Quantity and quality of graft flow in coronary artery bypass grafting is associated with cardiac computed tomography study-based anatomical and functional parameters.

OBJECTIVES: Graft flow in coronary artery bypass grafting (CABG) may be determined by the anatomical and pathological characteristics of the coronary artery and target myocardium. Our goal was to explore the relationships between graft flow and the cardiac/coronary parameters in CABG.

METHODS: We enrolled 63 patients who underwent isolated CABG and were examined by cardiac computed tomography. We statistically analysed the correlation between the intraoperative graft flow, such as the mean graft flow (MGF) or the pulsatile index (PI), and the computed tomography scan-based anatomy of the coronary artery tree and the left ventricle in 104 individually bypassed grafts.

RESULTS: The MGF displayed a significantly positive correlation with the perfused left ventricle mass volume (r = 0.3583, P = 0.0002), and the percentage of stenosis and the diameter of the coronary artery (r = 0.2396, P = 0.0148 and r = 0.2972, P = 0.0022). The PI displayed a negative correlation with the percentage of stenosis and the diameter of the coronary artery (r = -0.2826, P = 0.0038 and r = -0.2796, P = 0.0040). Abnormal graft flow (PI >5.0, and MGF <20 ml/min in arterial graft and MGF <40 ml/min in vein graft) was found in 9 grafts. The internal diameter of the coronary artery at the distal anastomosis site was significantly smaller [1.35 (1.15-1.64) mm vs 1.71 (1.5-2.1) mm, P = 0.0065], and the distal calcium score of the target coronary artery was significantly higher [40 (4-61) vs 0.4 (0-10), P = 0.014] in the abnormal grafts.

CONCLUSIONS: Intraoperatively measured MGF and PI in CABG were associated with cardiac anatomical parameters, such as the percentage of stenosis, internal diameter or calcium score of the target coronary artery or perfused left ventricle mass volume.