Rationale and design of COLchicine On-admission to Reduce inflammation in Acute Coronary Syndrome (COLOR-ACS) study

Biomarkers of residual risk and all-cause mortality after acute coronary syndrome

Background

Adverse cardiovascular events often recur after acute coronary syndrome (ACS), despite secondary prevention measures. Residual risk involves various inflammatory, metabolic and renal factors as well as lipid and thrombotic processes. This cohort study investigates the relationship between four risk biomarkers at 1 month after ACS and all-cause death within 3 years in patients treated with early invasive strategy and high-intensity statins from admission.

Methods

Levels of residual risk for the biomarkers were: low-density lipoprotein cholesterol (LDL-C) ≥ 70 mg/dl; high-sensitivity C reactive protein (hs-CRP) ≥ 2 mg/l; glycosylated hemoglobin (HbA1c) ≥ 7% in diabetic and ≥ 5.7% in non-diabetic patients; decrease in estimated glomerular filtration rate (eGFR) ≥ 25% compared to baseline. The association between the four biomarkers and all-cause death within 3 years was evaluated with Cox proportional analysis.

Results

This study included 1099 patients (68±12 years; 70.3% males). At 1 month the majority of patients had levels of LDL-C, hs-CRP and/or HbA1c above the risk cut-points, and only 7% of cases presented reduced eGFR. Reduced eGFR and hs-CRP ≥ 2 mg/l at 1 month were the sole independent biomarker predictors of 3-year mortality (adjusted hazard ratios 3.03 and 2.66, respectively).

Conclusions

In this population on high-intensity statin therapy only hsCRP and eGFR were independently associated with medium-term mortality. Diversification of secondary preventive measures based on routine evaluations of inflammation and kidney function markers, not only LDL-C, could lead to better targeted reduction of residual risk after ACS.

Low-Dose Colchicine for the Prevention of Cardiovascular Events After Acute Coronary Syndrome

Colchicine, an established anti-inflammatory drug, is examined for its potential in mitigating adverse cardiovascular events following acute coronary syndrome (ACS). ACS, primarily triggered by plaque rupture and subsequent thrombosis, is a critical cardiovascular condition. Colchicine's mechanism of action involves inhibiting microtubule activity, leading to immobilization of white blood cells and reducing inflammation. Clinical data from studies, including low-dose colchicine for secondary prevention of cardiovascular disease two and colchicine cardiovascular outcomes trial, support its efficacy in reducing major cardiovascular events post-ACS, though some studies report varying results. Colchicine can cause transient gastrointestinal side effects and is prescribed with caution in patients with certain medical conditions. The recent FDA approval of a low dose of colchicine reiterates its benefit in reducing cardiovascular risk. The cost-effectiveness of colchicine products (0.5 and 0.6 mg doses) are compared, suggesting the generic 0.6 mg dose of colchicine to be an alternative to branded forms of the drug.

Colchicine added to standard therapy further reduces fibrosis in pigs with myocardial infarction

BACKGROUND

The anti-inflammatory drug colchicine improves the outcome of patients with myocardial infarction (MI). As an intense inflammatory and fibrotic response after MI may lead to scar expansion and left ventricular (LV) remodeling, the clinical benefit of colchicine could be related to a positive effect on the infarct scar and LV remodeling.

METHODS

Pigs underwent left anterior descending artery occlusion through an angioplasty balloon for 90 min and were then randomized into two groups: standard therapy [ACE inhibitor, beta blocker, mineralocorticoid receptor antagonist (MRA), aspirin] plus colchicine (n = 14) or standard therapy alone (n = 13). The pigs were treated for 30 days and underwent two cardiac magnetic resonance (CMR) scans at 72 h and 30 days. The pigs were then sacrificed the day after the second CMR. The primary efficacy end point was the extent of fibrosis in the infarct zone (calculated on eight samples from this zone and averaged).

RESULTS

In the hearts explanted after 31 days, pigs in the colchicine group had less fibrosis in the infarct zone than the other animals [41.6% (20.4-51.0) vs. 57.4% (42.9-66.5); P = 0.022]. There was a trend toward a higher myocardial salvage index (MSI; an index of the efficacy of revascularization) in pigs on colchicine (P = 0.054). Conversely, changes in LV volumes, ejection fraction and mass did not differ between groups.

CONCLUSION

Colchicine therapy for 1 month after reperfused MI further reduces myocardial fibrosis when added to standard therapy, while it does not have additional effects on LV remodeling.