Low-Dose Colchicine Stabilizes Dangerous Plaques in the Coronary Arteries

Why Is This Study Important?

In people with chronic coronary artery disease, one of the major risks leading to a heart attack is “plaque rupture,” meaning a break in a plaque within an artery. In recent years, statins have been shown not only to lower cholesterol but also to stabilize plaques by promoting calcification . Could the anti-inflammatory medicine colchicine have the same effect?

This question has practical as well as theoretical relevance, because the US Food and Drug Administration (FDA) approved colchicine in 2023 (at 0.5 mg/day, under the brand Lodoco), to reduce the risk of heart attack, stroke, revascularization, and cardiovascular death in adults with atherosclerotic cardiovascular disease .

However, this FDA approval did not provide a mechanistic explanation of how colchicine exerts its protective effect. This is why the new study discussed here, published on May 19, 2025, in Heart , is particularly important. The study seeks to assess whether colchicine really improves plaque stability —particularly by examining levels of calcification and inflammation markers —with the aim of explaining the clinical benefits of colchicine treatment that led to FDA approval. It seeks to shed light on the underlying biological mechanisms .

🧪 Study Summary: A LoDoCo2 Subanalysis

🔍 Objective:

To assess whether colchicine reduces inflammation in the fat surrounding coronary arteries and increases the stability of plaque composition.

👥 Participants:

• A total of 151 patients (mean age: 64.4 years; 14% women)
• All patients had previously received coronary stents and were taking high-dose statins (atorvastatin 40–80 mg) and antiplatelet/anticoagulant treatment.
• They were randomly assigned to two groups:
  • Colchicine group: 0.5 mg/day (79 patients)
  • Placebo group: (72 patients)

🕒 Follow-Up:

Median 28 months

🛠 Method Used:

• At the end of treatment, all patients underwent coronary CT angiography .
• The assessment evaluated both pericardial adipose tissue inflammation and plaque composition .

📊 Main Findings: Colchicine Increases Plaque Stability

🔹 Inflammation:

• Pericardial adipose tissue attenuation, a marker of inflammation, did not differ significantly between the colchicine and placebo groups.

🔹 Plaque Composition:

In the colchicine group compared with placebo:

🔹 Low-Attenuation Plaques (a High-Risk Plaque Type):

• In patients taking low-dose statins, colchicine significantly reduced the burden of these plaques.
• This effect was not observed with high-dose statins in patients receiving them, unlike the lower-dose group.
• P for interaction = 0.037

In the LoDoCo2 substudy, almost all patients were taking atorvastatin 40–80 mg or a similarly high statin dose. However, some subgroups included patients taking atorvastatin 10–20 mg or a similarly low dose. The study showed that the effect of colchicine was more pronounced in this low-dose group .

P for interaction = 0.037indicates that this difference was statistically significant ; in other words, the effect of colchicine on plaques may vary according to statin dose.

🔬 What Does This Mean?

Although colchicine did not suppress inflammation:

• It made plaques more densely calcified ,
• which means a lower risk of rupture and a more stable arterial structure .

Especially in people who are not taking high-dose statins, this effect of colchicine could provide additional protective treatment .

🧩 What Changes in Clinical Practice?

• Low-dose colchicine may be considered not only for rheumatologic conditions such as gout but also in people with chronic heart disease for secondary prevention .
• However, because this study had a cross-sectional design , a clear cause-and-effect relationship could not be established.
• Nevertheless, taken together with the positive findings of the main LoDoCo2 trial , it provides strong clues that colchicine contributes to plaque stabilization .