Background Subintirnal plaque modification (SPM) is often performed to restore antegrade flow and facilitate subsequent lesion recanalization.This study aimed to compare the safety and efficacy of modified SPM with traditional SPM.Methods A total of 1454 consecutive patients who failed a chronic total occlusion percutaneous coronary intervention (CTO PCI) attempt and underwent SPM from January 2015 to December 2019 at our hospital were reviewed retrospectively.Fifty-four patients who underwent SPM finally were included in this study.We analyzed the outcomes of all the patients,and the primary endpoint was recanalization rate,which was defined as Thrombolysis in Myocardial Infarction (TIMI) grades 2-3 flow on angiography 30 to 90 days post-procedure.Results The baseline characteristics were similar between the two groups.In the follow-up,the recanalization rate was noticeably higher in the modified SPM group compared with the traditional SPM group (90.9％ vs.62.5％,P ＜ 0.05).The proposed strategy in the modified group was more aggressive,including a larger balloon size (1.83 ± 0.30 vs.2.48 ± 0.26 mm,P ＜ 0.05) and longer subintimal angioplasty (0.59 ± 0.16 vs.0.92 ± 0.12 mm,P ＜ 0.05).Also,the common use of a Stingray balloon and guide catheter extension resulted in improvement of patients in the modified SMP group (12.5％ vs.100％,P ＜ 0.05).Conclusion Modified SPM,which is associated with a high likelihood of successful recanalization,is an effective and safe CTO PCI bail out strategy.