Prospective randomized comparison of CarboMedics and St. Jude Medical bileaflet mechanical heart valve prostheses: ten-year follow-up

Abstract

Objective: This is the final report of a randomized controlled trial comparing the performance of CarboMedics (CarboMedics Inc., Austin, Tex) and St. Jude Medical (St. Jude Medical Inc, St Paul, Minn) bileaflet mechanical heart valve prostheses 10 years after surgery.

Methods: Between 1992 and 1996, 485 patients undergoing mechanical heart valve replacement were randomized to receive CarboMedics (n = 234) or St. Jude Medical (n = 251) prostheses for aortic (n = 288), mitral (n = 160), or double (n = 37) valve replacements. Patients were followed annually to the end of 2004.

Results: Demographic, preoperative, and operative characteristics were similar between the 2 groups. The median follow-up was 10 years in both groups (CarboMedics 99% complete, St. Jude Medical 98% complete; 3879 patient-years of follow-up). Overall, 165 patients died, 25 of valve-related causes. Ten-year survivals were 66.4% (95% confidence interval: 59.6%-72.3%) and 64.7% (95% confidence interval: 58.0%-70.6%) in the CarboMedics and St. Jude Medical groups, respectively (P = .94). Freedom at 10 years from valve-related mortality was 95.0% (95% confidence interval: 90.8%-97.3%) in the CarboMedics group and 93.0% (95% confidence interval: 88.3%-95.9%) in the St. Jude Medical group. During follow-up, 34 patients had a thromboembolic event, 79 patients had at least 1 bleeding event, and 14 patients required reoperation. There were no significant differences between the groups with respect to freedom from complications (P > or = .12); freedom from thromboembolism at 10 years (CarboMedics: 91.5%, 95% confidence interval: 86.5%-94.7%; St. Jude Medical: 92.2%, 95% confidence interval: 87.5%-95.2%); freedom from bleeding events (CarboMedics: 83.0%, 95% confidence interval: 76.6%-87.8%; St. Jude Medical: 77.5%, 95% confidence interval: 71.1%-82.7%); and freedom from death or valve-related complication (CarboMedics: 51.6%, 95% confidence interval: 44.7%-58.0%; St. Jude Medical: 46.2%, 95% confidence interval: 39.7%-52.4%). Linearized rates per patient-year were 1.1% in the CarboMedics group and 0.8% in the St. Jude Medical group for thromboembolism; 2.3% in the CarboMedics group and 3.2% in the St. Jude Medical group for bleeding events; and 0.72% in the CarboMedics group and 0.47% in the St. Jude Medical group for nonstructural valve dysfunction. International normalized ratio values were similar between the 2 groups throughout the study period.

Conclusion: At 10 years, the clinical outcome was similar with respect to these 2 mechanical bileaflet prostheses.