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Background: Coronary angiography is actually the gold standard to visualize coronary artery bypass graft patency and to detect bypass stenoses. However, it is an invasive examination that makes use of X-ray emission and it may lead to deleterious effects even at low dosage. Therefore, it is still needed a non-invasive examination with good diagnostic accuracy for the follow-up of patients with coronary artery bypass grafts. The aim of this study was to evaluate the diagnostic accuracy of a 40-row multidetector computed tomography scanner for the assessment of bypass surgery versus coronary angiography., Methods: Twenty-six consecutive patients (20 male, 6 female, mean age 65 years) and a total number of 68 coronary bypass grafts (25 arterial and 43 venous grafts, 111 anastomoses) were examined by 40-row multidetector computed tomography., Results: It was possible to analyze coronary artery bypass graft patency for every patient. At coronary angiography 23 patients showed bypass stenoses or occlusion: 19 of them were correctly diagnosed by computed tomography (sensitivity 84%, specificity 100%). In particular, computed tomography showed a sensitivity of 90% and a specificity of 100% for coronary artery bypass grafts, whereas it showed a sensitivity of 88% and a specificity of 94% for anastomoses., Conclusions: On the basis of the results of our study, computed tomography is a valuable tool for assessing coronary artery bypass graft patency in patients with clinical suspect of coronary occlusion.

Background: Multidetector computed tomography coronary angiography (MDCT-CA) is a non-invasive technique that clearly shows coronary anatomy and correctly identifies plaque location and morphology. In this study we assessed diagnostic accuracy of MDCT-CA in detectiong significant stenosis in patients with clinically relevant coronary tree disease., Methods: . Fifty patients (38 males, 12 females, mean age 60.9 +/- 9.2 years) with atypical chest pain, stable or unstable angina pectoris, or non-ST-elevation myocardial infarction underwent MDCT-CA (Brilliance 40, Philips Medical Systems, Cleveland, OH, USA) within 3 days before diagnostic conventional coronary angiography. Inclusion criteria were sinus rhythm, heart rate <70 b/min, and ability to hold breath for more than 12 s. Exclusion criteria were known intolerance to contrast medium, serum creatinine >2 mg/dl, pregnancy, respiratory insufficiency, unstable clinical conditions, and severe heart failure. Beta-blockers were administered if heart rate was >70 b/min. To synchronize arrival of the contrast bolus (Iomeron 400, Bracco, Milan) in the coronary arteries with the start of the scan the bolus-tracking technique was used. Diagnostic accuracy was evaluated per segment, per vessel, and per patient., Results: Mean heart rate during examination was 61.9 +/- 6.2 b/min; 618 segments were evaluated. The assessment was impaired by respiratory artifacts only in 1 patient (2%). MDCT-CA showed good sensitivity, specificity, and positive and negative predictive values in detecting significant coronary artery stenosis (94, 94, 91, and 96% per segment; 91, 97, 95, and 92% per vessel; 100, 100, 100, and 100% per-patient, respectively)., Conclusions: Forty-slice MDCT-CA showed a good diagnostic capability in detecting significant coronary artery stenosis in patients referred to our institution for suspected or known significant coronary artery disease.