Compared with placebo, the addition of subcutaneous biweekly alirocumab to high-intensity statin therapy resulted in significantly greater coronary plaque regression in non-infarct-related arteries after 52 weeks in patients with acute myocardial infarction (AMI), based on findings from PACMAN-AMI trial presented April 3 at ACC.22 and simultaneously published in JAMA. However, researchers noted that further studies are needed to understand whether alirocumab improves clinical outcomes in this patient population.

Researchers randomized 300 patients undergoing PCI for AMI to receive biweekly subcutaneous alirocumab (150 mg; n=148) or placebo (n=152), initiated less than 24 hours after urgent PCI 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 IVUS-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 vs. −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 vs. 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," said Lorenz Räber, MD, PhD, the trial's principal investigator. "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."

Raber also 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 [shape and structure].

Clinical Topics: Atherosclerotic Disease (CAD/PAD)

Keywords: ACC Annual Scientific Session, ACC22, Coronary Artery Disease, Myocardial Infarction

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