Outcomes of quantitative fl ow ratio - based functional incomplete revascularization after coronary artery bypass grafting surgery

Objective: Quantitative fl ow ratio is a novel functional assessment tool of coronary diseases. Whether quantitative fl ow ratio could improve the outcomes of coronary artery bypass grafting is undetermined. This study aimed to investigate the association between the quantitative flow ratio based functional incomplete revascularization and the outcomes after coronary artery bypass grafting surgery. Methods: The quantitative fl ow ratio assessment was retrospectively performed in patients undergoing coronary artery bypass grafting surgery in the PATENCY trial. The anatomic complete revascularization denoted revascularizing each territory with stenosis greater than 50 % evaluated by angiography. The functional complete revascularization was de fi ned as grafting all vessels with a quantitative fl ow ratio 0.80 or less. The primary end point was the 12-month composite major adverse cardiac or cerebral vascular events. Results: A total of 2024 patients with available quantitative fl ow ratio values were included. Functional complete revascularization was achieved in 1846 patients (91.2 % ), and 1600 received anatomic complete revascularization (79.1 % ). Both the functional incomplete revascularization and anatomic incomplete revascularization groups were associated with signi fi cantly increased risks of 12-month major adverse cardiac or cerebral vascular events (functional: hazard ratio, 2.91; 95 % con fi dence interval, 1.56 to 5.43; P = .001; anatomic: hazard ratio, 2.82; 95 % con fi- dence interval, 1.54 to 5.16; P = .001). Additionally, for the subgroup of patients (n = 246) receiving anatomic incomplete revascularization but judged as functional complete revascularization by quantitative fl ow ratio, the risk of the 12-month major adverse cardiac or cerebral vascular events was not signi fi cantly increased (adjusted hazard ratio, 1.36; 95 % con fi dence interval, 0.71-2.60; P = .35). Conclusions: Both the functional incomplete revascularization and anatomic incomplete revascularization were associated with increased risks of 12-month major adverse cardiac or cerebral vascular events after coronary artery bypass grafting surgery. The quantitative fl ow ratio can serve as a supplementary tool for the decision-making of surgical revascularization. (J Thorac Cardiovasc Surg 2024;168:548-58)