2223Effect of ticagrelor plus aspirin, ticagrelor alone, or aspirin alone on vein-graft patency 1 year after coronary artery bypass grafting with or without diabetes: a post-hoc analysis of the DACAB tria
Authors: Zhu Y P , Liu H , Zhang M L , Mei J , Zhao Q 
Published: October 2019

Abstract

Introduction
The association of diabetes and vein graft patency after coronary artery bypass grafting (CABG) remains controversial. In patients with diabetes, impaired endothelial function in vein grafts and high platelet turnover might result in early vein graft failure. The DACAB trial showed ticagrelor plus aspirin significantly increased 1-year vein graft patency vs. aspirin alone, while no significant difference between ticagrelor alone and aspirin alone. However, whether the results is different between the patients with or without diabetes is unknown.

Purpose
To assess the effects of ticagrelor with or without aspirin vs. aspirin alone on 1-year vein grafts patency after CABG in patients with or without diabetes.

Methods
We examined the subgroups of patients with and without diabetes from DACAB trial (NCT02201771), in which 500 patients were randomized to 1 of 3 antiplatelet regimens (ticagrelor 90mg twice daily plus aspirin 100mg once daily, T+A group; ticagrelor 90mg twice daily, T group; or aspirin 100mg once daily, A group) within 24 hours post-CABG. The primary outcome was 1-year vein graft patency (FitzGibbon grade A) assessed by multi-slice computed tomographic angiography or coronary angiography.

Results
According to the baseline medical history and/or glycated hemoglobin (HbA1c) ≥6.5%, 283 patients with 818 vein grafts were allocated to the non-diabetes subgroup, remaining 217 patients with 642 vein grafts to the diabetes subgroup. By per-graft analysis, no significant difference on 1-year vein graft patency rate was observed between non-diabetes and diabetes subgroup (84.6% [692/881] for non-diabetes vs. 80.2% [515/642] for diabetes, adjusted odds ratio (OR) =1.39, 95% CI: 0.92–2.09, P=0.116). In T+A group, 1-year vein graft patency rates were 91.0% (244/268) for non-diabetes vs. 85.8% (188/219) for diabetes; In T group, 85.0% (221/260) for non-diabetes vs. 80.3% (183/228) for diabetes; In A group, 78.3% (227/290) for non-diabetes vs. 73.9% (144/195) for diabetes. Ticagrelor plus aspirin showed higher vein graft patency rate than aspirin alone in both non-diabetes and diabetes subgroup (non-diabetes: adjusted OR = 0.34, 95% CI: 0.17–0.69, and diabetes: adjusted OR = 0.42, 95% CI: 0.19–0.91, P for interaction = 0.524), whereas ticagrelor alone did not show improvement on vein graft patency compared with aspirin alone in both subgroups (non-diabetes: adjusted OR=0.62, 95% CI: 0.32–1.20, and diabetes: adjusted OR = 0.65, 95% CI: 0.33–1.31, P for interaction = 0.795). Similar results were showed by per-patient analysis. A total 16 major adverse cardiovascular events occurred, 8 (2.8%) for non-diabetes and 8 (3.7%) for diabetes.

Conclusion
In the DACAB trial, diabetes was not found to be associated with decreased vein graft patency at 1 year after CABG. The effect of ticagrelor plus aspirin on improvement of 1-year vein graft patency, when compared with aspirin alone, is consistent in patients with or without diabetes.

Acknowledgement/Funding
AstraZeneca