Background:Debate on treatment for young patients with coronary artery disease still exists.This study aimed to investigate the intermediate-and long-term outcomes between coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) in patients aged 18-45 years with diabetes mellitus (DM).Methods:Between January 2006 and March 2016,a total of 2018 DM patients aged 18-45 years including 517 cases of CABG and 1501 cases of PCI were enrolled in the study.Using propensity score matching (PSM),406 patients were matched from each group.The intermediate-and long-term data were collected.The primary end point of this study was long-term death.The secondary end points included long-term major adverse cardiovascular and cerebrovascular events (MACCEs),stroke,angina,myocardial infarction (MI),and repeat revascularization.Results:Before PSM,the in-hospital mortality was 1.2％ in the CABG group and 0.1％ in the PCI group,with statistically significant difference (P ＜ 0.0001).The 10-year follow-up outcomes including long-term survival rate and freedom from MACCEs were better in the CABG group than those in the PCI group (97.3％ vs.94.5％,P =0.0072;93.2％ vs.86.3％,P ＜ 0.0001),but CABG group was associated with lower freedom from stoke compared to PCI group (94.2％ vs.97.5％,P =0.0059).After propensity score-matched analysis,these findings at 10-year follow-up were also confirmed.Freedom from MACCEs was higher in CABG group compared to PCI group,but no significant difference was observed (93.1％ vs.89.2％,P =0.0720).The freedom from recurrent MI was significantly higher in CABG patients compared with PCI patients (95.6％ vs.92.5％,P =0.0260).Furthermore,CABG was associated with a higher rate of long-term survival rate than PCI (97.5％ vs.94.6％,P =0.0403).There was no significant difference in the freedom from stroke between CABG and PCI groups (95.3％ vs.97.3％,P =0.9385).The hospital cost was greater for CABG (13,936 ± 4480 US dollars vs.10,926 ± 7376 US dollars,P ＜ 0.0001).Conclusions:In DM patients aged 18-45 years,the cumulative survival rate,and freedom from MI and repeat revascularization for CABG were superior to those of PCI.However,a better trend to avoid stroke was observed with PCI.