In my case, I have had heart attacks and have a couple of stents in my RCA. I suffer with alot of chest pains. So much so that I recently went to the ER thinking it was another heart attack. While there it was found that I suffer with coronary artery spasms and they do put me down. I have to stop what I am doing and wait for it to pass. There are other reasons for chest pains, and I wish there was a way to stop these. Take care, Ally
For heart attacks to be occurring, there should be evidence with a troponin level blood test to confirm this. If his troponin levels are not elevated, then the pain could be related to something else. Do you know what his EF is from an echo scan? This will basically tell you how efficiently his heart is pumping blood. If Nitro relieves the symptoms, then it certainly does sound convincing that there is a blood supply problem, but this is counteracted by the recent Angiography which reveals nothing. However, there is still the possibility that he may be suffering a different form of angina, such as vasospasm. This is when a coronary artery decides to go into spasm mode, and contracts/dilates continually over the period of the attack. The amount the artery contracts varies in different people, ranging they suspect from 70-95%. Obviously the more it contracts, the higher the symptoms. Nitro spray does affect spasms in most people, calming them down and forcing the vessel to fully open. Nitro spray isn't for everyone, for example it gives me severe headaches. Smooth muscle, such as that in arteries, requires calcium for the muscle to work and this is supplied through tiny channels in the artery lining. There are medications called calcium channel blockers which cut this feed down and keep the arteries more relaxed. It might be worth at least trying one of these to see if it helps.
I recently had 5 stents inserted to open my left artery and Cardiologist couldn't find any causes for my angina on echo scans, ecg's, nuclear scans, lung function tests etc. Everything looked really good but I was still getting chest pains on and off. My local Doctor recommended at least trying CCB and I was amazed at the difference.
With regards to tissue damage, this is something which will have been evaluated by your cardiologist from test results.
Another possible cause for the angina could be MVD (microvascular disease) and this is when the tiny vessels in the heart are damaged or blocked. These vessels unfortunately are far too small to be seen on a standard Angiogram. Nitro medication also opens these vessels improving symptoms. There is no cure, but I believe there is a scan which can evaluate the condition of these arteries.
So, a few things to consider and question your cardiologist over. I hope they find the problem and please keep us informed.