Is an adjunctive subvalvular repair during mitral annuloplasty for secondary mitral regurgitation effective in preventing recurrent regurgitation?

Abstract

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: Is an adjunctive subvalvular repair during mitral annuloplasty for secondary mitral regurgitation effective in preventing recurrent regurgitation? Altogether, 353 studies were found using the reported search, of which 9 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers were tabulated. The best evidence regarding adjunctive subvalvular repair during mitral annuloplasty for secondary mitral regurgitation was from retrospective analyses. The studies reported outcomes of mitral valve repair (MVr) with annuloplasty alone (ring MVr) versus adjunctive papillary muscle approximation (PMA; n = 3), papillary muscle relocation (PMR; n = 3), secondary chordal cutting (n = 2) and PMA + PMR (n = 1). All but one study included concomitant coronary artery bypass grafting, whereas additional ventriculoplasty was performed in three studies. Follow-up ranged from 1 month to 5 years. The performance of PMA was associated with a lower mitral regurgitation (MR) grade when combined with ventriculoplasty in one study, whereas a greater improvement in left ventricular end-diastolic diameter and left ventricular ejection fraction at follow-up was observed with PMA alone in a separate study. Three studies of ring + PMR reported a reduction in ≥ 2+ recurrent MR, whereas two studies also observed a greater reduction in left ventricular end-diastolic diameter. The two studies on secondary chordal cutting reported a lower MR grade, lower recurrence of ≥ 2+ MR and a greater left ventricular ejection fraction at follow-up. Combining PMA + PMR + ventriculoplasty significantly reduced left ventricular end-systolic volume index at short-term follow-up in one study. Finally, none of the studies reported a significant difference in operative mortality between ring MVr (0-13%) versus ring MVr + subvalvular repair (0-15%). We conclude that an adjunctive subvalvular repair performed at the time of mitral annuloplasty for secondary MR can be safely performed, improves the durability of valve repair and enhances left ventricular reverse remodelling.

Keywords: Functional mitral regurgitation; Ischaemic mitral regurgitation; Mitral valve repair; Secondary mitral regurgitation; Subvalvular repair.