BACKGROUND: Coronary chronic total occlusions (CTO) are commonly encountered complex lesions identified in about 15% of all patients referred for coronary angiography (CAG). Despite improving techniques for opening CTO, the benefit of successful recanalization of the artery remains unclear. The aims of this study were to investigate the efficacy and safety of percutaneous coronary interventions (PCI) for CTO, defined by Thrombolysis In Myocardial Infarction (TIMI) flow grade 0 and duration >3months, and to compare the outcome of successful versus failed procedures. METHODS: 176 consecutive patients with de novo CTOs of native vessels confirmed by angiographic review in which PCI were attempted was studied. Among 176 patients, 106 (60.2%) were by Transfemoral intervention (TFI) and 72 (39.8%) were transradial Intervention(TRI). Primary end points included long-term major adverse cardiac events (MACE) and in-hospital complications in the successful or failed procedure group. RESULTS: Technical success was obtained in 71% of CTO lesions (128 of 176). 3 (1.7%) deaths or nonfatal QMI occurred in the hospital. No repeat PCI in the hospital were required. Coronary perforation during the initial failed attempts occurred in 4.1% of patients (2 of 48). After an average follow-up period of 1 year, patients with successful or failed procedures experienced no difference in MACE (6.2% and 6.7%, respectively, p =0.473). In addition, there was no diffence in MACE and in hospital mortality beween TFI and TRI. Patients with readmission for refractory angina was 2 (1.1%) and Patients with successfully opened arteries required target vessel revascularization rate was 5%(8/176). CONCLUSION: There was no difference in long-term an short-term clinical outcomes between successful recanalization group and failed procedures group.