Late Catch-Up Phenomenon Associated with Stent Fracture after Sirolimus-Eluting Stent Implantation: Incidence and Outcome

Abstract

To examine the long-term outcome of the stent fracture (SF) and the potential predictive factors contributing to in-stent restenosis (ISR) in the fractured stent. The SF is thought to be a higher risk of ISR in drug-eluting stent, although SF does not always develop ISR. The consecutive 1,228 de novo lesions in 1,079 patients who underwent sirolimus-eluting stents implantation and assessed by 8 months follow-up coronary angiography were retrospectively analyzed. One hundred and seventeen SFs (9.5%) were identified in 100 patients and 22 (18.8%) SFs revealed ISR at the first follow-up. In addition, 16 (13.7%) developed new ISRs from 95 residual SFs without ISR prior to the second follow-up. Overall, 38 (32.5%) of all 117 SFs developed ISR, and 16 (42.1%) of 38 SFs occurred in a late phase beyond the first 8 months follow-up. A higher risk of ISR in the SF site was associated with the chronic total occlusion (ISR vs. no ISR: 34.2% vs. 16.5%, P = 0.0304), calcified lesions (55.3% vs. 34.2%, P = 0.0299), and correspondence 89.5% versus 43.0%, P < 0.0001 (SF site occurring at the original target lesion site) in the univariate analysis. The correspondence was identified as the only strong predictive factor for ISR at the SF site according to a multivariate logistic regression analysis (odds ratio 12.6, 95% confidence interval 3.82-53.5, P < 0.0001). SF occurring at the site of the original target lesion was a strong independent predictor of ISR. This indicates the need for a careful, long-term follow-up in those situations, even when no significant ISR is initially detected.