Embolic protection device could minimize stroke in patients undergoing heart valve replacement surgery

A medical device, termed the embolic protection device (EPD), could reduce the risk of a stroke during transcatheter aortic replacement surgery (TAVR) especially in patients who have previously had a stroke.

To remedy the lack of data on the efficacy of EPDs in TAVR, a clinical trial collaboration across US research institutes studied 414,649 patients and determined that EPDs reduced the likelihood of ‘disabling stroke’, which is a stroke that leads to more disabling symptoms, especially in patients who had previously experienced a stroke.

TAVR is a minimally invasive surgery that treats aortic stenosis, the narrowing of the aortic valve, which strains the heart’s ability to pump blood across the body. Aortic stenosis often occurs as we age, but its severity requires surgery in some cases. For older patients, often individuals in their 70s or 80s, the minimally invasive approach is needed as their bodies cannot handle open heart surgery. To perform TAVR, clinicians send a scrunched up aortic valve up through an artery in the leg. They then expand the valve either blowing up a balloon inside the valve or using a self-expanding one.

Stroke is one of the complications of TAVR and it is important to know which patients may be at higher risk. Stroke happens when particles of calcium get past the new valve and into the brain. These particles block the blood vessels in the brain, leading to a stroke. EPDs put a filter in the blood vessels extending from the heart to the brain to prevent calcium from passing to the brain.

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Previous studies examining the efficacy of EPDs in TAVR have shown mixed results. A randomized trial called PROTECTED-TAVR demonstrated that EPDs reduced the risk of a stroke that causes disabling symptoms. To identify disabling stroke, the researchers used the proxy of hospital discharge: if patients were discharged home, then they weren’t experiencing a disabling stroke but if discharged to a care facility then it was a disabling stroke.

The new study looked at over 414,649 patients with over 53,398 receiving an EPD. The device only reduced disabling stroke and this was to a borderline significant degree (from 0.9% to 0.7%). Non-disabling stroke wasn’t reduced and a possible reason for this was that the EPD could be causing such strokes by allowing calcium particles past, or by damaging the blood vessels itself. Importantly, the benefit of the device was greater if patients had previously experienced a stroke.

Neel Butala, the first author of the study (University of Colorado Department of Medicine; CO, USA), commented: “We added more information through our findings that the device can reduce disabling stroke in some patients, although the magnitude is small. But as these devices are being used on even younger patients, we need to get a better sense of what we can do to prevent strokes.”