What changed in this filing

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Item 1. Business

2025-02-20 compared with 2024-02-22 · 155 added, 154 removed, 340 unchanged (48% of the section changed)

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Each Zio System combines an FDA-cleared and CE-marked, wire-free, patch-based, 14-day wearable biosensor that continuously records electrocardiogram (“ECG”) data with a proprietary, FDA-cleared, CE-marked cloud-based data analytic software to help physicians monitor patients and diagnose arrhythmias.

Since receiving FDA clearance, we have provided the Zio Services to over six million patients and have collected over 1.8 billion hours of curated heartbeat data.

Since receiving FDA clearance, we have provided the Zio Services to over eight million patients and have collected over 2 billion hours of curated heartbeat data.

The Company was incorporated in the state of Delaware in September 2006.

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Our common stock is listed on The Nasdaq Global Select Market under the symbol “IRTC”, and we employ approximately 2,000 regular full-time employees as of December 31, 2024.

Our website address is http://www.iRhythmtech.com, and our investor relations website is located at https://www.investors.irhythmtech.com.

Our website address is https://www.irhythmtech.com, and our investor relations website is located at https://investors.irhythmtech.com.

Our Annual Report on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K and amendments to reports filed pursuant to Sections 13(a) and 15(d) of the Exchange Act are available free of charge on our investor relations website as soon as reasonably practicable after we file such material with the SEC.

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Every year, millions of patients experience symptoms potentially associated with cardiac arrhythmias, a condition in which the electrical impulses that coordinate heartbeats do not occur properly, causing the heart to beat too quickly, too slowly, or irregularly.

Early detection of heart rhythm disorders, such as atrial fibrillation (“Afib”) and other clinically relevant arrhythmias, supports appropriate medical intervention and can help avoid more serious downstream medical events, including stroke.

1 As used throughout the text of Items 1 to 7, on Form 10-K, the term “iRhythm,”, “the Company,” “we” or “us,” refers to iRhythm Technologies, Inc., a Delaware corporation, or iRhythm Technologies Inc.

and its consolidated subsidiaries, as the context requires.

As of 2008, it was estimated that the prevalence of a heart rhythm disorder, or arrhythmia, is between 1.5% and 5% in the general population in the United States.

The most common sustained type of arrhythmia is Afib, a condition which causes the upper chambers of the heart to beat irregularly and blood not to flow properly to the lower chambers of the heart.

The prevalence of atrial fibrillation in the United States is estimated to increase from approximately 5.2 million in 2010 to 12.1 million in 2030, and it is estimated that more than 50 million patients worldwide have Afib with at least one-third of these patients presenting as asymptomatic at the time of their diagnosis.

More than 450,000 hospitalizations occur each year in the United States because of Afib, and the condition contributes to an estimated 350,000 deaths globally each year.

There are many different types of arrhythmias which are typically categorized based on where in the heart they originate - in either the atria or ventricles - and their speed - tachycardia for fast rhythms, bradycardia for slow rhythms.

The causes of arrhythmias are diverse, and they can be triggered by conditions such as heart disease, high blood pressure, electrolyte imbalances, drug use, or stress.

Some arrhythmias may not show symptoms, while others may lead to dizziness, shortness of breath, fainting, or chest pain.

The most common sustained type of arrhythmia is atrial fibrillation (“Afib ” ), a condition which causes the upper chambers of the heart to beat irregularly and blood not to flow properly to the lower chambers of the heart.

It is estimated that more than 50 million patients worldwide have Afib with at least one-third of these patients presenting as asymptomatic at the time of their diagnosis, and the condition contributes to an estimated 350,000 deaths globally each year.

The prevalence of Afib in the United States is estimated to increase from approximately 5.2 million in 2010 to 12.1 million in 2030, and more than 450,000 hospitalizations occur each year in the United States because of Afib.

Since Afib is more common among people over the age of 60, these numbers are expected to increase as the U.S.

population ages.

In Europe, the prevalence of arrhythmias is also expected to continue to rise with atrial fibrillation affecting an estimated 7.6 million people over 65 in the EU in 2016 and projections indicating a surge to 9.5% of individuals over 65 by 2060.

and its consolidated subsidiaries, as the context requires.

Atrial Fibrillation and Stroke

Early detection of heart rhythm disorders, such as Afib and other clinically relevant arrhythmias, supports appropriate medical intervention and can help avoid more serious downstream medical events, including stroke.

In 2021, it was estimated that the age-adjusted US stroke death rate as an underlying cause of death was approximately 41.1 per 100,000, and there were approximately 7.4 million deaths attributable to stroke worldwide.

