Class I indications for aortic valve replacement with a mechanical aortic valve prothesis:
-acquired chronic aortic regurgitation requiring aortic valve replacement + absence of contraindications to anticoaugulation + high probability of effective anticoagulation,

-acquired chronic aortic regurgitation requiring aortic valve replacement + risk of accelerated biological aortic valve prothesis degeneration,
-acquired chronic aortic regurgitation requiring aortic valve replacement + mechanical heart valve prothesis in another position.

Class IIa indications for aortic valve replacement with a mechanical aortic valve prothesis:
-acquired chronic aortic regurgitation requiring aortic valve replacement + patients in whom life expectancy is reasonable and risk of  future redo aortic valve surgery is high,
-acquired chronic aortic regurgitation requiring aortic valve replacement + patients aged < 60 years.

Class IIb indications for aortic valve replacement with a mechanical aortic valve prothesis:

-acquired chronic aortic regurgitation requiring aortic valve replacement + long-term anticoagulation because of high risk for thromboembolism.