No prognostic significance of chronic infection with Chlamydia pneumoniae in acute coronary syndromes: insights from the Global Utilization of Strategies to Open Occluded Arteries IV Acute Coronary Syndromes trial.
BACKGROUND
Although relationships between chronic Chlamydia pneumoniae (Cpn) infection and the risk of coronary events in stable coronary artery disease patients have been reported, a similar link in acute coronary syndrome (ACS) patients has not been consistently observed.


METHODS
In a nested case-control substudy of the Global Utilization of Strategies to Open Occluded Arteries IV Acute Coronary Syndromes trial, 295 cases (30-day death/myocardial infarction [MI]) were matched by age, sex, baseline creatine kinase-myocardial kinase, and smoking status with 295 control subjects. To test the hypothesis on 1-year mortality, another subset (n = 276) was drawn from the 590-patient cohort; 138 patients who died at 1 year plus the matching controls who survived at 1 year. We measured Cpn IgG and IgA antibody titers in baseline serum with microimmunofluorescence. Conditional logistic regression was used to quantify the prognostic relevance seropositivity (IgG > or = 1:32; IgA > or = 1:16) and elevated titer levels.


RESULTS
The prevalence of Cpn IgG and IgA was similar between cases and controls (30-day death/MI: IgG, 80% vs 85%, P = .126; IgA, 45% vs 37%, P = .079), and were not statistically significant predictors of 30-day death/MI after baseline adjustment. Likewise, the 1-year death cohort had comparable proportions of Cpn IgG and IgA among cases and controls (86% vs 91% [P = .265] and 49% vs 43% [P = .334], respectively), and did not add prognostic value.


CONCLUSIONS
These findings are in concert with study results suggesting that chronic Cpn infection is not associated with 30-day death/MI or 1-year mortality in non-ST elevation ACS.
Westerhout
Cynthia M
CM
Heritage Medical Research Centre, University of Alberta, Edmonton, Alberta, Canada T6G 2S2. cindy.westerhout@ualberta.ca
Gnarpe
Judy
J
Chang
Wei-Ching
WC
FitzPatrick
Susan
S
Barnathan
Elliot S
ES
Boersma
Eric
E
Califf
Robert M
RM
Wallentin
Lars
L
Simoons
Maarten L
ML
Armstrong
Paul W
PW
D000368:Aged; D000789:Angina, Unstable / Q000453:epidemiology* / Q000209:etiology; D016022:Case-Control Studies; D023521:Chlamydophila Infections / Q000150:complications / Q000453:epidemiology* / Q000276:immunology; D016993:Chlamydophila pneumoniae; D002908:Chronic Disease; D005260:Female; D006801:Humans; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology* / Q000209:etiology; D015995:Prevalence; D011379:Prognosis
D007070:Immunoglobulin A; D007074:Immunoglobulin G