Acute Coronary Syndrome in Alpha-Gal Syndrome: A Rare Immune-Cardiac Intersection.

Alpha-gal syndrome (AGS) is an IgE-mediated hypersensitivity reaction to galactose-α-1,3-galactose (alpha-gal) following exposure to lone star tick bites. While classically associated with anaphylactic and delayed gastrointestinal-predominant allergic reactions to mammalian meat products, emerging evidence suggests an association between alpha-gal sensitization and accelerated coronary atherosclerosis. This case is presented to highlight the potential cardiovascular implications of AGS and its impact on acute coronary syndrome presentation and management. We report a case of a 51-year-old man with a medical history significant only for AGS who presented with a two-day history of severe retrosternal chest pain radiating to the left shoulder. Electrocardiography revealed ST-segment elevations in the inferior leads and severely elevated high-sensitivity troponin levels, prompting activation of an ST-elevation myocardial infarction protocol. Emergent coronary angiography revealed a 100% occlusion of the distal right coronary artery and a 90% stenosis of a marginal artery. Successful percutaneous coronary intervention was performed, followed by a staged intervention guided by intravascular ultrasound. Given the patient's AGS, bivalirudin was used for anticoagulation to avoid porcine- or bovine-derived heparin products. This case supports a growing body of evidence linking AGS with coronary atherosclerosis and acute coronary syndrome. It highlights AGS as a potential isolated risk factor for coronary artery disease and underscores the importance of individualized diagnostic and therapeutic decision-making in affected patients.