Wearable ECG patch helps detect AF
A home-based, self-applied wearable electrocardiogram (ECG) patch facilitates the diagnosis of atrial fibrillation (AF) among high-risk individuals, according to the mSToPS* trial.
“When identified clinically, AF increases the risk of stroke fivefold and accounts for almost one-third of all strokes,” the researchers stated. “Early identification could allow for the initiation of appropriate therapies to prevent the adverse health outcomes associated with AF.”
The mSToPS trial with a pragmatic design comprised two components: a randomized clinical trial and a prospective observational cohort study. The clinical trial phase randomized 2,659 individuals (mean age 72.4 years, 38.6 percent women) identified from a health insurance database to receive active home-based immediate monitoring (n=1,364) or delayed monitoring (start after 4 months; n=1,291) using a wearable ECG patch for up to 4 weeks. [JAMA 2018;320:146-155]
Within 4 months after randomization, the primary outcome of incident AF was identified in more individuals assigned to active monitoring compared with delayed monitoring (3.9 percent vs 0.9 percent; absolute difference, 3.0 percent, 95 percent confidence interval [CI], 1.8–4.1).
In the observational study, 1,738 participants from randomized trial who completed active monitoring were matched to 3,476 unmonitored controls based on age, sex, and CHA2DS2-VASc score. Similar to the randomized trial, the incidence rate of newly-diagnosed AF was higher in actively monitored participants than unmonitored controls at 1 year (6.7 vs 2.6 per 100 person-years; difference, 4.1, 95 percent CI, 3.9–4.2).
“There was no difference in the clinical characteristics of those individuals diagnosed by ECG patch as those diagnosed clinically, with age and heart failure most strongly associated with a new AF diagnosis,” observed the researchers.
In addition, more actively monitored individuals initiated anticoagulant therapy both in general (5.7 vs 3.7 per person-years) and specifically for AF (2.4 vs 1.3 per 100 person-years) at 1 year. Active monitoring was also associated with a greater utilization of healthcare resource in terms of outpatient cardiology visits (33.5 vs 26.0 per 100 person-years) and primary care visits (83.5 vs 82.6 per 100 person-years).
No difference was seen for emergency department visits or hospitalizations related to AF (1.3 vs 1.4 per 100 person-years).
“Future screening programmes will benefit from being able to target those at highest risk for undiagnosed AF,” the researchers suggested.
However, two key questions should be considered before the findings were incorporated into clinical practice with regard to AF screening, raised Drs Benjamin Steinberg and Jonathan Piccini from Utah Health Sciences Center in Salt Lake City, Utah and Duke University Medical Center in Durham, North Carolina, US, respectively in an editorial. “[First,] does earlier or more sensitive detection of AF improve clinical outcomes? And if so, is it cost-effective?” [JAMA 2018;320:139-141]
While favourable outcomes have been demonstrated for symptomatic patients with intermittent AF, the editorialists noted that “the net clinical benefit of stroke prevention for patients with lower-burden … or subclinical AF is more complicated.”
“While existing epidemiologic and outcomes data support interventions for risk factors and symptoms of AF early in the disease process, clinical trials demonstrating improvement in cardiovascular outcomes, such as reduced occurrence of stroke, will be necessary to take action and screen for AF at the population level,” wrote Steinberg and Piccini.
According to the researchers, clinical outcome data will be reported after the completion of the planned 3-year follow-up.