The calcium score gives and indication of the amount of calcium found in your coronary arteries. Although a low score is of course better than a high one, it does not mean that you have severe blockages.
It can very well be that the calcium is evenly distributed along the arteries without causing any serious problems for a adequate blood flow.
The only reliable way to check for blockages is a heart cath, which you say was done half a year ago.
I can imagine that your cardiologist is a little annoyed by the fact that your GP ordered a calcium score test and confronts him with the results as it would have been more logic if your had gone to your cardiologist directly with your complaints.
Hi there. When you went back to the Cardiologist, did they see you? It seems from your post that it was their PA you were dealing with? In fairness to you, you should be seeing the Cardiologist, not the PA. Whats the PA's medical qualification? Anyway speaking from my own experience, I had a Heart Cath which showed no blockages. 8 Months later I was having real difficulty with Angina symptoms on even small exertion. They didnt want to do another Cath. I kept insisting as it was so horrid , the ache when I would walk that I just knew something was wrong. I had the second cath then, and had 2 90% blockages in my LAD which required urgent stenting.