TCT-599 Enlargement of Distal Vessel Diameter after Percutaneous Coronary Intervention of Chronic Total Occlusion - Relationship with Collateral Flow and Intravascular Ultrasound Findings

Abstract

Background: Although the vessel diameter distal to the recanalized CTO lesion is often smaller than expected immediately after recanalization, the vessel tends to increase their diameter after one year. Therefore, we assessed how the distal segment vessel diameter would increase at 1-year follow-up. Methods: Consecutive patients (n1⁄488) who received successfully recanalization of CTO lesions from July 2007 to September 2011 and had 1-year follow-up catheterization were analyzed. We classified them into two groups by the Rentrop collateral flow grade: Group A, grade 0 to 2 and Group B, grade 3. We evaluated by IVUS the plaque burden and minimum lumen diameter of the distal vessel segment immediately after recanalization. Vessel diameter distal to the recanalized CTO lesions (at 10mm from distal stent edge) was compared between follow-up and immediately after recanalization (baseline) by quantitative coronary angiography. Results: Vessel diameter increased significantly from baseline to follow-up (2.0 0.7mm vs. 2.4 0.7mm, P<0.05). Vessel diameter increased more in Group B than in Group A (76.9% vs. 94.3%mm P<0.05). There was no significant difference in IVUS findings between the patients with and without vessel diameter increase. Conclusions: Vessel diameter in the distal segment of CTO lesion increased at 1-year follow-up especially in the patients with good collateral flow.