Coronary-Artery Bypass Grafting.

To the Editor: In their article on coronary-artery bypass grafting (CABG), Alexander and Smith (May 19 issue)1 state that “the usefulness of FFR [fractional flow reserve] in selecting patients with multivessel coronary artery disease for CABG or in identifying bypass graft targets in patients undergoing CABG has not been studied.” However, a prospective study by Botman et al.2 showed a relationship between the physiological severity of coronary stenosis (as assessed by measurement of FFR) and graft patency on angiographic assessment at 1 year in 164 patients who underwent CABG. We extended this observation in 627 patients who underwent CABG that was guided by either angiography or FFR.3 The use of FFR assessment was associated with a reduced rate of multivessel disease and a significant reduction in the number of anastomoses per patient. Off-pump surgery was more frequent in the FFR group than in the angiography group (51% vs. 31%, P<0.001). No signal of a hazard of major adverse cardiovascular events was detected in these patients; this finding supports the safety of FFR-guided surgical revascularization. Finally, in a study involving patients who had aortic stenosis and coronary artery disease and who underwent CABG, the use of FFR guidance was associated with a reduction in the number of venous grafts and anastomoses without an increase in the rate of adverse events at up to 5 years.4 Emanuele Barbato, M.D., Ph.D.