Objective·To investigate the predictive value of the Clinical Frailty Scale(CFS)in the long term outcomes in acute myocardial infarction(AMI)patients who completed in-hospital cardiac rehabilitation(CR).Methods·A total of 501 AMI patients treated in the Cardiology Center of Shanghai Sixth People's Hospital,Shanghai Jiao Tong University of Medicine from May 2020 to May 2022 were prospectively enrolled,with their baseline clinical data collected.The patients completed graded in-hospital CR and were assessed by CFS based on their completion of CR before discharge.Patients were then categorized into three groups(norm group,vulnerable group and frail group)according to their CFS level.The difference in 1-year major cardiovascular event(all-cause death and re-hospitalization for heart failure)rates among the three groups was investigated.Logistic regression analysis was performed to explore the effective risk factors relevant to the outcomes,and receiver operator characteristic(ROC)curves were generated to analyze the prognostic value.Finally,an optimal prediction model was developed.Results·The CFS level in AMI patients who completed CR was positively correlated with age and peak pro-B-type natriuretic peptide(peak proBNP),and inversely correlated with gender difference(P<0.05).Accompanied with the elevated CFS level,the incidence of both outcomes increased,and there were significant differences in all-cause death(2.6%,5.6%and 15.2%,P=0.002),and while no significant differences in re-hospitalization for heart failure among the three groups(19.6%,22.2%and 24.2%).All-cause death of the frail group was significantly higher than that of the norm group(P=0.004),while there was no significant difference between the vulnerable group and the norm group.CFS could sensitively predict the 1-year all-cause death in AMI patients(β=1.89,OR=6.61,P=0.001),and the risk model combined with CFS had the best predictive effect(AUC=0.845,P=0.000).Conclusion·Assessment by CFS in AMI patients who completed in-hospital CR contributes to identifying AMI patients with high risk of all-cause death in 1 year.