Infective endocarditis

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Trustees Discretionary Award

Professor Thornhill, University of Sheffield

Amount: £33,832       Duration: 6 months

Investigating who is at risk of developing or dying from infective endocarditis

Summary: Infective endocarditis is a serious and life-threatening infection of the inner lining of the heart.  This project will quantify the risk of developing or dying from infective endocarditis, in patients with different predisposing heart conditions.

Infective endocarditis (IE) is a serious infection of the inner lining of the heart.  It affects around one in 10,000 people every year in the UK and can be life-threatening.  Dental procedures are thought to be one of the main causes of infective endocarditis, with up to one half of all cases being caused by bacteria found in the mouth. 

People with certain heart conditions are thought to be at increased risk of IE, and for the past 50 years it has been standard practice for dentists to give a dose of antibiotics to these patients before dental treatment.  However, in 2008 the National Institute for Health and Care Excellence (NICE) recommended an end to antibiotic cover for at-risk patients.  Previous HRUK-funded research by Professor Thornhill has shown that since 2008 there has been a significant increase in cases of IE and as a result, the NICE guideline was changed.  This change allows flexibility so that dentists and cardiologists can recommend antibiotic cover when it is in the best interests of the patient, and means that at-risk heart patients can make an informed decision about their treatment.

We have very little data, however, to quantify the risk of IE in different groups of patients or how long after procedures, such as insertion of an artificial heart valve, patients remain at increased risk of developing IE.  Furthermore, there are a number of procedures such as insertion of a pacemaker, where cardiologists have no idea if the patient is at increased risk of IE or not. 

Using a national database that records every hospital admission, Professor Thornhill will identify every patient admitted to hospital between 2000 and 2014 that had a diagnosis, or had a procedure, that could have made them susceptible to developing IE.  He will then follow each patient to see if they developed IE later.  By doing this, Prof Thornhill will be able to identify all the different conditions and procedures that put patients at risk of IE, quantify exactly how great that risk is, and also see if/how that risk changes over time.

The findings will help doctors to accurately predict the risk of developing IE in patients with different heart conditions.  Importantly, this means that prevention strategies, such as antibiotic cover and improved oral health can be better targeted to the specific needs of individual patients.  Also, it will help these prevention strategies to be better timed to cover those periods when the patient is at greatest risk.