CTA accurate?

[momto2]

Hi! I am 41y/o female.non- smoker. no family hx. heart dx. I have hx frequent PVCS (10,000/day). I have been having pain in the center of my chest along with pain in my shoulder blades and sometimes in my upper arms. No SOB or diaphoresis. I had a nuclear stress test done that showed subtle distal anterior ischemia. I get mixed comments about this from physicians. They tend to think this was a false positive since I am a younger female and all other aspects of the stress test was WNL. However, some have said that if this was truly a false positive it would have been positive in both the resting and stress parts of the nuclear scan.  Anyway, the cardiologists did order a CTA. Apparently from what I have read this test is not for everyone  because of the accuracy of picking up soft plaque. The scan showed I had a 0 calcium scoring. I am happy about that but still wondering about the stress test and the validity of the CTA. Does the CTA show more than what I am aware of? Do you think it is safe to assume this pain is not my heart? The cardiologist seemed very comfortable with interpreting the CTA and said for him it was just as accurate as a cath. Could the frequent PVCs have effected the stress test? The articles I have read about the CTA may not have been current so maybe the technology has improved? I really just want to relax about my heart so I can start researching what else that might be causing this pain (gallbladder?)  
To:

[Darcy Green Conaway, MD]

1) It is not true that your defect should have been in both the rest and stress images if it is attenuation artifact; it could certainly (and often is) is one and not the other-- so I wouldn't  say that. I think if you see it in both you certainly feel more comfortable thinking it is artifactual
2)CTA has excellent negative predictive value, but since you already have a zero calcium score I'm not sure it is warranted. Calcium scores predict the burden of atherosclerotic plaque by measuring those which are stable (calcified)-- the more calcium (or stable) plaque, the more atherosclerotic disease. A score of zero means you don't have any calcium, but it does not guarantee that you don't have any soft (non-calcified) plaque. Studies have shown, though, that people with scores of zero have exceedingly low event rates. If this were myself or my family member, I would only proceed to CTA if I had continued chest pain and there is true concern for soft plaque-- at 41 years of age it is very unlikely.