Effects of alirocumab on endothelial function and coronary atherosclerosis in myocardial infarction: A PACMAN-AMI...

Area of Science:

• Cardiology
• Vascular Biology
• Pharmacology

Background:

• Endothelial function, assessed by flow-mediated dilation (FMD), is crucial in cardiovascular health.
• The impact of protein convertase subtilisin/kexin type 9 (PCSK9) inhibitors on FMD in acute myocardial infarction (AMI) patients remains unclear.
• High-intensity statin therapy is a cornerstone of secondary prevention after AMI.

Purpose of the Study:

• To investigate the effect of the PCSK9 inhibitor alirocumab, added to high-intensity statin, on FMD in AMI patients.
• To explore the association between FMD and coronary atherosclerosis in non-infarct related arteries.
• To utilize advanced intracoronary imaging techniques (IVUS, NIRS, OCT) for detailed plaque analysis.

Main Methods:

• A substudy of the randomized-controlled PACMAN-AMI trial involving patients treated with alirocumab or placebo plus rosuvastatin.
• Brachial artery FMD measurements at 4 and 52 weeks.
• Intracoronary imaging (IVUS, NIRS, OCT) performed at baseline and 52 weeks for plaque characterization.

Main Results:

• No significant difference in FMD at 52 weeks between the alirocumab and placebo groups (5.44% vs. 5.45%).
• FMD significantly improved over 52 weeks in both groups.
• Early FMD (4 weeks) was associated with baseline plaque burden (IVUS) but not with lipid pool (NIRS) or fibrous cap thickness (OCT).

Conclusions:

• In AMI patients, adding alirocumab to high-intensity statin therapy did not enhance FMD compared to statin therapy alone.
• FMD is linked to the overall burden of coronary plaque but not specifically to lipid content or fibrous cap stability.
• These findings suggest that PCSK9 inhibition may not directly improve endothelial function in this patient population beyond standard statin therapy.