Scientists identify a rise in life-threatening heart infection

Scientists at the University of Sheffield have identified a significant rise in the number of people diagnosed with a serious heart infection alongside a large fall in the prescribing of antibiotic prophylaxis to dental patients.

The pioneering study is the largest and most comprehensive to be conducted with regards to the National Institute for Health and Care Excellence (NICE) guidelines, which recommended dentists should no longer give antibiotics before invasive treatments to people considered at risk of the life threatening heart infection, Infective Endocarditis (IE), which in 40 per cent of cases is caused by bacteria from the mouth.

The team of international researchers, led by Professor Martin Thornhill at the University of Sheffield’s School of Clinical Dentistry, discovered that since the NICE guidelines were introduced in March 2008, there has been an increase in cases of Infective Endocarditis above the expected trend. By March 2013 this accounted for an extra 35 cases per month.

They also identified that the prescribing of antibiotic prophylaxis fell by 89 per cent from 10,900 prescriptions a month, before the 2008 guidelines, to 1,235 a month by March 2008.

Martin Thornhill, Professor of Translational Research in Dentistry at the University of Sheffield, said: “Infective Endocarditis is a rare but serious infection of the heart lining. We hope that our data will provide the information that guideline committees need to re-evaluate the benefits, or not, of giving antibiotic prophylaxis.

Professor Thornhill stressed that healthcare professionals and patients should wait for the guideline committees to evaluate the evidence and give their advice before changing their current practice.

He added: “In the meantime, healthcare professionals and patients should focus on maintaining high standards of oral hygiene. This will reduce the number of bacteria in the mouth which have the potential to cause Infective Endocarditis and reduce the need for invasive dental procedures to be performed.”

The data analysed by an international collaboration of experts from the University of Sheffield, Oxford University Hospitals NHS Trust, Taunton and Somerset NHS Trust, and the University of Surrey in the UK, as well as from the Mayo Clinic and the Carolinas HealthCare System’s Carolinas Medical Center in the USA, is published in The Lancet and will be presented to more than 19,000 delegates from across the world at the American Heart Association annual meeting in Chicago.

The research was funded by a grant from national heart charity Heart Research UK, healthcare provider Simplyhealth and the National Institute for Dental and Craniofacial Research (NIDCR).

Barbara Harpham, National Director of Heart Research UK, said: “The findings play an important part in the ongoing exploration of the link between dental and heart health.

“Projects such as this one are vital to the ongoing collation of evidence to support our understanding of how oral health can impact upon the heart and other conditions within the body. We are committed to furthering medical research in the UK and welcome these new findings.”

http://www.medicalnewstoday.com/releases/285754.php

 

 

 

Scientists identify a rise in life-threatening heart infection

Scientists at the University of Sheffield have identified a significant rise in the number of people diagnosed with a serious heart infection alongside a large fall in the prescribing of antibiotic prophylaxis to dental patients.

The pioneering study is the largest and most comprehensive to be conducted with regards to the National Institute for Health and Care Excellence (NICE) guidelines, which recommended dentists should no longer give antibiotics before invasive treatments to people considered at risk of the life threatening heart infection, Infective Endocarditis (IE), which in 40 per cent of cases is caused by bacteria from the mouth.

The team of international researchers, led by Professor Martin Thornhill at the University of Sheffield’s School of Clinical Dentistry, discovered that since the NICE guidelines were introduced in March 2008, there has been an increase in cases of Infective Endocarditis above the expected trend. By March 2013 this accounted for an extra 35 cases per month.

They also identified that the prescribing of antibiotic prophylaxis fell by 89 per cent from 10,900 prescriptions a month, before the 2008 guidelines, to 1,235 a month by March 2008.

Martin Thornhill, Professor of Translational Research in Dentistry at the University of Sheffield, said: “Infective Endocarditis is a rare but serious infection of the heart lining. We hope that our data will provide the information that guideline committees need to re-evaluate the benefits, or not, of giving antibiotic prophylaxis.

Professor Thornhill stressed that healthcare professionals and patients should wait for the guideline committees to evaluate the evidence and give their advice before changing their current practice.

He added: “In the meantime, healthcare professionals and patients should focus on maintaining high standards of oral hygiene. This will reduce the number of bacteria in the mouth which have the potential to cause Infective Endocarditis and reduce the need for invasive dental procedures to be performed.”

