Stress testing-guided assessment of coronary artery bypass grafts patency, at 6 months of follow up. A prospective study

Abstract

Purpose: To assess the coronary bypass grafts patency and the repeat revascularization rate, six months after coronary artery bypass grafting (CABG). Methods: We prospectively enrolled 145 consecutive patients undergoing isolated CABG between June 2014 and June 2016. We performed at 6 months of follow up a coronary computed tomography angiography (CTA) in patients whose stress tests were negative and an invasive coronary angiography (ICA) in the opposite case. Results: A total of 134 CTA and 11 ICA were performed, allowing the analysis of 321 grafts, including 143 left internal thoracic arteries (LITA), 89 right internal thoracic arteries (RITA) and 89 saphenous veins grafts (SVG). The average graft patency was 95.1% for LITA, 84.3% for RITA and 64% for SVG. The best patencies were obtained when these grafts were anastomosed to the left anterior descending artery (LAD): 96.3% for LITA, and 87.5% for RITA. SVG patency was homogeneous whether between the main right coronary artery and its branches (63.4% versus 65% respectively. p = 1), or between circumflex and RCA (72.7% versus. 63.9% respectively. p=0.6). On the right and circumflex coronary arteries, the patency of the SVG was significantly lower than that of RITA (66.26% versus 83.95% respectively, p = 0.011). At 6 months of follow up, the repeat revascularization rate was 2.07% (n=3/145). Conclusions: 6 months after CABG, RITA and LITA had good patencies especially on LAD, while SVG was occluded in almost a third of cases. On the circumflex and right coronary arteries, SVG patency was significantly lower than that of RITA. Keywords: Coronary Artery Bypass; Exercise Testing; Coronary Angiography; Computed Tomography Angiograph