title: Chlamydia pneumoniae in the atherosclerotic plaques of patients with unstable angina undergoing coronary artery bypass grafting: does it have prognostic implications?
abstract: OBJECTIVE
  This study sought to evaluate the prognostic significance of the presence of DNA of Chlamydia pneumoniae in the coronary atherosclerotic lesions of patients with unstable angina.
  
  
  BACKGROUND
  C. pneumoniae has been implicated in the pathogenesis of coronary artery disease by serological and pathological studies, but whether antichlamydial antibodies and the presence of this pathogen in the coronary atherosclerotic tissue are related to prognosis in unstable angina remains unclear.
  
  
  METHODS
  A total 76 coronary specimens from 45 patients with unstable angina undergoing bypass surgery were subjected to nested polymerase chain reaction (PCR) for C. pneumoniae. Antichlamydial immunoglobulin G (IgG), A (IgA) and M (IgM) were also examined by an enzyme immunoassay. Patients were followed during a 2-year period to determine the incidence of adverse cardiovascular events.
  
  
  RESULTS
  DNA of C. pneumoniae was detected in 57 (75%) of 76 atherosclerotic lesions: 39 patients showed a positive PCR result in at least one plaque. Of the 45 patients, 44 (97.7%) showed a positive serological result: IgG was positive in 39 (86.6%) patients, IgM in five (11.1%) patients and IgA in 42 (93.3%). Clinical characteristics and serologic results were similarly distributed in patients with and without infected lesions at enrollment. At least one adverse event occurred in 21 (46.6%) of the 45 patients at 2 years: death in nine (20%), recurrent angina in 12 (26.6%), revascularization in six (13.3%) and myocardial infarction in two (4.4%) patients. The composite endpoint of death, myocardial infarction, recurrent angina and revascularization at 2-year follow-up did not differ according to the PCR or serologic results.
  
  
  CONCLUSIONS
  The presence of C. pneumoniae in coronary atherosclerotic plaques of patients with unstable angina undergoing coronary bypass grafting does not have prognostic significance. In addition, serology does not allow us to differentiate those patients with plaque infection by C. pneumoniae and also does not provide any prognostic information in these patients.
authors.affiliation: Hospital Clinico San Carlos, Plaza de Cristo Rey, 28040 Madrid, Spain. jlzamorano@vodafone.es
authors.forename: José
authors.initials: J
authors.lastname: Zamorano
authors.forename: Julio
authors.initials: J
authors.lastname: García-Tejada
authors.forename: Avelina
authors.initials: A
authors.lastname: Suárez
authors.forename: Esther
authors.initials: E
authors.lastname: Culebras
authors.forename: José
authors.initials: J
authors.lastname: Castañón
authors.forename: Raúl
authors.initials: R
authors.lastname: Moreno
authors.forename: Fernando
authors.initials: F
authors.lastname: Reguillo
authors.forename: Manuel
authors.initials: M
authors.lastname: Gil
authors.forename: Juan
authors.initials: J
authors.lastname: Picazo
authors.forename: Luis
authors.initials: L
authors.lastname: Sánchez-Harguindey
mesh_terms: D000368:Aged; D000789:Angina, Unstable / Q000150:complications / Q000382:microbiology* / Q000601:surgery; D016009:Chi-Square Distribution; D002690:Chlamydia Infections / Q000150:complications / Q000453:epidemiology*; D016993:Chlamydophila pneumoniae / Q000302:isolation & purification*; D001026:Coronary Artery Bypass; D003324:Coronary Artery Disease / Q000150:complications / Q000382:microbiology* / Q000601:surgery; D003331:Coronary Vessels / Q000382:microbiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011379:Prognosis; D011446:Prospective Studies; D012698:Serologic Tests