Objective:To compare the effects of staged percutaneous coronary intervention(PCI)after emergency PCI and emergency culprit-only PCI on clinical outcomes of elderly patients with ST-segment elevation myocardial infarction(STEMI)and multivessel disease.Methods:A retrospective analysis was performed on 389 elderly patients with STEMI and multivessel lesions, aged ≥70 years and within 12 h of onset, admitted to the Clinical College of Thoracic Medicine, Tianjin Medical University, between January 2014 and September 2019.According to different revascularization strategies, enrolled patients were divided into the culprit-only PCI group(79.18%, 308)and the staged PCI group(20.82%, 81). Kaplan-Meier analysis and the Cox proportional hazards regression model were used to compare the incidences of major adverse cardiac and cerebrovascular events(MACCE), all-cause death, cardiac death, recurrent myocardial infarction, stroke and ischemia-driven revascularization between the two groups and to evaluate the effects of different revascularization strategies on MACCE and all-cause death.Then subgroup analysis was performed.Results:During a 56-month follow-up, 131 patients developed MACCE and 96 patients died.Compared with the culprit-only PCI group, the staged PCI group had a lower risk of MACCE( HR: 0.404, 95% CI: 0.227-0.716, P=0.002), all-cause death( HR: 0.354, 95% CI: 0.171-0.730, P=0.005), cardiac death( HR: 0.363, 95% CI: 0.157-0.838, P=0.018), and recurrent myocardial infarction( HR: 0.229, 95% CI: 0.055-0.953, P=0.043). There was no significant difference in the incidence of stroke or ischemia-driven revascularization between the two groups( P>0.05). The reduced risk with staged PCI for MACCE and for all-cause mortality persisted in all subgroups.Multivariate Cox proportional hazards regression revealed that, after adjusting for confounding factors, staged PCI was an independent protective factor for MACCE( HR: 0.44, 95% CI: 0.239-0.815, P=0.009)and for all-cause death( HR: 0.390, 95% CI: 0.90, P=0.020). Conclusion:Compared with culprit-only PCI, staged PCI can significantly improve the long-term prognosis of elderly patients ≥70 years with STEMI and multivessel disease within 12 h of onset.