Anterior STEMI Revealing Homozygous Familial Hypercholesterolemia With Supravalvular Aortic Stenosis

Homozygous familial hypercholesterolemia (HoFH) causes markedly elevated low-density lipoprotein cholesterol from birth, accelerated atherosclerosis, and early cardiovascular death. Supravalvular aortic stenosis is an uncommon but serious cardiovascular manifestation.

A 20-year-old Asian man presented with a 4-hour history of rest angina associated with diaphoresis and was diagnosed with an anterior ST-segment elevation myocardial infarction (STEMI). Lipid testing showed a total cholesterol level of 570 mg/dL and a low-density lipoprotein cholesterol level of 510 mg/dL, with an elevated lipoprotein(a) level of 176 nmol/L. Echocardiography demonstrated supravalvular flow acceleration across normal tricuspid aortic valve with a Doppler peak/mean gradient of 43/12 mm Hg. Computed tomography aortography showed focal sinotubular junction/ascending aortic narrowing with a planimetry area of 1.09 cm². Coronary angiography showed left main and triple-vessel coronary artery disease. Whole-exome testing revealed a homozygous pathogenic LDLR variant in exon 11. He underwent coronary artery bypass grafting with supra-aortic patch aortoplasty.

This case highlights genetically confirmed HoFH presenting as anterior ST-segment elevation myocardial infarction with surgically repaired supravalvular aortic stenosis at 20 years of age, emphasizing multimodality imaging, heart team planning, and lipid-lowering therapy.

HoFH should be suspected in any very young patient with myocardial infarction, severe hypercholesterolemia, and a family history of dyslipidemia or sudden death.