Description and Status of the Azithromycin and Coronary Events Study (ACES)

The Azithromycin and Coronary Events Study is a randomized, double-blind, placebo controlled trial of azithromycin among adults with stable coronary artery disease. The study is based on the hypothesis that infection with Chlamydia pneumoniae may be causally associated with cardiovascular disease and therefore that treatment directed against this organism may reduce the risk of subsequent coronary events. Participants randomized to treatment will receive 600 mg of azithromycin orally once a week for 1 year and will be followed a mean of 4 years for the composite primary outcome of coronary heart disease death, nonfatal myocardial infarction, hospitalization for unstable angina, and coronary revascularization. Secondary objectives include those related to a better understanding of the relationship between antibody titer and inflammatory markers with treatment status and outcome; therefore, all participants will have blood specimens obtained at enrollment and a random 25% will have additional specimens collected periodically during follow-up.