by Matt Batcheldor
Vanderbilt University Medical Center is participating in a trial for a device that could revolutionize the way patients are treated for atrial fibrillation (AF or AFib.)
The CATALYST trial is examining a stroke protection option called the Amulet, a two-part left atrial appendage (LAA) closure device that prevents blood flow into the LAA. This eliminates the need for blood thinners, the usual course of treatment to prevent stroke in AFib. The device, which has not yet been FDA approved, will be evaluated in the trial.
AFib, the most common cardiac arrhythmia, affects more than 5 million Americans. It is a heart condition in which the upper chambers of the heart beat too fast and with irregular rhythm, putting patients at a higher risk for blood clots that cause strokes.
VUMC has participated in several trials for other atrial closure devices over the last decade, but they have been limited to a small subset of the AFib patient population who are deemed a high risk for bleeding or cannot take blood thinners.
What makes this trial different is that it is studying the efficacy of such devices in the general AFib population, said Christopher Ellis, MD, associate professor of Medicine, who implants the devices.
“It would be a paradigm shift if these trials end up showing that if you have AFib, you might as well just get your appendage closed up, that it’s as good or better than taking a blood thinner of any type,” Ellis said.
Tom Dowd of Old Hickory, Tennessee, hopes to be one of those people. He received his Amulet device in January, and if scans in the coming months allow for it, he may be able to drop use of his blood thinner. “That’s what I’d like to do,” he said.
The trial intends to enroll 2,650 people worldwide, said Michael Baker, MD, assistant professor of Medicine and principal investigator for the trial at VUMC. He said the study will help determine the best way of treating AFib — better, more modern blood thinners such as Pradaxa, Eliquis and Xarelto, or closure devices such as the Amulet. Participants will be randomized to receive one or the other treatment.
“This is really one of the first opportunities to now get both of those newer therapies head-to-head to determine if the next-generation blood thinners are better than the left atrial closure devices or not,” Baker said. “I think this is really an exciting trial.”
Vanderbilt’s research team includes Christina McDougall, the primary study coordinator, and Dawn Sabin, RN, the left atrial appendage (LAA) coordinator.
They help guide patients through the trial, educating them on LAA devices before implantation, immediately afterward and long term.
Previous studies in selected groups of patients who have had bleeding complications on older blood thinners like warfarin have shown that closure devices are equivalent in reducing stroke risk with fewer bleeding events, Baker said.
Each method has advantages and disadvantages. The blood thinners, though improved, continue to have issues with bleeding complications and require the vigilance of the patient taking them.
Compliance with therapy is a big problem long term, and interruptions in blood thinner therapy can increase risks for stroke.
The closure devices are a much newer concept, invented within the last decade, and they require an invasive procedure that can present procedural complications.
Ellis, who has been part of several trials for closure devices, agreed the study could help tip the scales toward the devices as the best treatment for reducing stroke related to Afib, particularly as complications from implanting the device are reaching less than 1%.
“To be able to change guidelines to say that the appendage closure option is a first-line therapy for people is a major undertaking,” Ellis said. “You have to have big, multiple randomized trials to change guidelines. And this would be one of those trials.”
Terry Humphres of Vina, Alabama, is another participant in VUMC’s trial. He also looks forward to the prospect of discontinuing blood thinners.
“I feel great,” he said. “For 68 years old, I’m doing great. I couldn’t ask for better care anywhere. The nurses were great, and I don’t think there’s anybody in this country better at what they do than Dr. Ellis.”
