Antibiotics do not prevent repeat heart attacks or related problems in patients with heart disease. Researchers from the Brigham and Women's Hospital in Boston started patients on an antibiotic targeting the bug Chlamydia pneumoniae (C. pneumoniae) soon after a cardiac event, but failed to see a reduction in the rate of repeat events. As such, only drugs with a proven track record should be used to prevent repeat heart attacks in these patients. C. pneumoniae has been found in blood vessel plaques and its presence has been linked to a higher risk of heart attacks. Some studies have suggested that antibiotic therapy may reduce the risk of heart attacks and strokes. The researchers randomly assigned 4162 patients with a recent heart attack or related problem to take the antibiotic gatifloxacin or inactive placebo. At 2-year follow-up, gatifloxacin-treated patients were just as likely as those given placebo to experience another heart attack, or stroke, or related problems. Roughly, one quarter of patients in each group experienced such problems The findings suggest that while C. pneumoniae might have played a role in starting the process (of plaque build-up), once patients have documented heart disease, it appears to be too late to treat the infection.
The New England Journal of Medicine,
April 2005