The aim of this randomized prospective study was to evaluate the quality of life (QoL) using the "Seattle Angina Questionnaire" (SAQ) in patients with chronic total occlusion (CTO) in coronary arteries treated with either percutaneous coronary intervention (PCI) or optimal medical therapy (OMT), or only with OMT.The potential benefits of recanalization of CTO by PCI have been controversial because of the scarcity of randomized controlled trials.A total of 100 patients with CTO were randomized (1:1) prospectively into the PCI CTO or the OMT group (50 patients in each group). There were no baseline differences in the SAQ scores between the groups, except for physical limitation scores (P = 0.03). During the mean follow-up (FUP) of 275 ± 88 days, patients in the PCI group reported less physical activity limitations (72.