Complete Revascularization in Coronary Artery Bypass Grafting: Separating the Wheat from the Chaff

Coronary artery bypass grafting (CABG) has been established as the most effective treatment for patients with multi-vessel coronary artery disease. To maximize outcomes by restoring perfusion to the largest possible myocardial territory, complete revascularization (CR) has long been a key objective of CABG. Because the anatomic severity of coronary artery stenosis on coronary angiography has been the main criterion for selecting target vessels for several decades, the definition of CR has traditionally been based on angiographic anatomy. Numerous studies have examined the impact of anatomic CR on outcomes after CABG; however, the results remain controversial. At the same time, there has been increasing interest in ischemia-inducing coronary artery stenosis assessed by functional studies such as dobutamine-stress echocardiography, nuclear imaging tests, fractional flow reserve, and quantitative flow ratio. This has raised the importance of defining CR based on functional ischemia rather than anatomic stenosis. Nevertheless, only a few studies have reported the impact of functional CR on CABG outcomes. Therefore, this narrative review summarizes the various definitions of CR in CABG, highlights its benefits and shortcomings, and introduces the available literature evaluating the effects of anatomic and functional CR on long-term clinical outcomes.