25 April 2024
A recently published study in the New England Journal of Medicine has found that the use of a heart pump alongside standard treatment helps reduce the risk of death in patients with STEMI-related cardiogenic shock.
Undertaken at Royal Brompton and Harefield hospitals, and other sites across Europe, the clinical trial looked at the use of microaxial flow pump alongside standard of care, and compared it to patients receiving standard of care only.
The flow pump works by draining the blood from the heart and diverting it directly to the vessel (aorta) which delivers blood to the body, essentially taking over a large part of the work of the failing heart.
To find out more about the study and what this could mean for patients we spoke with Dr Vasileios Panoulas, cardiology consultant, who led on the study at Harefield Hospital.
What is STEMI-related cardiogenic shock and how serious of a condition is it?
STEMI (ST-segment elevation myocardial infarction) is a type of heart attack where there is a long interruption to the blood supply and it’s the worst type of heart attack a person can get.
This can lead to cardiogenic shock, which is when the heart muscle becomes so damaged the heart can no longer pump enough blood to maintain many of the body's functions.
This leads to not enough oxygen getting to the tissues and as a result the body begins to find ways to make energy without oxygen, a by-product of which is lactate, which builds up in the body.
What is the current standard of treatment for this group of patients?
What is recommended by the guidelines for those with STEMI-related cardiogenic shock is to immediately carry out a primary angioplasty, which is where we open up the vessel that has been blocked with balloons and stents to improve the blood flow to that region.
After that the pumping inefficiency of the heart is usually managed with drugs known as inotropes that change the force of the heart's contractions and make it work harder.
However, the problem with this is that you have a heart that is suffering and instead of allowing it to rest and recover, you're ‘whipping’ it even more in order to meet the demands of the body.
We thought that by using the microaxial pump, it would mean that rather than subjecting the heart to inotropes the heart is allowed to rest and recover.
What did your study find?
For this study we included 360 patients with STEMI-related cardiogenic shock. We defined this as those with low blood pressure, poor heart function (as determine by an echocardiogram) and high levels of lactate in the blood.
Roughly half of the patients were randomised to have the flow pump in addition to standard of care, with the other half having standard of care treatment only.
Our results found that the group provided the flow pump had a lower risk of death at 180 days by nearly 13%, compared to the patients who received standard of care only. The number of patients needed to treat with the flow pump to save one life was 8.
What do these results mean for patients?
Ultimately, it means that we have a treatment that can save lives in this subset of patients.
One in 10 patients who come in with STEMI go on to develop cardiogenic shock, and for those patients the mortality rate at 30 days is approximately 50%. We now have a therapy that we can use to reduce that mortality.
And even though the data on quality of life has not yet been published, I think quality of life will increase for these patients because the device acts to protect the heart while it's recovering and those who use the device will probably end up having a better functioning heart to live with in the future.
What’s next?
We’re currently undertaking another trial in patients with STEMI who have not yet entered cardiogenic shock.
For this study we will use the flow pump device to determine if we can reduce the level of damage to the heart caused by STEMI before cardiogenic shock happens. We aim to establish if there is improvement in the heart function by using the flow pump device and ultimately reduce the number of people who develop heart failure.
The study was undertaken in collaboration with Odense University Hospital, Denmark, and sponsored by Abiomed, Johnson & Johnson.
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