Hello Doctor, In 2007 My Mother Had Under Gone Angioplasty,

Hello Doctor, In 2007 my mother had under gone Angioplasty, one stint is already installed in left.
Now after chest pain found, doctor done Angiogram the result is one vein which is having stint is having blockage not before sting but after stint position-it is mild 40% , In right side 80% blocked and again in right side in one vein 40 % blocked. Please suggest further treatment. Please suggest further steps .