Correlation between clinical and histologic patterns of degenerative mitral valve insufficiency: A histomorphometric study of 130 excised segments

The objectives of this study were to examine quantitatively the histologica l changes in incompetent degenerative mitral valves obtained at surgery for mitral valve repair, and to determine whether Barlow's disease (BD) and fi broelastic deficiency (FED) can be distinguished by histology. The billowin g mitral leaflet syndrome (or Barlow's disease) and I;ED can be distinguish ed on the basis of clinical patterns and gross features, but their histolog ic patterns have not been described. One hundred thirty patients were studi ed. Thirty-nine (24 males) had ED; 44 (38 males) FED; 15 (7 males) Marfan's syndrome (MS); and 32 patients (25 males) a non-determined degenerative di sease. Histological changes of the resected segment of the valve were quant itatively evaluated using scores of severity. A discriminant analysis was p erformed. The groups defined by the computer were checked for concordance w ith groups defined by the surgeon, Collagen alterations were found the most severe in MS patients. ED and MS had the most myxoid infiltration. MS and FED patients had the most elastic fiber alterations. No ED in males and onl y one in females were misclassified by the discriminant procedure into the FED group. Overall, the percentages of correct matchings were 54% in males and 62% in females. When the age of patients and the size of ring were adde d to histology to determine whether this additional information provided mo re discrimination, the percentages of correct matchings reached 90% in male s and 100% in females. ED and FED are two fairly distinct entities, which c an be distinguished by quantitative histology, whereas only modest differen ces were found in qualitative histology. (C) 1999 by Elsevier Science Inc.