Colchicine a New Tool for Stroke, CVD Event Recurrence?

BASEL, SWITZERLAND — The anti-inflammatory agent colchicine failed to show significant benefit in the treatment of patients with non-cardioembolic ischemic stroke in the primary analysis of the CONVINCE trial.

However, the results did reveal a significant reduction in recurrent stroke and cardiovascular events in the per-protocol analysis and in the subgroup of patients with coronary artery disease.

“Although the primary endpoint was neutral, the CONVINCE results support the hypothesis that long-term anti-inflammatory therapy with colchicine may reduce recurrent stroke and cardiovascular events, specifically in stroke patients with atherosclerosis,” lead investigator Peter Kelly, MD, University College Dublin School of Medicine, Dublin, Ireland, concluded.

The results were presented at the European Stroke Organization Conference (ESOC) 2024 in Basel, Switzerland.

Inflammation, he said, plays an important role in the pathophysiology of atherosclerotic plaque, a major cause of cardiovascular events and ischemic strokes.

Colchicine, an established, widely available, low-cost drug that reduces inflammatory response, has been shown to reduce recurrent vascular events in patients with coronary artery disease.

The CONVINCE trial was conducted to see whether colchicine could show similar benefits in patients with non-severe, non-cardioembolic stroke or transient ischemic attack.

Conducted in 16 European countries and Canada, the CONVINCE trial included 3154 patients with a recent non-cardioembolic nondisabling ischemic stroke or high-risk transient ischemic attack. They were randomly assigned to receive colchicine (0.5 mg/d) or placebo.

Key exclusion criteria included evidence of atrial fibrillation or other source of cardioembolism, a defined cause of stroke other than atherosclerosis or small vessel disease, a glomerular filtration rate below 50 mL/min, and the use of drugs that interact with colchicine.

The primary endpoint was a composite of first recurrent ischemic stroke, myocardial infarction, cardiac arrest, or hospitalization for unstable angina. Study participants were followed-up over 36 months.

Results of the primary intention-to-treat analysis showed that the primary endpoint occurred in 153 patients randomized to low-dose colchicine (9.8%) vs 185 in the placebo group (11.8%). This translated into a hazard ratio (HR) of 0.84 (95% CI, 0.68-1.05; P = .12) — a nonsignificant result.

Reduced levels of C-reactive protein in the colchicine group showed the anti-inflammatory effect of treatment with colchicine, Kelly reported.

In a pre-specified on-treatment analysis (excluding patients with major protocol violations), colchicine did show a significant benefit in the primary endpoint (HR, 0.80; 95% CI, 0.63-0.99).

A Novel Target for Stroke Treatment

In addition, significantly reduced rates of recurrent stroke or cardiovascular events were observed in the subgroup of patients with a history of coronary artery disease.

In an updated meta-analysis of existing colchicine studies including CONVINCE, there was a significant reduction in the risk for ischemic stroke (risk ratio, 0.73; 95% CI, 0.58-0.90).

“The signals of benefit of colchicine in secondary analyses are in line with findings from previous trials and indicate the potential of colchicine in prevention after stroke,” Kelly said.

He pointed out that the COVID pandemic reduced the planned follow-up time in the CONVINCE trial, which led to the study being underpowered for the primary analysis.

“Further trials are needed in all stroke subtypes, but with particular focus on patients with objective evidence of atherosclerosis,” he said.

Commenting on the findings, Mira Katan, MD, University Hospital of Basel, Basel, Switzerland, noted that inflammation represents a novel target for stroke treatment.

“We have never before looked at treating inflammation in stroke. Although the primary endpoint was not reached in the CONVINCE study, the on-treatment analysis and meta-analysis showed a risk reduction, and we know colchicine works in cardiology. I think this is a fantastic trial, giving us a new target for stroke therapy,” Katan said.

“I think we have a new tool, but of course we need further trials to confirm that,” she added.

The CONVINCE trial was supported by Health Research Board Ireland, Deutsche Forschungsgesellschaft, Fonds Wetenschappelijk Onderzoek (FWO), and the Irish Heart Foundation. Kelly received funding from the Irish Heart Foundation. RL is a senior clinical investigator of FWO Flanders. Katan reported no relevant disclosures.