iRhythm Launches Zio® Long-Term Continuous Monitoring Service in Japan as the Zio® ECG Recording and Analysis System, Advancing AI-Powered Arrhythmia Detection

iRhythm Zio^® Long-Term Continuous Monitoring (LTCM) system — commercially introduced in Japan as the Zio^® ECG Recording and Analysis System — brings AI-powered, continuous, uninterrupted ECG monitoring for up to 14 days to Japan
Launch is timely amid a growing demand for early, accurate detection of arrhythmias in Japan, the second largest ambulatory cardiac monitoring market in the world, where the prevalence is expected to rise alongside an aging population^1-3

SAN FRANCISCO, May 01, 2025 (GLOBE NEWSWIRE) — iRhythm Technologies, Inc. (NASDAQ:IRTC) today announced the commercial launch in Japan of its Zio^® long-term continuous ECG monitoring (LTCM) system, commercially introduced in this market as the Zio^® ECG Recording and Analysis System. The system provides up to 14 days of continuous, uninterrupted ECG monitoring and leverages a deep-learned artificial intelligence (AI) algorithm approved by Japan’s Pharmaceuticals and Medical Devices Agency (PMDA) – and represents a significant advancement over other ambulatory cardiac monitoring options in Japan, including commonly used wired Holter monitors, which capture only 24 to 48 hours of data and other patch-based services that monitor only up to 7 days.

“We are honored to introduce our AI-powered Zio ECG Recording and Analysis System that provides up to 14 days of continuous, uninterrupted cardiac monitoring to Japan, where we see a meaningful opportunity to help advance arrhythmia detection,” said Quentin Blackford, President and Chief Executive Officer of iRhythm. “Together with our trusted distribution partner, Senko Medical Instrument, we are committed to expanding access to advanced cardiac monitoring that supports clinical excellence and aligns with Japan’s dedication to high-quality, patient-centered care.”

Advancing Arrhythmia Detection in Japan

The Zio ECG Recording and Analysis System consists of a prescription-only, patch-based ECG monitoring device (Zio monitor, iRhythm’s latest-generation ECG patch), worn for up to 14 days, and the ZEUS (Zio ECG Utilization Software) system.

The unique attributes of the Zio ECG Recording and Analysis System offer meaningful advantages for patients and clinicians:

Zio monitor (Patch ECG Device): Improving Patient Monitoring Experience

The latest-generation patch ECG is thinner, lighter, and smaller—designed for comfortable, discreet wear, ease of use,⁴ and patient satisfaction^5,6
Enables up to 14 days of continuous, uninterrupted ECG monitoring
Demonstrates 99% patient compliance with prescribed wear time⁶^-8 and 99% analyzable data, delivering high-quality, actionable data^6,10,11

Zio Service (End-to-End Monitoring System): Combining Advanced AI with Human Expertise

PMDA-approved, deep-learned AI algorithm detects 13 arrhythmia types, as well as sinus rhythm and artifact, and is clinically proven to perform at the level of cardiologists^11-14
End-of-wear reports are reviewed and validated by certified cardiographic technicians (CCTs), with 99% physician agreement^6,8
Zio ECG Recording and Analysis System is associated with the highest diagnostic yield and lowest likelihood of retesting compared to other monitoring services, including other LTCMs and 24- to 48-hour duration Holter monitoring services^6,^8,^15-²⁰
In clinical settings, the Zio LTCM service may help reduce misinterpretation of ECG data and improve clinical efficiency¹²

Zio^® monitor by iRhythm Technologies,
part of the Zio^® ECG Recording and Analysis System

“The Zio service represents a new step forward in how we monitor for arrhythmias in Japan,” said Dr. Kohei Yamashiro, Vice President and Director of the Heart Rhythm Center at Takatsuki General Hospital (Osaka Prefecture), the first hospital in Japan to introduce the Zio ECG Recording and Analysis System. “Its ease of use, extended monitoring period, and clear reporting provide important benefits for both patients and clinicians.”

Clinically Proven Performance

The clinical value of the Zio LTCM service has been demonstrated in a robust, growing body of clinical evidence. The Cardiac Ambulatory Monitor EvaLuation of Outcomes and Time to Events (CAMELOT) study, published in the American Heart Journal, found that Zio LTCM service was associated with the highest yield of specified arrhythmia diagnosis and the lowest likelihood of repeat testing compared to all other monitoring services.

iRhythm’s comprehensive clinical evidence, encompassing more than 125 original research manuscripts²¹ and insights derived from over 2 billion hours of curated heartbeat data⁹ and more than 10 million patient reports posted since the company’s inception, underscore the company’s ongoing commitment to expanding evidence that supports improved patient outcomes.

“The Zio long-term continuous monitoring service offers a clinically validated approach to arrhythmia detection by combining advanced AI with expert clinical review to support accurate and timely diagnoses,” said Dr. Mintu Turakhia, iRhythm Chief Medical Officer, Chief Scientific Officer, and EVP of Product Innovation. “As the need for effective long-term monitoring grows, we believe the introduction of Zio LTCM in Japan presents an opportunity to enhance patient care and support evolving clinical needs in cardiac monitoring—an impact also recognized by the Japanese Heart Rhythm Society.”

Cardiac Arrhythmias and Prevalence in Japan

A cardiac arrhythmia is a condition in which the heart beats too quickly, too slowly, or irregularly due to abnormal electrical impulses. If undetected and untreated, some arrhythmias can damage the heart, brain, or other organs and lead to an increased risk of stroke and death.^22-24

These potential complications make accurate, timely arrhythmia detection and diagnosis critical to improving patient outcomes and quality of life.

