Prospective randomized comparison of CarboMedics and St Jude Medical bileaflet mechanical heart valve prostheses: an interim report.

Objective: This is a midterm report of a study comparing the clinical performance of CarboMedics and St Jude Medical heart valve prostheses through a projected 10-year period.
Methods: Between 1992 and 1996, a total of 485 patients undergoing mechanical valve replacement were prospectively randomly assigned to receive either CarboMedics (n = 234) or St Jude Medical (n = 251) prostheses for aortic (n = 288), mitral (n = 160), or double (n = 37) valve replacements and were followed up annually.
Results: Baseline and operative characteristics were similar between the two groups with respect to major demographic characteristics, preoperative clinical status, and operative data. Mean follow-up was 50 +/- 22 months for the CarboMedics group (97% complete) and 47 +/- 20 months for the St Jude Medical group (96% complete), yielding a total of 1959 patient-years. The 30-day mortality, and 5-year actuarial survival, and linearized survival were 6.0%, 82.4% +/- 2.6%, and 4.3% per patient-year in the CarboMedics group and 4.4%, 79.9% +/- 2.8%, and 4.7% per patient-year in the St Jude Medical group (log-rank P =.7). Freedom at 5 years from valve-related mortality, major thromboembolism, hemorrhage, and other nonstructural valve dysfunction was, respectively, 96.7% +/- 1.4% (0.7% per patient-year), 90.9% +/- 2.1% (2.2% per patient-year), 87.3% +/- 2.5% (3.6% per patient-year), and 96.1% +/- 1.4% (0.7% per patient-year) in the CarboMedics group and 95.9% +/- 1.5% (1.0% per patient-year), 92.5% +/- 1.8% (2.0% per patient-year), 82.6% +/- 2.8% (4.3% per patient-year), and 96.0% +/- 1.3% (0.6% per patient-year) in the St Jude Medical group, with no overall intergroup differences. No statistically significant intergroup differences in international normalized ratio values were detected during the study period.
Conclusions: This study shows no significant differences in the early and midterm clinical outcomes between patients who received CarboMedics valve prostheses and those who received St Jude Medical mechanical prostheses. Choices with respect to valve type can be based on considerations other than patient outcome.