Reviewer: Dr. Canan Elif YILDIZ

Name of the Study: PACMAN AMI (Effects of Alirocumab on Coronary Atherosclerosis Assessed by Serial Multimodality Intracoronary Imaging in Patients With Acute Myocardial Infarction)

Presented Congress: ACC 2022

Background

Different plaque properties, such as atheroma volume and lipid load, affect the likelihood of plaque progression and coronary event, and these properties can be evaluated with intracoronary imaging modalities like as IVUS, NIRS or OCT.

The addition of PCSK9 inhibitors to statin therapy in patients with elevated LDL cholesterol level had been shown to reduce cardiovascular events. Patients with AMI have an increased risk for recurrent cardiovascular events due to the presence of high-risk non-obstructive plaques in non-infarction-related arteries.

Objective
The effect of PCSK9 inhibitor alirocumab on coronary plaque regression was investigated with the PACMAN AMI study.

Method
Investigators enrolled 300 patients (mean age 58.5 years; 18.7% women) with acute STEMI (52.7%) or NSTEMI (47.3%) who underwent successful PCI of the infarct vessel and had angiographic evidence of nonobstructive atherosclerosis (20% to 50% diameter stenosis) in two non-infarct-related arteries. LDL-cholesterol level was >125 mg/dL (3.2 mmol/L) in statin-naive patients and >70 mg/dL (1.8 mmol/L) in statin-treated patients. Non-IRA plaque characteristics of patients were initially evaluated by IVUS, NIRS and OCT imaging. These imaging evoluations were repeated at the end of the first year. After baseline imaging evoluation, patients were randomized to alirocumab 150 mg delivered subcutaneously every 2 weeks plus rosuvastatin 20 mg or placebo plus rosuvastatin. Treatment was started within 24 hours of successful PCI.

Results
At the end of the 52-week follow-up period, the primary outcome, percent atheroma volume (PAV), was significantly reduced in the Alirocumab group compared to placebo (%-2,13  ; %-0,92; P < 0,001). There was no significant difference between the groups in all-cause mortality and MI, a significant decrease was observed in non-IRA revascularization due to ischemia with Alirocumab treatment.

Conclusion

Early addition of Alirocumab to high-intensity statin therapy in patients presenting with AMI resulted in significant reductions in percent atheroma volume (PAV) and lipid load and a significant increase in fibrous cap thickness.

Interpretation

This study is important to understand the mechanism of PCSK9 inhibitor Alirocumab and how it affects plaque modulation.