Condition category
Circulatory System
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
Not yet recruiting

Plain English Summary

Background and study aims
Over 100,000 coronary stent procedures, where small balloons are used to stretch open a narrowed blood vessel, are performed every year in the UK to treat people who have conditions such as angina or have suffered a heart attack.

For most patients the risk of complications is low, but for some, there is a higher risk of their heart failing during the procedure. Heart failure is a serious complication which can need treatment with a life support machine and lead to major damage to the heart muscle or even death. These risks are greatest in patients with severely diseased heart arteries and those who already have weakened heart muscle.

A new technology may be able to help with this problem. It consists of a small heart pump which is placed in the heart’s main pumping chamber (the left ventricle, LV). This pump is known as a LV unloading device. The LV unloading device is inserted into the heart through a blood vessel in the leg and supports the heart muscle. It is removed at the end of the procedure or when the heart can pump safely on its own. Whilst this heart pump is promising, it comes with some risks of its own. These include bleeding and damage to the arteries in the legs. It is also expensive, costing £8,000 per operation. Currently, there is no strong evidence to guide the use of this device.

The CHIP study aims to determine whether these heart pumps are beneficial and cost-effective in patients receiving a stenting procedure who are at high-risk of complications.

Who can participate?
This study is open to patients who are due to receive a Percutaneous Coronary Intervention (PCI), or stenting, to treat narrow arteries in their heart and whose doctor believes they are at high-risk of complications.

What does the study involve?
If a patient chooses to participate in the CHIP trial and provides informed consent, they will be randomly assigned to either the intervention or control arm. If they are assigned to the intervention arm, they will receive an LV unloading device with their stenting procedure. If they are assigned to the control arm, they will receive their stenting procedure as normal without the LV unloading device.

Before their procedure, participants will have a blood tests and be asked questions about their medical history. Patients will have heart scan, known as an ECG. These extra tests are to measure how well the patient’s heart functions. Patients will also be asked to fill in 2 health questionnaires which will take around 20 mins and they can ask the nurse for help.

Following the procedure, participants will be asked to come back to their Hospital to see a member of the research team 30 days and 12 months after their PCI. Participants will receive more blood tests and be asked to fill out 2 health questionnaires. There won’t have any more hospital visits because of the study after this and participant’s GP and Hospital records will be used to monitor their health up to 4 years following their enrollment in the trial.

What are the possible benefits and risks of participating?
There are a few potential risks that it is important to be aware of in this study. Participants who are randomised to the intervention arm will receive the LV unloading device. The device is passed into the heart on a thin catheter, this may cause bleeding, damage to the blood vessel or haemolysis. This happens in 1 in 20 cases. More major complications, such as severe bleeding, damage to the blood vessels which needs surgery, a stroke, damage to the heart or death, happens in less than 1 in 100 procedures. Additionally, as an X-ray is needed to help position the LV device, taking part in this study could involve an extra radiation dose of which can potentially be harmful. It is important to note that everyone in the study will have a PCI procedure, the risk and benefits of PCI will be discussed with you by your doctor. Any extra risk only affects those who have the LV unloading treatment.

As it is not known whether LV unloading is helpful it cannot be said whether or not there will be a direct benefit to participants. The information that is obtained when people take part in this study is likely to improve the treatment of people living with heart disease in the future.

Where is the study run from?
This study is run by King’s College London (UK) and Guy’s and St Thomas’ Hospital NHS Foundation Trust (UK) in collaboration with the London School of Hygiene and Tropical Medicine (UK)

When is the study starting and how long is it expected to run for?
From July 2020 to June 2025

Who is funding the study?
The National Institute of Health Research (NIHR) Health Technology Assessment (UK)

Who is the main contact?
1. Prof Divaka Perera
2. Mr Alexander Perkins
3. Dr Matthew Ryan

Trial website

Contact information



Primary contact

Prof Divaka Perera


Contact details

The Rayne Institute
King's College London
4th Floor Lambeth Wing
St Thomas Hospital
Westminster Bridge Road
United Kingdom
+44 (0)2071881048



Additional contact

Mr Alexander Perkins


Contact details

Keppel Street
United Kingdom
+44 (0)20 7927 2723



Additional contact

Dr Matthew Ryan


Contact details

The Rayne Institute
King's College London
4th Floor Lambeth Wing
St Thomas Hospital
Westminster Bridge Road
United Kingdom
+44 (0)2071881048

Additional identifiers

EudraCT number

Nil known number

Nil known

Protocol/serial number

IRAS 290599, HTA - NIHR130593

Study information

Scientific title

Controlled trial of High-risk coronary Intervention with Percutaneous left ventricular unloading (CHIP)



Study hypothesis

In patients undergoing high-risk percutaneous coronary intervention, a strategy of percutaneous left ventricular unloading is superior to standard care in terms of patient outcomes, quality of life and cost-effectiveness.

