A simple and cheap test could pick up early signs of heart disease, US researchers say.

They found that be checking the levels of a particular protein in the blood, it was possible to detect heart disease before a patient experienced any symptoms.

In a second study, doctors found antibiotics could protect against heart disease.

The US research looked at C-reactive protein (CRP), which is a marker of inflammation in the body.

Scientists from the US National Heart, Lung, and Blood Institute's Framingham heart study looked at the relationship between CRP and coronary calcium.

In the long term the findings of this research could help us treat more heart patients

Belinda Linden, British Heart Foundation

This indicates how much atherosclerosis, or the hardening of coronary arteries, has occurred.

The condition is a sign of heart disease.

Calcium levels

Researchers studied 321 people with an average age of 60 who had participated in the Framingham study since 1971.

Patients had blood tests to assess CRP levels and scans to assess how much calcium there was in their coronary arteries.

It was found that the higher their CRP score, the higher the level of coronary calcium.

Dr Thomas Wang, lead author of the study, said: "It has been known that inflammation plays a role in coronary artery disease but the direct link between the level of this marker of inflammation and the actual presence of calcium in the coronary arteries is a new finding."

But the researchers said more work needed to be done to confirm the link and its importance in heart care.

Anti-inflammatory effect

In a separate study, scientists have discovered that giving antibiotics to patients receiving hospital treatment reduces their risk of readmission within a year.

Researchers from the Mayday Hospital, Croydon, say antibiotics could have an anti-inflammatory benefit.

Over 300 patients who had received hospital treatment because they had suffered a heart attack or severe angina, took part in the study.

Whilst in hospital, they were given either the antibiotics amoxicillin, azithromycin, or a dummy pill for a week.

Azithromycin is known to have anti-inflammatory properties, though amoxicillin is not.

They said antibiotics had a beneficial effect even if two bacteria thought to play a role in heart disease - Helicobacter pylori (H. pylori) and Chlamydia pneumoniae - were present.

At the beginning of the study, just over half of all patients had antibodies to H. pylori, which can cause stomach ulcers, and just over 40% had antibodies to C. pneumoniae which causes a kind of pneumonia.

In the year following their treatment, patients who had received antibiotics were 36% less likely to be readmitted to hospital or to die from heart-related problems, than those who had taken the dummy pill.

Reducing risk

Dr Michael Mendall, a consultant gastroenterologist at the Mayday Hospital, who led the research, said: "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."

He added: "It is an interesting proposal that antibiotics can affect a condition that has always been regarded as non-infectious.

"The question is whether the antibiotics are working against bacteria to improve heart outcome or whether the antibiotics improve outcome by an anti-inflammatory action."

Belinda Linden, of the British Heart Foundation said more work needed to be done into the benefits of antibiotics.

"In the long term the findings of this research could help us treat more heart patients and reduce their risks of heart attack and angina.

"However, as the researchers point out, the antibiotics may be working against other bacteria in the body or reducing inflammation.

"Future research needs to determine which of these two actions the antibiotics are taking and how these antibiotics affect patients without the H. Pylori or C. Pneumoniae bacteria."

Both papers are published in Circulation, the journal of the American Heart Association.