SERIAL DOPPLER GRADIENTS ARE PREDICTIVE OF FUTURE BIOPROSTHETIC VALVEDEGENERATION

Doppler echocardiography and color flow imaging are helpful techniques in, evaluating the functional status of a bioprosthetic valve. The ai m of this study was to determine whether serial Doppler gradients are predictive of future bioprosthetic valve degeneration. Sire performed serial echo-Doppler studies over a 6-year period (1988-1994) on 228 pa tients who had undergone mitral (n = 112) or aortic (n = 126) bioprost hetic valve implantation between 1973 and 1994. Thirty-nine mitral pro stheses and 30 aortic prostheses became dysfunctional and required reo peration. A serial rise in mean gradient of 5 mmHg or more across the mitral valve and 25 mmHg or more across the aortic valve was significa ntly associated with increased valve degeneration (odds ratio 3.40 and 16.11 and 95% confidence intervals 1.31 and 8.80 and 13.6 and 72.13 f or the mitral and aortic valve, respectively). Both aortic and mitral valves began to degenerate after 8 years. Serial echo-Doppler studies showed a rise in transvalvular gradients around the same time. Closer evaluation for prosthetic valve dysfunction should be considered in pa tients 8 or more years status post surgery, especially those with high transvalvular gradients.