Though they might provide some benefit to high-risk patients in the month after a heart attack, wearable cardioverter-defibrillators don’t significantly lower the rate of arrhythmic death in those who have suffered myocardial infarctions, according to work published in the New England Journal of Medicine Sept. 27.
The VEST trial, led by Jeffrey E. Olgin, MD, and funded by the National Institutes of Health and Zoll Medical, found that, despite the high rate of sudden death among patients who have recently experienced MI, wearable trackers might not be the most effective or appealing option for therapy. They’re among the only options out there, though, since implantable cardioverter-defibrillators (ICDs) are contraindicated in MI patients with a low ejection fraction until 40 to 90 days after their heart attack.
“This paradox of increased risk of sudden cardiac death but lack of benefit with an ICD early after myocardial infarction has prompted interest in identifying a noninvasive intervention that could benefit this population of patients,” Michael E. Field, MD, and Richard L. Page, MD, wrote in an editorial linked to Olgin et al.’s study. The physicians hail from the Medical University of South Carolina and University of Wisconsin School of Medicine and Public Health, respectively.
Olgin and colleagues tested the utility of their wearable defibrillator—a device akin to a regular vest—in a population of 2,302 heart patients. Participants with acute MI and an ejection fraction of 35 percent or less were randomly assigned 2:1 to receive either a wearable cardioverter-defibrillator and guideline-directed therapy, or guideline-directed therapy on its own.
Patients wore the vest for an average of 18 hours a day, the authors reported, though wear time was bimodal. While patients who were consistently using the device wore it for more than 20 hours every day, those who used it less hardly wore it at all. According to the researchers’ data, the percentage of patients who wore the vest on any given day fell from 81 percent just after randomization to 41 percent at 90 days.
Olgin and co-authors said death rates were improved in the device group, with arrhythmic death and all-cause death occurring in 1.6 percent and 3.1 percent of patients in the wearable defibrillator group and 2.4 percent and 4.9 percent of patients in the control group, respectively. Of the 48 patients in the device group who died, 12 were wearing the vest when they passed.
Seventy-two percent of patients randomized to wear the defibrillator experienced an arrhythmia alarm, and just 1.3 percent received an appropriate shock. In their editorial, Field and Page said frequent device alarms were cited as a reason patients didn’t like wearing the defibrillator, alongside skin irritation, itching and emotional distress.
Ultimately, the numbers weren’t significant enough to indicate an immediate need for the wearable cardioverter-defibrillator, the pair said—which is why they think VEST is a trial “that is unlikely to ever be repeated.”
“Should the wearable cardioverter-defibrillator ever be provided to patients after myocardial infarction while they are waiting for reassessment of ejection fraction and eligibility for guideline-based placement of an ICD for primary prevention?” Field and Page wrote. “We would advocate for a thorough discussion with the patient that both acknowledges the limitations of the available evidence and provides an understanding of the potential harms, such as frequent device alarms and potential for inappropriate shocks.”
After graduating from Indiana University-Bloomington with a bachelor’s in journalism, Anicka joined TriMed’s Chicago team in 2017 covering cardiology. Close to her heart is long-form journalism, Pilot G-2 pens, dark chocolate and her dog Harper Lee.