Study Results Show Zio by iRhythm Improves Detection of Asymptomatic Atrial Fibrillation in At-Risk Population

Posted by iRhythm Technologies on Jul 10, 2018 8:37:05 AM
iRhythm Technologies
Results of first of its kind clinical study published in JAMA

SAN FRANCISCO, July 10, 2018 (GLOBE NEWSWIRE) -- iRhythm Technologies, Inc. (NASDAQ:IRTC), a leading digital health care solutions company focused on the advancement of cardiac care, today announced that results of the mHealth Screening to Prevent Strokes (mSToPS) study, which showed increased detection of asymptomatic atrial fibrillation (AF) in high-risk individuals using Zio by iRhythm, have been published in the Journal of the American Medical Association (JAMA).

Utilizing an innovative home-based study design, electrocardiogram (ECG) recording and analysis were carried out using the FDA-cleared Zio by iRhythm ambulatory continuous monitoring patch to evaluate detection of asymptomatic AF, also known as silent AF. At one-year, primary results showed that AF was newly diagnosed in 6.7 percent of patients who were actively monitored by the Zio service versus 2.6 percent in the observational control group receiving routine care. In addition, 4.0 percent of patients in the Zio monitored group were found to have potentially actionable arrhythmias other than AF including ventricular tachycardia, pause, AV block, and symptomatic supraventricular tachycardia.

Researchers at the Scripps Translational Science Institute (STSI) conducted the study in partnership with collaborators, Aetna and Janssen Pharmaceuticals.

Our study shows an almost threefold improvement in the rate of diagnosis of AF in those actively monitored compared to usual care, said Steven Steinhubl, MD, director of digital medicine at STSI and an associate professor at The Scripps Research Institute (TSRI). Diagnosing AF more effectively can enable the initiation of effective therapies and help reduce strokes and death.

Monitoring with Zio led to significant change in clinical treatment of the actively monitored group including initiation of anticoagulation therapies (5.7 percent), antiarrhythmic medications (0.8 percent), and pacemaker placement (0.8 percent). Patients receiving anticoagulation for AF appeared to fulfill current clinical guidelines for appropriateness and need. Mean wear time for the Zio patch was 12 days with 98 percent analyzable ECG data.

Studies like mSToPS play a significant role in defining at-risk patient populations that can benefit from extended continuous cardiac monitoring, ultimately resulting in more accurate and efficient AF diagnoses, said Judy Lenane, RN, MHA, executive vice president of operations and chief clinical officer of iRhythm. Publication of the mSToPS study in JAMA further reinforces the important role Zio by iRhythm plays in the advancement of cardiovascular research, while having a practical, real-world impact on patient outcomes.

The study involved 5214 eligible Aetna members who were identified through claims data to have risk factors for AF but had not been previously diagnosed. One-third of individuals were enrolled via a web-based platform to undergo either immediate or delayed active ECG monitoring at home for up to 4 weeks with a Zio XT patch monitor (two-week monitoring periods spaced four months apart). Each monitored participant was matched with two non-monitored participants with a similar CHA2DS2-VASc, a standardized stroke-risk assessment score, to act as controls. The study looked at time to first diagnosis of AF and its clinical consequences for the active monitoring cohort as well as the cohort undergoing usual care.

Utilizing the digital Zio monitoring service by iRhythm enabled the team to approach a large, geographically diverse population of at-risk individuals and include people who otherwise may have no access to participation in clinical trials because they do not live close to a research center.

This study demonstrates the utility of a digital approach not only to diagnosing asymptomatic AF, but to the clinical research field as a whole, said Steinhubl. We hope that it will set a precedent for future real-world, participant-centric clinical trials that leverage the power of digital medicine technologies.

STSI’s founder and director Eric Topol, MD, also a TSRI professor, added that, For clinical research to change practice it needs to be more participant focused and reflect the real world of those participants, by taking advantage of digital tools and infrastructure that is possible as never before, says Topol.

About Atrial Fibrillation

Atrial fibrillation (AF or AFib) is a quivering or irregular heartbeat, also known as an arrhythmia, which can lead to blood clots, stroke, heart failure and other heart-related complications.

Normally, your heart contracts and relaxes to a regular beat. In AF, the upper chambers of the heart (the atria) beat irregularly instead of beating effectively to move blood into the ventricles.

AF is associated with a five-fold increase in the risk of stroke, with these strokes tending to be more severe and associated with higher mortality.1 However, approximately one-third of those who have AF are not aware that they have it.2 Asymptomatic AF is referred to as being silent and there are certain risk factors like high blood pressure, diabetes and sleep apnea that increase an individual’s likelihood for developing it.

You can learn more about the study and silent AF at

About iRhythm Technologies, Inc.
iRhythm is a leading digital health care company redefining the way cardiac arrhythmias are clinically diagnosed. The company combines wearable biosensor devices worn for up to 14 days and cloud-based data analytics with powerful proprietary algorithms that distill data from millions of heartbeats into clinically actionable information. The company believes improvements in arrhythmia detection and characterization have the potential to change clinical management of patients.

1Circulation. 2017;135:00–00. DOI: 10.1161/CIR.0000000000000485. Heart Disease and Stroke Statistics—2017 Update.
2Friberg L, Rosenqvist M, Lindgren A, Terént A, Norrving B, Asplund K. High prevalence of atrial fibrillation among patients with ischemic stroke. Stroke 2014;45:2599-605.

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