Wearable ECG Patches Can Detect AF in Asymptomatic Patients: Presented at ACC

By Alex Morrisson

ORLANDO, Florida -- March 14, 2018 -- Screening of asymptomatic individuals for atrial fibrillation (AF) using a variety of technologies may result in prescriptions for anti-coagulation, according to results of the mHealth Screening to Prevent Strokes (mSTOPS) intent-to-treat analysis presented at the 2018 Annual Meeting of the American College of Cardiology (ACC).

After 4 months, 5.1% patients wearing a telemetry patch on their chest were diagnosed with AF compared with 0.60% of control subjects, translating to a 9-fold increase in diagnoses (P < .0001), reported lead author Steven Steinhubl, MD, Scripps Translational Science Institute, La Jolla, California, speaking at an his oral presentation here on March 10. The study defined a diagnosis of AF as more than 30 consecutive seconds of AF recorded by a wearable electrocardiogram (ECG) device or a new diagnosis of AF through claims data.

The goal of the mSTOPS trial was to determine whether the use of the Internet and smartphones would drive individuals to participate in a clinical trial that could test whether screening for AF might be of clinical utility.

The researchers invited 53,553 Aetna clients to participate in the study, and followed up the email with a direct mailing to 50,000 of these individuals. In all, 2,655 of these individuals consented to participate, and eligibility was confirmed. The researchers randomly assigned 1,364 patients to immediate monitoring, and 1,291 individuals to delayed monitoring; however, 456 patients and 457 patients in the immediate- and delayed-monitoring groups, respectively, never wore the patch.

The remaining 906 individuals (average 73 years; 62% male) were actively monitored immediately; later, 834 patients in the delayed-monitoring group also wore monitors.

The primary endpoint was a new diagnosis of AF after 4 months of wearing an ECG patch.

After 1 year, 6.3% of the actively monitored patients had been diagnosed with AF compared with 2.3% of an observational matched-control cohort of 3,476 patients (adjusted odds ratio 3.0; 95% confidence interval: 2.2 to 4.0; P < .0001).

During the study, the average patient wore the patch for 11 days. On average, the first episode of AF was recorded after 2 days passed. The median duration of the longest AF episode in each patient with arrhythmia was 185.5 minutes.

Almost 10% of patients with AF experienced episodes that lasted more than 24 hours, Dr. Steinhubl noted.

About 5.4% of the actively managed group went to a pharmacist with a prescription for an anticoagulant. Of the control subjects, 3.4% were provided a prescription for an anti-coagulant (P = .0004).

“Through remote digital enrollment and use of participant-generated data, we observed a markedly improved rate of atrial fibrillation diagnosis relative to routine care: 9-fold in the short term, and 3-fold in the long term,” Dr. Steinhubl concluded. “Monitoring was associated with greater initiation of guideline-recommended therapies, but also increased utilisation at 1 year.”

“Adults over age 55 [years of age] have a 37% lifetime risk of developing atrial fibrillation, which is associated with a 5-fold risk of stroke, but, once recognised, anti-coagulation can reduce the risk of stroke by around 65% and reduce stroke-related mortality by 30%,” Dr. Steinhubl noted in discussing the need to identify patients who might have undiagnosed AF.

Patients were excluded from this study who had already been diagnosed with heart-rhythm abnormalities or were on anti-coagulation, although many of the subjects had previous cardiovascular events or risk factors such as diabetes or sleep apnoea.

[Presentation title: A Digital End-to-End, Nationwide, Pragmatic Trial of Screening for Undiagnosed Atrial Fibrillation Within a Health Insurance System Using a Self-Applied ECG Patch: Primary Results of the mHealth Screening to Prevent Strokes (mSToPS) Trial. Abstract LB-402-19]

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