A comparative study in patients with Omnicarbon and Björk-Shiley heart valve replacement

Area of Science:

• Cardiovascular Surgery
• Biomaterials Science
• Medical Device Engineering

Background:

• Mitral valve replacement is a critical procedure for managing severe mitral valve disease.
• Comparing prosthetic heart valves is essential for optimizing patient outcomes.
• The Omnicarbon and Björk-Shiley valves represent different designs for mitral valve prostheses.

Purpose of the Study:

• To compare the clinical performance of the Omnicarbon heart valve against the Björk-Shiley spherical valve after mitral valve replacement.
• To evaluate operative results, hemodynamic parameters, and long-term outcomes for both valve types.

Main Methods:

• Comparative analysis of patient data following mitral valve replacement with either Omnicarbon or Björk-Shiley valves.
• Assessment of early and late mortality, survival rates, and valve-related complications.
• Hemodynamic evaluation using pressure gradients, effective mitral valve areas, cardiac index, and Doppler echocardiography.
• Phonocardiographic analysis of valve click intervals (AC-OpC, Q-CC) and assessment of hemolysis.

Main Results:

• No early deaths were observed in either group; late deaths occurred in 6 Omnicarbon patients (2.9% per patient-year).
• Actuarial survival at 6 years was 82.1% for Omnicarbon, with 86.4% freedom from valve-related complications.
• Hemodynamic parameters at rest were satisfactory for both valves; however, Omnicarbon showed a significant decrease in cardiac index at 160 bpm.
• Regurgitant flow was noted in 28% of Omnicarbon patients versus 10% of Björk-Shiley patients at 160 bpm (p=ns).
• The Björk-Shiley valve demonstrated a statistically significant shorter aortic closure to mitral opening click (AC-OpC) interval (70.9 msec vs 76.8 msec, p < 0.05).
• Hemolysis was clinically insignificant in Omnicarbon valves with intact function.

Conclusions:

• Both Omnicarbon and Björk-Shiley valves provide satisfactory hemodynamic function post-mitral valve replacement.
• The Björk-Shiley valve exhibited a slight advantage in the AC-OpC interval, suggesting potentially better valve dynamics.
• Long-term survival and complication rates were comparable, indicating acceptable performance for both prostheses, though further investigation into regurgitant flow differences may be warranted.