you have mild disease in almost all vessels supplying blood to heart , from your history your chest pain
and breathlessness looks to be related to your heart problem
you need to do now is take regular medication with out missing any single dose of any medication adviced by your Dr. ,
life style modification like low cholesterol
diet , avoid dhee ,butter, fried ,junk foods , take good quntity of green leafy vegetables , fresh fruits , quit tabacco use in any form (if using), limit alcohol intake ,
regular follow up with your Dr. and regular monitoring of your Blood Pressure and cholesterol level .
any amount of heart problem we cant neglect , we need to take it seriously ,dont panic but dont neglect also