hi dear a pain responding to nitrates can be of cardiac origin considering your family ghistory your lipid profile and cardiac events earlier , a possibility of this pain to be a stable angina has to be ruled out i would suggest you to go for a test called stress thallium a stress thallium is a highly sensitive non invasive test and can rule out cardiac disease in 97% of the cases i woulsd like to see a copy of your angigraphy reports if possible angiography and plasty video also as many a times the blockage are diffused so major blockage are treated by stents and other diffuse blockages are managed medically if possible message to me your angiogram reports i have read medication you are on as angina and pain is your leading problem so i would suggest you to add some chronic antianginal medications which are highly efficient add trimetazidine 35 mg twice daily(highly efficient does not effects bp of the patient also improves cardiac functions) nikorandil 10mg twice daily ( a potassium channel opener highly effective in chronic stable angina) ranolazine 500mg twice daily( very effective in chronic stabl;e angina) take nitates only for acute chest pain sublingually ( if systolic bp is more then 100mm of hg) please consult your cardiologist for prescription before starting these medication thanks