From Biermers Disease to Stemi: Hyperhomocysteinemia as a Thrombotic Bridge a Case Report

Vitamin B12 deficiency due to pernicious anaemia may be accompanied by hyperhomocysteinaemia, a potential contributor to thrombosis. Its identification during the assessment of myocardial infarction in a young adult can reveal an otherwise unrecognised, treatable disorder.A 32-year-old man without known conventional cardiovascular risk factors presented six hours after the onset of chest pain with an anterior ST-elevation myocardial infarction (STEMI). Coronary angiography showed a sub-occlusive thrombotic lesion of the proximal left anterior descending artery with TIMI II flow. Tirofiban was administered, and stenting was deferred. Repeat angiography showed thrombus regression without significant residual stenosis, and no stent was implanted. The aetiological work-up identified macrocytic anaemia, vitamin B12 deficiency and hyperhomocysteinaemia. Positive anti-intrinsic-factor and anti -parietal cell antibodies, together with biopsy confirmed atroph ic gastritis, supported the diagnosis of pernicious anaemia.The in hospital course was favourable, and parenteral vitamin B12 replacement was initiated alongside cardiovascular treatment. This case highlights the value of investigating vitamin B12 deficiency when coronary thrombosis in a young adult is accompanied by macrocytic anaemia. Hyperhomocysteinaemia was a plausible contributing factor, but a causal relationship could not be established.