Post-intervention minimal stent area as a predictor of target lesion revascularization after everolimus-eluting stent implantation for in-stent restenosis: a single-center observational study.

BACKGROUND Everolimus-eluting stent (EES) is effective for treating in-stent restenosis (ISR). However, the long-term incidence of target lesion revascularization (TLR) is unknown. Further, the role of post-intervention minimal stent area (MSA) measured by intravascular ultrasound (IVUS) in TLR is unknown in this setting. PATIENTS AND METHODS Overall, 223 ISR lesions (192 patients) that were treated with EES between 2010 and 2016 were analyzed retrospectively. Lesions were divided into two groups according to the post-intervention MSA [≤5.3 mm: 72 lesions (67 patients), and >5.3 mm: 151 lesions (138 patients)]. The cut-off point was determined on the basis of receiver operating characteristic curve analysis. RESULTS The cumulative 5-year incidence of TLR was significantly higher in the group with MSA of 5.3 mm or less than in the group with MSA more than 5.3 mm (15.8 and 7.2%, P=0.01). After adjusting for confounders, the excess risk of the group with MSA of 5.3 mm or less relative to the group with MSA more than 5.3 mm for TLR remained significant [hazard ratio: 3.07, 95% confidence interval (CI): 1.17-8.51, P=0.02]. Using multivariate logistic regression analysis, we identified female sex (odds ratio: 2.39, 95% CI: 1.06-5.49, P=0.04) and stent size of 3.0 mm or less (odds ratio: 13.43, 95% CI: 6.23-32.38, P<0.0001) as independent predictors of MSA of 5.3 mm or less. CONCLUSION EES implantation for ISR was associated with an acceptable rate of TLR through long-term follow-up. Post-intervention MSA of 5.3 mm or less was associated independently with a higher risk for TLR.