Background ann aim of the study: The bileaflet St. Jude Medical mechanical
prosthesis has been implanted for over 20 years. The purpose of this study
was to evaluate the clinical performance of the bileaflet CarboMedics (CM)
prosthesis, which was introduced in 1986.
Methods: The CM prosthesis was implanted in 1,258 patients (709 males, 549
females; mean age 60.9 +/- 12.3 years) between 1989 and 1997. The prosthesi
s distribution was aortic valve replacement (AVR) 613; mitral valve replace
ment (MVR) 447; and multiple replacement (MR) 231. Coronary artery bypass (
CAB) was performed in 334 (26.6%) patients; previous procedures had been pe
rformed in 346 (27.5%). The age distribution was <60 years (n = 527), 61-70
years (n = 424) and >70 years (n = 307). Risk factors assessed were age or
age groups, gender, CAB, previous surgery, rhythm, valve position, status
and NYHA functional class. The total follow up was 4,765.0 patient-years (p
t-yr), and was 98.4% complete.
Results: The early mortality rate was 5.6% (AVR 4.8%, MVR 3.7%, MR 11.5%).
The late mortality rate was 3.7%/pt-yr (n = 174), and valve-related mortali
ty 1.1%/pt-yr (n = 50). The total thromboembolism (TE) rate was 4.1%/pt-yr
(n = 195) (p = NS by valve position); the major TE rate was 1.9%/pt-yr and
fatal TE rate 0.31%/pt-yr (n = 15). The valve thrombosis rate was 0.31%/pt-
yr (n = 15; 11 MVR, four MR). The fatal thrombosis rate was 0.06%/pt-yr (n
= 3; two MVR, one MR). The hemorrhage rate was 2.7%/pt-yr (n 128) and fatal
hemorrhage rate 0.4%/pt-yr (n = 20). The reoperation rate was 1.0%/pt-yr (
n = 46), fatal 0.1%/pt-yr (n = 5). The actuarial freedom from overall TE at
eight years was 77.3 +/- 2.8%; major TE 88.5 +/- 1.6%, and hemorrhage 76.4
+/- 3.2% tall p = NS by valve position). There were no independent predict
ors of overall TE and TE exclusion of early events. The only predictor for
TE major was status (emergency > urgent > elective). The actuarial freedom
from valve-related mortality at eight years was 91.4 +/- 1.8% (p = NS by po
sition) tactual freedom 93.0 +/- 1.3%). The actuarial freedom from valve-re
lated reoperation was 91.1 +/- 2.4% (p <0.05; AVR > MVR and MR, MVR > MR) (
actual freedom 92.2 +/- 2.7%). Overall survival rate at eight years was 68.
2 +/- 2.3% (p <0.05; AVR > MVR and MR, MVR > MR).
Conclusion: The clinical performance of the CarboMedics mechanical prosthes
is is satisfactory when implanted in the mitral, aortic and multiple positi