NMMC in AFib Study: Blood Thinner vs. Device
Cardiac electrophysiologist Jim Stone, M.D., and his partners are participating in a clinical trial at NMMC comparing treatment options for atrial fibrillation.
TUPELO, Mississippi—Cardiac electrophysiologists with North Mississippi Medical Center are participating in a clinical trial that compares the WATCHMAN FLX™ device to blood thinner medication for preventing stroke in people who have atrial fibrillation (AFib).
AFib is a heart condition in which the upper chambers of the heart quiver. This condition can cause blood clots to form in an area of the heart called the left atrial appendage. “The left atrial appendage is like a little windsock which projects off the side of the left atrium,” explains NMMC cardiac electrophysiologist Jim Stone, M.D. “As long as your heart is in normal rhythm, that windsock contracts and pumps blood in and out. But when you go into atrial fibrillation, that windsock stops pumping. The blood inside the appendage pools, and when it does, it forms a clot. If the clot breaks loose, it can travel through an artery to the brain and cause a stroke.”
People with AFib have a five times greater risk of stroke than people with normal heart rhythm. “There are two ways to prevent stroke—blood thinner and the WATCHMAN device,” Dr. Stone says. “With the WATCHMAN device, we basically plug off the entrance to that appendage so that blood can’t get in there to clot. It's a plug, and after a period of time, the body covers over it with tissue, so it's like that appendage was never even there.”
Dr. Stone says NMMC was involved in the early research for the original WATCHMAN device dating back to 2011. “NMMC was instrumental in bringing forth a revolutionary therapy for stroke prevention in atrial fibrillation,” he says. Over the years, technology has improved and resulted in a newer generation of the device, called the WATCHMAN FLX™.
While the new device is approved by the U.S. Food and Drug Administration, guidelines require doctors to treat the patient initially with blood thinners. “The problem with blood thinners is that they thin the blood throughout the entire body when what we want to do is target a specific area in the heart, so there's a lot of unnecessary risk in using blood thinners to prevent stroke,” Dr. Stone says. “But the way the guidelines are now, we have to start there. The problem with that is that we almost have to demonstrate a problem with blood thinner before we can consider a WATCHMAN device.”
NMMC’s cardiac electrophysiologists have implanted more than 400 WATCHMAN devices over the years with outstanding results. The procedure takes about 20 to 30 minutes and the individual is monitored for several hours before going home the same day. “It's very comparable to blood thinner without the bleeding risk,” Dr. Stone says. “The question is, are we starting with the wrong therapy?”
This is precisely the question the CHAMPION-AF clinical trial aims to answer. “We're very fortunate that Boston Scientific has asked us to participate in this trial along with a lot of large centers in the United States—centers like Mayo Clinic, Cleveland Clinic and Vanderbilt,” Dr. Stone says.
People who participate in the study will be “randomized” into either the “device” or “control” group. “A computer program will randomly decide whether or not you remain on blood thinner—the control group--or you get a WATCHMAN FLX device implanted,” Dr. Stone explains. “You have to do it that way to determine benefit. After we enroll enough people to determine our endpoints, we'll analyze the data and decide if this new novel technology is going to be a first line therapy as opposed to second line.”
The CHAMPION-AF clinical trial is being overseen locally by NMMC’s Institutional Review Board. Individuals considered eligible for the study must be willing to take one of the following blood thinning medications: Pradaxa (dabigatran), Xarelto (rivaroxaban) or Eliquis (apixaban). For more information speak with your primary care provider or cardiologist, or call the research nurse at (662) 620-6875.