Final answer:
MV repair is preferred over MV replacement in asymptomatic primary MR because it preserves the patient's own valve tissue and function.
Step-by-step explanation:
Mitral valve (MV) repair is preferred over MV replacement in asymptomatic primary mitral regurgitation (MR) because it preserves the patient's own valve tissue and function. MV repair aims to restore the normal anatomy and function of the valve, allowing it to properly close and prevent backflow of blood, while MV replacement involves removing the damaged valve and replacing it with a prosthetic valve. The advantages of MV repair include better long-term survival, lower risk of complications, and avoidance of long-term anticoagulation therapy, which is often required with MV replacement.