There is no benefit to using temporary, miniaturised heart pumps to support patients undergoing a high-risk stent procedure, a study from King's College London has found.
Results from the first randomised trial of Impella pumps during complex stent procedures, published in The New England Journal of Medicine, have shown that the pumps offer no significant benefit to patients compared to standard care.
An Impella pump is a miniaturised, catheter-based pump that is inserted through an artery in the leg and designed to take over part of the heart's pumping work to help reduce strain on the heart.
Clinicians sometimes use it to support patients undergoing a high-risk percutaneous coronary intervention (PCI), where a patient may be at risk of cardiac arrest. A PCI is a procedure used to restore blood flow to the heart by widening blocked blood vessels with a tiny balloon, before a metal stent is added to keep it open. This method has become known in clinical settings as 'Protected PCI'.
The CHIP-BCIS3 trial, led by Divaka Perera, Professor of Cardiology at King's, and funded by the National Institute for Health and Care Research (NIHR), recruited 300 patients with severe coronary heart disease and moderate to severe heart failure from 21 UK hospitals between 2021 and 2024. The researchers compared outcomes between patients who had a PCI with the pump, and those who had it without, and learned there was no advantage to using the miniaturised heart pump.
They also found evidence that patients who received the device had higher rates of heart injuries during and after treatment. Two years after the procedure, patients who had used the Impella pump had a 12% higher risk of death from heart-related issues.
The technology behind these pumps is impressive, and we believed they may be protecting the heart during these high-risk procedures, allowing more extensive treatment to be done. However, our findings show that routine use of the Impella pump in this setting does not translate into better outcomes for patients and furthermore, there were potential signals of harm."
Divaka Perera, Professor of Cardiology at King's College London and Consultant cardiologist and professor of interventional cardiology, Guy's and St Thomas' NHS Foundation Trust
He added: "The results highlight the importance of relying on robust randomised evidence to guide practice and ensuring that new technologies are adopted only where there is clear patient benefit."
Impella pumps are widely used in many countries. Data from four major hospitals in the United Kingdom shows that the pumps were used just a handful of times in 2008, but they had been used cumulatively nearly 300 times by 2021. In the United Kingdom, guidance from the National Institute for Health and Care Excellence (NICE) in 2018 urged caution due to safety and efficacy concerns and recommended the device be used in specialist centres, ideally in the context of audit or research. They were approved for use in 2015 by the Food and Drug Administration (FDA) in the United States, where they have been used more widely.
Impella pumps are also used in another context, to support the heart during cardiogenic shock, which is a life-threatening medical emergency where the heart suddenly cannot pump enough blood to meet the body's needs. A previous randomised trial had shown that in patients in cardiogenic shock, use of the Impella device reduced the likelihood of death, albeit with increased bleeding and vascular complications.
