Chlamydia pneumoniae and cardiovascular disease: Could we treat cardiovascular disease with antibiotics?

Although many seroepidemiological and case-controlled studies have shown an association of Chlamydia pneumoniae infection and coronary heart disease (CHD), the role of this organism in the pathogenesis of atheroslerosis remains controversial. Most of these studies found odd-ratios of 2 or more, and some reported increasing ratios with increasing antibody titers. C. pneumoniae has also been detected in atherosclerotic plaque either by electron microscopic study, PCR or immunocytochemistry methods. This organism was detected in atheromatous lesions about ten times more frequently than in control samples of arterial tissue. Until now, the causal relationship between C. pneumoniae and atherosclerosis remained unresolved. However, various potential causative mechanisms that may act either acutely (e.g precipitating plaque rupture) or chronically (e.g promoting plaque growth) have been proposed for the reported association between infection and CHD. Preliminary reports showed *hat short courses of macrolide antibiotic therapy can reduce recurrent coronary events in patients with recent myocardial infarction or unstable angina pectoris and elevated anti C. pneumoniae anti body titers. Although the findings were encouraging, they came from small pilot studies. Large randomized, double-blind, placebo-controlled studies are needed to establish the value of antibiotic eradication therapy in patients with acute coronary syndromes.