As one of the largest cardiovascular (heart and blood vessels) specialist centres in the UK, we carry out lots of different research in this area. This includes new surgical treatments, and better ways to manage disturbances in heart rhythm (known as arrhythmias).
TAVI - a surgical device
TAVI (transcatheter aortic valve implantation) is an alternative to open heart surgery to replace the aortic valve in the heart. It is recommended for patients as being ‘high risk’ for the usual surgical procedure, and it is only carried out at specialist centres. Recovery times are quicker because TAVI uses keyhole surgery.
For the last few years only two TAVI devices have been available. However, 3 new devices were recently launched. As a centre of cardiovascular expertise, we trialled and are reviewing the new devices.
We are also involved, through King’s Health Partners, with a European randomised trial of TAVI for treatment of coronary heart disease.
Effect of strong emotion on the heart
If people with arrhythmia suffer a severe shock or strong emotion, it can affect the electrical behaviour of their heart, potentially ‘short circuiting’ and leading to heart failure. For example, there are stories of people who have a heart attack after their house has burnt down, and studies show that the number of arrhythmia-related heart attacks in a population doubles the month after a bad earthquake.
However, there is little experimental data on exactly how the heart muscle is affected. An ECG (electrocardiogram), which uses sensors on your skin, can tell us the heart’s electrical activity has changed – but not how or why. To do this, you need to have sensors on the heart muscle itself.
We have patients who, as part of a planned medial procedure, have sensors placed directly on or in their heart. Some have agreed to help us research the emotional response. They watch a five minute clip from the film ‘Vertical Limit’, where a family has to make a life-threatening decision under stressful circumstances. We record information about their heart’s electrical activity, as well as their blood pressure and breathing.
The results are fascinating, and match up with work on heart cells that have been grown in the lab. This cutting edge research will help us to understand the effects of shock and trauma on those with mild arrythmias, and develop better monitoring and treatments for them.
Better treatment for arrhythmia
Arrhythmia is often treated by implanting a pacemaker. Most patients with a pacemaker see an improvement in their condition, but 1/3 of patients don't. This may be because the pacemaker is on scar tissue on their heart which does not respond to the electrical signal, or because the pacemaker is not in the best position.
In general, the pacemaker is inserted into any vein in the left ventricle of the heart. Our staff, with the Imaging Sciences team at King’s College London, have developed a new technique to test different positions within the left ventricle to see if this improves the effect of the pacemaker.
They use MRI imaging to develop a ‘bullseye’ diagram of the left ventricle that shows which part is most out of sync. The MRI also shows scar tissue. They use this diagram over the top of an X-ray to guide the placement of the pacemaker, making sure that it is in the area worst affected and not on scar tissue.
The results from the pilot study were encouraging and a new, international trial is starting. The team is also working with industrial partners to develop software. This research may change the way arrhythmia patients receiving a pacemaker are treated – and will most benefit patients who do not benefit from the current procedure.
Service evaluation for infective endocarditis
This department service evaluation is to establish the relapse rate of infective endocarditis in patients who have been treated surgically at the cardiovascular centre over a 10 year period. In the past, the practice has been to use abbreviated post-operative antibiotic courses. This service evaluation may provide evidence that the duration of recommended antibiotic courses as stated in the current guidelines may be excessive.
In order to complete the service evaluation, patients who fall under the criteria have been identified and patient identifiers including NHS number, gender, postcode and date of birth are disclosed to the Health and Social Care Information Centre (HSCIC) so that the HSCIC can link those identifiers to the Hospital Episode Database (HES) and provide a file back to the centre which contains the identifying information together with the Hospital Episode information from databases held by the HSCIC. It may be necessary for us to contact the Consultant responsible for the care episode to discuss and clarify diagnosis should, and only if, a HES suggest a possible episode of IE. The data received then has the identifiers removed so that the analysis can be conducted on a pseudonymised dataset which protects patient confidentiality.
Any patients who do not wish for their data to be used in this way can easily opt out of the analysis by contacting the centre on 020 7188 1047 (Professor John Chambers) or by emailing the centre on firstname.lastname@example.org.
This is just a small amount of the research we do in this area. If you’re a patient interested in finding out more, then speak to your consultant at your next appointment. If you are not a patient at Guy’s and St Thomas’ then speak to your own consultant in the first instance.