Treatment with antibiotics may reduce the risk of heart attack and chest pain in some patients with heart disease, according to the results of a new study.
In a study of 148 patients who experienced a heart attack or an episode of severe, heart-related chest pain, those who took a 3-month course of the antibiotic clarithromycin were 41% less likely to have another cardiovascular "event" during the next year and a half than patients who received an inactive (placebo) pill.
"Antibiotics seem to be a beneficial option" for patients with coronary heart disease, the study's lead author, Dr. Juha Sinisalo of Helsinki University Central Hospital in Finland, told Reuters Health.
But the Finnish researcher cautioned that the results are preliminary. "Larger studies are needed before this treatment can be justified for routine use," Sinisalo said.
One potential problem with using antibiotics to treat heart attack patients is that such widespread use of the drugs could increase the rate at which bacteria become resistant to antibiotics, Sinisalo noted. If antibiotics were to be used to treat heart attack in large numbers of people, "it would be better to limit the use to one certain group of antibiotics," according to Sinisalo. Widespread use of several different types of antibiotics could lead to more antibiotic resistance, the researcher explained.
Inflammation plays a role in both heart attacks and unstable angina, a type of heart-related chest pain that occurs when a person is at rest. Recently, more and more attention has been paid to the idea that infections may contribute to this inflammation.
Based on the potential link between infections and the inflammation involved in heart disease, investigators have tried to find out whether clearing infections with antibiotics can benefit heart disease patients. So far, the results of these studies have not been conclusive.
Unlike other studies that tested the effectiveness of short-term antibiotic treatment, Sinisalo's team evaluated the effects of a 3-month course of the antibiotic clarithromycin. The study included patients who had had a severe heart attack or unstable angina. The findings will be published in the April 2nd issue of Circulation: Journal of the American Heart Association.
Patients treated with the antibiotic were 41% less likely to have another heart attack, unstable angina or other type of cardiovascular event. The apparent beneficial effect of clarithromycin began while patients were taking the drug, but this effect did not diminish after the patients stopped taking it.
The researchers suspect that most of the benefits were due to clarithromycin's antibacterial effect. They note that a bacterium called Chlamydia pneumoniae, which is targeted by clarithromycin, can produce inflammation in blood vessels. But the authors point out that clarithromycin may have affected other infections, too. In addition, the antibiotic has a direct anti-inflammatory effect, which could have accounted for some of the benefits, they note.
SOURCE: Circulation 2002;105.