Background: Five definitions of peri-procedural myocardial infarction (PMI) following percutaneous coronary intervention (PCI) are used in clinical trials; their clinical relevance in coronary bifurcation stenting remains unclear.Objectives: To understand the correlation between PMI and mortality in bifurcation lesions from the DKCRUSH studies.Methods: PMI was defined using serum creatine kinase-myocardial band (CK-MB) values within 48 h of PCI according to the SYNTAX, Fourth Universal Definition of MI (4th UDMI), ISCHEMIA, SCAI, and EXCEL definitions. Overall, 1300 patients with both CK and CK-MB measurements pre-and post-stenting were evaluated. The association of each PMI type and all-cause death or cardiac death at a median of 5.58 years of follow-up was analyzed using Cox regression.Results: In total, 56 (4.3%) patients had PMI. According to SYNTAX, 4th UDMI or ISCHEMIA, SCAI, and EXCEL definitions, PMI occurred in 21 (1.6%), 56 (4.3%), 29 (2.2%), and 32 (2.5%) patients, respectively. All definitions were significantly correlated with unadjusted mortality at the end of follow-up but not at 30 days or 1-year after stenting. PMI using SYNTAX, SCAI, and EXCEL definitions rather than 4th UDMI definition was strongly associated with adjusted all-cause death. By adjusted analysis, PMI according to 4th UDMI, SCAI, and EXCEL definitions but not SYNTAX definition was positively correlated with cardiac death at a median of 5.58 years of follow-up. CK-MB ≥ 5 x UNL strongly enhanced the correlation of CK-MB values with mortality.Conclusions: PMI rate varies with the definition following stenting for bifurcation lesions. PMI defined by SCAI and EXCEL definitions is strongly correlates with adjusted all-cause and cardiac death.Imad Sheiban, Zhen Ge, and Jing Kan contributed equally to manuscript.