Ethics approval

Approval pending

Study design

Multicentre open-label randomized controlled superiority trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

No participant information sheet yet available


Ischaemic heart failure


Participants will be randomized on a 1:1 basis prior to the PCI procedure using an electronic randomisation service.

Participants in the elective unloading (intervention) group will have a percutaneous left ventricular unloading device (pLVAD) inserted at the start of the procedure, before the coronary intervention. Maximal support will be provided throughout the procedure, following which support will be weaned and the device removed should the patient remain haemodynamically stable.

Participants in the control arm will receive the planned high-risk percutaneous coronary intervention as is the current standard of care without elective left ventricular unloading. Alternative mechanical circulatory support devices (such as the intra-aortic balloon pump (IABP) or extracorporeal membrane oxygenation (ECMO) will only be permitted in case of complications.

Intervention type



Phase III

Drug names

Primary outcome measure

Composite hierarchical outcome of death, stroke, spontaneous myocardial infarction, cardiovascular hospitalisation (including prolongation of the index admission for bleeding and vascular complications) and periprocedural myocardial infarction analysed using a Win Ratio method between 1 and 4 years

Secondary outcome measures

1. Individual components of the primary outcome (as well as repeated occurrences of these events) between 1 and 4 years
2. Completeness of revascularisation measured by the change in anatomic BCIS-JS and anatomic SYNTAX score between baseline and the completion of the final planned PCI procedure
3. Major bleeding (BARC 3 or 5) using the BARC classification between baseline and 30 days after completion of the final planned PCI procedure
4. Vascular complication measured as the incidence of injury to a major artery or vein resulting in either major bleeding, tissue ischaemia/necrosis requiring percutaneous or surgical intervention, or death between baseline and 30 days after completion of the final planned PCI procedure
5. Procedural complication measured as the incidence of VT/VF requiring defibrillation, cardiorespiratory arrest, acute pulmonary oedema requiring assisted ventilation or prolonged hypotension between baseline and 30 days after completion of the final planned PCI procedure
6. Unplanned revascularisation between baseline and 30 days after completion of the final planned PCI procedure
7. Health-related quality of life/functional status measured by the EuroQol 5-Dimension 5-level questionnaire (EQ-5D-5L) at 30 days and 1 year
8. Resource utilisation and cost effectiveness measured by incremental costs, quality-adjusted life years (QALYs) and net monetary benefit at 12 months

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Extensive coronary disease defined by a British Cardiovascular Intervention Society (BCIS) Jeopardy Score ≥8
2. Severe left ventricular systolic dysfunction defined as an LVEF ≤35% (or ≤45% in the presence of severe mitral regurgitation)
3. Complex PCI defined by the presence of at least one of the following criteria:
3.1. Unprotected left main intervention in the presence of
3.1.1. An occluded dominant right coronary artery or
3.1.2. A left dominant circulation or
3.1.3. Disease involving the entire bifurcation (Medina 1,1,1 or 0,1,1)
4. Intended calcium modification (by rotational atherectomy, lithotripsy or laser)
4.1. In multiple vessels or
4.2. In the left mainstem or
4.3. In a final patent conduit or
4.4. Where the anatomic SYNTAX score is ≥32
5. Target vessel is a chronic total occlusion with a planned retrograde approach

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Cardiogenic shock or acute STEMI at randomization
2. Contraindication to pLVAD insertion
3. Inability to give informed consent
4. Previously enrolled in CHIP or current enrolment in another interventional study that may affect CHIP outcomes

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

St Thomas' Hospital
Westminster Bridge Road
United Kingdom

Sponsor information


King's College London

Sponsor details

The Strand
United Kingdom
+44 (0)20 7188 7188

Sponsor type




Guy’s and St Thomas’s NHS Foundation Trust

Sponsor details

NIHR GSTFT/KCL Biomedical Research Centre
16th Floor
Tower Wing
Guy's Hospital
United Kingdom
+44 (0)20 7188 7188

Sponsor type

Hospital/treatment centre



Funder type


Funder name

National Institute for Health Research

Alternative name(s)


Funding Body Type

government organisation

Funding Body Subtype

National government


United Kingdom

Results and Publications

Publication and dissemination plan

Results of the trial will be published in an academic journal and presented at international conferences. Participants will be provided with summaries of the results in lay language.

IPD sharing statement:
The data sharing plans for the current study are unknown and will be made available at a later date.

Intention to publish date


Participant level data

To be made available at a later date

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

28/10/2020: Trial's existence confirmed by the NIHR.