Final answer:
Mechanical heart valves are more durable than bioprosthetic valves but require lifelong anticoagulation therapy to prevent blood clots.
Step-by-step explanation:
Mechanical valves are known for their durability compared to bioprosthetic (tissue) valves. However, one significant requirement for patients with mechanical valves is the necessity for long-term anticoagulation therapy. This is because mechanical valves increase the risk of blood clots forming, which can lead to serious complications such as stroke.
Anticoagulants, such as warfarin, are prescribed to reduce this risk by thinning the blood. In contrast, bioprosthetic valves generally do not require long-term anticoagulation, but they may have a shorter lifespan and can degrade over time, potentially requiring replacement after several years.