Chlamydia pneumoniae as an emerging risk factor in cardiovascular disease

JAMA. 2002 Dec 4;288(21):2724-31. doi: 10.1001/jama.288.21.2724.


Recent appreciation of atherosclerosis as a chronic, inflammatory disease has rekindled efforts to examine the role that infectious agents may play in atherogenesis. In particular, much interest has focused on infection with Chlamydia pneumoniae. The possibility that a prokaryote contributes to atherogenesis has high clinical interest, as C pneumoniae infection may be a treatable risk factor. To review the evidence implicating C pneumoniae in the pathogenesis of atherosclerosis, we searched MEDLINE for articles published between January 1966 and October 2002 on the association of C pneumoniae and atherosclerosis. We also used online resources, texts, meeting abstracts, and expert opinion. We included 5 types of studies (epidemiological, pathology based, animal model, cell biology, and human antibiotic treatment trials) and extracted diagnostic, pathophysiologic, and therapeutic information from the selected literature; consensus was reached on interpretation discrepancies. Chlamydia pneumoniae is associated with atherosclerosis by epidemiological and pathology-based studies. Animal model and cell biology studies suggest that the pathogen can modulate atheroma biology, including lipid- and inflammatory-related processes. Although some preliminary antibiotic treatment trials in patients with coronary artery disease indicated a reduction in recurrent coronary events, larger studies have not shown benefits in individuals with stable coronary artery disease. It is unlikely that C pneumoniae infection is necessary to initiate atherosclerosis. Furthermore, conventional antibiotic therapy may not eradicate the organism or reduce mortality in individuals with atherosclerotic vascular disease. Nevertheless, the current body of evidence establishes this pathogen as a plausible, potentially modifiable risk factor in cardiovascular disease.

Publication types

  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • Animals
  • Anti-Bacterial Agents / therapeutic use
  • Arteriosclerosis / microbiology*
  • Arteriosclerosis / pathology
  • Arteriosclerosis / prevention & control
  • Chlamydia Infections / complications*
  • Chlamydia Infections / drug therapy
  • Chlamydia Infections / epidemiology
  • Chlamydia Infections / pathology
  • Chlamydophila pneumoniae* / physiology
  • Coronary Artery Disease / microbiology*
  • Coronary Artery Disease / pathology
  • Coronary Artery Disease / prevention & control
  • Humans
  • Models, Animal
  • Risk Factors
  • Seroepidemiologic Studies


  • Anti-Bacterial Agents