Background Strategies ofpercutaneous coronary intervention (PCI) for chronic total occlusion(CTO) with multivessel disease remain to be unknown as more new devices and techniques have developed.Methods 166 consecutive patients with CTO in multivessel disease recruited from October 2010 to October 2011 were randomly divided into CTO-First (PCI for CTO first, then non-CTO stenosis; n=85) and CTO-Second (PCI for non-CTO stenosis first, then CTO, n=81) in the prospective, double-blind trial.The primary endpoint was the occurrence of major adverse cardiac events (MACE) at the end of follow-up.