Angiographic definition, incidence, predictors and clinical impact of early coronary graft failure in patients undergoing coronary artery bypass graft surgery
Authors: Van Oort M J H , Al Amri I , De Weger A , Regeer M V , Jukema J W , Montero Cabezas J M 
Published: November 2023

Abstract

Introduction
Coronary graft failure (CGF) may occur early after coronary bypass graft surgery (CABG), potentially leading to adverse clinical outcomes. However, data regarding incidence, diagnostic strategies and identification of individuals at risk of developing early CGF are scarce.

Purpose
The aim of this study was to establish a definition of early CGF based on invasive coronary angiography (CAG), to identify clinical and perioperative risk factors of early CGF and to define the clinical impact of early CGF in terms of major adverse cardiovascular events (MACE: death, myocardial infarction and revascularisation) at 5-years follow-up.

Methods
This retrospective observational study included CABG patients who underwent CAG prior to post-surgery discharge between 2012-2022 in a tertiary center. The decision to perform a CAG was based on clincal criteria indicative of myocardial ischemia. All CAGs were reviewed by two interventional cardiologist and a thoracic surgeon. Early CGF was defined as a dysfunctional coronary graft resulting from any of the following angiographic findings: stenosis of proximal or distal anastomosis, stenosis of the bypass conduit, bypass occlusion, reduced bypass flow (TIMI&lt;1) and kinking/tenting/dissection of the bypass leading to lumen reduction. Clinical data and ECG recordings during hospitalization were collected. Comparisons between patients with vs. without early CGF were performed. Kaplan-Meier analysis was performed to estimate cumulative survival free of MACE at 5-years follow-up. Multivariate analysis was performed to identify predictors of early CGF.

Results
A total of 92 patients (79% male, 66.1±10 years-old) were included. CGF was present in 55 patients (60%). Compared to the patients without graft failure (n=37 (40%), there were no differences in baseline demographics and intra- and postoperative technical and clinical parameters. At 5-years follow-up, MACE was observed in 57 patients (18 death, 34 myocardial infarction, 42 revascularization). There were 50 revascularization procedures performed in 42 patients (46%). Of them, 35 (83%) were performed in patients with early CGF vs. 7 (17%) in patients without CGF (p&lt;0.001). Patients with early CGF showed a significantly lower MACE-free five-year survival rate (p&lt;0.001) (Figure) 1). On multivariate analysis, venous grafts (p=0.006), Y-graft configuration (p&lt;0.001) and the need of inotropic agents for hemodynamic support (p=0.029) showed a significant association with early CGF.

Conclusion
In CABG patients undergoing clinically indicated CAG prior to discharge, early CGF was observed in 60%. Most patients underwent new revascularisation. Patients with early CGF showed a higher rate of MACE at 5-years follow-up, emphasizing the necessity to recognize and treat CGF. Venous grafts, Y-graft configuration and the need of inotropic agents for hemodynamic support 12h postoperatively were associated with early CGF.