Application of 256-slice CT coronary angiography in postoperative evaluation of graft patency after coronary artery bypass grafting in elderly patients

Bo CHEN; Wenbo WU; Mingying WU; Ziqiang ZHOU; Fei LIU

ABSTRACT

Objective:

To investigate the value of 256-slice CT coronary angiography(CTA)in evaluating graft patency after coronary artery bypass grafting(CABG)in elderly patients.

Methods:

A total of 30 elderly patients under follow-up after CABG surgery in our hospital from May 2016 to May 2018 were randomly selected.During the same period, coronary angiography(CAG)and 256-slice CTA were performed to evaluate the patency of grafts.The diagnostic efficacy of CTA in evaluating the patency of bypass grafts was assessed by using CAG results as the gold standard.

Results:

In all, 82 grafts were observed on CAG, of which 31 were arterial grafts and 51 were saphenous vein grafts(SVG). Arterial grafts involved 27 original left internal mammary arteries(LIMA)→left anterior descending branch(LAD)grafts, 1 original right internal mammary artery(RIMA)→LAD graft, 1 aorta(AO)→LIMA→LAD graft, and 2 AO→radial arteries(RA)→right coronary artery(RCA)grafts.Venous grafts involved 9 AO→SVG→LAD grafts, 20 AO→SVG→left circumflex artery(LCX)grafts, and 22 AO→SVG→RCA grafts.CAG results showed that 28 arterial grafts were unobstructed with a patency rate of 90.3%, while 3 arterial grafts(9.7%)were occluded.Meanwhile, 34 venous grafts were unobstructed with a patency rate of 66.7%, 11 venous grafts(21.6%)had stenosis and 6 grafts(11.8%)were occluded.A total of 87 grafts were observed by using CTA.Based on the results from CAG, the overall sensitivity, specificity and Kappa value of CTA for the assessment of grafts were 95.1%, 97.6% and 0.93, respectively.The sensitivity, specificity and Kappa value of CTA were 96.8%, 95.0% and 0.90 for assessing unobstructed grafts, 81.8%, 97.2% and 0.79 for assessing stenosed grafts, and 100%, 98.6%, and 0.94 for assessing occluded grafts, respectively.

Conclusions:

256-slice CT coronary angiography can be used to accurately evaluate graft status and possesses advantages such as non-invasiveness, simplicity and low risk.Therefore, it should be recommended as the first choice in the evaluation of graft patency after CABG in elderly patients.