[Doppler hemodynamic evaluation of bioprosthetic valve failure in the mitral position]

M-mode and two-dimensional echocardiography (2DE) allows the accurate assessment of primary tissue degeneration of bioprosthetic valves. The Doppler method permits quantitative evaluation of the pressure gradient across the prosthetic valve or detection of regurgitant flow. The present study summarized our clinical experiences of serial cases of mitral valve replacement (MVR) with bioprostheses at the mitral position, and clarified the clinical usefulness and limitations of Doppler and 2DE examinations for the early detection of primary valve dysfunction. Consecutive 65 patients undergoing single mitral valve replacement from April, 1977 to November, 1979 were listed for the study. A survey of the present clinical status was carried out from July, 1988 to July, 1990 (a follow-up period ranged from 84 to 127 months) for all patients, and the information was available from 53 patients (47 adults and six infants). Twenty-four survived patients without re-MVR were examined by Doppler and 2DE. Among the 53 patients, 34 were alive and 19 dead, and the total survival rate was 64.2%. The reasons for death in 19 patients were perioperative death in seven (including four infants with severe calcification of bioprostheses), chronic heart failure in three, cerebral infarction in two, post blood transfusion hepatitis in two, endocarditis in one, and non-cardiac death such as cancers in four. During the long-term observation of 47 adult patients, 14 cases (30%) had re-MVR (one for a stenotic lesion with massive calcification, and 13 for torn leaflets). Thickening and/or torn leaflets were noted in 13 (54%) of the 24 survived patients without re-MVR.2+ suggests that bioprosthetic valve replacement at the mitral position may not be recommended.