Subgroup analyses demonstrated that the relationship between the PNI and the risk of MACCEs remained consistent across various patient strata, including age, sex, BMI, diabetes mellitus, hypertension, current smoking status, LVEF, LDL-C, Hb, WBC, PLT, ALT, AST, FPG, Cr, number of CTO vessels, number of stents implanted, overall stent length, total procedural time, and contrast volume, with no significant interactions observed (all P for interaction > 0.05) (Figure 3). This evidence concerns the gene GSTM1 and diabetes mellitus.