RESUMO
INTRODUCTION AND OBJECTIVES: Coronary artery disease has been related to infection by Chlamydia pneumoniae even only in a few studies the association between presence of antibodies to this microorganism and the prognosis of patients with ischemic heart disease has been assessed. The objective of our study was to assess the impact of positivity of anti-Chlamydia pneumoniae antibodies in the morbidity and mortality associated to ischemic heart disease. METHODS: 249 patients with ischemic cardiopathy were evaluated (97 with myocardial infarction, 83 with unstable angina and 69 with stable angina), recluted along 1 year and with 3-year follow-up. IgG anti-Chlamydia pneumoniae antibodies were measured with microimmunofluorescence. The cut off point considered for positive serology was set in 1/64. RESULTS: In the group of 97 patients with acute myocardial infarction, 43% showed positive titers of IgG antibody to C. pneumoniae. We observed a statistically significant association (p = 0.007) between positive serology and higher survival of acute myocardial infarction patients. A logistic regression was carried out with mortality, age, and serology as variables; age was the only variable that explained mortality (p = 0.0012), and the serology lost its statistical meaning. In the groups of 83 patients with unstable angina and of 69 patients with stable angina, 42% and 58%, respectively, showed positive serology for C. pneumoniae. We did not find a statistically significant association in both groups between positive serology to C. pneumoniae and the prognostic factors related to morbidity and mortality (rehospitalization and mortality). CONCLUSIONS: The presence of IgG antibodies to C. pneumoniae is not a marker of morbidity and mortality in our population of patients with ischemic heart disease.