CarboMedics Mitroflow Pericardial Aortic Bioprosthesis - Performance in Patients Aged 60 Years and Older after 15 Years

Abstract

The purpose of this study was to carry out a current assessment of the Mitroflow pericardial bioprosthesis (model 11) according to the durability of the prosthesis after 15 years in patients aged 60 years or older. This bioprosthesis was implanted in 161 patients (mean age 69.5 +/- 6.3 years; range 60 - 94 years) undergoing aortic valve replacement (AVR) between 1982 and 1992. There were 84 patients aged 60 - 69 years (mean 64.5 +/- 3.1years) and 77 patients aged 70 years or older (mean 74.8 +/- 4.3 years). Of the total population, concomitant procedures were performed in 63 patients (39.1 %); of these, coronary artery bypass grafting was performed in 39 (24.2 %). Early mortality was 4.8 % (4 patients) in the 60 - 69 year age group and 10.4 % (8) in patients aged 70 years or older ( P = 0.290). Late mortality was 4.5 %/patient-year (35) for those aged 60 - 69 years and 8.1 %/patient-year (49) for those aged 70 years or older ( P = 0.007). Patient survival at 15 years of patients aged 60 - 69 years was 47.6 +/- 6.3 % and of patients aged 70 years or older was 20.9 +/- 5.4 % ( P = 0.003) ( ). Freedom from valve-related mortality for patients in the 60 - 69 year age group was 92.1 +/- 3.5 % at 15 years (0.6 %/patient-year [5]), and in the patient group aged 70 years or older it was 84.4 +/- 5.3 % (1.3 %/patient-year [8]; P = 0.194). Freedom from reoperation for patients in the 60 - 69 year age group was 73.9 +/- 5.0 % (2.6 %/patient-year [20]), and for patients aged 70 years or older it was 91.4 +/- 3.4 % (1.0 %/patient-year [6]; P = 0.029). The structural valve deterioration (SVD) rate for patients in the 60 - 69 year age group was 2.4 %/patient-year (19), and for patients aged 70 years or older it was 1.0 %/patient-year (6) ( P = 0.041). Actuarial freedom from structural valve deterioration at 15 years for patients aged 60 - 69 years was 62.0 +/- 7.3 %, and 80.8 +/- 7.9 % for patients aged 70 years and older ( P = 0.049) (actual freedom 73.9 +/- 5.2 % and 91.4 +/- 3.4 %, respectively). The Mitroflow pericardial bioprosthesis can still be recommended for aortic valve replacement in patients 70 years and older.