[Diagnostic value of 64-slice spiral CT coronary angiography for restenosis after bypass surgery].

OBJECTIVE

To assess the accuracy of 64-slice spiral CT in diagnosis of restenosis of coronary artery bypass grafts (CABG) and native coronary arteries in patients after bypass surgery.

METHODS

Fifty-eight patients receiving bypass surgery with totally 140 CABG (43 arterial and 97 venous grafts) were examined using 64-slice spiral CT. CABG and all native coronary arteries with a diameter of >1.5 mm were evaluated for the presence of significant stenoses (>50% diameter reduction) in comparison with the results by coronary angiography as the golden standard.

RESULTS

Of the 140 CABG examined, 38 were occluded and 104 remained patent, all of which were accurately identified by 64-slice spiral CT. The sensitivity of CT for restenosis detection in the patent graft was 100% (18/18) with a specificity of 95.2% (80/84). In the segmental evaluation of the native coronary arteries, the sensitivity of the CT in identifying significant stenosis in the evaluable segments (90%) was 84% (87/103) with a specificity of 74% (384/518). The accuracy of CT in detecting the presence of at least 1 stenosis in the CABG, distal runoff vessels or nongrafted arteries was 91% (53/58).

CONCLUSION

CT allows noninvasive angiographic evaluation of both the native coronary arteries and bypass grafts after bypass surgery.