Inflammation and platelet reactivity during adjunctive colchicine versus aspirin in patients with acute coronary syndrome treated with potent P2Y12 inhibitor

Background: In patients undergoing percutaneous coronary intervention (PCI), the use of anti-inflammatory therapy with colchicine is associated with a reduction of recurrent ischemic events. The mechanisms of such findings are not fully elucidated. Objectives: To investigate the effects of colchicine versus aspirin on inflammation and platelet reactivity in patients with acute coronary syndrome (ACS) undergoing PCI. Methods: This observational study compared laboratory measurements in ACS patients receiving single antiplatelet therapy with ticagrelor or prasugrel plus colchicine (MACT) (n = 185) versus conventional dual-antiplatelet therapy (DAPT) with aspirin plus ticagrelor or prasugrel (n = 497). The primary outcome was the frequency of high residual inflammation, defined as high-sensitivity C-reactive protein (hs-CRP) ≥2 mg/L at 1 month post-PCI. Multiple sensitivity analyses were performed for the primary outcome, including multivariable adjustment, propensity-score matching, and inverse-probability weighted methods. Results: One month after PCI, patients treated with MACT had significantly lower levels of hs-CRP compared to those treated with DAPT (0.6 [0.4–1.2] vs. 0.9 [0.6–2.3] mg/L, p < 0.001). The frequency of high residual inflammation was also lower in the MACT group (10.8% vs. 27.2%, p < 0.001) (odds ratio [95% confidence interval] = 0.33 [0.20–0.54], p < 0.001). This effect was consistent across sensitivity analyses. There was no difference in platelet reactivity between MACT and DAPT (49.6 ± 49.0 vs. 51.5 ± 66.4 P2Y ₁₂ reaction unit [PRU] measured by VerifyNow, p = 0.776). Conclusion: In ACS patients undergoing PCI, MACT was associated with a lower rate of high residual inflammation without increasing platelet reactivity compared to conventional DAPT. Clinical trial registration: NCT04949516 for MACT pilot trial and NCT04650529 for Gyeongsang National University Hospital registry.