Intervention with Clarithromycin in Patients with Stable Coronary Heart Disease

Background: There is a growing body of evidence linking Chlamydia pneumoniae to the progression of coronary heart disease. Smaller studies have indicated that intervention with macrolide antibiotics might reduce coronary events in patients with cardiovascular diseases. Objective: To describe the design of a large-scale intervention study on the effects of a macrolide antibiotic on coronary events in patients with stable coronary heart disease (documented myocardial infarction and/or angina pectoris). Methods: This study is a double-blind, randomised, placebo-controlled, multicentre study with parallel groups. Patients are randomised to 14 days of treatment with clarithromycin (500 mg, once daily) or matching placebo. The follow-up period is 2 years, and the primary end point is a composite end point of death, non-fatal myocardial infarction or unstable angina pectoris, whichever occurs first. Recruitment began in October 1999 and will be completed in 2000. In total, 4,600 patients will be randomised. Prospectives: The study is powered to detect a reduction in coronary events of 20%. Also, the study will examine the question of whether the presence of a C. pneumoniae antibody titre is associated with a significantly increased risk of future coronary events. Finally, in the case of a significant outcome, it will be possible to test whether the effect is restricted to patients with C. pneumoniae antibodies only, or to a universal effect without any coherence to C. pneumoniae antibodies.