Coronary bypass graft patency cannot be determined by multidetector spiral computed tomography.
OBJECTIVE
Angiography by selective catheterization is the reference standard for coronary bypass graft patency assessment but carries a risk of serious complications. We have investigated whether 16-slice multidetector spiral computed tomography (MDCT) can substitute for selective angiography.


METHODS
Two to three years after coronary artery bypass grafting, 45 patients with a total of 156 bypasses (100 single and 28 sequential grafts) were examined with both MDCT and conventional selective angiography on the same day. The bypasses were classified as patent, stenotic or occluded.


RESULTS
The likelihood ratio for MDCT-detected occlusion was 40, reflecting a fairly high combined sensitivity and specificity. However, 24% of the distal anastomoses could not be evaluated by MDCT, mainly because of respiratory movements, artifacts due to metal clips, and small vessel dimensions. Moreover, seven out of 117 bypasses (6%) deemed evaluable by MDCT were wrongly classified by this method.


CONCLUSIONS
At present, 16-slice MDCT cannot replace selective angiography for assessment of coronary bypass graft patency since 24% of bypasses could not be evaluated by this method, and an error rate of 6% is unacceptable.
Bartnes
Kristian
K
Department of Cardiothoracic and Vascular Surgery, University Hospital North Norway, Tromsø, Norway. kristian.bartnes@unn.no
Sildnes
Trude
T
Iqbal
Amjid
A
Dahl-Eriksen
Oystein
O
Trovik
Thor
T
Steigen
Terje Kristian
TK
Mortensen
Rica
R
Mannsverk
Jan Torbjørn
JT
Sørlie
Dag Glen
DG
Myrmel
Truls
T
D000328:Adult; D000368:Aged; D003287:Contrast Media; D017023:Coronary Angiography / Q000379:methods / Q000592:standards*; D001026:Coronary Artery Bypass; D005260:Female; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009664:Norway; D011237:Predictive Value of Tests; D012119:Respiration; D013673:Technology Assessment, Biomedical; D036542:Tomography, Spiral Computed / Q000379:methods / Q000592:standards*; D014654:Vascular Patency
D003287:Contrast Media