Severe angioedema requiring airway intervention following evolocumab administration: a case report

Evolocumab is a human monoclonal antibody that effectively reduces low-density lipoprotein (LDL) cholesterol levels by inhibiting proprotein convertase subtilisin-kexin type 9 (PCSK9). Although generally well tolerated, evolocumab may rarely lead to severe hypersensitivity reactions, including angioedema. To the best of our knowledge, severe angioedema requiring airway intervention has not been reported previously in the US population. A 64-year-old woman with hypertension, hypothyroidism, hyperlipidemia, and active tobacco use presented with acute chest pain and was diagnosed with ST-segment elevation myocardial infarction. She underwent percutaneous coronary intervention with two stents placed in the right coronary artery. Despite maximum lipid-lowering therapy, her LDL level remained elevated at 125 mg/dL, prompting the addition of evolocumab (Repatha). Within 24 hours, she experienced progressive tongue and facial swelling, with oropharyngeal edema threatening airway obstruction. Urgent laryngoscopy confirmed early oropharyngeal involvement, which necessitated endotracheal intubation. She received intravenous corticosteroids and antihistamines in the intensive care unit, with symptoms resolving within 48 hours, allowing for extubation and discharge after three days. This case highlights a rare but potentially life-threatening adverse effect of evolocumab.