The intravascular ultrasound (IVUS) criteria for stent optimization have not been determined in stenting long lesions. We evaluated the predictors of angiographic restenosis and compared it with stent lumen cross-sectional area (CSA) and stent length between short (stent length <20 mm) and long (greater than or equal to 20 mm) coronary stenting. IVUS-guided coronary stenting was successfully performed in 285 consecutive patients with 304 native coronary lesions. Six-month follow-up angiogram was performed in 236 patients (82.8%) with 246 lesions (80.9%). Results were evaluated using conventional (clinical, angiographic, and IVUS) methods. The overall angiographic restenosis rate was 22.8% (56 of 246 lesions) (short stent 17.6% vs long stent 32.2%, p 0.009). Using multivariate logistic regression analysis, the independent predictors of angiographic restenosis were the IVUS stent lumen CSA (odds ratio 1.51, 95% confidence intervals 1.18 to 1.92, p = 0.001) and stent length (odds ratio 0.95, 95% confidence intervals 0.91 to 1.00, p = 0.039). The angiographic restenosis rate was 54.8% for stent lumen CSA of <5.0 mm(2) (short stent 37.5% vs long stent 73.3%, p = 0.049), 27.4% for CSA between 5.0 and 7.0 mm(2) (short stent 24.1% vs long stent 31.7%, p = 0.409), 10.5% for CSA between 7.0 and 9.0 mm(2) (short stent 10.0% vs long stent 12.5%, p = 0.772), and 11.4% for stent lumen CSA of greater than or equal to 9.0 mm(2) (short stent 10.4% vs long stent 13.3%, p = 0.767) (p = 0.001). Compared with short coronary stenting, long coronary stenting is effective treatment modality to cover long lesions with comparable long-term clinical outcomes in cases of stent lumen CSA of greater than or equal to 7.0 mm(2). Regardless of the stent length, the most important factor determining angiographic restenosis was the IVUS stent lumen CSA in relatively large coronary artery lesions. (C) 2000 by Excerpta Medica, Inc.