Predictive Factors for Restenosis after Drug-Eluting Stent Implantation

Background and Objectives:Despite the dramatic reduction in restenosis conferred by drug-eluting stents (DES), restenosis remains a significant problem for real-world patients. Restenosis is a complex phenomenon, and a variety of stent-, drug-, patientand lesion-related factors have been studied as the determinants of restenosis after DES implantation. Methods and Results:The stent delivery system, the polymer and the drug are integral components of DES, and these are the device-specific factors that can affect restenosis. While the sirolimuseluting Cypher stent appears to provide better outcomes than the paclitaxel-eluting Taxus stent in high-risk patient groups with complex lesions, such differences between the two DES are not apparent in the low-risk groups. Diabetic patients are generally prone to restenosis after percutaneous coronary intervention, but there are conflicting findings regarding the impact of diabetes mellitus on restenosis after DES implantation. The postintervention final lumen area continues to be the most important determinant of restenosis after DES implantation, indicating that a greater stented area contributes to a decreased rate of restenosis even in the DES era. Nonuniform strut distribution and stent fracture also contribute to the development of restenosis after DES implantation. In addition, the risk of restenosis increases linearly according to lesion length, and a “full metal jacket” approach in small vessels is related to a high risk of DES failure. Conclusion:Small vessel disease, diffuse disease and the type of DES are important predictors of restenosis after DES implantation. However, predicting restenosis remains difficult, and this indicates the need for further studies in order to ultimately identify those patients who are at high risk for DES failure. (Korean Circulation J 2007;37:97-102)