Role of coronary angiography MDCT in the clinical setting: changes in diagnostic workup in the real world.

PURPOSE

The authors sought to evaluate the incremental value of introducing coronary angiography with multidetector computed tomography (MDCT-CA) compared with the conventional diagnostic workup in managing patients with suspected coronary artery disease (CAD) workup.

MATERIALS AND METHODS

A total of 531 consecutive patients underwent MDCT-CA between April 2008 and August 2010. For each patient the pretest probability of CAD was obtained by using the Morise score as well as the diagnostic performance of the exercise test and of MDCT-CA, considering conventional coronary angiography (CCA) as the gold standard. Based on these results, we calculated the posttest likelihood of CAD after stress testing, comparing the incremental diagnostic value for each category of cardiovascular risk with data obtained with MDCT-CA. The conventional diagnostic workup (without MDCT-CA) was then compared with the modified workup (including MDCT-CA).

RESULTS

The diagnostic performance of the exercise test for identifying patients with significant lesions had a sensitivity and specificity of 20% and 88%, respectively, with positive (PPV) and negative (NPV) predictive value of 41% and 72%, respectively. Taking CA as the gold standard, MDCT-CA had 93% sensitivity, 89% specificity, 88% PPV and 93% NPV compared with CCA in evaluating significant stenoses in the per-patient analysis. The overall diagnostic accuracy of MDCT-CA was 91%. The exercise tests provided no significant incremental diagnostic value compared with cardiovascular history in patients with a low to intermediate risk. Comparison of the diagnostic accuracy of these protocols showed improved performance results for the modified protocol.

CONCLUSIONS

MDCT-CA is the reference modality for the noninvasive exclusion of critical CAD. It provides a very high incremental diagnostic value compared with exercise testing in patients with a low to intermediate risk of CAD. The use of diagnostic protocols based on MDCT-CA ensures improved diagnostic performance compared with those involving conventional exercise electrocardiograms.