About the study

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.

How long will the study run for?

CHIP-BCIS3 will open to recruitment in summer 2021 and recruit participants for 3 years. The results of this important study are expected in 2026.

Results

The primary results of the CHIP-BCIS3 trial were presented at the American College of Cardiology Scientific Session in New Orleans on 29 March 2026 and simultaneously published in The New England Journal of Medicine.

CHIP-BCIS3 showed that in patients with severe LV dysfunction and severe coronary heart disease undergoing complex PCI, planned LV unloading with the heart pump did not reduce the risk of major adverse clinical outcomes. An increased risk of all-cause and cardiovascular death was also found in patients who had the heart pump.

The findings strongly suggest that use of the heart pump shouldn't be routinely used in patients receiving a stenting procedure who are at high-risk of complications without more evidence of benefit.

Current trial protocol

• Current trial protocol

For more information, please email [email protected].