The efficacy of colchicine compared to placebo for preventing ischemic stroke among individuals with established atherosclerotic cardiovascular diseases: a systematic review and meta-analysis

<i>Background.</i> Colchicine is an anti-inflammatory drug with promising efficacy for preventing cardiovascular events. We aimed to assess the pooled effect of colchicine on ischemic stroke among patients with established atherosclerotic cardiovascular diseases. <i>Methods</i>. PubMed, Scopus, Web of Science, and the Cochrane Library were systematically searched from the inception to August 5, 2024. A random-effects (DerSimonian–Laird) model was used to conduct this meta-analysis. The inclusion criteria were as follows: (I) being a randomized controlled trial; and (II) measuring the efficacy of colchicine compared to placebo for preventing ischemic stroke among those with established atherosclerotic cardiovascular diseases. <i>Results</i>. We identified 13 eligible clinical trials with 24900 participants. Colchicine significantly decreased the risk of ischemic stroke (relative risk (RR) 0.85, 95% confidence interval (CI) (0.72, 0.99), I²=2.92%) among those with established atherosclerotic cardiovascular diseases. Colchicine was more effective when used at 0.5 mg/day (RR 0.86, 95% CI (0.75, 0.99)), prescribed for more than 30 days (RR 0.86, 95% CI (0.75, 1.00)) or for more than 90 days (RR 0.65, 95% CI (0.46, 0.92)), or administered for patients with acute coronary syndrome (RR 0.46, 95% CI (0.23, 0.92)). In addition, colchicine was more effective in studies with a sample size of more than 500 patients, consistent with sensitivity analysis, which indicated that the results relied on large-sized clinical trials. <i>Conclusion</i>. Colchicine may decrease the risk of ischemic stroke among patients with established atherosclerotic cardiovascular diseases, particularly after long-term use; however, future studies are needed due to inconsistencies between existing trials.