Single-center experience with the On-X prosthetic heart valve between 1996 and 2005

Herein are presented long-term results for the On-X mechanical heart valve. All On-X heart valve recipients since the first implantation worldwide at the University of Bochum in September 1996 were followed retrospectively; the present authors' single-center experience over a period of almost 10 years is reported.

A total of 428 patients (255 males, 173 females; mean age 62.7 years) underwent either aortic valve replacement (AVR; n = 264) or mitral valve replacement (MVR; n = 164) using the On-X prosthesis. Preoperatively, 329 patients (76.8%) were in NYHA class III or IV. Approximately 5% of AVR and 23% of MVR patients had undergone previous cardiac surgery. Concomitant surgery was performed in 189 patients (44.2%). The mean follow up was 3.9 years, and cumulative follow up 1,625 patient-years (pt-yr); the overall follow up rate was 98.7%.

Early mortality (< or = 30 days) was 3.7% after AVR and 14.0% after MVR, with valve-related mortality rates of 0.4% and 1.2%, respectively. At autopsy (n = 12) all implants were intact. Freedom from valve-related death at nine years was 85.0 +/- 3.9% after AVR and 87.6 +/- 3.2% after MVR. The overall survival rate was 67.9 +/- 4.3% after AVR and 52.7 +/- 8.1% after MVR. The linearized rate of thromboembolism for AVR and MVR was 1.49%/pt-yr and 1.61%/pt-yr; of thrombosis 0%/pt-yr and 0.35%/pt-yr; of hemorrhage 0.93%/pt-yr and 1.43%/pt-yr; of endocarditis 0.37%/pt-yr and 0.17%/pt-yr; of non-structural failure 0.18%/pt-yr and 1.43%/pt-yr; and of reoperation 0.28%/pt-yr and 0.53%/pt-yr. There were no cases of structural valve failure.

After almost one decade of clinical experience in a single center, the On-X heart valve continues to be reliable and effective.