The study suggests that antiobiotics might have an anti-inflammatory benefit. The study appears in today's rapid access issue of Circulation: Journal of the American Heart Association.
Researchers were surprised to find that the reduced risk was not related to the presence of two bacteria suspected of playing a role in heart disease Helicobacter pylori and Chlamydia pneumoniae.
"The beneficial effect of the antibiotics was independent of whether a person was infected with H. pylori or C. pneumonia," says author Michael A. Mendall, M.D., a consultant gastroenterologist at the Mayday Hospital in Croydon, England. "This implies these antibiotics are not working against these organisms. The antibiotics may be acting against other organisms to reduce the overall infectious burden of the body or may have their own anti-inflammatory properties."
The study is the first to compare two different classes of antibiotics in treating acute coronary syndromes. Researchers enrolled 325 patients (225 men and 100 women, ages 39 to 80) hospitalized with a heart attack or unstable angina (severe, unexpected chest pain that occurs at rest). Within 48 hours after being admitted, the patients were randomized to receive amoxycillin, azithromycin, or a placebo for one week. Those in the antibiotic groups also received omeprazole and metronidazole, drugs used in combination with the antibiotics to eradicate H. pylori.
At the start of the study, tests revealed that 157 of 310 patients (51 percent) had antibodies to H. pylori and 132 of 325 patients (41 percent) had antibodies to C. pneumoniae. Blood tests for antibodies detect the dormant bacteria. C. pneumoniae causes
Contact: Carole Bullock
American Heart Association