ORLANDO — A self-applied electrocardiogram (ECG) chest patch improved the rate of atrial fibrillation (Afib) diagnosis versus routine care, researchers said here.
After 4 months in the mSToPS trial, 5.1% patients wearing the patch were diagnosed with Afib, with more than 30 consecutive sessions of Afib recorded by the device, or a new diagnosis of Afib through claims data, compared with 0.60% of controls, reported Steven Steinhubl, MD, of Scripps Translational Science Institute in La Jolla, California, and colleagues.
That translated to a nine-fold increase in diagnoses based on an intent-to-treat analysis (P<0.0001), Steinhubl said in presentation at the American College of Cardiology annual meeting.
Adults age >55 have a 37% lifetime risk of developing Afib, which is associated with a five-fold risk of stroke. Once recognized, anticoagulation therapy can reduce the risk of stroke by around 65%, and reduce stroke-related mortality by 30%, Steinhubl said.
mSToPS (mHealth Screening to Prevent Strokes) was a digital screening study designed to detect Afib in higher risk participants, in an effort to facilitate more timely stroke prevention treatment.
The researchers invited 53,553 Aetna clients to participate, and followed the email invitation with a direct postal mailing to 50,000 of these individuals. Ultimately, 2,655 consented to participate and their eligibility was confirmed. Each case was paired with two age-, sex-, and CHA2DS2-VASc-matched controls. Data on Afib treatment, physician and emergency department visits (ED), and blood clot and stroke events were collected. Patients already diagnosed with heart rhythm abnormalities or were on anticoagulation were ineligible.
The researchers randomly assigned 1,364 patients (ages ≥55) to active monitoring (at home with an iRhythm Zio patch) and 1,291 to delayed monitoring (control).
The participants did not have known Afib but were at moderate risk, and did have diabetes or sleep apnea, among other risk factors. They study-arm group was instructed on how to apply the patch, which they wore for an average of 12 days. The primary endpoint was a new diagnosis of Afib at 1 year.
The incidence of Afib at 1 year was 6.3% of monitored patients and 2.3% of controls. Active monitoring led to a significantly higher rate of initiating anticoagulant therapy (5.4% versus 3.4%) and a small, but significant, increase in antiarrhythmic therapy (0.8% versus 0.3%) and pacemaker or implantable cardioverter-defibrillator placement (0.7% versus 0%).
The median duration of the longest Afib episode in each patient with arrhythmia was 185.5 minutes. Almost 10% of the patients with Afib had experienced episodes that lasted more than 24 hours, Steinhubl said.
The monitored patients had significantly more primary care visits versus controls (78.7% versus 75%) and cardiology outpatient visits (31.6% versus 23.6%). The authors reported no difference in ED visits or hospitalizations.
“Through remote digital enrollment and use of participant-generated data, we observed a markedly improved rate of atrial fibrillation diagnosis nine-fold in the short term, and three-fold in the long term — relative to routine care,” Steinhubl said. “Monitoring was associated with greater initiation of guideline-recommended therapies but also increased utilization at 1 year.”
N.A. Mark Estes, MD, of the New England Cardiac Arrhythmia Center at Tufts University School of Medicine in Boston, called mSToPS “very innovative, and [a] potentially useful approach to screening for atrial fibrillation.”
However, Estes, who was not involved in the study, pointed out that screening programs in this patient population are controversial. “The reason it is controversial is that you have this information, and you don’t know what to do with it. So you find atrial fibrillation in an asymptomatic individual, and it is not clear what you do with that information. Until we know what to do with this data it is difficult to advocate for screening.”
Study participants will be followed for an additional 2 years, according to the investigators.
Steinhubl disclosed relevant relationships with Janssen, Novartis, Qualcomm, Spry Health and DynoSense.
Estes disclosed relevant relationships with Boston Scientific, Medtronic, and Saint Jude Medical.