The prospective association of Chlamydia pneumoniae and four otherpathogens with development of coronary artery calcium: TheMulti-Ethnic Study of Atherosclerosis (MESA)

Objective: Previous basic and cross-sectional studies obtained conflicting results regarding the association of pathogens with coronary artery calcium (CAC). The aim of this study is to prospectively evaluate this association in a population-based cohort. Methods: We examined 5744 individuals aged 45-84 years at baseline (2000-02) who underwent repeated CAC assessment on average 2.4 years later (a half at visit 2 [2002-04] and the other half at visit 3 [2004-05]). CAC incidence was defined as newly detectable CAC at follow-up (475 cases of 2942 participants). CAC progression was defined as annualized change in CAC Agatston score ≥10units/year if baseline CAC score >0 to <100 or ≥10%/year if baseline score≥100 (1537 cases of 2802 participants). Seropositivity was assessed in the entire cohort for Chlamydia pneumoniae and in a random sample (. n=873) for Helicobacter pylori, cytomegalovirus, herpes simplex virus, and hepatitis A virus. Results: Seropositivity to C. pneumoniae was not significantly associated with CAC incidence (odds ratio [OR] 1.11 [95% CI, 0.88-1.39], P=0.371) or progression (1.14 [0.96-1.36], P=0.135) even in unadjusted models. When CAC incidence and progression were combined, we observed significant association with C. pneumoniae seropositivity before adjustment (OR 1.17 [1.03-1.33], P=0.016) but not in a model adjusting for traditional risk factors (1.04 [0.90-1.19], P=0.611). The results were consistent across subgroups according to age, sex, and race/ethnicity. None of five pathogens or their accrual was associated with CAC incidence and progression in the subsample. Conclusion: Our prospective study does not support the pathophysiological involvement of these pathogens in CAC development.