Another Minimally Invasive Stroke Prevention Option for Atrial Fibrillation Patients Who Can’t Use Blood Thinners
The University of Maryland Comprehensive Heart Center has expanded the stroke prevention options for patients with a heart rhythm disorder called atrial fibrillation (AF), who face the risk of stroke because they cannot use anticoagulation therapy, the primary stroke reduction treatment that works by thinning blood to slow clotting. About 15 percent of all people who have strokes have AF, according to the National Stroke Association.
Heart Center surgeons are now using a minimally invasive approach to implant a clip that closes off a section of the heart, called the left atrial appendage, where blood stagnates in AF patients. Stagnant or pooling blood can form clots, which can travel to the brain and cause the most common type of stroke. The clip expands the Heart Center’s personalized approach to patient treatment, providing another way to match a patient’s individual medical needs with specific therapies. Other Heart Center options to close the appendage and prevent stroke include a device called LARIAT.
“The rationale behind anticoagulation therapy in atrial fibrillation patients is that if the blood is thinned enough, you minimize the chances of clot formation,” says Murtaza Dawood, MD, instructor of surgery at the University of Maryland School of Medicine and a cardiac surgeon at the University of Maryland Comprehensive Heart Center. “The rationale for excluding the left atrial appendage is that if you remove the appendage, the site where blood can potentially form clots, then that’s another way to reduce the stroke risk without having to thin the blood. As it happens, the appendage is a remnant of the developing heart and does not contribute to cardiac function.”
In AF patients, electrical signals, which control how the heart beats to pump blood, are rapid and disorganized, causing the heart’s two upper chambers, the atria, to contract very fast and irregularly. In the normal heart, blood is pumped completely from the atria to the heart’s lower chambers, the ventricles. By contrast, when the heart begins to quiver in atrial fibrillation, blood flow can slow down or pool in the left atrial appendage.
The stroke risk weighs heavily on a woman who has coped with atrial fibrillation for many years, Lucille Jones, of St. Michaels, Md. Despite AF, she raised three children and says she has always been extremely active. Now in her eighties, her AF raises new concerns. “With age, atrial fibrillation puts more strain on the heart. My doctors said I would have to worry about the risk of stroke, so they put me on anticoagulation,” she says.
The problem for Ms. Jones is that anticoagulation therapy has not worked well. No matter which anticoagulant her community doctors prescribed, each produced an unwelcome side effect: bleeding. She’s been hospitalized numerous times to stop the bleeding. It stopped only when anticoagulation was stopped, but as soon as the therapy resumed, so did the bleeding. “When they stopped the anticoagulants, I didn’t have to worry about the bleeding, but it added an extra problem. It didn’t alleviate my concern about stroke.”
Ms. Jones says she read about LARIAT, a catheter-based procedure available at the University of Maryland Comprehensive Heart Center, which uses a lasso-like device to close off the left atrial appendage. “LARIAT looked perfect for me,” says Ms. Jones. “It was the answer I was looking for.”
But it turns out LARIAT was not the right answer for Ms. Jones. Dr. Dawood says because she had had numerous abdominal surgeries, Ms. Jones was not a good candidate for LARIAT. Further, he says, an anticoagulant must be given to the patient during the LARIAT procedure. For Ms. Jones, this could have raised her chance of bleeding, a risk her doctors wanted to avoid.
Instead, Dr. Dawood proposed another option, the clip-based procedure that she ultimately chose. “They showed me a video and I thought it was fantastic to see this done,” says Ms. Jones.
Previously, the clip had been applied during a traditional chest-splitting open-heart procedure when surgeons were treating another heart problem. However, says Dr. Dawood, “For isolated left atrial appendage management, we can do this through a minimally invasive approach…a left video-assisted thoracoscopic surgery.” In an operation that takes less than an hour, the clip is deployed over the left atrial appendage using instruments and a camera placed through tiny openings in the chest. The clip, which remains in place permanently, closes the appendage so blood cannot enter and form clots.
“This device has been in use for about five years,” says Dr. Dawood. “Researchers who looked inside hearts with implanted clips found that what was once the opening to the appendage had become a smooth surface. Blood flow does not slow down. Outside, you see the clip and the atrophied part of the appendage.”
“Everything is good,” says Ms. Jones, who had her surgery in early May. Her worries about stroke are reduced. Best of all, she’ll never have to take anticoagulants.
This page was last updated: August 19, 2014