At the recently concluded Arab Health Exhibition and Congress, Dr. Simon Davies, consultant interventional cardiologist at the Royal Brompton & Harefield Hospitals Specialist Care, conducted a simulated transcatheter aortic valve implantation. This is an alternative approach to conventional open-heart surgery. However, it is not just for those who benefit from a minimally invasive approach but can show better results in patients who are suitable for open-heart surgery too.
Transcatheter aortic valve implantation (also known as TAVI) is mainly used to correct aortic stenosis, sometimes with aortic regurgitation – conditions that account for 75 per cent of all patients with valve disease. Royal Brompton and Harefield Hospitals runs the largest transcatheter aortic valve implantation programme in the UK, carrying out hundreds of TAVIs since its start in 2007.
The aortic valve and valve disease
Cardiovascular disease (CVD) remains one of the leading causes of fatality in the Middle East. Faulty heart valves are a common cause of CVD and can be a result of age-related changes to the heart.
The aortic valve is one of four valves in the heart and is the outlet valve from the main pumping chamber. It controls the blood flowing out of the heart and around the body with thin leaflets of tissue that open and close when the heart beats to regulate blood flow. Aortic stenosis is the most common and serious form of valve disease. The condition causes the leaflets to stiffen so that the valve does not open properly, and this narrowing of the valve makes it harder for the heart to pump blood to the body. This causes symptoms including shortness of breath, heart murmur, fainting and fatigue.
Aortic regurgitation occurs when the aortic valve doesn’t close tightly and allows some of the blood that was pumped out of the left ventricle (the heart’s main pumping chamber) to leak back in. TAVI cannot be used for aortic regurgitation alone but can be used for mixed aortic valve disease where the aortic regurgitation is accompanied by aortic stenosis.
Patients with aortic stenosis do not always need intervention, in moderate cases, there often are no specific symptoms and medications are sufficient. In severe cases, however, the only effective, long-term treatment is to replace the valve. Severe aortic stenosis tends to present in people in their 70s and 80s, due to wear and tear, although others may develop this younger, even in childhood on rare occasions.
Until very recently, open-heart surgery was the only option for replacing the aortic valve, but not all patients are suitable for this. Since the TAVI procedure was first developed in 2002 it has been refined and is now lifesaving, less invasive, non-surgical alternative for many patients worldwide.
How TAVI works
During the procedure, which can be performed under general or local anaesthetic, a catheter is guided through an artery to the patient’s heart using special scanning equipment. Access to the heart is via a small incision in the groin and the new valve is then advanced along the blood vessels leading to the heart. The new valve is then placed within the narrowed aortic valve and is then expanded to relieve the obstruction. This all takes places within the cardiac catheter laboratory.
Dr. Davies says: “Imaging is a very important part of the process. The combination of a very low dose X-ray and, where necessary, an echocardiogram, helps to guide the device into position and checks it is working properly. One week before the procedure high-quality computed tomography (CT) scans are taken to provide images of the patient’s aortic valve. This identifies the right size and type of replacement valve.”
He continues, “The same CT scan shows us the access routes, as with some patients we need to go in behind the collarbone or the carotid artery, located on each side of the neck, for example. Before being discharged from the hospital, patients have another echocardiogram.
“A patient requiring treatment is not just getting me as a consultant, they are getting a whole team. I work closely in a highly skilled multi-disciplinary team, so the procedure is backed up by surgeons, cardiologists, anaesthetists, imaging experts, specialist nurses and technicians.”
Royal Brompton and Harefield Hospitals is the only medical centre in the UK with transcatheter programmes for all four of the heart’s valves: mitral, pulmonary and tricuspid as well as aortic. With aortic valve implantation, there is also a choice of two types of valve – a self-expanding or balloon-expanding version.
Dr. Davies says: “We think that it’s important patients and doctors have a choice, based on the person’s anatomy and medical condition.”
Transcatheter aortic valve implantation is certainly less traumatic than open-heart surgery for many patients, especially if they have existing comorbidities. But Dr. Davies says Royal Brompton and Harefield Hospitals now offer TAVIs to patients who are good candidates for open-heart surgery too.
He says: “Recent clinical trials showed TAVI is as good as conventional surgery in those people. We now offer more routinely to people in their late 60s and early 70s without other health problems.”
Patients with failing surgical valves made from tissue, which degenerate in 10 to 15 years, are also excellent candidates for TAVI, as younger people would otherwise need several open-heart surgeries in their lifetimes.
Dr. Simon Davies
Benefits for patients
Most patients who have had TAVI find that their heart is almost immediately able to pump better as there is no longer any hindrance to blood leaving the organ.
However, Dr. Davies explains: “For many patients who have been deconditioned by their illness, their bodies take a little longer to recover. For example, an older person who has suffered serve heart failure for some time will need to build up condition again over a few weeks. However, their breathing will be better pretty much from the start.”
Dr. Davies sees many patients, male and female, from the Middle East for transcatheter aortic valve implantation to treat aortic stenosis. The multi-disciplinary team carefully review each individual patient to ensure they are on the best treatment as soon as possible.
Links with the Middle East
RB&HH Specialist Care has a strong and long-established relationship with the Gulf region. The organisation works closely with health authorities including the Dubai Health Authority, Hamad Medical Corporation and the Ministry of Health and Prevention.
Royal Brompton & Harefield Hospitals Specialist Care is known across the world over for its expertise, standard of care and research success. This is one of the reasons Royal Brompton and Harefield Hospitals operates a visiting doctor programme with key hospitals across the Middle East region. The programme helps to provide better clinical outcomes and strengthen relationships with the region’s healthcare providers.
Dr. Davies practises at the Royal Brompton and Harefield Hospitals NHS Foundation Trust, as well as its private arm Royal Brompton & Harefield Hospitals Specialist Care. He is director of the TAVI programme there and has wide-ranging clinical interests including valve repair and replacement, coronary angioplasty, and cardio-oncology.
Procedure: Transcatheter aortic valve implantation (TAVI)
How does it work? A catheter is guided through an artery to the heart using imaging equipment, then a new valve placed within the narrowed aortic valve and expanded to relieve the obstruction there.
What problem does it solve? It corrects a narrowed valve which makes the heart’s work pumping blood around the body harder and which otherwise causes symptoms such as breathlessness, heart murmur, chest pain and fainting.
References available on request.
This article appears in the March/April edition of Omnia Health Magazine. Other topics include AI in healthcare, patient safety, mobile healthcare and further updates around on COVID-19 from the healthcare industry.