Abstract 4733: Bending of Coronary Artery Contributes Proximal-edge Restenosis in Patients After Implantation of the Sirolimus-eluting Stent
Background: The mechanisms of the proximal-edge restenosis (PER) of sirolimus-eluting stent (SES) remains unknown. We hypothesized that repetitive bending of coronary artery at the stent-edge may contribute the PER. In this study, we evaluated magnitude of the bending with detailed analysis of intravascular ultrasosound (IVUS) and studied its relation to late-loss at proximal edge of SES.
Methods and Results: We studied 27 patients undergoing single SES implantation in the left anterior descending artery (LAD). Mean age was 69±10 years old, 22 % was diagnosed as diabetes mellitus. Reference diameter was 2.48±0.49 mm, minimum lumen diameter was 0.95±0.40 mm, lesion length was 13.2±6.1 mm. Magnitude of coronary bending was defined as maximal distance of intimal contour in one cardiac cycle toward the epicardium. This measurement was performed in longitudinal view of IVUS. The maximal distance of the intima at proximal and distal edges were 0.21±0.14 mm and 0.23±0.15 mm, respectively. In the follow up period (295±142 days), late loss was calculated as 0.11±0.21 mm, and no patients had target lesion revascularization. Proximal-edge late loss was significantly correlated with the maximal distance of the intimal motion at the proximal stent edge (R=0.716, P<0.001). Multivariate analysis revealed that the maximal distance at the proximal edge was the independent predictor of the proximal-edge late loss (Hazard ratio 2.184, P<0.001).
Conclusion: Magnitude of distance in intimal motion during one cardiac cycle is related to the proximal-edge late loss in LAD. Repetitive bending of coronary artery at the edge of SES may be one of the mechanisms of PER.