Efficacy and Safety of Mono Antiplatelet Therapy with Colchicine in Acute Coronary Syndrome Patients Following Percutaneous Coronary Intervention: Rationale and design of the MACT II Trial

Ji Yong Jang¹Yongsung Suh²Choongki Kim³Jeong Tae Byoun⁴Kyeong Ho Yoon⁴Jung-Hee Lee⁵Ki-Hyun Jeon⁶Sungsoo Cho⁷Hyuk-Joon Yoon⁸Jin Won Kim⁹Bom Lee¹⁰Se Hun Kang¹⁰Sang-Hoon Kim¹⁰Jae Youn Moon¹⁰Yangsoo Jang¹¹Seung-Yul Lee^10*

• ¹National Health Insurance Service Ilsan Hospital, Goyang-si, Republic of Korea
• ²Myongji Hospital, Goyang-si, Republic of Korea
• ³Ewha Womans University Seoul Hospital, Seoul, Republic of Korea
• ⁴Wonkwang University Hospital, Iksan-si, Republic of Korea
• ⁵Wonju Severance Christian Hospital, Wonju-si, Republic of Korea
• ⁶Seoul National University Bundang Hospital, Seongnam-si, Republic of Korea
• ⁷Gangnam Severance Hospital, Seoul, Republic of Korea
• ⁸Keimyung University Dongsan Medical Center, Daegu, Republic of Korea
• ⁹Korea University Guro Hospital, Guro-gu, Republic of Korea
• ¹⁰CHA Bundang Medical Center, Seongnam-si, Republic of Korea
• ¹¹Health Insurance Review & Assessment Service, Seoul, Republic of Korea

Abstract Introduction. Early discontinuation of aspirin after percutaneous coronary intervention (PCI) reduces bleeding risk, while inflammation-targeted strategies may offer additional benefit in patients with acute coronary syndrome (ACS). Residual inflammatory risk—reflected by persistently elevated high-sensitivity C-reactive protein (hs-CRP) levels—remains a significant contributor to adverse cardiovascular outcomes despite guideline-directed therapy. Colchicine has emerged as a potential anti-inflammatory agent in this context, but its optimal use remains uncertain. Methods and analysis. MACT (Mono Antiplatelet and Colchicine Therapy) II is an investigator-initiated, prospective, multicenter, single-arm study designed to evaluate the safety and efficacy of an aspirin-free, inflammation-guided treatment strategy in 490 patients with troponin-positive ACS or ST-segment elevation myocardial infarction undergoing PCI with a sirolimus-eluting stent. Aspirin is discontinued on the day after PCI, and ticagrelor is continued at the standard dose. Colchicine (0.6 mg once daily) is initiated within 24 hours after PCI. At 1 month, colchicine is continued or discontinued based on hs-CRP levels. The primary outcome is the 12-month incidence of net adverse clinical events, a composite of cardiovascular death, nonfatal myocardial infarction, nonfatal ischemic stroke, unplanned urgent revascularization, and major bleeding (Bleeding Academic Research Consortium type 3 or 5). Secondary outcomes include longitudinal hs-CRP trends, platelet reactivity, and adverse drug reactions. Conclusions. MACT II evaluates an aspirin-free, inflammation-guided treatment strategy in patients with ACS undergoing PCI. Colchicine therapy is initiated early during the acute phase of ACS and continued or discontinued based on inflammatory response as measured by hs-CRP. By tailoring treatment duration in this manner, the trial aims to reduce both ischemic and bleeding risks while avoiding unnecessary drug exposure. The findings may inform personalized anti-inflammatory strategies in contemporary clinical practice. Trial registration. ClinicalTrials.gov Identifier: NCT06543082