Detection of Chlamydia pneumoniae but not cytomegalovirus in occluded saphenous vein coronary artery bypass grafts

Background-A causal relation between atherosclerosis and chronic infection with Chlamydia pneumoniae and/or cytomegalovirus (CMV) has been suggested. Whether the unresolved problem of venous coronary artery bypass graft occlu sion is related to infection with C pneumoniae and/or CMV has not been addr essed. Methods and Results-Thirty-eight occluded coronary artery vein grafts and 2 0 native saphenous veins were examined. Detection of C pneumoniae DNA was p erformed by use of nested polymerase chain reaction (PCR). Homogenisates fr om the specimen were cultured for identification of viable C pneumoniae. Bo th conventional PCR and quantitative PCR for detection of CMV DNA were appl ied. Differential pathological changes (degree of inflammation, smooth musc le cell proliferation [MIB-1]) were determined and correlated to the detect ion of both microorganisms. C pneumoniae DNA could be detected in 25% of oc cluded vein grafts. Viable C pneumoniae was recovered from 16% of occluded vein grafts. Except for 1 native saphenous vein, all control vessels were n egative for both C pneumoniae detection and culture. All pathological and c ontrol specimens were negative for CMV DNA detection. Pathological changes did not correlate with C pneumoniae detection. Conclusions-Occluded aorto-coronary venous grafts harbor C pneumoniae but n ot CMV. The detection of C pneumoniae in occluded vein grafts warrants furt her investigation.