A self-applied electrocardiogram (ECG) chest patch markedly improves the rate of atrial fibrillation (AFib) diagnosis compared with routine care, according to results of the mSToPS trial presented by Steven R. Steinhubl, MD, on Saturday, March 10 at ACC.18 in Orlando, FL.

mSToPS was a digital screening study to detect AFib in higher risk participants to facilitate more timely stroke prevention treatment. A total of 1,732 Aetna members were enrolled directly through a web-based platform to undergo active monitoring at home with an iRhythm Zio patch, which continuously records an ECG. They were provided instructions for applying the patch and wore it for an average of 12 days. The participants did not have known AFib but were at moderate risk. Each case was paired with two age-, sex-, and CHA₂DS₂-VASc-matched controls (n=3,646). Data on AFib treatment, physician and emergency department (ED) visits, and blood clot and stroke events were collected.

The incidence of AFib at one year – the primary endpoint – was 6.3 percent of monitored patients and 2.3 percent of controls. Active monitoring led to a significantly higher rate of initiating anticoagulant therapy (5.4 vs. 3.4 percent in controls), as well as small but significant increase in antiarrhythmic therapy (0.8 vs. 0.3 percent) and pacemaker or implantable cardioverter-defibrillator placement (0.7 vs. 0 percent).

No difference in the stroke rate between the two groups was observed at the time of the analysis (1.9 vs. 2.1 percent). The monitored patients compared with controls had significantly more primary care visits (78.7 vs. 75 percent) and cardiology outpatient visits (31.6 vs. 23.6 percent), but there was no difference in ED visits or hospitalizations. Study participants will be followed for an additional two years.

The researchers concluded that remote AFib monitoring is a feasible, scalable and clinically valuable way to screen for AFib in an at-risk nationwide population. “The quality of data collected through the patch is as good as what we see clinically,” Steinhubl said. “What was fascinating is that for the people with AFib, the burden of AFib was quite low—approximately 1 percent of the time on average.”

Keywords: ACC18, ACC Annual Scientific Session, Arrhythmias, Cardiac, Atrial Fibrillation, Anticoagulants, Incidence, Stroke, Morbidity

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