MITROFLOW PERICARDIAL BIOPROSTHESIS - CLINICAL-PERFORMANCE TO 10 YEARS

The Mitroflow pericardial bioprosthesis, a second generation pericardial prosthesis, has clinical performance assessment to 10 years. This bioprosthesis was used in 445 operations in 445 patients between 1982 and 1992 inclusive (mean age, 59.1 years; age range, 19 to 94 years). There were 253 aortic valve replacements (AVR), 155 mitral valve replacements (MVR), 31 multiple valve replacements (MR), and 6 tricuspid valve replacements. Concomitant procedures, were performed in 40 patients (14.2%). The age group distributions (years) were less than or equal to 35 years, 28 patients; 36 to 50 years, 79; 51 to 64 years, 167; 65 to 69 years, 70; and 70 years or more, 101 patients. The total follow-up was 1,524 patient-years (mean, 5.4 years), 96% complete. The early mortality was 6.3%/patient-year (28 patients) and the late mortality was 4.1%/patient-year (96 patients). Concomitant procedures did not influence either early or late mortality (p = not significant [NS]). The overall patient survival at 10 years was 58% +/- 5% (p = NS by valve position). The overall freedom from structural valve deterioration (SVD) at 8 years was 69% +/- 3% and at 10 years, 45% +/- 7%; and at 8 years AVR 80% +/- 4%, MVR 58% +/- 6%, and MR 38% +/- 11% (p < 0.05, AVR > MVR > MR). The freedom from thromboembolism (TE) was 87% +/- 2%, overall at 10 years, and was not different by valve position (p = NS). The freedom from major TE at 10 years was 76% +/- 9% (p = NS by valve position) and from fatal TE, 99% +/- 1% (p = NS by valve position). The freedom from valve-related reoperation overall at 10 years was 48% +/- 5% (p < 0.05, AVR > MVR); and from valve-related mortality, 88% +/- 3% (p = NS by valve position). The freedom from valve-related residual morbidity (permanent morbidity) at 10 years was 94% +/- 2% (p = NS by valve position). The freedom from SVD by age groups by valve position was 35 years or less (p = NS), 36 to 50 years (p = NS), 51 to 64 years (p < 0.05, AVR > MVR), 65 to 69 years (p = NS), and 70 years or more (p < 0.05, AVR, MVR > MR). The freedom from SVD by valve position for age groups was for AVR at 10 years for 51 to 64 years, 64% +/- 9% and for 70 years or more, 97% +/- 3% (p < 0.05, greater than or equal to 70 years > all age groups). The freedom from SVD for MVR was at 5 years for 36 to 50 years, 85% +/- 6% and for 70 years or more, 100% (p < 0.05, greater than or equal to 70 years > 36 to 50 years). The overall freedom from valve-related complications was overall at 10 years 23% +/- 5% and for AVR, 25% +/- 6% and for MVR, 11% +/- 13% (p < 0.05, AVR > MVR). The second generation Mitroflow pericardial bioprosthesis has SVD as a major valve-related complication but is recommended for AVR in patients 70 years and older.