Comprehensive noninvasive evaluation of bypass grafts and native coronary arteries in patients after coronary bypass surgery: accuracy of 64-slice multidetector computed tomography compared to invasive coronary angiography

Abstract

We assessed the accuracy of 64-slice multidetector computed tomography (MDCT) compared with that of invasive coronary angiography (ICA) in the evaluation of symptomatic postcoronary artery bypass graft (post-CABG) patients. MDCT and ICA were performed in 44 consecutive post-CABG patients with chest pain (mean age 66 +/- 10 years, mean duration post-CABG 9 +/- 5 years). MDCT findings were compared with the corresponding ICA, which was read by an interventional cardiologist blinded to the MDCT findings. Significant stenosis was defined as at least 50% luminal stenosis. One hundred and thirty-seven grafts (31 arterial and 106 venous), all evaluable by MDCT, were assessed. In a 'per graft' analysis, MDCT could detect significant disease in bypass grafts (graft occlusion or stenosis) with a sensitivity of 98% and specificity of 98%. In a 'per segment' analysis, MDCT could detect significant disease in all native coronary arteries with a sensitivity of 91% and specificity of 79% and in clinically relevant native coronary arteries with a sensitivity of 92% and specificity of 84%. In a 'per vessel' analysis, MDCT could differentiate native arterial occlusion from nonocclusive stenosis with a sensitivity of 68% and specificity of 70%. In a 'per patient' analysis, MDCT could detect significant disease in bypass grafts or clinically relevant native coronary arteries with a sensitivity of 100%, specificity of 40% and accuracy of 93%. Sixty-four-slice MDCT allows evaluation of bypass grafts and native coronary arteries in post-CABG patients. Although accurate for detecting bypass graft disease, 64-slice MDCT has significant limitations when evaluating native arteries in post-CABG patients.