Aortic stenosis is a common cardiological
condition in the elderly. Once patients
develop symptoms, aortic stenosis carries
a poor prognosis. In patients with aortic
stenosis, mortality rates at 3 years are 25-
50% and in the elderly, this increases to a
2-year mortality from 50% to 60%.
The condition also substantially interferes
in quality of life, resulting in a reduced
exercise tolerance due to shortness of
breath and chest pain, along with pre-
syncopal or syncopal episodes.
The standard treatment for this condition
is surgical Aortic Valve Replacement (AVR).
This is a highly successful operation in
patients with no co-morbidities. However,
in the elderly patient with co-morbidities,
cardiac surgery can carry a very high
risk, often resulting in withholding of this
therapy. It is estimated that up to one-
third of patients with symptomatic aortic
stenosis are never referred for cardiac
surgery because the referring doctor
considers the risk too high.There is no
effective medical therapy for severe aortic
stenosis, and thus these patients will
continue with a poor quality of life with
a high mortality.
This new technique is catheter based and
a balloon expandable valve mounted on
a stent is delivered either ante-gradely
(through a small incision at the apex)
or retro-gradely via the femoral artery.
At present, the procedure is restricted
to patients at high surgical risk, or who
have been turned down for conventional
AVR. Patients will have severe aortic
stenosis (valve area < 0.8 sq cm) and at
least moderate left ventricular function
(ejection fraction >20%).The decision to
perform the procedure via the femoral
artery or apex is largely down to the
presence of peripheral vascular disease –
if the ilio-femoral vessels are <7mm
and/or significantly calcified, the
procedure may need to be performed
apically.The screening process includes
risk assessment, echocardiography, CT
of aorta and peripheral vessels and
coronary and peripheral angiography.
The procedure is performed under
general anaesthesia by a team including
Cardiologists, Cardiac Surgeons,
Echocardiographers and Anaesthetists.
It is performed either ante-gradely, via
a 4-5cm incision at the apex to gain
direct access to the left ventricle, or
retro-gradely via the femoral artery.
In both approaches, a valvuloplasty is
performed prior to introducing the
valve mounted on a balloon. After
careful positioning with angiography
and trans-oesophageal echo guidance,
the balloon is inflated thus deploying
the valve in the aortic root.
Worldwide implants currently total
greater than 3,000 using the Edwards
Sapien valve.The predicted surgical
mortality in these patients is >20% and
the current trial data demonstrates that a
30-day mortality of <10% can be achieved.
Haemodynamic improvements include
a reduction in aortic valve gradient to
<10mm Hg associated with an increase
in aortic valve area. Clinically, a marked
improvement in symptoms and quality
of life has been demonstrated.
Although this is still a very new procedure,
these preliminary results are highly
encouraging and it is likely that, over time,
this therapy will become more widely
available to less high-risk patients.
Trans-femoral approach – This figure shows the balloon
catheter passing up the aorta from the femoral artery
with the balloon inflated when deploying the valve.
Avg. Survival (Yrs)
2 4 6
Transcatheter Aortic Valve Implantation (TAVI)
Dr Simon Redwood
MD FRCP FACC FSCAI
Reader and Consultant Interventional Cardiologist at St Thomas’ Hospital and London
Bridge Hospital. He is also Director of the Cardiac Cath labs at St Thomas’ Hospital,
and Treasurer and a Council Member of BCIS. He has extensive experience in high-
risk and complex interventional procedures including rotablation, laser, chronic total
occlusions and mitral valvuloplasty.
For further information, please contact Suzanne Pattinson on
020 7188 0955
This is a very exciting innovation where the aortic valve is replaced without the
requirement for open heart surgery or heart bypass. Although it is currently only
performed in high-risk surgical patients, it is likely that in the near future this will
start to be performed on lower risk patients. At present, the procedure requires
a multidisciplinary team involving interventional cardiology, echocardiography,
cardiothoracic surgery and cardiac anaesthesia.