RESUMO
Coronary heart disease remains the most common cause of death in industrialized countries. Although atherosclerosis is generally asymptomatic in the early stages, progressive plaque development leads to arterial stenosis which is characterized by angina and may eventually lead to unstable angina, myocardial infarction and cardiac death. Evidence that the coagulation cascade is activated during acute coronary events has justified the use of antithrombotic agents such as aspirin, heparin and low molecular weight heparin (LMWH) in the standard management of acute coronary syndromes. The inflammatory process is also known to play a significant role in the pathogenesis of atherosclerosis, resulting in a cycle of continued inflammatory cell activation and ongoing cell recruitment. As the human leukocyte-associated antigen (HLA) system plays a key role in the regulation of the inflammatory process, the expression of HLA antigens in patients with symptomatic coronary heart disease has been investigated. These studies have demonstrated a relationship between the major histocompatibility complex (MHC) class II expression and the most severe pattern of angina refractory to conventional therapy, within the framework of a chronic infectious disease. A number of studies have documented an association between coronary heart disease and the presence of high titres of antibodies to Chlamydia pneumoniae, and this organism has been implicated in plaque instability. Such findings have stimulated interest in the role of C. pneumoniae in the pathogenesis of coronary heart disease, with a view to developing novel and effective treatment approaches. The ROXIS study showed a lower incidence of acute ischaemic events in patients with unstable angina treated with an antichlamydial antibiotic, roxithromycin.
Assuntos
Angina Instável/microbiologia , Infecções por Chlamydia/diagnóstico , Chlamydophila pneumoniae/isolamento & purificação , Doença da Artéria Coronariana/microbiologia , Infecções por Chlamydia/complicações , Ensaios Clínicos como Assunto , Humanos , Inflamação/etiologiaRESUMO
OBJECTIVES: Evidence exists showing an association between Chlamydial infection and infarction. Our purpose was to identify an interactive relationship between Chlamydia pneumoniae and unstable angina. METHODS: We analyzed IgG antibodies for Chlamydia pneumoniae, Mycoplasma pneumoniae, and C reactive protein in patients during the acute phase of unstable angina. RESULTS: Chlamydia antibodies were present in 16.92% (11 cases) of the unstable angina patients. They were also present in 34.61% of those patients who experienced ischemic events vs 5.1% who did not (odds ratio 9.79, 95% CL 1.65 to 75.26, p = 0.002). Mycoplasma pneumoniae antibodies were present in 12.30% of patients but did not emerge as a predictive variable. C-reactive protein was present in 22 cases (33.84%), 9 of which were associated with recurrent events (34.61%) vs 13 which were free of them (odds ratio, p = 0.5). The interactive relationship between infection plus C-reactive protein achieved a statistical significant association with ischemic events (odds ratio 14, 95% CI 1.49-331.1; p = 0.003). CONCLUSIONS: These findings suggest a pathophysiologically based relationship between infective and inflammatory processes related to poor clinical outcome during the in-hospital stay in the setting of unstable angina patients.