ORIGINAL PAPER
Chlamydia pneumoniae infection and inflammatory proteins in CABG patients referred to percutaneous coronary intervention for angina recurrence

Background: Several inflammatory factors, including Chlamydia pneumoniae (ChP) infection, have been implicated in the pathogenesis of native coronary artery disease but their potential role in bypass graft disease has not been established.
Aim: To search for a relationship between ChP infection, the level of inflammatory proteins and angina recurrence in patients (pts) with prior CABG referred for invasive evaluation. To evaluate the impact of inflammation on long-term results of PCI in those pts.
Methods: The level of ChP antibodies (IgM, IgA, IgG) and hs-CRP, fibrynogen, IL-6, TNFa was determined in 111 consecutive patients (90 men) aged 63.2±7.7 (48-79 years) who underwent PCI due to recurrent angina in the mean time of 99.1±52.3 months after CABG.
Results: ChP IgA and/or IgG level indicating probable chronic ChP infection was found in 50 (55%) pts whereas an increased level of IgG but not IgA (prior ChP infection) was present in 25 (22,5%) pts. Forty one (36.9%) pts had hs-CRP >5 mg/L and 34 (30.6%) fibrinogen >3,5 g/L. ChP antibodies level showed a significant correlation with age (r=0.235 and p=0.013 for IgA, r=0.294 and p=0.002 for IgG). The level of hs-CRP and IL-6 showed a negative correlation with time to angina recurrence after CABG (r=–269; p=0.005 and r=–0.183; p=0.057, respectively). In a long-term follow-up, 32(28.8%) patients had a major cardiac event (MACE). The risk of MACE was related to the ChP IgA and IgG level (p=0.026, p=0.031).
Conclusions: Markers of chronic or past ChP infection are found in 2/3 of patients with angina recurrence after CABG and 1/3 pts show elevated inflammatory markers. ChP antibodies level is significantly higher in patients who experience MACE. There is a negative correlation between inflammatory protein levels and time to symptom recurrence after CABG.