for CTO and follow-up angiography were included. Angiographic parameters were assessed qualitatively and quantitatively at baseline and follow-up. Gray-scale IVUS images during the PCI procedure were also analyzed. Lumen diameter (LD) at distal reference on the post-PCI angiogram was compared with corresponding LD at follow-up coronary angiography. RESULTS: At the mean follow-up of 10.0 ± 2.7 months, LD at distal reference was significantly increased by 15.9% from baseline to follow-up (2.06 ± 0.62 vs. 2.30 ± 0.55 mm, p < 0.001). Univariable analysis indicated that the left anterior descending artery (LAD), no moderate or severe calcification, presence of peri-medial high-echoic band on IVUS, and impairment of final coronary flow and small distal reference diameter at baseline were associated with greater late lumen enlargement. Multivariable analysis showed the LAD, no moderate or severe calcification, and small LD at distal reference as independent predictors of greater late lumen enlargement. CONCLUSION: The segment distal to recanalized CTO showed significant late lumen enlargement, especially in the cases with small distal reference, in the LAD, and without moderate or severe calcification.