Computed Tomography: Coronary Angiography
Coronary CT angiography (CCTA) noninvasively assesses patency of the coronary lumen, the arterial wall, calcified and noncalcified plaques, and ventricular function

In addition to many single-center studies, 3 multicenter trials evaluated the diagnostic use of 64-slice CCTA and reported sensitivities for detecting a 50% stenosis from 85% to 99%, with negative predictive values from 83% to 99% .

It is not known, however, whether CCTA can be used as a prognostic tool, independent of CACS ( Coronary artery Calcium Score) and clinical risk models, to stratify asymptomatic patients and predict future cardiac events.

In patients who had suspected but undocumented CAD, Russo et al evaluated the incremental prognostic value of CCTA against both a traditional clinical-risk model and calcium scoring.
While CACS again had significant incremental prognostic value compared with a baseline clinical-risk model, CCTA provided an additional incremental prognostic value, compared with a baseline clinical-risk model plus CACS.

The presence of non calcified or mixed plaques, regardless of lesion severity, was found to be the strongest predictor of events (P<.0001) as a potential marker of plaque vulnerability. Using CCTA in asymptomatic patients remains controversial, primarily because of the higher radiation dose, added cost, and use of nephrotoxic contrast, but it has the potential to identify useful data beyond what is derived from CACS. As detailed in the 2010 ACCF/AHA Guideline for Assessment of Cardiovascular Risk , CCTA is not recommended for cardiovascular risk assessment in asymptomatic adults . G Mohan.