Beyond the numbers: the challenge of FFR-guided strategies in multivessel disease undergoing CABG-think differently

Fractional flow reserve (FFR) is a cornerstone in guiding percutaneous coronary intervention (PCI) for intermediate coronary lesions, supported by robust evidence and guidelines. Its application in coronary artery bypass grafting (CABG), however, remains uncertain, with no validated thresholds or standardized integration into surgical planning.

We report the case of a 69-year-old man with three-vessel coronary artery disease who underwent total arterial revascularization using a bilateral internal mammary artery Y-graft. Despite a pre-operative FFR of 0.78 in the left anterior descending artery (LAD), intra-operative transit-time flow measurements revealed severely impaired graft flow, prompting revision of the left internal mammary artery-LAD anastomosis. Post-revision flow remained poor. At 3-month follow-up, angiography confirmed graft failure, yet myocardial perfusion imaging showed no significant ischaemia in the LAD territory.

This case underscores the limitations of applying FFR as a primary determinant in surgical revascularization. In the absence of validated cut-offs for CABG, reliance on PCI-based thresholds may lead to inappropriate grafting strategies, competitive flow, and early graft failure. Fractional flow reserve should be seen as a physiological adjunct-not a directive-within a broader framework of clinical, anatomical, and intra-operative assessment. Current evidence does not support replacing angiographic judgment with FFR in surgical decision-making. The integration of FFR into CABG planning requires a nuanced, individualized approach, guided by future trials and multidisciplinary expertise.

In surgical revascularization, the question is not whether a lesion crosses an FFR threshold, but how to best achieve durable myocardial protection.FFR should guide strategy, not dictate it-think differently.