Coronary physiology based versus angiography guided coronary artery bypass grafting

Abstract

Introduction. Coronary artery bypass grafting (CABG) remains the recommended revascularization strategy for multi-vessel coronary artery disease (MVD) (1,2,3). The selection of which vessels to bypass is usually at the discretion of the surgeon and based on angiographic imaging. Coronary physiology measurements is more accurate at determining the hemodynamic significance of coronary lesions and has been demonstrated to improve outcomes when used to guide percutaneous intervention (4,5,6). The use of intracoronary physiology has not been extensively studied or validated in patients undergoing coronary artery bypass grafting. Non-randomized single center registry studies have demonstrated that grafting vessels without haemodynamically significant stenoses predispose to graft failure (7,8). However, no study has prospectively assessed the role of physiology in determining which vessels should be grafted and how this approach compares to traditional methods. Research aim. This pilot, blinded study is designed to prospectively compare graft patency and outcomes using a physiologically guided approach compared to standard angiographicaly guided CABG. Research methods and organization. Study so far included 35 patients (pts.) (mean age 68±7 years) with multi-vessel coronary artery disease (MVD) when optimal revascularization method had been decided as CABG. Measurements of instantaneous wave-free ratio (iFR) was made in 105 vessels suitable for grafting according to standardized technique. Patients randomized to standard therapy underwent CABG with the number of grafted vessels dictated by the treating clinical team. Patients randomized to physiology-guided CABG only had grafts placed onto vessels that had been proven to have haemodynamically significant stenoses on a pressure wire measurement with an expectation with left internal mammary artery (LIMA) on left anterior descending artery (LAD). Post-surgery follow-up: gra