Antibiotics may benefit heart patients: study

Last Updated: 2002-08-19 16:10:34 -0400 (Reuters Health)

NEW YORK (Reuters Health) - A short course of antibiotics may keep high-risk heart attack patients from being readmitted to the hospital, according to a team of British researchers who conducted the first-of-its-kind study.

"It is an interesting proposal that antibiotics can affect a condition that has always been regarded as noninfectious," said co-author Dr. Michael A. Mendall of Mayday Hospital in Surrey, England, in a prepared statement.

While earlier studies have suggested that certain inflammatory proteins play a key role in atherosclerosis--the accumulation of fatty plaques in arteries that can lead to a heart attack or stroke others have indicated that chronic infection may also be involved.

In the current study, lead author Dr. Adam F.M. Stone and colleagues investigated whether or not antibiotics would decrease the chances of a first or second heart attack in high-risk patients infected with either the ulcer-causing bacteria Helicobacter pylori or the bacteria Chlamydia pneumonia.

A total of 325 patients who were admitted to the hospital for heart attack or severe chest pains took part in the study. About half of the group tested positive for Helicobacter pylori and 41% for Chlamydia pneumonia.

The researchers split the patients into three groups; each group received one of two antibiotics (amoxicillin or azithromycin) or a dummy pill (placebo) for 1 week. Those taking antibiotics also received omeprazole and metronidazole, which are drugs used in combination with antibiotics to rid the body of H. pylori.

After 12 weeks, those who received either of the antibiotics saw a 36% reduction in their chances of dying from a heart attack or being re-hospitalized for heart complications compared with those taking the placebo. What's more, the researchers point out that the benefits were still apparent 1 year later.

In their report, released August 20 in the online rapid access issue of Circulation: Journal of the American Heart Association, Stone's team writes that the "main clinical benefit of treatment" was the reduction in the number of patients being hospitalized for severe chest pains.

"The beneficial effect of the antibiotics was independent of whether a person was infected with H. pylori or C. pneumonia," said Mendall. "This implies (that) these antibiotics are not working against these organisms."

Mendall added, "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."

However, the authors point out that the study does not allow the researchers "to draw a conclusion regarding the mechanism responsible" for the long-term benefits that they measured in the group of patients they studied.

The researchers are calling for more studies.

SOURCE: Circulation 2002;10.1161/01.CIR.0000027820.66786.CF.