ObjectivesFollow-up invasive coronary angiography (FUICA) after percutaneous coronary intervention (PCI) has been shown to increase the rate of early coronary revascularisation without reducing the incidence of subsequent myocardial infarction or death. However, no studies have evaluated the cost-effectiveness of FUICA in patients after coronary stenting. Therefore, this study aimed to evaluate the cost-effectiveness of FUICA after PCI.DesignRetrospective observational cohort study.Setting497 hospitals.Participants and interventionsOverall, 558 patients who underwent coronary artery stenting between April 2014 and March 2015 were matched and included in the invasive angiographic follow-up (AF) group (n=279), in which patients underwent FUICA 6–12 months after PCI, or in the clinical follow-up alone group (CF; n=279) using propensity scores.Primary and secondary outcome measuresThe primary endpoint was the composite outcome of death, myocardial infarction, urgent coronary revascularisation, stroke or hospitalisation for the heart failure. The secondary endpoints included all-cause death, non-fatal myocardial infarction, urgent revascularisation, coronary artery bypass grafting, stroke, hospitalisation for the heart failure and any coronary revascularisation after a minimum of 6 months of follow-up.ResultsCosts were calculated as direct medical expenses based on medical fee billing information. The cumulative 3-year incidence of the primary endpoint was 5.3% in the AF group and 4.7% in the CF group (HR 1.02; 95% CI 0.47 to 2.20; p=0.98). The total incremental cost at the 3-year endpoint in the AF group was US$1874 higher than that in the CF group (US$8947±US$5684 vs US$7073±US$6360; p≤0.001).ConclusionsFUICA increased the costs but did not improve clinical benefits. Thus, FUICA is not economically more attractive than CF alone.Trial registration numberUMIN000039768.