CTA in roadmapping post-CABG evaluation

Although coronary artery bypass grafting (CABG) outcomes are typically highly successful, outpatient evaluation of bypass grafts is an important step. Moreover, the return of myocardial ischemia and acute coronary syndrome (ACS) events after bypass is not uncommon. Whether due to failure of prior bypass grafts or progression of underlying arteriosclerosis in native coronaries, regularly evaluating if a patient requires intervention (and assessing graft patency vs. closure) is essential. Imaging via cardiac computed tomography angiography (CTA) offers a gold standard anatomical map to facilitate efficiency and accuracy in later invasive coronary angiography (ICA) or surgical re-CABG intervention. This review discusses the utility of CTA as a safe pre and post CABG evaluation tool, in guiding outpatient evaluation of graft patency and roadmapping subsequent reintervention if needed. We seek to ameliorate clinical uncertainties and synthesize growing amounts of research, to help encourage a homogenous approach to post-CABG evaluation. This comprehensive review paper introduces the indications for bypass grafting surgery and transcatheter PCI approaches, details techniques and strategies for bypass surgery, discusses CTA in evaluating post-CABG graft patency, and consolidates research surrounding pre-reintervention CTA in post-CABG patients. Last, this review explores future directions in standardizing post-CABG evaluation guidelines.