Hello Thanks for posting here. I would be able to help you better if you share the findings of the angiography. What did the angiogrpahy show and what was adviced. whether there were any blockages in the heart. If the heart side is cleared, then he may be suffering from some lung problems leading to breathlessness. I recommend him to do a pulmonary function test which requires the patient to forcefully blow into a machine and the lung capacities are determined. It will give a fair idea about presence of some lung disease. But this should be done only if he is clear from the heart side. If he has some significant heart blockages it must be first tackled with an angioplasty or bypass. Wishing him good health Regards