Noninvasive diagnosis of coronary artery bypass graft disease by dobutamine stress real-time myocardial contrast perfusion imaging.

BACKGROUND

The aim of this study was to assess the accuracy of real-time myocardial contrast perfusion imaging (MCPI) during dobutamine stress echocardiography, for the diagnosis of coronary artery bypass graft disease.

METHODS

MCPI was performed using commercially available ultrasound contrast agents (Optison or Definity) at rest and at peak dobutamine-atropine stress in 64 patients with previous coronary artery bypass graft. Significant disease was defined as 70% or greater stenosis in one or more grafts or a native nongrafted coronary artery. MCPI was considered diagnostic in the presence of reversible perfusion abnormalities (RPA).

RESULTS

Significant stenosis (>or=70% by quantitative angiography) in one or more grafts was detected in 49 patients (77%). RPA were detected in 44 of these patients (sensitivity 90%, confidence interval [CI] 81-98). Significant stenosis was detected in 74 of the 176 bypass grafts (42%). RPA were detected in the distribution of 55 diseased grafts and 21 nondiseased grafts (regional sensitivity 74%, CI 64-84; specificity 79%, CI 71-87; and accuracy 77%, CI 71-84). RPA were detected in two or more vascular distributions in 25 of 33 patients with multivessel stenotic lesions and in 4 of 31 patients without (sensitivity 76%, CI 61-90; specificity 87%, CI 75-99; and accuracy 81%, CI 72-91).

CONCLUSION

Dobutamine stress MCPI is a useful technique for the evaluation of coronary artery bypass graft disease.