The article presents a non-systematic literature review aimed at studying the efficacy and safety of using the technique of resection of secondary chords in ischaemic mitral insufficiency. The review includes studies comparing the use of an isolated undersized ring annuloplasty and undersized ring annuloplasty with chordal cutting. This study is an analysis of publications devoted to the surgical treatment of patients with ischaemic mitral insufficiency (type IIIb according to A. Carpentier classification). Intervention on the subvalvular structures was of interest, particularly the use of a chordal cutting technique in combination with undersized ring annuloplasty versus isolated undersized ring annuloplasty.The Patient Intervention Comparison Outcome (PICO) strategy was used to find articles. During the initial search, 72 articles were selected, of which 36 articles corresponded to the purpose of the search. After analysing the headings and abstracts, 14 articles were selected according to the inclusion criteria. Full-text copies were obtained for all of them. The review design included retrospective cohort studies. Articles in which the assessment of the effectiveness and safety of the technique was not the main topic of the study were excluded from the analysis. Samples of three articles were formed after reviewing and analysing the texts.The results of the study found that the implementation of the combined operation—undersized ring annuloplasty plus secondary chordal cutting—is significantly more effective in comparison with an isolated undersized ring annuloplasty.Received 28 July 2020. Revised 6 October 2020. Accepted 7 October 2020.Funding: The study did not have sponsorship.Conflict of interest: Authors declare no conflict of interest.