This implant can make a life-saving difference. It’s being tested in Fort Worth
A Fort Worth hospital is participating in an international research study working to better understand how to treat patients who suffer sudden cardiac arrest, a leading cause of death in the U.S.
Texas Health Harris Methodist Hospital Fort Worth is participating in the Enlighten Study, a research study that is observing how extravascular implantable cardioverter defibrillators operate in patients with ventricular arrhythmias, which can cause cardiac arrest.
“The Enlighten study is a real world experience of what happens to patients who get this device,” said Dr. Theodore Takata, a cardiac electrophysiologist and the director of cardiac electrophysiology at Texas Health Fort Worth.
The study involves hundreds of patients, and will follow them for five years.
More than 350,000 out-of-hospital cardiac arrests happen annually in the U.S. and almost all of them — 89% — are fatal, according to data from 2023. That can change if a patient has an implantable cardioverter defibrillator, or ICD, which shocks the heart back to beating normally.
Takata likens having an ICD implanted to having an airbag in a car.
“Most people you know own a vehicle for a decade and never use the airbag,” Takata said. “But we also know that anytime you drive, you’re at risk of having an accident for no fault of your own, and an airbag can be absolutely life saving.”
ICDs work similarly: Most people with them implanted won’t need them, but they can quickly shock a heart back into beating normally during a sudden cardiac arrest. ICDs are implanted in people with ventricular arrhythmias, which can cause sudden cardiac arrest. Ventricular arrhythmias are an abnormal heartbeat that occurs in the lower heart chambers.
ICDs continuously monitor the heart. If a fast, irregular rhythm is recognized, the device corrects it by sending a small electrical signal, according to a news release. If the rhythm remains erratic, the device sends an electric shock, or defibrillation, to the heart.
The problem with traditional ICDs, Takata said, is that, in rare cases, the wires that connect the battery to the heart can get infected. Extravascular ICDs, on the other hand, are implanted outside of the heart and veins, lowering the risk for infection. Extravascular ICDs were first approved by the U.S. Food and Drug Administration in 2023. The Enlighten Study is collecting more information about extravascular ICDs, to help researchers and the public better understand their long-term outcomes.
“What it’s trying to achieve is the same protection that we’ve been able to offer people for 30 years, without the limitations of the current existing defibrillators,” Takata said.
Cardiac arrests are different from heart attacks, although the two are often confused. During a heart attack, blood flow to the heart is blocked, but the heart itself continues to beat. Someone suffering a heart attack can be alert and conscious in the middle of an attack, and will also usually have symptoms, like chest pain. But during a cardiac arrest, the heart stops beating, meaning there is no blood flow to the heart, brain, or other organs. Someone suffering a cardiac arrest will usually collapse suddenly, and stop breathing or moving.
The study is sponsored by Medtronic.
