Does alcohol weaken heart valves and is it bad to drink if you have had mitral valve repair heart surgery to fix leaky valve.

Alcohol. Alcohol weakens heart muscle, it doesn't do much to the valves. More than one drink a day is 'bad' for everybody and recently suggested to be even worse as you get past middle age.
No. Alcohol won't damage the heart valve, or affect the repair. Remember however that moderation is key with alcohol consumption. Hope this helps!