Noninvasive assessment of coronary artery bypass graft patency by multislice computed tomography.

Follow-up of coronary artery bypass after cardiac surgery is routinely performed by means of X-ray coronary angiography. However, this is an invasive procedure, expensive and includes ionizing radiation exposure, hospitalization and a small risk of complications. Multislice computed tomography is a noninvasive diagnostic tool that permits the visualization of the cardiac structures, including the coronary arteries. The purpose of our study was to compare multislice computed tomography with conventional angiography for the evaluation of graft patency following cardiac surgery.Forty-seven asymptomatic patients (44 men and 3 women, mean age 67 +/- 7 years) who had undergone coronary bypass surgery at least 10 years previously, were retrospectively investigated by means of ECG-gated multislice computed tomography, within 6 months of coronary angiography.Overall, 116 out of the possible 127 (91.4\%) grafts were assessable at computed tomography, including 87 saphenous vein grafts, 26 left internal mammary artery, 2 right internal mammary artery, and 1 gastroepiploic artery. Coronary angiography showed that 79 of 116 grafts (68.1\%) were patent and that 37 (31.9\%) were occluded. All grafts which were patent and occluded at coronary angiography were correctly identified at multislice computed tomography, with a sensitivity and specificity of 100\%.Multislice computed tomography with retrospective gating permits an accurate and noninvasive evaluation of coronary artery bypass patency, and could replace conventional angiography for the follow-up of asymptomatic, stable patients.