‘Microsphere’ protein could help 50 per cent of patients who have heart bypass surgery failure

A new £147,000
research project funded by Heart Research UK aims to help 50 per cent of
patients who suffer from failed heart bypass surgery, saving them from further
invasive surgery and potentially fatal heart attacks.

The project, led by
Professor Sarah George, Professor of Cardiovascular Signalling
from the Bristol Medical School and Bristol Heart
Institute at the University of Bristol will look at how to prevent the
failure of leg vein grafts used to treat blocked coronary arteries.

Currently just over
16,000 heart bypass operations are carried out in the UK each year. Heart
attacks are usually caused by blockage of the coronary arteries supplying blood
to the heart muscle. One of the treatments for blocked coronary arteries is
heart bypass surgery using sections of vein from the patient’s leg to bypass
the blockage.

However, vein graft
failure occurs in around 50 per cent of cases within ten years, due to an
increased activity of cells within the vein graft which causes thickening of
the inner layer of the vein.

Professor George’s
team has already been studying a protein that plays an important role in ‘cell
adhesion’ – where cells bind together. This protein reduces over-activity of
cells within the vein and graft thickening, without harmful effects on the
blood vessel wall. They have also found that a very small part of the protein
can act as a mimic for the full-length version and has similar effects on the
vein graft.

In this project
they will package the mimic in small, biodegradable spheres called
‘microspheres’, as a way of slowly delivering the mimic to the vein graft.

If the mimic
reduces over-activity of the cells within the vein graft without adverse
effects on the blood vessel wall, it may have potential as a treatment to
prevent vein graft failure following bypass surgery. If successful, it
could be used to improve the outcome of heart bypass surgery and reduce the
need for surgery to be repeated.

Professor
Sarah George said:

“Whilst it’s considered to be a standard treatment, 50 per
cent of heart bypass grafts using leg vein fail within ten years meaning that
some patients go on to have further angina or heart attacks, and need further
operations. This is an unacceptable figure.

“By researching the
benefits of the adhesion protein mimic, we hope to improve the long-term
success of heart bypass surgery and reduce this figure.”

The University of
Bristol is just one recipient of Heart Research UK’s Translational Research
Project Grants. Awarded since 2009, the national charity based in Leeds has
given almost £5m to fund these innovative and pioneering medical research projects
across the UK.

Barbara
Harpham, Chief Executive of Heart Research UK, said:

“Our Translational
Research Project Grants aim to bridge the gap between laboratory-based
scientific research and patient care with the aim that patients benefit as soon
as possible.

“This
innovative research project has the potential to help people who have heart
bypass surgery by reducing the need for further invasive surgery to be carried
out again later.”