Use of 64-slice CT in symptomatic patients after coronary bypass surgery: evaluation of grafts and coronary arteries

Area of Science:

• Cardiovascular Imaging
• Radiology
• Medical Diagnostics

Background:

• Coronary artery bypass graft surgery is a common procedure for ischemic heart disease.
• Late graft failure and progression of native coronary artery disease are frequent causes of symptoms after bypass surgery.
• Accurate assessment of both bypass grafts and native coronary arteries is crucial for managing these patients.

Purpose of the Study:

• To evaluate the diagnostic performance of 64-slice computed tomography (CT) angiography.
• To assess the capability of 64-slice CT in detecting obstructive disease in bypass grafts and native coronary arteries in symptomatic patients.
• To compare CT findings with conventional quantitative angiography.

Main Methods:

• 52 symptomatic patients who underwent bypass surgery were included.
• 64-slice CT angiography was performed 10 +/- 5 years post-surgery.
• Two blinded observers analyzed grafts and coronary arteries for stenosis, with quantitative angiography as the reference standard.

Main Results:

• Per-segment detection of graft disease showed 99% sensitivity and 96% specificity.
• Detection of significant stenosis in non-grafted coronary segments had 97% sensitivity and 86% specificity.
• Overestimation of coronary obstruction was more frequent in calcified segments.

Conclusions:

• 64-slice CT angiography is a valuable tool for evaluating bypass grafts and native coronary arteries.
• The technique demonstrates high accuracy in identifying obstructive disease.
• Overestimation of stenosis, particularly in calcified lesions, should be considered during interpretation.