A non-surgical procedure could help prevent strokes in patients with a heart condition known as atrial fibrillation, and eliminate the need for blood thinners. The procedure, identified by scientists from the Bluhm Cardiovascular Institute in Illinois, involves tying off the left atrial appendage (LAA), where most stroke-inducing blood clots come from.
Atrial fibrillation is the most common cardiac arrhythmia, or irregular heartbeat. It involves the upper chambers of the heart, or the atria. During an episode of atrial fibrillation, the atria beat out of rhythm very quickly and then slow as the impulse travels to the lower chambers, the ventricles, which then pump blood to the body.
Atrial fibrillation typically does not lead to a heart attack, but it is a significant risk factor for stroke. This increased risk occurs because during an episode of atrial fibrillation, blood cannot easily flow through the atria. Instead, the blood pools, particularly in the left atrial appendage – a small structure located off the left atrium – creating an ideal environment for a blood clot to form.
About 90 percent of blood clots that form due to atrial fibrillation start in the left atrial appendage. A clot that breaks loose and travels in the bloodstream to the brain can cause a stroke.
Treatment for patients with atrial fibrillation involves decreasing the blood’s ability to clot, and is often treated with anti-clotting agents such as aspirin or the blood thinner warfarin. All blood thinners carry a risk for internal bleeding, which can be serious. Thus, patients on warfarin must be monitored on a regular basis.
In 2010, a new anti-coagulant, Pradaxa, was approved for the prevention of blood clots in atrial fibrillation patients with hopes that it would carry a lower risk for bleeding. However studies have shown that not to be the case. In some ways, Pradaxa is more dangerous because unlike warfarin, there is no antidote for Pradaxa. Once the bleeding starts, doctors are sometimes unable to stop it.
This bleeding risk can be too great for some populations of patients with atrial fibrillation, which makes the procedure identified by Bluhm scientists an attractive option.
“Traditionally, surgery was required to close off the LAA,” says Dr. Brad Knight, medical director of the Center for Heart Rhythm Disorders at Bluhm. “Now we have the ability to safely and permanently close it using a minimally invasive, non-surgical approach.”
Scientists say the new procedure has the ability to revolutionize stroke prevention in atrial fibrillation patients without the complications involved with blood thinners.