Ischemic mitral regurgitation: mitral valve replacement, restrictive annuloplasty or multi-component reconstruction with subvalvular intervention (systematic review and meta-analysis)

Objective: The study is aimed at assessing short- and long-term results of various strategies of surgical treatment in patients with ischemic mitral insufficiency. Methods: The study design was accomplished according to the PRISMA criteria in the PubMed, Google Scholar and eLibrary databases. Surgical treatment included 3 strategies: mitral valve replacement (MVR) with preservation of subvalvular structures, restrictive annuloplasty (RA) and reconstruction with intervention on subvalvular structures (RISS). The primary endpoint included all-cause death during 30 days or follow-up period, as well as rehospitalization caused by heart failure progression. The secondary endpoint was related to recurrence of mitral regurgitation - 2 degree, effective reverse left ventricular remodeling and reoperation. The discussion presents own authors’ experience based on treatment of 100 patients with type IIIb ischemic mitral regurgitation and low reconstructive potential (median follow-up 62 months). Results: The analysis involved 29 papers (n = 4,857) representing by 2 randomized controlled trials (7 %, n = 347) and 27 retrospective investigations (93 %, n = 4,424). All patients underwent coronary artery bypass grafting or stenting of the coronary arteries. All included studies were divided into 2 groups according to the compared type of surgery strategies: 1) isolated restrictive annuloplasty (RA) versus mitral valve replacement (MVR) with preservation of subvalvular structures (19 papers, n = 4,020); 2) isolated restrictive annuloplasty (RA) versus reconstruction with intervention on subvalvular structures (RISS) (10 papers, n = 751). Comparison of MVR and RA: 30-day mortality was 11.78% (164/1,392) in the MVR group vs 6.28% (150/2,389) in the RA group, p < 0.0001 (further indicators are referred to MVR and RA comparison, respectively); long-term mortality reached 28.62% (281/982) vs 25.35% (413/1,629), p = 0.067; mitral regurgitation - 2 degree manifested at the level of 3.82% (27/707) (paraprosthetic regurgitation) vs 18.91% (173/915), p < 0.0001; reoperation was performed in 6.56% (49/747) of patients vs 9.21% (63/684), p = 0.0622. Comparison of RISS and RA: 30-day mortality was 4.86% (15/307) in the RISS group vs 7.93% (28/353) in the RA group, p = 0.11 (further indicators are referred to RISS and RA comparison, respectively); long-term mortality was 12.62% (13/103) vs 15.53% (16/103), p = 0.55; mitral regurgitation - 2 degree was detected in 7.30% (17/233) of cases vs 24.19% (67/277), p < 0.01; rehospitalization was performed in 17.48% (18/103) of cases vs 28.16% (29/103), p = 0.07; reoperation was accomplished in 2.94% (4/136) of cases vs 7.41% (12/162), p = 0.09; effective reverse left ventricular remodeling was characterized by left ventricular end-diastolic dimension of –8.9%, p < 0.01 vs –2.2%, p = 0.04. Conclusion: The choice of a surgical treatment strategy in patients with ischemic mitral regurgitation should be determined by the type of mitral dysfunction. In type I, restrictive annuloplasty may be an effective technique, while in type IIIb, reconstruction with intervention on subvalvular structures or mitral valve replacement with preservation of subvalvular structures is necessary.