Coronary artery bypass grafting (CABG) remains the primary revascularisation strategy to relieve myocardial ischaemia in patients with complex coronary stenoses. Patients with diffuse coronary artery disease (DCAD) experience higher rates of perioperative myocardial infarction (PMI) and long-term major adverse cardiovascular and cerebrovascular events (MACCEs) following CABG compared with less extensive disease.
Coronary microcalcification activity, quantified by uptake of 18F-NaF on PET imaging and expressed as the tissue-to-background ratio (TBR), has been shown to have predictive value for adverse events after CABG and reflects the coronary immunoinflammatory microenvironment. The 2024 European Society of Cardiology guidelines recommend low-dose colchicine (0.5 mg/day) as an adjunct to statins and standard secondary prevention in chronic coronary syndromes for MACCE prevention. Colchicine is hypothesised to stabilise coronary plaques and reduce adverse events, but the mechanistic link—particularly its effect on microcalcification activity—remains unclear.
The COL-CABG trial is designed to evaluate whether low-dose colchicine alters coronary microcalcification activity and to explore associated clinical outcomes in patients with DCAD undergoing CABG.
COL-CABG is a single-centre, prospective, randomised, open-label, blinded-endpoint trial conducted at Beijing Anzhen Hospital, Capital Medical University. The open-label treatment allocation will be counterbalanced by blinded endpoint assessment to reduce bias in outcome adjudication.
Recruitment is planned from July 2026 to June 2028.
The study will prospectively enrol 108 patients with DCAD who meet the imaging criterion of baseline TBR > 3.6 on 18F-NaF PET. All enrolled patients are planned to undergo CABG.
Details of additional inclusion and exclusion criteria were not reported in the source.
Enrolled patients will be randomised in a 1:1 ratio to one of two groups:
All participants will receive CABG according to usual clinical practice at the treating centre.
Randomisation is described as 1:1; further details of allocation concealment, stratification, or blinding procedures beyond blinded endpoint assessment were not reported in the source.
The primary endpoint is the change in coronary microcalcification activity measured as the difference in TBR between baseline (pre-CABG) and 90 days after CABG (TBR at baseline minus TBR at 90 days). This quantitative imaging endpoint using 18F-NaF PET aims to detect short-term modulation of microcalcification activity that could reflect changes in plaque biology induced by colchicine.
Imaging protocols, PET acquisition parameters, and central reading procedures beyond the prespecified TBR threshold were not detailed in the source.
Secondary clinical outcomes are designated as exploratory and hypothesis-generating. These include:
The source states these clinical outcomes will be interpreted as exploratory; detailed adjudication criteria and event definitions beyond the listed components were not provided.
Baseline screening for enrolment requires an 18F-NaF PET-derived TBR > 3.6, reflecting elevated coronary microcalcification activity. The primary imaging assessment is planned at 90 days after CABG to measure change from baseline.
Further specifics on image analysis methodology, region-of-interest definitions, or inter-reader variability measures were not reported in the source.
The trial will compare the change in TBR at 90 days between the colchicine and control groups as the primary analysis. Secondary analyses will examine the incidence of PMI within 7 days and MACCEs within 90 days as exploratory endpoints.
Sample size calculations, power assumptions, handling of missing data, and planned statistical methods were not included in the source article excerpt.
The study protocol has been approved by the Institutional Review Board of Beijing Anzhen Hospital, Capital Medical University (approval number: 2025202x). Written informed consent will be obtained from all participants prior to enrolment.
Results are planned to be disseminated through peer-reviewed publications and presentations at scientific conferences.
The COL-CABG trial is registered with the Chinese clinical trial registry under number ChiCTR2500111659. Recruitment is scheduled from July 2026 through June 2028, with the primary imaging endpoint assessed at 90 days post-CABG.
Further operational details, including full eligibility criteria, imaging protocols, and statistical analysis plans, were not reported in the provided source text.