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According to the AHA, stroke costs the United States an estimated $34.5 billion each year in healthcare costs and lost productivity and is a leading cause of serious long-term disability.

The AHA estimates that ischemic strokes represent approximately 85% of all strokes in the United States, with an estimated 690,000 ischemic strokes per year.

Between 15% and 20% of people who have strokes also have Afib.

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These early treatments include medications such as oral anticoagulants, treatment with anti-arrhythmic drugs, and interventions such as cardiac ablation therapy to help control heart rhythm and rate.

Afib burden, or the amount of time a patient spends in Afib during the period of time the patient is wearing a heart monitor, has been identified in the clinical community as an clinically relevant measure for helping to determine appropriate and effective therapeutic interventions to manage patients with Afib and for assessing stroke risk.

Afib burden, or the amount of time a patient spends in Afib during the period of time the patient is wearing a heart monitor, has been identified in the clinical community as a clinically relevant measure for helping to determine appropriate and effective therapeutic interventions to manage patients with Afib and for assessing stroke risk.

We believe the calculated Afib burden is only as good as the data available for analysis during the monitoring period.

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Ambulatory Cardiac Monitoring Overview

The ambulatory cardiac monitoring market is well-established in the United States with an estimated 6.4 million diagnostic tests performed annually with meaningful expansion anticipated in the coming years due to an aging population, a rising number of heart-related disorders globally, and broader acceptance of innovative medical technologies.

The ambulatory cardiac monitoring (“ACM”) market is well-established in the United States with an estimated 6.5 million diagnostic tests performed annually with meaningful expansion anticipated in the coming years due to an aging population, a rising number of heart-related disorders globally, and broader acceptance of innovative medical technologies.

Traditional ambulatory cardiac monitoring devices used by physicians for diagnosing patients with suspected arrhythmias – such as traditional, 24-to-48-hour Holter and cardiac event monitors – are constrained by short-term monitoring times, non-continuous data collection and reporting, cumbersome equipment, and/or lower patient compliance.

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We currently offer three Zio System options — the Zio Monitor System, the Zio XT System, and the Zio AT System.

Zio ECG monitors are designed to provide high-quality, accurate data with patient compliance for up to 14 days of wear time.

Data on file.

iRhythm Technologies;

Data on file.

iRhythm Technologies;

Data on file.

iRhythm Technologies;

Zio XT Clinical Reference Manual, iRhythm Technologies;

Zio AT Clinical Reference Manual.

iRhythm Technologies;

Zio Monitor Instructions for Use.

iRhythm Technologies, 2023.

Data on file.

iRhythm Technologies;

Continuous, uninterrupted refers to the recording of ECG data.

Zio AT Gateway transmissions may be impacted by a variety of factors.

See Product Labeling for more information.

Zio AT is contraindicated for critical care patients.

Do not use Zio AT for patients with symptomatic episodes where variations in cardiac performance could result in immediate danger to the patient or when real-time or in-patient monitoring should be prescribed.

Refer to the Zio AT labeling and Clinical Reference Manual for full contraindications.

The Zio Service Monitoring Solutions

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The Zio XT System is the previous generation of the Zio Monitor System and is a prescription-only, remote ECG monitoring system that consists of a patch ECG monitor (the “Zio XT patch”) that records the electric signal from the heart continuously for up to 14 days and the ZEUS System, which supports the capture and analysis of ECG data recorded by the Zio XT patch at the end of the wear period, including specific arrhythmia events detected by the ZEUS System.

The Zio Monitor patch is 72% smaller, 62% lighter, and 23% thinner than our Zio XT patch, attributes which we believe will have a positive impact on patient experience, patient satisfaction, and associated improvement in device wear times.

The Zio Monitor patch is 72% smaller, 62% lighter, and 23% thinner than our Zio XT patch, attributes which have contributed to a positive impact on patient experience, including improved patient satisfaction, and associated improvement in device wear times.

Furthermore, the Zio Monitor patch incorporates a breathable adhesive construct, which enhances the patient experience by removing moisture otherwise captured next to the patient’s skin, as well as Bluetooth communication capabilities and improved processing efficiency.

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Zio AT Patch and Wireless Gateway

We support physician and patient use of our Zio Systems through our Medicare-enrolled IDTF and certified cardiographic technicians (“CCTs”), who perform the technical monitoring services associated with a physician’s order for long-term continuous monitoring or MCT monitoring services.

Long-term continuous monitoring and MCT services are diagnostic medical procedures typically ordered by physicians for patients not suspected of having life-threatening arrhythmias, but who are suspected of having infrequent, difficult-to-detect, or asymptomatic arrhythmias.

