Rationale and design of COLchicine On-admission to Reduce inflammation in Acute Coronary Syndrome (COLOR-ACS) study

Aims: The aim of the colchicine on-admission to reduce inflammation in acute coronary syndrome (COLOR-ACS) study is to evaluate the effects of the addition of short-term, low-dose colchicine to high-dose atorvastatin in limiting levels of inflammatory markers, such as high-sensitivity C-reactive protein (hs-CRP), in patients with non-ST-elevation acute coronary syndrome (NSTE-ACS). Methods: The COLOR-ACS study is a multicenter, randomized, open-label, two-arm trial. Statin-naive patients with NSTE-ACS, scheduled for an early invasive strategy, are randomized on admission to receive standard treatment of atorvastatin 80 mg or standard treatment plus colchicine (1 mg loading dose followed by 0.5 mg/day until discharge). The main exclusion criteria are prior statin and/or colchicine treatment, current treatment with potent inhibitors of CYP3A4, P-glycoprotein or immunosuppressive drugs, known active malignancy, severe kidney, cardiac, liver disease. There is clinical and biochemical follow-up at 30 days after discharge and telephone interview at 6 months. The primary end point is the change in hs-CRP from admission to discharge. Secondary end points include: incidence of acute kidney injury; MB fraction of creatine kinase peak value; glomerular filtration rate change from baseline to 30 days; persistence of hs-CRP ≥2 mg/dl at 30 days; adverse clinical events within 30 days; tolerance to colchicine. Conclusion: The COLOR-ACS study will provide evidence on the efficacy of early short-term treatment with colchicine in addition to high-dose atorvastatin compared to atorvastatin alone in ACS patients. The potential anti-inflammatory action of colchicine plus atorvastatin is expected to limit hs-CRP increase with resultant clinical benefits. Trial registration: ClinicalTrials.gov; NCT05250596