The present study seeks to evaluate the effectiveness of the use of perioperative colchicine with regard to operative complications, in patients with acute coronary syndrome and indication for cardiac post-surgical revascularization.

Patients will be selected and randomized while still in the emergency room and medication (colchicine 0.5mg every 12 hours or placebo) will be started within 24 hours of randomization, being maintained for 30 days after surgery.

Atherosclerotic cardiovascular disease remains a leading cause of global morbidity and mortality. Despite advances in medical therapy, patients presenting with Acute Coronary Syndrome (ACS) sustain a high residual risk of recurrent events, largely driven by inflammatory pathways.

Consequently, targeting inflammation has become a major focus of recent cardiovascular research. Colchicine, a widely available and low-cost anti-inflammatory agent, has demonstrated significant benefits in both acute and chronic coronary syndromes. In the setting of elective coronary artery bypass grafting (CABG), prophylactic colchicine has been shown to reduce perioperative myocardial injury and the incidence of post-pericardiotomy syndrome, with a strong pathophysiological rationale for preventing postoperative atrial fibrillation (POAF).

However, evidence regarding the use of perioperative colchicine in the highly vulnerable scenario of patients presenting with ACS who require surgical revascularization (a "double inflammatory hit" model) is scarce. The present study seeks to evaluate the effectiveness of perioperative colchicine in preventing major operative complications in this specific high-risk ACS population. Objective documentation of the benefit of colchicine in this setting could pioneer a new therapeutic approach with great potential to modify current medical guidelines.

To address this gap, the trial utilizes a Prospective Randomized Open-label Blinded Endpoint (PROBE) design. While the allocation to the intervention (colchicine) or standard of care is open-label to both patients and the clinical care team, the assessment of all clinical endpoints is strictly masked.

To mitigate detection and observer bias, an independent Clinical Events Committee (CEC) was established. This committee is composed of physicians who are not involved in patient recruitment or direct clinical care. The CEC performs the formal, blinded adjudication of all clinical efficacy and safety events. The adjudication process is conducted using raw, anonymized clinical data (ECGs, cardiac biomarkers, surgical reports, and imaging), with the committee completely blinded to the randomized treatment allocation.

Inclusion Criteria:

• Patients with acute coronary syndrome, with indication for myocardial revascularization surgery
• Patients of both genders, aged over 18 years.

Exclusion Criteria:

• Inability to sign the informed consent form;
• Current use of colchicine;
• Current use of long-term corticosteroid therapy
• Inflammatory bowel disease or chronic diarrhea;
• Clinically significant non-transient haematological abnormalities;
• Renal dysfunction, with creatinine greater than 2 times the upper limit of normality;
• Severe liver disease;
• Drug addiction or alcoholism;
• History of clinically significant sensitivity to colchicine.