A possible association of Chlamydia pneumoniae infection and acute myocardial infarction in patients younger than 65 years of age.
OBJECTIVE
We conducted a retrospective study on patients with acute myocardial infarction (AMI) and evaluated the incidence and prevalence of Chlamydia pneumoniae infection.


METHODS
Sixty-one consecutive patients with AMI aged younger than 65 years were enrolled. Within 24 h of hospital admission, serum samples and pharyngeal swab specimens were obtained from all patients. In 49 of 61 patients, after a mean of 28 days from hospital admission, a second serum sample was drawn. A third serum sample was obtained in 23 of 61 patients. Serologic testing for Chlamydia pneumoniae was performed by a microimmunofluorescence test. We applied a nested-polymerase chain reaction for C pneumoniae DNA detection to pharyngeal swab specimens. Simultaneously, we performed a serologic study for C pneumoniae infection on 61 serum samples obtained from blood donors, matched for age, sex, and smoking habits.


RESULTS
Serologic test results for C pneumoniae were consistent with acute reinfection in 12 patients, with chronic infection in 23 patients, and results were negative in 26 patients with AMI. In 3 of 12 patients with acute reinfection pattern and in 3 of 23 patients with chronic infection pattern, C pneumoniae DNA was detected on pharyngeal swab specimens. A significantly higher prevalence of IgG titers was observed in patients with AMI (35/61) compared to blood donors (18/61) (p=0.003).


CONCLUSIONS
Our data confirm the possible role of C pneumoniae infection in coronary heart disease and suggest that reinfection may trigger the onset of AMI.
Blasi
F
F
Institute of Respiratory Diseases, University of Milan, Italy.
Cosentini
R
R
Raccanelli
R
R
Massari
F M
FM
Arosio
C
C
Tarsia
P
P
Allegra
L
L
D000907:Antibodies, Bacterial / Q000097:blood; D016022:Case-Control Studies; D002690:Chlamydia Infections / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology; D016993:Chlamydophila pneumoniae / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000032:analysis; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology / Q000209:etiology / Q000382:microbiology*; D010614:Pharynx / Q000382:microbiology; D015995:Prevalence; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors
D000907:Antibodies, Bacterial; D004269:DNA, Bacterial