Recently evidence has emerged suggesting the prognostic value of CT coronary angiography (CTCA), however whether it can provide extra information over and above routine clinical workup – including exercise treadmill testing – remains uncertain.  Dedic et al. determined to answer this question in patients with stable chest pain and suspected coronary artery disease (CAD).

The study enrolled 471 patients who underwent exercise ECG testing and CTCA, with exercise ECG tests being classified as either normal, ischaemic, or non diagnostic.  The primary outcome measure was a major adverse cardiac event (MACE), defined either as cardiac death, nonfatal myocardial infarction, or unstable angina requiring hospitalization and revascularization (beyond 6 months). Univariable and multivariable Cox regression analysis was used to determine the prognostic values, while clinical impact was assessed with the net reclassification improvement metric.

Over a mean follow-up of 2.6 years 44 MACEs occurred in 30 patients.  The presence of coronary calcification (hazard ratio [HR], 8.22 ), obstructive CAD (HR, 6.22), and nondiagnostic stress test results (HR, 3.00) were univariable predictors of MACEs. In the multivariable model, CT angiography findings (HR, 5.0) and nondiagnostic exercise ECG results (HR, 2.9) remained independent pre-dictors of MACEs. CT angiography findings showed incremental value beyond clinical predictors and stress testing (P <.001), whereas coronary calcium scores did not have further incremental value (P = .40).

Conclusions:

This study shows again that CT angiography findings are a strong predictor of future adverse events, in this study showing incremental value over clinical predictors, stress testing, and coronary calcium scores.

• Dedic A, Genders TSS, Ferket BS et al.  Stable Angina Pectoris: Head-to- Head Comparison of Prognostic Value of Cardiac CT and Exercise Testing.  Radiology 2011;261:428-436.