The prevalence of cardiac arrhythmias continues to rise globally, and Japan is the second largest ambulatory cardiac monitoring market in the world with an estimated 1.6 million tests prescribed annually. This number is expected to continue to increase based on stroke and cardiovascular disease burden in Japan’s aging population.^1-3

Availability in Japan
Zio^® ECG Recording and Analysis System will be available to healthcare customers beginning May 2025, with nationwide availability anticipated by July 2025, through Senko Medical Instrument, iRhythm’s exclusive distribution partner in Japan.

Outside of Japan, iRhythm offers its Zio^® portfolio of cardiac monitoring solutions in Austria, the Netherlands, Spain, Switzerland, the United States, and the UK – and remains dedicated to bringing access to its advanced cardiac monitoring to even more patients, clinicians and healthcare systems around the world.

About iRhythm Technologies, Inc.
iRhythm is a leading digital health care company that creates trusted solutions that detect, predict, and prevent disease. Combining wearable biosensors and cloud-based data analytics with powerful proprietary algorithms, iRhythm distills data from millions of heartbeats into clinically actionable information. Through a relentless focus on patient care, iRhythm’s vision is to deliver better data, better insights, and better health for all. To learn more about iRhythm and the Zio^® LTCM service in Japan, please visit irhythmtech.com/jp/ja. For additional information about iRhythm, please visit its corporate website at i rhythmtech.com.

Forward-Looking Statements
This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, and the Private Securities Litigation Reform Act of 1995. An investor can identify these statements by the fact that they do not relate strictly to historical or current facts. They use words such as ‘anticipate’, ‘estimate’, ‘expect’, ‘intend’, ‘will’, ‘project’, ‘plan’, ‘believe’, ‘target’ and other words and terms of similar meaning in connection with any discussion of future actions or operating or financial performance. In particular, these include statements regarding the Japanese market opportunity, our ability to penetrate the Japanese market, and expansion of patient access to our products and services in Japan. Such statements are based on current assumptions that involve risks and uncertainties that could cause actual outcomes and results to differ materially. These risks and uncertainties, many of which are beyond our control, include risks described in the section entitled “Risk Factors” and elsewhere in our filings made with the Securities and Exchange Commission, including those on the Form 10-Q expected to be filed on or about May 1, 2025. These forward-looking statements speak only as of the date hereof and should not be unduly relied upon. iRhythm disclaims any obligation to update these forward-looking statements.

Media Contact
Kassandra Perry
irhythm@highwirepr.com

Investor Contact
Stephanie Zhadkevich
investors@irhythmtech.com

—-
Footnotes

Irie S, Tada H. The Relationship between Holter Electrocardiography and Atrial Fibrillation Diagnosis Using Real-World Data in Japan. Int Heart J. 2023;64(2):178-187.
Matsuda S. Health Policy in Japan – Current Situation and Future Challenges. JMA Journal, 2019.
Annual Pharmaceutical Production Statistics, Ministry of Health, Labour, and Welfare (“MHLW”).
Data on file. iRhythm Technologies, 2023.
Zio monitor Instructions for Use. iRhythm Technologies, 2023.
Based on US data.
Data on file. iRhythm Technologies, 2022.
Zio service provides continuous, uninterrupted recording and a comprehensive end-of-wear report.
Data on file. iRhythm Technologies, 2024.
Analyzable time is based off median values for a 14-day prescription
Data on file. iRhythm Technologies, 2020.
Hannun et al. Cardiologist-level arrhythmia detection and classification in ambulatory electrocardiograms using a deep neural network. Nat Med. 2019;25:65-69. https://doi.org/10.1038/s41591-018-0268-3
Deep learned algorithm is only available in the United States, European Union, Switzerland, United Kingdom, and Japan.
FDA 510K clearance, CE mark, UKCA mark, and PMDA-approval.
Reynolds et al. Comparative effectiveness and healthcare utilization for ambulatory cardiac monitoring strategies in Medicare beneficiaries. Am Heart J. 2024;269:25–34. https://doi.org/10.1016/j.ahj.2023.12.002
Diagnostic yield was assessed based upon the evaluation of specified arrhythmias, which refer to an arrhythmia encounter diagnosis as per Hierarchical Condition Categories (HCC) 96.
Based on previous generation Zio XT device data. Zio monitor utilizes the same operating principles and ECG algorithm. Additional data on file.
Zio LTCM service refers to Zio XT and Zio monitor service.
Contraindications: Do not use the Zio monitor for critical care patients or for patients with symptomatic episodes where instance variations in cardiac performance could result in immediate danger to the patients or when real-time or in-patient monitoring should be prescribed. (Refer to the Zio monitor Instructions for Use for the full list of contraindications)
Zio monitor and ZEUS are Japan PMDA approved.
Data on file. iRhythm Technologies, 2025.
Ataklte et al. Meta-analysis of ventricular premature complexes and their relation to cardiac mortality in general populations. The American Journal of Cardiology. 2013;112(8):1263-1270. doi:10.1016/j.amjcard.2013.05.065
Lin et al. Long-term outcome of non-sustained ventricular tachycardia in structurally normal hearts. PLOS ONE. 2016;11(8). doi:10.1371/journal.pone.0160181
Wolf et al. Atrial fibrillation as an independent risk factor for stroke: The Framingham Study. Stroke. 1991;22(8):983-988. doi:10.1161/01.str.22.8.983