on behalf of the EVENT InvestigatorsBackground-Prediction of restenosis after percutaneous coronary intervention (PCI) remains challenging, and existing risk assessment algorithms were developed before the widespread adoption of drug-eluting stents (DES). Methods and Results-We used data from the EVENT registry to develop a risk model for predicting target lesion revascularization (TLR) in 8829 unselected patients undergoing DES implantation between 2004 and 2007. Using a split-sample validation technique, predictors of TLR at 1 year were identified from two thirds of the subjects (derivation cohort) using multiple logistic regression. Integer point values were created for each predictor, and the summed risk score (range, 0 to 10) was applied to the remaining sample (validation cohort). At 1 year, TLR occurred in 4.2% of patients, and after excluding stent thrombosis and early mechanical complications, the incidence of late TLR (more likely representing restenosis-related TLR) was 3.6%. Predictors of TLR were age Ͻ60, prior PCI, unprotected left main PCI, saphenous vein graft PCI, minimum stent diameter Յ2.5 mm, and total stent length Ն40 mm. Comparison of observed versus predicted rates of TLR according to risk score demonstrated good model fit in the validation set. There was more than a 3-fold difference in TLR rates between the lowest risk category (scoreϭ0; TLR rate, 2.2%) and the highest risk category (score Ն5; TLR rate, 7.5%). Conclusions-The overall incidence of TLR remains low among unselected patients receiving DES in routine clinical practice. A simple risk model incorporating 6 readily available clinical and angiographic variables helps identify individuals at extremely low (Ͻ2%) and modestly increased (Ͼ7%) risk of TLR after DES implantation. (Circ Cardiovasc Interv. 2010;3:327-334.)