Selection of a prosthetic valve for mitral valve replacement

The early and the late results of mitral valve replacement were retrospectively evaluated to delineate the concept of selection of the prosthetic valve for the mitral position. The mitral valve was replaced with porcine bioprosthesis (P-B) in 102 patients and with St. Jude Medical prosthesis (SJM) in 341 patients between 1975 and 1987. Operative mortality was 5.3% for the SJM and 8.8% for the P-B group (N.S.). Cumulative duration of follow up was 1479.8 patient-years for the SJM and 888.9 patient-years for the P-B group. Actuarial survival rate was 90% for the SJM at 9 years and 81%, 76% for the P-B group at 10 and 13 years (N.S.). Freedom from valve-related death was 94% for the SJM at 9 years and 94% for the P-B at 13 years (N.S.). Thrombo-embolic complications occurred at an incidence of 0.47%/patient-years (p-y) for the SJM and 0.67%/p-y for the P-B group (N.S.). Freedom from prosthetic valve dysfunction due to primary tissue failure (PTE) lowered rapidly after the seventh postoperative year from 88% to 35% in the P-B group. Prosthetic valve dysfunction free rate was significantly lower in the P-B group compared with the SJM between the seventh post operative year and ninth postoperative year (p less than 0.01). From this analysis, we believe that the SJM prosthesis is suitable cardiac valve prosthesis to the mitral position.