Bacteria could cause heart attacks, study finds 
By Maggie Fox LONDON (Reuter) - British researchers said Tuesday they have found intriguing evidence that a common bacteria can cause heart attacks. They said men who had suffered one heart attack and who had antibodies to Chlamydia pneumoniae were four times more likely to suffer second heart attacks. Treating them for the infection lowered the risk. The findings, published in the American Heart Association journal Circulation, add to a growing body of evidence that heart attacks may sometimes be due to infection rather than genetics or lifestyle. "We know that antibodies seem to be linked to heart disease," Dr. Sandeep Gupta at St. George's Hospital Medical School in London, who led the study, said in a telephone interview. In addition, the chlamydia bacteria, which cause a chest infection and which are a close relative of a common sexually transmitted disease, have turned up in the fatty plaques that line clogged arteries. Gupta's British Heart Foundation team joined the race of researchers trying to establish a more than circumstantial link between the bug and heart attacks. His team took 213 survivors of heart attacks and divided them into three groups according to how many chlamydia antibodies they had in their blood. They watched for heart attacks for 18 months. "The group of heart patients with negative antibodies, they had an approximately seven percent event rate over 18 months,'' Gupta said. Those with intermediate levels of antibodies had double that risk, while those with high antibody levels -- meaning bigger chlamydia infection -- had a 28 percent ``event rate'' of heart attacks. That was four times the risk of the group that had no antibodies. "But the guys that had high antibodies and also got antibiotics, their risk went down to eight percent," Gupta added. They were given a single three-day course of azithromycin, although Gupta said he believed several antibiotics such as tetracycline would also have worked. "This is a small study," Gupta noted. He said his team would now start a two-year study with 2,500 volunteers. "I don't think we are in a position yet to tell people you should be having antibiotics. No way,'' he added. Gupta said he thought chlamydia was causing inflammation, which in turn caused blood clots. The chlamydia was somehow crossing into the arteries, he added. Immune system cells could be the key. "It's a lung infection but it's found in the coronary,'' he said. "It may be transported in the monocyte, the warrior, the white cell." Activated monocytes produce a chemical on their surface known as tissue factor. Meant to be part of the healing process, it can help trigger blood clotting. Chlamydia was a logical culprit because it was so insidious, Gupta added. It could lurk in the body a long time, causing few symptoms but a lot of damage. "If you look at other chlamydia species, it's the commonest cause of infertility in the USA," he said. "It causes inflammation of the Fallopian tubes and then it causes scarring." With another chlamydial infection, trachoma, blindness is caused in a similar way by scarring eye tissue.
If antibiotics could help even a small percentage of people with heart disease, many lives would be saved by something as easy as taking a few tablets, Gupta said.
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