To test this hypothesis, we examined whether the functional polymorphism of the catechol-O-methyltransferase (COMT) gene, resulting in several-fold differences in the metabolism of circulating catecholamines, modifies the effect of heavy consumption of caffeine-containing coffee on the risk of acute coronary events in a cohort of middle-aged eastern Finnish men initially free from symptomatic CHD. Here, COMT is linked to coronary artery disorder.