# Protocol for the CABG-PRIME Study (Coronary Artery Bypass Graft—Platelet Response and Improvement in Medicine Efficacy)—An Exploratory Study to Review the Role of Platelet Function Testing in Improving Patient Outcomes Post-CABG Surgery

## TL;DR

This study explores whether platelet function testing can improve outcomes after heart bypass surgery by identifying patients who may not respond well to standard antiplatelet drugs.

## Contribution

The study introduces an exploratory protocol to evaluate the role of platelet function testing in personalizing antiplatelet therapy after CABG surgery.

## Key findings

- Platelet function testing may help identify patients at higher risk of thrombotic complications post-CABG.
- The study will assess the prevalence of aspirin and clopidogrel resistance in CABG patients using TEG6s PFT.
- Feasibility of integrating PFT into clinical workflows will be evaluated for future personalized antiplatelet management.

## Abstract

Background: Coronary artery bypass grafting (CABG) is a well-established revascularization strategy for patients with multivessel coronary artery disease. The effectiveness of CABG is significantly influenced by antiplatelet therapy aimed at maintaining graft patency and reducing thrombotic complications. However, substantial inter-individual variability exists in platelet function responses to standard therapies such as aspirin and clopidogrel, leading to antiplatelet resistance. This variability has been linked to increased risks of myocardial infarction, stroke, and early graft failure. Platelet function testing (PFT) offers a potential strategy to identify resistance and guide more personalized antiplatelet therapy. This study aims to evaluate the association between perioperative platelet function test results and clinical outcomes following CABG. By assessing platelet responsiveness at multiple timepoints and correlating findings with postoperative events, the study seeks to determine whether PFT can stratify risk and improve patient management. Methods: This is a prospective, single-centre, observational cohort study conducted at a tertiary NHS cardiac surgery centre. Patients having elective or urgent isolated CABG will be enrolled and undergo perioperative PFT using the TEG6s system. Clinical outcomes will be monitored for 12 months postoperatively, with primary endpoints assessing the correlation between platelet function results and major adverse cardiovascular and cerebrovascular events (MACCE). Secondary endpoints will include the prevalence of antiplatelet resistance, demographic predictors, and the feasibility of integrating PFT into clinical workflows. Results: This study will report the prevalence of aspirin and clopidogrel resistance in CABG patients based on TEG6s PFT, as well as the correlation between platelet function results and MACCE, postoperative bleeding, and the need for surgical re-exploration. Additionally, it will examine the associations between demographic and clinical factors—such as diabetes status, renal function, BMI, and surgical technique—and variability in platelet responsiveness. The feasibility of incorporating PFT into perioperative workflows will also be evaluated, assessing whether results could support personalized antiplatelet management in future clinical trials. Conclusions: Findings from this study will provide real-world evidence regarding platelet function variability in CABG patients and suggest that PFT may identify those at increased risk of thrombotic complications. This exploratory analysis supports the need for larger interventional trials aimed at optimizing individualized postoperative antiplatelet therapy to improve surgical outcomes.