RESUMO
BACKGROUND AND OBJECTIVES: Percutaneous coronary intervention with stent implantation has been shown to reduce the rate of restenosis as compared with conventional balloon angioplasty, but the risk of in-stent restenosis continues to be a significant limitation of this procedure. Of the numerous studies evaluating the predictors of in-stent restenosis, several have indicated that smaller stent sizes, smaller reference diameters and smaller final stent diameters maybe be associated with an increased risk of restenosis. SUBJECTS AND METHODS: We studied 164 patients with native coronary artery lesions who were treated with coronary stent and underwent angiographic follow up from April 1999 to Jan 2002. Clinical characteristics, angiographic features, and factors related to stenting procedure were analyzed in order to evaluate the affect of predictors on in-stent restenosis. RESULTS: Angiographic analysis presented in-stent restenosis in 86 patients (52.3%). Between the in-stent restenosis group and the non-restenosis group, there were no differences in baseline characteristics except for smoking. The in-stent restenosis group had a significantly smaller reference diameter (2.94+/-0.47 vs. 3.12+/-0.59 mm, p=0.039), smaller stent diameter (3.05+/-0.45 vs. 3.21+/-0.55 mm, p=0.012) and longer stent length (19.98+/-4.12 vs. 17.89+/-4.06 mm, p=0.048) than the non-restenosis group by angiographic analysis (p<0.05). Multivariate analysis revealed that stent length (odds ratio, 1.20) is a predictive factor for in-stent restenosis. In the in-stent restenosis group, the diffuse type, in-stent restenosis group (45.4%) showed more frequent ACC/AHA type C lesions than focal type, in-stent restenosis group (15.2%) (p<0.001). CONCLUSION: Longer coronary stent length is associated with an increased risk of in-stent restenosis and diffuse type, in-stent restenosis. ACC/AHA class C lesions are associated with an increased risk of diffuse type, in-stent restenosis.