Effect of Recurrent Mitral Regurgitation Following Degenerative Mitral Valve Repair: Long-Term Analysis of Competing Outcomes.

BACKGROUND: The risk for and consequences of recurrent mitral regurgitation (MR) following degenerative mitral valve repair are poorly understood.

OBJECTIVES: This study sought to examine recurrent MR risk along with reoperation and survival rates.

METHODS: We evaluated patients undergoing primary mitral repair for isolated degenerative MR over 1 decade. Median follow-up was 11.5 years (interquartile range: 9.2 to 13.6 years) and was 99% complete. Multivariate analysis of post-repair MR recurrence employed Cox proportional hazards and multistate modeling.

RESULTS: A total of 1,218 patients met the study criteria; the mean age was 64 ± 13 years, mean ejection fraction was 63 ± 9%, and 864 (71%) patients were men. Prolapse was posterior in 62%, bileaflet in 26%, and anterior in 12%. The 15-year incidence of recurrent MR (i.e., MR ≥2) was 13.3%, incidence of mitral reoperation was 6.9%, and overall mortality was 44.0%. Repair before 1996 independently predicted MR recurrence (hazard ratio: 1.52). Additional determinants were: age, mild intraoperative residual MR, anterior leaflet prolapse, bileaflet prolapse, perfusion time >90 min, and lack of annuloplasty. Recurrence of moderate or greater MR was associated with adverse left ventricular remodeling and increased likelihood of death (hazard ratio: 1.72). Among those undergoing repair after 1996, MR recurrence rate was 1.5 per 100 patient-years during the first year post-repair, decreasing markedly to 0.9 thereafter.

CONCLUSIONS: Our study demonstrated that recurrent MR following degenerative mitral valve repair is associated with adverse left ventricular remodeling and late death. The incidence of MR recurrence decreases markedly following the first year after intervention. A transparent discussion of recurrent MR risk has pressing relevance when referring patients with complex mitral valve prolapse.