Seeking a higher standard for degenerative mitral valve repair: begin with etiology.

doi:10.1016/j.jtcvs.2007.10.060 D espite the widely held consensus that valve repair is the preferred surgical treatment for patients suffering from degenerative mitral valve disease, valve replacement for this condition remains all too prevalent. In the past few years interest in mitral valve repair has expanded among cardiologists and surgeons, with the recognition that asymptomatic patients with severe mitral regurgitation may be candidates for surgery provided they are likely to undergo valve repair and obtain a durable result. We address both issues in the context of a recent article published in the Journal, which explored the results of mitral valve repair in degenerative disease according to etiologic classification – Barlow’s disease or fibroelastic deficiency. Most reports in the mitral valve repair literature define patient subsets on the basis of leaflet dysfunction (posterior, anterior or bileaflet prolapse) and repair techniques (chordal shortening or artificial chordoplasty; annuloplasty ring or no annuloplasty ring, etc.), without clarification of the etiology of degenerative disease. Furthermore, these studies traditionally used patient survival and freedom from re-operation as the principal indicators of a durable result. Recently, however, it has been appreciated that a proportion of patients free from reoperation after mitral valve repair have significant recurrent mitral regurgitation implying that freedom from reoperation is not a robust measure of durability of mitral valve repair. In their recent article, Flameng and co-workers introduced a fresh dimension into mitral valve repair outcomes research, by attempting to define the long-term outcome of mitral valve repair, including the freedom from recurrent mitral regurgitation, on the basis of etiology of degenerative mitral valve disease. Their data suggest, perhaps surprisingly, that, provided the surgical techniques were optimal, patients have a similar rate of recurrent regurgitation after mitral valve repair regardless of whether the original disease was Barlow’s or fibroelastic deficiency. There are several limitations in their analysis which deserve emphasis and suggest the need for further study, including retrospective classification of etiology and non-standardized and evolving surgical techniques – both of which limit the robustness of outcomes data. Nonetheless, this emphasis on etiologic classification in outcomes analysis of degenerative mitral valve repair is significant. We believe accurate etiologic classification is crucial to outcomes research, and indeed to achieving a higher standard of clinical care, as it does not seem logical that degenerative valves with very diverse characteristics (Figure 1a, 1c) are considered the same.