The data analysed by an international collaboration of experts from the University of Sheffield, Oxford University Hospitals NHS Trust, Taunton and Somerset NHS Trust, and the University of Surrey in the UK, as well as from the Mayo Clinic and the Carolinas HealthCare System’s Carolinas Medical Center in the USA, is published in The Lancet and will be presented to more than 19,000 delegates from across the world at the American Heart Association annual meeting in Chicago.

The research was funded by a grant from national heart charity Heart Research UK, healthcare provider Simplyhealth and the National Institute for Dental and Craniofacial Research (NIDCR).

Barbara Harpham, National Director of Heart Research UK, said: “The findings play an important part in the ongoing exploration of the link between dental and heart health.

“Projects such as this one are vital to the ongoing collation of evidence to support our understanding of how oral health can impact upon the heart and other conditions within the body. We are committed to furthering medical research in the UK and welcome these new findings.”

http://www.medicalnewstoday.com/releases/285754.php

 

 

 

The heart’s own immune cells can help it heal

The heart holds its own pool of immune cells capable of helping it heal after injury, according to new research in mice at Washington University School of Medicine in St. Louis.

Most of the time when the heart is injured, these beneficial immune cells are supplanted by immune cells from the bone marrow, which are spurred to converge in the heart and cause inflammation that leads to further damage. In both cases, these immune cells are called macrophages, whether they reside in the heart or arrive from the bone marrow. Although they share a name, where they originate appears to determine whether they are helpful are harmful to an injured heart.

In a mouse model of heart failure, the researchers showed that blocking the bone marrow’s macrophages from entering the heart protects the organ’s beneficial pool of macrophages, allowing them to remain in the heart, where they promote regeneration and recovery. The findings may have implications for treating heart failure in humans.

The study is now available in The Proceedings of the National Academy of Sciences Early Edition.

“Researchers have known for a long time that the neonatal mouse heart can recover well from injury, and in some cases can even regenerate,” said first author Kory J. Lavine, MD, PhD, instructor in medicine. “If you cut off the lower tip of the neonatal mouse heart, it can grow back. But if you do the same thing to an adult mouse heart, it forms scar tissue.”

This disparity in healing capacity was long a mystery because the same immune cells appeared responsible for both repair and damage. Until recently, it was impossible to distinguish the helpful macrophages that reside in the heart from the harmful ones that arrive from the bone marrow.

The new research and past work by the same group – led by Douglas L. Mann, MD, the Tobias and Hortense Lewin Professor of Medicine and cardiologist-in-chief at Barnes-Jewish Hospital – appear to implicate these immune cells of different origins as responsible for the difference in healing capacity seen in neonatal and adult hearts, at least in mice.

“The same macrophages that promote healing after injury in the neonatal heart also are present in the adult heart, but they seem to go away with injury,” Lavine said. “This may explain why the young heart can recover while the adult heart can’t.”

Because they are interested in human heart failure, Lavine and his colleagues developed a method to progressively damage mouse cardiac tissue in a way that mimicked heart failure. They compared the immune response to cardiac damage in neonatal and adult mouse hearts.

The investigators found that the helpful macrophages originate in the embryonic heart and harmful macrophages originate in the bone marrow and could be distinguished by whether they express a protein on their surface called CCR2. Macrophages without CCR2 originate in the heart; those with CCR2 come from the bone marrow, the research showed.

Lavine and his colleagues asked whether a compound that inhibits the CCR2 protein would block the bone marrow’s macrophages from entering the heart.

“When we did that, we found that the macrophages from the bone marrow did not come in,” Lavine said. “And the macrophages native to the heart remained. We saw reduced inflammation in these injured adult hearts, less oxidative damage and improved repair. We also saw new blood vessel growth. By blocking the CCR2 signaling, we were able to keep the resident macrophages around and promote repair.”

Some CCR2 inhibitors are being tested in phase 1 and 2 clinical trials for treating rheumatoid arthritis. But before these drugs can be evaluated in people with heart failure, more work must be done to find out whether the same mechanisms are at work in human hearts, according to the researchers.

“We have identified similar immune cell subtypes that are present in the human heart,” Lavine said. “We need to find out more about their roles in heart failure in patients and understand more about how macrophages that reside in the heart promote repair.”

http://www.medicalnewstoday.com/releases/284750.php