50%). All the patients were catagorized into 3 groups according to the intervention (stenting, PTCA or no touch) applied in the side branches and the clinical outomes of the three different groups were compared. Results Among the 93 patients, 21 patients received stenting and 24 patients received balloon angioplasty in the side branches. No intervention was given in 48 patients. Although patients in the stenting group and the PTCA group could maintain a greater vessel lumen in the side branches compared with patients without intervention (40.21%, 41.76% and 80.23%, P