Recent high-quality trials have shown that the anti-inflammatory effects of colchicine reduce the risk of cardiovascular events in patients suffering post-myocardial infarction and chronic coronary disease. The effect of colchicine in patients undergoing non-coronary artery bypass grafting (non-CABG) with cardiopulmonary bypass remains unclear. We aim to evaluate the effect of colchicine on myocardial protection in patients who underwent non-CABG cardiac surgery.Patients were randomly assigned to colchicine or placebo groups starting 72 h before scheduled cardiac surgery and for 5 days thereafter (0.5 mg daily).The primary outcome was the level of cardiac troponin T (cTnT) at postoperative 48 h. The secondary outcomes included troponin I (cTnI) and creatine kinase-MB (CK-MB), inflammatory biomarkers (procalcitonin and interleukin-6, etc.), and adverse events (30-day mortality, stroke, ECMO and IABP use, etc.).A total of 132 patients underwent non-CAGB cardiac surgery, 11were excluded because of diarrhea (n = 6) and long aortic cross-clamp time > 2 h (n = 5), 59 were assigned to the colchicine group and 62 to the placebo group. Compared with the placebo group, cTnT (median: 0.3 μg/L, IQR 0.2-0.4 μg/L vs. median: 0.4 μg/L, IQR 0.3-0.6 μg/L, P < 0.01), cardiac troponin I (median: 0.9 ng/ml, IQR 0.4-1.7 ng/ml vs. median: 1.3 ng/ml, IQR 0.6-2.3 ng/ml, P = 0.02), CK-MB (median: 1.9 ng/ml, IQR 0.7-3.2 ng/ml vs. median: 4.4 ng/ml, IQR 1.5-8.2 ng/ml, P < 0.01), and interleukin-6 (median: 73.5 pg/ml, IQR 49.6-125.8 pg/ml vs. median: 101 pg/ml, IQR 57.5-164.7 pg/ml, P = 0.048) were significantly reduced in colchicine group at postoperative 48 h. For safety evaluation, the colchicine (n = 65) significantly decreased post-pericardiotomy syndrome (3.08% vs. 17.7%, P < 0.01) and increased the rate of diarrhea (9.23% vs. 0, P = 0.01) compared with the placebo group (n = 62). No significant difference was observed in other adverse events between the two groups.A short perioperative course of low-dose colchicine was effective to attenuate the postoperative biomarkers of myocardial injury and inflammation, and to decrease the postoperative syndrome compared with the placebo. Trial registration ChiCTR2000040129. Registered 22nd Nov. 2020. This trial was registered before the first participant was enrolled. http://www.chictr.org.cn/showproj.aspx?proj=64370 .© 2023. The Author(s).