AIMS: METHODS AND RESULTS: Of 11 957 consecutive patients referred for nonurgent PCI between 2003 and 2010, 1110 displayed single CTO and were enrolled to the central CTO-registry database. The primary end-point included all-cause mortality, the secondary end-point a composite of safety outcome measure of all-cause death, nonfatal-MI, the need for urgent revascularization and stroke. The major adverse cardiovascular event (MACE) records were extracted from the national administrative database and all patients were linked to the long-term follow-up. Since the patient assignment was not random, we performed the propensity scoring to minimize selection bias; 734 patients (66%) had a successful PCI-CTO. Compared with successful procedures, unsuccessful procedures had similar rates of all-cause death both in crude (HR, 0.78; 95%CI, 0.49–1.25; P = 0.30) and adjusted analysis (HR, 0.80; 95%CI, 0.50-1.28; P = 0.34). A similar, significant reduction in overall MACE was noted with successful PCI-CTO compared with unsuccessful procedure in unadjusted (HR, 0.74; 95%CI, 0.56–0.96; P = 0.020) and adjusted calculation (HR, 0.73; 95%CI, 0.56–0.96; P = 0.019). Patients after successful PCI-CTO as compared with failed recanalization less frequently underwent surgical revascularization. The benefit was sustained at 3 years follow-up. CONCLUSIONS