In a placebo-controlled randomized trial, a preprocedural dose of colchicine administered immediately before percutaneous coronary intervention (PCI) for an acute ST-segment elevated myocardial infarction (STEMI) did not reduce the no-reflow phenomenon or improve outcomes.
No-reflow, in which insufficient myocardial perfusion is present even though the coronary artery appears patent, was the primary outcome, and the proportion of patients experiencing this event was exactly the same (14.4%) in the colchicine and placebo groups, reported Yaser Jenab, MD, at CRT 2021 sponsored by MedStar Heart & Vascular Institute.
The hypothesis that colchicine would offer benefit in this setting was largely based on the Colchicine Cardiovascular Outcomes Trial (COLCOT). In that study, colchicine was associated with a 23% reduction in risk for major adverse cardiovascular events (MACE) relative to placebo when administered within 30 days after a myocardial infarction (hazard ratio, 0.77; P = .02).
The benefit in that trial was attributed to an anti-inflammatory effect, according to Dr. Jenab, associate professor of cardiology at Tehran (Iran) Heart Center. In particular as it relates to vascular disease, he cited experimental studies associating colchicine with a reduction in neutrophil activation and adherence to vascular endothelium.
The rationale for a preprocedural approach to colchicine was supplied by a subsequent time-to-treatment COLCOT analysis. In this study, MACE risk reduction for colchicine climbed to 48% (HR 0.52) for those treated within 3 days of the MI but largely disappeared (HR 0.96) if treatment was started at least 8 days post MI.
PodCAST-PCI trial
In the preprocedural study, called the PodCAST-PCI trial, 321 acute STEMI patients were randomized. Patients received a 1-mg dose of oral colchicine or placebo at the time PCI was scheduled. Another dose of colchicine (0.5 mg) or placebo was administered 1 hour after the procedure.
Of secondary outcomes, which included MACE at 1 month and 1 year, ST-segment resolution at 1 month, and change in inflammatory markers at 1 month, none were significant. Few even trended for significance.
For MACE, which included cardiac death, stroke, nonfatal MI, new hospitalization due to heart failure, or target vessel revascularization, the rates were lower in the colchicine group at 1 month (4.3% vs. 7.5%) and 1 year (9.3% vs. 11.2%), but neither approached significance.
For ST-segment resolution, the proportions were generally comparable among the colchicine and placebo groups, respectively, for the proportion below 50% (18.6% vs. 23.1%), between 50% and 70% (16.8% vs. 15.6%), and above 70% (64.6% vs. 61.3%).
The average troponin levels were nonsignificantly lower at 6 hours (1,847 vs. 2,883 ng/mL) in the colchicine group but higher at 48 hours (1,197 vs. 1,147 ng/mL). The average C-reactive protein (CRP) levels at 48 hours were nonsignificantly lower on colchicine (176.5 vs. 244.5 mg/L).
There were no significant differences in postprocedural perfusion, as measured with TIMI blood flow, or in the rate of stent thrombosis, which occurred in roughly 3% of each group of patients.
The small sample size was one limitation of this study, Dr. Jenab acknowledged. For this and other reasons, he cautioned that these data are not definitive and do not preclude a benefit on clinical outcomes in a study with a larger size, a different design, or different dosing.