Aims Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has been shown to reduce angina and improve quality of life, but the frequency of new or residual angina after CTO PCI and its relationship with titration of anti-anginal medications (AAMs) has not been described. Methods and results Among consecutive CTO PCI patients treated at 12 US centres in the OPEN CTO registry, angina was assessed 6 months after the index PCI using the Seattle Angina Questionnaire (SAQ) Angina Frequency scale (a score Conclusions One in five patients reported angina 6 months after CTO PCI. Although patients with new or residual angina were more likely to have escalation of AAMs in follow-up compared with those without residual symptoms, only one in four patients with residual angina had escalation of AAMs. Although it is unclear whether this finding reflects maximal tolerated therapy at baseline or therapeutic inertia, these findings suggest an important potential opportunity to further improve symptom control in patients with complex stable ischaemic heart disease.