Long term follow up after deferral of revascularisation in patients with intermediate coronary stenoses and negative dobutamine stress echocardiography

Head-to-head comparison of dobutamine stress echocardiography and cardiac computed tomography for the detection of significant coronary artery disease

OBJECTIVES

Dobutamine stress echocardiography (DSE) and contrast-enhanced electron beam tomography (EBCT) both have the potential to noninvasively detect coronary artery disease (CAD). We compared the accuracy of both methods to detect significant CAD in a direct comparison.

METHODS

79 patients (32 women, 47 men, mean age 62 years) who were admitted for coronary angiography due to suspected CAD were studied. By EBCT coronary calcification (CAC) as well as angiography (CTA) was assessed. Presence of significant CAD was assumed if the calcium score exceeded 400 or the contrast-enhanced images displayed significant lumen reduction. DSE was performed using a standard protocol (5-40 microg/kg/min dobutamine plus 0.25-1.0 mg atropine if necessary). DSE and EBCT were independently evaluated concerning the presence of significant CAD. Results were compared to invasive, quantitative coronary angiography.

RESULTS

6 patients (8%) in DSE and 2 patients (3%) in EBCT were unevaluable for various reasons and therefore excluded from further analysis. In the remaining 71 patients, 33 patients (46%) showed significant CAD. DSE demonstrated a sensitivity of 70% (23/33) and a specificity of 84% (32/38). EBCT showed a sensitivity of 91% (30/33) and a specificity of 74% (28/38). By combining DSE and EBCT sensitivity increased to 97% with a specificity of 63%.

CONCLUSIONS

In a blinded comparison, DSE demonstrated lower sensitivity but higher specificity than EBCT for the detection of significant CAD. Sensitivity was improved by combining both modalities.