Aortic valve replacement

i am a 45 y old man, underwent Aortic valve replacement along with mitral valve and tricuspid valve repair about 16 years ago. The aortic valve used was Jude No. 21 type. Eversince then i am on anticoagulant and assymptotic. I am also undergoing annual check-up. In the recent check-up it was revealed that the pressure gradient across aortic valve has increased to 80/50 mm HG, but the valve is functioning normally. I am also assymptotic and no sign of any physicall discomfirt. Based on the above info, can i know what is the risk i am facing in life? should i undergo another surgery? is there so way I can avoid and prolong it further? I am worried since i am married and have family to support. kindly advice.