Lowering low-density lipoprotein cholesterol (LDL-C) with statins or ezetimibe reduces major adverse cardiovascular events (MACE) in patients with coronary heart disease. Additional treatment with proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors may lower LDL-C to levels not achievable with conventional lipid-lowering agents. This review summarizes findings from two large, placebo-controlled trials that evaluated the cardiovascular efficacy of monoclonal antibodies directed against PCSK9, added to background statin therapy, in patients with established atherosclerotic cardiovascular disease (ASCVD) or recent acute coronary syndrome (ACS) and persistent elevation of atherogenic lipoproteins despite statin treatment.

The FOURIER trial with evolocumab and the ODYSSEY OUTCOMES trial with alirocumab demonstrated 15% overall reductions in MACE compared to placebo, associated with average achieved LDL-C levels as low as 30–40 mg/dl. Alirocumab treatment was associated with fewer deaths after ACS. Subgroups with large absolute treatment benefit included those with baseline LDL-C ≥100 mg/dl, diabetes, polyvascular or peripheral artery disease, prior coronary bypass surgery, statin intolerance, or elevated lipoprotein(a) levels. No safety concerns arose with use of PCSK9 monoclonal antibodies, even in patients who achieved LDL-C levels below 20 mg/dl.

In selected patients with established ASCVD or recent ACS, PCSK9 inhibitors can play an important role in reducing the risk of MACE, and may also reduce the risk of death after ACS.