Aortic valve replacement has been applied for over half a century. Two
classes of devices have been developed: mechanical and biological valve prostheses.
For biological devices, autografts, homografts and xenografts (porcine and pericardial)
have been developed. For mechanical devices, cage ball, tilted disc and bi-leaflet valves
have been designed.
For BHV, the main drawback is a limited durability, the main advantage is the low rate
for TE events, which obviates the need for peroral anticoagulation. Age is a major
determinant for durability. In contrast, MHV are very durable, but they require a lifelong
anticoagulation with all their side effects. The choice for a valve in each individual
patients depends on several factors: age and life expectancy are the main factors.
In difficult situations, i.e. an age between 55 and 70 years, results of comparative
studies might be helpful in the decision making. Comparison should include
contemporary devices and techniques. Use of historical series are confounded by
changes and improvements in peri and postoperative care. A RCT remains the gold
standard, but these are few in numbers.
The only recent RCT did not change much: the outcome is still more dependent on
patient related factors than on the type of the valve, except 1) for bleeding, which is
more common with MHV and 2) for SVD, which is observed with BHV. These
observations are hardly surprising.
Results for a twenty-year follow-up might be needed. The preference of physician and
patients for the choice of a valve is important. The dilemma between anticoagulation
related bleeding and SVD remains for the time being.
Keywords: Anticoagulation, autografts, biological heart valve prosthesis,
bleeding, calcification, effective orifice area, homografts, mechanical heart valve
prosthesis, mortality, stentless xenografts, structural valve degeneration,
thrombembolism, transvalvular gradient, tissue engineered heart valves, valve
prosthesis patient mismatch.
