Welcome to HCM,
You have significant coronary artery disease,I presume because you have undergone angioplasty
with stent placement if it restored blood flow then you should not have any pain angina.
Your pain and burning could be due to acid re-flux or it may be due to angina.
You have said the stress test
is positive then what you are having should be angina and which is more dangerous and acid reflux
can be easily treated by acid suppressing drugs.
You should discuss with your cardiologist about your chest pain( Angina) if optimal anti ischemic therapy fail to relive your symptoms,there is no harm in taking second opinion
from other cardiologist.
By chance if you smoke or drink you should stop both. take care of your diet and exercise and stress level do Yoga and meditation
Your myocardial perfusion studies may be performed to be sure that there is no Ischemia in the heart and if there is any it can be treated with drugs and life style changes.
Your doctor may consider other differential diagnosis as well
Please take care.
Best of Luck.