Mitral valve replacement with the SORIN valve. Long-term follow-up of 1,161 patients

From 1 March 1977 through 31 December 1987, 1,252 patients underwent mitral valve replacement with a SORIN-Biomedica 60 degrees tilting-disc prosthesis at our institution. Hospital mortality was 7.3% (91 patients); prosthesis-related deaths, expressed as a percentage of hospital mortality, accounted for 12.1% of these early deaths. The 1,161 patients who survived hospitalization have been followed up for a total of 4,835 patient-years (range, 1 to 128 months; mean, 50.4 +/- 27.3 months). Forty-three (3.7%) of these patients were lost to follow-up. The late mortality was 6.3% (1.5% +/- 0.2% per patient-year), and the 10-year actuarial survival rate, excluding hospital mortality, was 89.1% +/- 1.6%. The 10-year actuarial (and linearized) rates of freedom from valve-related complications were as follows: embolism, 94.4% +/- 1.0% (0.93% +/- 0.1% per patient-year); thrombosis of the prosthesis, 99.8% +/- 0.1% (0.06% +/- 0.03% per patient-year; hemorrhage, 93.7% +/- 1.5% (0.95% +/- 0.1% per patient-year); prosthetic valve endocarditis, 99.3% +/- 0.3% (0.14% +/- 0.05% per patient-year); reoperation, 90.6% +/- 2.1% (1.1% +/- 0.2% per patient-year); and overall complications, 76.6% +/- 2.5% (2.9% +/- 0.2% per patient-year). No structural deterioration was noted. These data not only confirm our previous reports concerning the reliability and durability of the SORIN prosthesis but also reveal a significant reduction, over the long term, in the overall incidence of valve-related complications.