Context Increasing evidence supports the hypothesis of a
causal association between certain bacterial infections and increased
risk of developing acute myocardial infarction. If such a causal
association exists, subjects who used antibiotics active against the
bacteria, regardless of indication, might be at lower risk of
developing acute myocardial infarction than nonusers.
Objective To determine whether previous use of antibiotics
decreases the risk of developing a first-time acute myocardial
Design Population-based case-control analysis.
Setting The United Kingdom–based General Practice Research
Database comprising 350 general practices.
Patients A total of 3315 case patients aged 75 years or younger
with a diagnosis of first-time acute myocardial infarction between 1992
and 1997 and 13,139 controls without myocardial infarction
matched to cases for age, sex, general practice attended, and calendar
Main Outcome Measures Use of antibiotics among those who did or
did not have a first-time acute myocardial infarction.
Results Cases were significantly less likely to have used
tetracycline antibiotics (adjusted odds ratio [OR], 0.70; 95%
confidence interval [CI], 0.55-0.90) or quinolones (adjusted OR,
0.45; 95% CI, 0.21-0.95). No effect was found for previous use of
macrolides (primarily erythromycin), sulfonamides, penicillins, or
Conclusions The findings from this large case-control analysis
provide further, albeit indirect, evidence for an association between
bacterial infections with organisms susceptible to tetracycline or
quinolone antibiotics and the risk of acute myocardial infarction.
These results of preliminary nature should stimulate more research to
further explore the role of infections in the etiology of acute