Can Degenerative Aortic Valve Stenosis Be Related to Persistent Chlamydia pneumoniae Infection?

BACKGROUND: The cause of age-related degenerative (tricuspid) aortic valve calcification is largely unknown, but one typical characteristic is an active inflammatory process. The presence of Chlamydia pneumoniae in aortic valve stenosis was recently shown. OBJECTIVE: To test the hypothesis that if persistent C. pneumoniae infection plays an active role in the development of aortic stenosis, the organism can be detected in the healthy aortic valves of young persons. DESIGN: A cadaver study. SETTING: Oulu University Hospital, Oulu, Finland. SUBJECTS: 46 consecutive cadavers undergoing autopsy. MEASUREMENTS: Macroscopic and histologic pathology of aortic valves was determined. The presence of C. pneumoniae was determined by immunohistochemistry. RESULTS: 34 of 46 valves were macroscopically normal. Early lesions of aortic valve disease were found in 12 valves (no lesions in valves from persons 20 to 40 years of age n = 15, 4 lesions in valves from persons 41 to 60 years of age n = 16, and 8 lesions in valves from persons older than 60 years of age n = 15; P = 0.004). Fifteen of 34 normal valves (44%) and 10 of 12 valves with early lesions (83%) had positive results on staining for C. pneumoniae (P = 0.02). In persons older than 60 years of age, the chance of an early lesion was higher if the valve tested positive for C. pneumoniae (7 of 8 valves with C. pneumoniae infection compared with 1 of 7 valves without C. pneumoniae infection; P = 0.01). CONCLUSIONS: Chlamydia pneumoniae is frequently present in aortic valves and is associated with early lesions of aortic valve stenosis in elderly persons.