Iron and cardiac ischemia: a natural, quasi-random experiment comparing eligible with disqualified blood donors.

Background: The theory that elevated iron stores can induce vascular injury and ischemia remains controversial. We conducted a cohort study of the effect of blood donation on the risk of coronary heart disease (CHD) by taking advantage of the quasi-random exclusion of donors who obtained a falsely reactive test for a transmissible disease (TD) marker.

Study Design And Methods: Whole blood donors who were permanently disqualified because of a false-reactive test between 1990 and 2007 in the province of Quebec were compared to donors who remained eligible, matched for baseline characteristics.