Wearable defibrillators could be lifesaving for heart attack patients waiting for permanent devices, based on a study presented recently at the American College of Cardiology’s 67th Annual Scientific Session.
Wearable cardioverter defibrillators are devices that can be worn under the clothes to detect and correct abnormal heart rhythms. They’re typically used to prevent life-threatening heart events in patients waiting for a long-term treatment plan.
While wearable defibrillators can be used in patients with a variety of conditions, the recent study tested their benefits in heart attack survivors. All participants had recently suffered a heart attack and had reduced heart function (reduced left ventricular ejection fraction), putting them at increased risk for sudden cardiac arrest.
Sudden cardiac arrest occurs when the heart suddenly stops beating. It requires immediate medical attention and usually causes death if it’s not treated immediately.
The study included a total of 2,302 heart attack patients from four different countries. Two-thirds of participants were randomly assigned to receive a wearable defibrillator in the three months after their heart attack, in addition to standard therapy, such as medication and lifestyle changes. The rest of participants were assigned to standard therapy alone to serve as a control group.
When comparing outcomes after three months, researchers did not find a significant difference in the occurrence of sudden cardiac death between either group. However, there were significantly fewer strokes and deaths in patients with wearable devices than those standard therapy alone. Researchers also note that participants with wearable devices had significantly less shortness of breath, which is a common symptom of reduced heart function.
"This study found that the device was associated with fewer deaths among people recovering from a heart attack with low ejection fraction," explains lead author and the principal investigator of the study, Jeffrey Olgin, MD. "It's also the first therapy associated with a mortality benefit above and beyond standard medical therapy immediately after heart attack."
As a result, authors concluded that prescribing wearable defibrillators is reasonable to help protect high-risk patients after a heart attack. Wearable devices could be useful in the few months after a heart attack, while patients are waiting to be evaluated for implantable devices.
However, authors note that 19% of patients receiving the wearable defibrillator never actually wore the device. This number was higher than expected and highlights the need to improve adherence among patients prescribed wearable cardioverter defibrillators.