I was really hoping this would be a great article that convinced me that my hesitancy towards cardiac CTA is unfounded. I feel, based on the literature, that we’re misusing cardiac CTA – or at least, the current generation of technology and reconstruction methods aren’t leading us in the right direction. Angiography, whether radiographic or invasive, describes anatomy, and then we use the anatomy as our basis whether to attribute chest pain to cardiac causes or not. Many situations, this works – the STEMI goes to the cath lab and the occlusion correlates with symptoms. But, we’re trying to use CTA in our low-risk population to draw conclusions about the etiology of chest pain – and it’s much harder to say someone’s troponin-negative and EKG non-specific chest pain comes from a stenosis of a certain percentage.
The problem with their article is that they completely underestimate the number of false-positives cardiac CTA is generating. There are several articles out there showing that the population considered for cardiac CTA is generally a population that just does great in follow-up, and that the number of negative follow-up studies generated after cardiac CTA – nuclear stress and invasive angiography – tend to far outnumber the number of positives. They base their cost estimates on numbers that just don’t reflect reality, and I just can’t believe that cardiac CTA is a test that saves money and gives me better answers compared to functional cardiac testing. If you wanted to use it as a screening tool for identifying a population that needs aggressive secondary-prevention of progressive atherosclerotic coronary disease, it would do great at that – but we know that plenty of ACS comes from ruptured plaque and hemodynamically insignificant disease, and someone who had a “negative” cardiac CTA that morning doesn’t preclude them from needing an enzymatic rule-out.