A study of an abnormal heart rhythm occurring after transcatheter aortic valve implantation and its effect on survival - a United Kingdom experience.

Plain English summary of protocol

Background and study aims
With every heartbeat the aortic valve opens to allow blood to leave the main pumping chamber of the heart to supply the tissues and organs of the human body. Over time and as a natural consequence of ageing, the aortic valve leaflets (there are usually three) can become stiff, open less well and the valve opening (orifice) is narrowed as a result. This is called aortic valve stenosis, which is the most common form of heart valve disease in the developed world. The aortic valve orifice can become so narrowed that an individual can become symptomatic and suffer chest pain, shortness of breath, a reduction in exercise capacity and loss of consciousness. Before these symptoms can take hold it is standard medical practice for the patient to be considered for aortic valve replacement via open heart surgery. Indeed severe symptomatic aortic stenosis is often fatal if left untreated, whilst timely relief of the mechanical obstruction can restore normal life expectancy. Surgical aortic valve replacement is an operation associated with a small but significant risk of death and other complications. In those patients who may be frail and/or suffer other medical problems, that risk may be heightened to such an extent that the benefits of the operation may be outweighed by the risks attached. In the past, patients declined for an aortic valve operation would have no other alternative but to continue their tablet therapy. In 2002, the first transcatheter aortic valve implantation (TAVI) procedure was performed. This was a new method of replacing the aortic valve without having to perform open heart surgery. With TAVI a replacement aortic valve, fashioned from cow or pig heart tissue mounted on an expandable metallic frame, is placed across the native aortic valve via a main artery in the groin, chest, or neck or directly through the bottom tip of the heart via a small incision in the lower left ribcage. The TAVI procedure has now become established as a therapeutic strategy for the management of severe aortic stenosis in those patients who do not qualify for a surgical aortic valve replacement. The close proximity of the aortic valve apparatus to the native electrical conduction system of the heart lends to an increased propensity for the development of excessively slow heart rhythms. Following traditional surgical aortic valve replacement, for instance, a permanent pacemaker is required in 2-8% of patients postoperatively to prevent the heart rate from falling too low. Following a TAVI procedure the occurrence of electrical conduction abnormalities can be even higher. For the purposes of the 3B Study, we are focusing on a specific heart rhythm abnormality called Left Bundle Branch Block (LBBB), which has been noted to occur following a small percentage of TAVI procedures. The exact percentage of patients likely to suffer LBBB following a TAVI procedure is unknown as is its relation to harmful complications such as an impairment in the overall pumping function of the heart, and more seriously, whether the emergence of LBBB can increase the likelihood of death following a TAVI procedure. We will study, in a retrospective fashion, all the TAVI procedures that have taken place since the inception of the service at each participating institution up until the 31st of December 2013. This study will represent the largest database of TAVI procedures in which the occurrence of LBBB post procedure has been analysed in the medical literature to date. The information gleaned from the study will help us to determine the prognostic significance of LBBB post TAVI procedure. If LBBB is found to be detrimental to the survival of patients post TAVI, further studies can then be designed to determine what therapeutic interventions can be put in place to improve outcome in this specific patient subgroup.

Who can participate?
Patients undergoing the TAVI procedure at one of the participating centres within the period from the start of the TAVI programme at their trial participating centre until the 31st December 2013.

What does the study involve?
For all the participants in the study we will determine: (1) how many developed LBBB following TAVI; (2) whether the development of LBBB led to an increased risk of death within a year following the TAVI operation; (3) whether the development of LBBB led to an increased risk of death from a cardiovascular cause 1 year after the TAVI operation; and (4) whether the development of LBBB led to a reduction in the pumping function of the heart at 30 days and at 1 year after the TAVI operation.

What are the possible benefits and risks of participating?
There are no benefits of risks associated with taking part in this study

Where is the study run from?
A total of 18 NHS hospitals across the UK

When is the study starting and how long is it expected to run for?
February 2015 to December 2015

Who is funding the study?
King's College London (UK)

Who is the main contact?
1. Dr Satpal Arri (public)
satpal.arri@gmail.com
2. Dr Aung Myat (public)
aung.myat@nhs.net (scientific)
3. Professor Simon Redwood
simon.redwood@gstt.nhs.uk

Contact information

Study information

Eligibility

Locations

Countries of recruitment

• England
• United Kingdom
• Virgin Islands, U.S.

Study participating centres

Sponsor information

King's College London
University/education

K0.58 King's Building Strand Campus
London
WC2 R2LS
United Kingdom

Phone	+44 (0)207 848 6960
Email	barbara.dahill@kcl.ac.uk
"ROR"	https://ror.org/0220mzb33

Funders

Funder type

University/education

Results and Publications

Study outputs

Additional files

ISRCTN11188205_BasicResults_03Apr19.pdf

Uploaded 03/04/2019

Editorial Notes

13/07/2021: Internal review.
03/04/2019: The basic results of this trial have been uploaded as an additional file.
26/03/2019: Internal review.
09/05/2018: Intention to publish date added.
08/05/2018: IPD sharing statement added.