PACMAN-AMI Evaluates Alirocumab Added to High-Intensity Statin Therapy to Reduce High-Risk Plaques

April 3, 2022—The American College of Cardiology (ACC) announced findings from a study showing that the addition of subcutaneous biweekly alirocumab to high-intensity statin therapy—compared with placebo—resulted in significantly greater coronary plaque regression in non–infarct-related arteries after 52 weeks in patients with acute myocardial infarction (AMI). However, investigators noted that further studies are needed to understand whether alirocumab improves clinical outcomes in this patient population.

The PACMAN-AMI trial data were presented at ACC.22, the society's annual meeting held April 2-4 in Washington, DC. The study was simultaneously published by primary investigator Lorenz Räber, MD, et al in JAMA, Journal of the American Medical Association.

According to ACC, the PACMAN-AMI investigators randomized 300 patients undergoing PCI for AMI to receive biweekly subcutaneous alirocumab (150 mg; n = 148) or placebo (n = 152), initiated < 24 hours after urgent percutaneous coronary interventions of the culprit lesion, for a total of 52 weeks. All patients received high-intensity statin therapy (rosuvastatin, 20 mg).

The primary efficacy endpoint was the change in intravascular ultrasound-derived percent atheroma volume from baseline to week 52. Secondary endpoints included changes in near-infrared spectroscopy-derived maximum lipid core burden index within 4 mm, as well as optical coherence tomography-derived minimal fibrous cap thickness from baseline to week 52.

According to the researchers, the mean change in percent atheroma volume was −2.13% with alirocumab versus −0.92% with placebo at 52 weeks. In addition, the mean change in maximum lipid core burden index within 4 mm was −79.42 in the alirocumab group compared with −37.60 in the placebo group, while the mean change in minimal fibrous cap thickness was 62.67 μm with alirocumab versus 33.19 μm with placebo. Adverse events were reported in 70.7% of patients treated with alirocumab compared with 72.8% receiving placebo.

"Following early initiation of alirocumab on top of high-intensity statin therapy in a high-risk population with AMI, we observed a twofold regression of coronary atherosclerosis and stabilization of high-risk plaques when compared with treatment with statins alone," commented Dr. Räber in the ACC press release. "These findings provide insights to support more-frequent, early and targeted use of alirocumab on top of high-intensity statin therapy in patients who have had a heart attack and are at high risk for a second one."

Additionally, Dr. Räber noted that the study is the first to use three intracoronary imaging tests in combination to provide a comprehensive picture of plaque size, composition, and morphology.