My ct scan involved pumping an isotope through my arteries and while pictures of the heart were taken in the usual fashion, this enabled the arteries to show up very well. There are pros and cons for both Angiograms and CT scans, and so it depends what the cardiologist wants. For example, an angiogram is totally internal and relies on blood so If a vessel is completely blocked and dry, it will be invisible. Narrowings in vessels can be seen in a CT and it will clearly show up calcium deposits (hard plaque). Softer fat will not be so obvious, but the narrowing will still be seen. Common sense will obviously tell the cardiologist that if it has no calcium, it can't be hard plaque, so it likely softer material.
You should, in my opinion, ask the company that offered the scan to explain what a 'calcium' score means. I do know that my 'hard' calcium deposits in my arteries haven't been as significant as the 'soft' deposits, when include blood clots, etc. An angiogram is far more accurate than a CAT scan, in my opinion. It will also indicate heart pressures and other data that simply can't be shown with a scan.
Your post suggests you are still smoking. If so, I strongly urge you to quit. If you continue to smoke, you will develop heart disease. Millions of us have quit, hopefully you have as well.
A normal CT-Scan will only Calcium deposits, even a CT-A misses the soft plaque a lot of times.
look on ekg there is alot of people where it comes back normal, like in my case mine came back normal 8 time in days and they did a cath on me where they put the tube down your throught, and yes soft plague showed on my dads chest ct some, but a cath was better, but the ekg was normal but just remember on some people the ekg comes up normal, they need to do a cath, blood work. etc/
my dad had a heart attack when they said he was normal, and they didnt even know the first time, so they always have to do cts and caths on him, also have them try that ultasound like they do on women, now that is better than a ct