Early Clinical Experience in Valve Replacement Using On-X Prosthetic Heart Valve / 대한흉부외과학회지

ABSTRACT

Background: The On-X valve was recently introduced. It was the aim of this study to assess the safety and feasibility from the data derived from 28 patients who underwent aortic and/or mitral valve replacement with this prosthesis in National Medical Center. Material and Method: From May 1999 and May 2003, a series of 28 consecutive patients who had been implanted with 32 On-X prosthesis were reviewed. The operative procedure comprised of 12 MVR, 10 AVR and 6 DVR. The study followed the guidelines of AATS/STS. Mean follow-up was 27 months (total 64 patient-years). Result: Early (mortality was 7.14% (2/28) and no late mortality occurred in the study. Total actuarial freedom from mortality at 2 years was 92.86+/-4.87% for all cases, 100% for MVR, 90+/-9.49% for AVR, and 83.3+/-1.52% for DVR. Thromboembolic event occurred in 2 MVR patients and that was the only complication; therefore, the linearized incidence of valve related complications was 3.17%/ patient- years for all cases and 6.5%/patient-years for MVR and the actuarial freedom from valve related complications at 2 years was 84.85+/-10.75%. Preoperatively, 24 (85.71%) patients were in NYHA functional class III or IV but postoperatively, 25 (89.29%) patients were in NYHA functional class I or II. The levels of hemoglobin, hematocrit, serum LDH, reticulocyte rate and indirect bilirubin were all within normal range at postoperative 3 month. In mitral position, the peak gradient was 6.1+/-1.8 mmHg and the mean gradient was 3.0+/-0.6 mmHg and EOA were 2.54+/-0.56 m2, 2.39+/-0.73 m2, 2.34+/-0.55 m2, 2.40+/-0.63 m2 at 27 mm, 29 mm, 31 mm, 33 mm respectively. In aortic postion, the peak gradient was 21.1+/-14.12 mmHg and the mean gradient was 12.3+/-6.52 mmHg.

Conclusion:

Since there was no significant difference in the postoperative mortality, valve related complications and echocardiographic hemodynamic data compared to standard bileaflet design and since there was an improvement in the NYHA functional class and normal values of hemolytic indicators, it can be assumed that On-X valve is safe and feasible. However, accumulation of cases and long-term follow-up of this patient group is needed to establish this result.