At the Kahn Center, we utilized CT imaging of coronary arteries for direct and accurate detection of atherosclerosis. This is an example of "personalized medicine".
It is great news to have a calcium CT scan or a coronary CT angiogram (CCTA) that does not find coronary artery disease (CAD). However, individuals with normal coronary arteries may develop CAD in years ahead. CCTA offers a non-invasive method to assess the development of CAD that is even more advanced than calcium scoring and offers a chance to assess the de novo development of CAD in a person previously judged to be without CAD.
In a post-hoc observational study of the Scottish Computed Tomography of the HEART (SCOT-HEART) trial, the authors identified patients with normal coronary arteries on initial CCTA who subsequently underwent clinically indicated CT. Images were visually assessed for the presence, severity, and type of CAD.
Normal coronary arteries on baseline CCTA were present in 524 patients (mean age 53 years old, 38% male).
After a median of 9.3 years, 31 (6%) underwent repeat CCTA and 162 (31%) underwent chest CT. There were no differences in baseline clinical characteristics amongst those who did or did not have repeat CCTA, but those with subsequent chest CT were older and had higher cardiovascular risk scores.
CAD was identified on 48% (n = 15) of CCTA and 25% (n = 41) of chest CT. Median time to CT scan on which CAD was identified was 8 years.
There was no difference in all-cause mortality or combined CAD death or non-fatal myocardial infarction in patients who had CAD identified on subsequent CT.
However, they were more likely to undergo invasive coronary angiography and revascularization.
One third of patients with previously normal CCTA will develop CAD on clinically indicated CT imaging over a 10-year period.
Education on risk factors, even after a "normal" CCTA, is important. In this study, the 162 patients with CAD identified on subsequent CT were older, more likely to smoke, and had a higher 10-year cardiovascular risk score compared to those who did not have subsequent chest CT imaging. The 31 patients with CAD on subsequent cardiac CT were more likely to smoke, but had no other differences from those without subsequent imaging.
The findings suggest that more evaluation of the development and progression of CAD with serial CCTA is needed, along with further refining of risk-prediction metrics.
“Understanding the natural history of CAD development and progression would be invaluable for recommendations regarding optimal time intervals for follow-up imaging and initiation of preventative therapies,” the authors concluded.
In certain patients, a repeat Calcium CT Score or CCTA in about 5 years after a normal study can be considered.
