Triple-Vessel Coronary Artery Disease Associated with Familial Hyperhomocysteinemia

Homocysteine is a sulfhydryl containing amino acid implicated in the pathogenesis of cardiovascular disease in multiple epidemiologic studies. However, elevated homocysteine in isolation is not known to lead to severe coronary artery disease requiring emergency intervention. We report a previously asymptomatic 55-year-old gentleman who presented with an acute myocardial infarction with bradycardia and was found to have triple-vessel coronary artery disease on angiography. After stabilization, he underwent a coronary artery bypass grafting in view of the severity of disease. A thorough evaluation revealed the absence of all traditional risk factors except elevated serum homocysteine. The evaluation of family members also revealed elevated homocysteine levels in both his sons and wife. Mutation testing of the methylenetetrahydrofolate reductase (MTHFR) gene showed homozygous Q429A mutation in the patient and heterozygous A222V and Q429A mutation in both his sons. The patient was discharged successfully and is well after 9 months of follow-up. Homocysteine has been implicated in the pathogenesis of cardiovascular disease in synergy with other traditional risk factors. This is a rare presentation of familial hyperhomocysteinemia presenting with severe coronary artery disease and elevated homocysteine levels in all family members. Elevated homocysteine levels in isolation may lead to significant cardiovascular disease and should be checked if no other risk factors are present. It may be useful to screen the patient and family members for underlying MTHFR mutations. In the absence of prospective evidence, there appears to be little harm in providing multivitamins to attempt to reduce homocysteine levels.