Combined papillary muscle sling and ring annuloplasty for moderate-to-severe secondary mitral regurgitation.

BACKGROUND: There is a 30-60% incidence of recurrent mitral regurgitation (MR) after mitral valve annuloplasty (Ring) for secondary MR. A concomitant papillary muscle sling (Ring+Sling) may improve valve repair by providing a more physiologic geometry of the mitral apparatus.
METHODS: We retrospectively identified 58 consecutive patients with moderate-to-severe secondary MR who underwent a Ring+Sling repair, between March 2008 and May 2015. A Ring+Sling consisted of combined annuloplasty and papillary muscle approximation, utilizing a 4-mm polytetrafluoroethylene graft placed around the base of each muscle. Comparison of echocardiographic variables with patients who underwent a Ring only was performed utilizing 2:1 propensity-score matching (Ring+Sling = 34; Ring = 17).
RESULTS: The baseline demographics were similar between the groups. The mean time to follow-up echocardiogram was 10.1 months (range 0.25-42 months). At follow-up, a Ring+Sling repair was associated with a lower mitral valve tenting height (p = 0.005), mitral valve tenting area (p = 0.009), and interpapillary muscle distance (p = 0.001); a smaller posterior leaflet tethering angle (p = 0.003); and a greater leaflet coaptation length (p = 0.002), when compared with Ring only. Recurrence of moderate or greater MR occurred significantly less in the Ring+Sling group (14.7%), as compared with Ring only (35.3%) (p < 0.001). Finally, actuarial survival at three years was 87% for Ring+Sling, and 82% for Ring only (p = 0.49).
CONCLUSIONS: A Ring+Sling for secondary MR results in favorable changes in the mitral valve apparatus geometry, and is associated with less MR recurrence in the early postoperative period. Longer-term follow-up is needed to assess its durability and effects on left ventricular remodeling and survival.