We support physician and patient use of our Zio Systems through our Medicare-enrolled IDTF and qualified technicians, who perform the technical monitoring services associated with a physician’s order for long-term continuous monitoring or MCT monitoring services.

Long-term continuous monitoring services (the “Zio LTCM Service”) and MCT services (the “Zio MCT Service”) are diagnostic medical procedures typically ordered by physicians for patients not suspected of having life-threatening arrhythmias, but who are suspected of having infrequent, difficult-to-detect, or asymptomatic arrhythmias.

When physicians order long-term continuous monitoring services with our Zio System, our biosensor technology collects an uninterrupted, long-term continuous recording of ECG data for up to 14 days and delivers a comprehensive end-of-wear report, which includes specific arrhythmia events detected by the ZEUS algorithm upon return of the Zio Monitor patch or Zio XT patch (and with the Zio AT patch, each, a “Zio patch”) and analysis of the stored data by qualified technicians.

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After we receive the Zio patch at our IDTF, the ECG data is uploaded to our secure cloud and preliminary findings are generated by our proprietary FDA-cleared deep learning algorithms.

Each report is then validated by CCTs and sent to the patient’s prescribing physician who may access the Zio report on our proprietary, web-based portal, referred to as ZioSuite, and also through our Electronic Health Record ("EHR") connections or ZioSuite mobile apps.

Each report is then validated by qualified technicians and sent to the patient’s prescribing physician who may access the Zio report on our proprietary, web-based portal, referred to as ZioSuite, and also through our Electronic Health Record (“EHR”) connections or ZioSuite mobile apps.

Our technicians also notify physicians of potential urgent arrhythmias according to the ordering physician’s specified notification criteria.

ZioSuite web portal via desktop or mobile application

For our MCT services, the Zio AT patch and wireless gateway also offer the additional capability of providing actionable transmissions during the wear period to assist physicians in diagnosing and treating patients in situations where their physician has determined that there is a medical need to receive more timely, clinically actionable information.

For the MCT services, physicians will receive daily reports, routine reports, and notifications from CCTs if there are significant events that meet predetermined and physician-specified notification criteria.

For the Zio MCT Services, the Zio AT patch and wireless gateway also offer the additional capability of providing actionable transmissions during the wear period to assist physicians in diagnosing and treating patients in situations where their physician has determined that there is a medical need to receive more timely, clinically actionable information.

For the MCT services, physicians will receive daily reports, routine reports, and notifications from qualified technicians if there are significant events that meet predetermined and physician-specified notification criteria.

While wearing a Zio patch, patients can mark when symptoms occur by pressing a trigger button on the device and separately recording contextual data like activities and circumstances in a written symptom diary or digitally via the myZio application.

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• sufficient battery power for the entire wear period, without the need to recharge or replace batteries.

We believe a clinical need and an opportunity exists to expand our Zio platform into clinical grade wrist-worn wearables to detect and characterize Afib while integrating with clinicians’ workflows.

As part of this expansion strategy, we partnered with Verily (see “Collaboration with Verily” below) to develop their Verily Study Watch wearable device into a clinical platform.

We have since developed the Zio® Watch (Study Watch with Irregular Pulse Monitor) with our clinically integrated ZEUS System, a new health solution that is intended to be integrated into clinical care delivery and to assist healthcare providers in identifying and monitoring Afib.

We have what is believed to be the world’s largest repository of labelled ECG data, which we leveraged to develop our proprietary photoplethysmography (PPG) algorithms utilized in both the Zio Watch and the ZEUS System.

The Zio Platform for Clinical-grade Wearables

We believe a clinical need and an opportunity exists to expand our Zio platform into clinical-grade wearables to detect and characterize arrhythmias while integrating with clinicians’ workflows.

As part of this expansion strategy, we partnered with Verily Life Sciences LLC, an Alphabet Company (“VLS”) and Verity Ireland Limited (“VIL,” and together with VLS, “Verily”) to develop their Verily Study Watch wearable device into a clinical platform.

We developed the Zio ® Watch (Study Watch with Irregular Pulse Monitor) with our clinically integrated ZEUS System, a solution that is intended to be integrated into clinical care delivery and to assist healthcare providers in identifying and monitoring Afib.

We have what we believe to be the world’s largest repository of labelled ECG data, which we leveraged to develop our proprietary photoplethysmography (“PPG”) algorithms utilized in both the Zio Watch and the ZEUS System.

In July 2022, we received FDA clearance on the clinically integrated ZEUS System, the AI algorithm and solution component of the Zio Watch.

Also in July 2022, Verily received FDA clearance for the Zio Watch (Study Watch with Irregular Pulse Monitor).

In addition to Zio Watch, we are evaluating potential opportunities to leverage our PPG algorithms and ZEUS System with other PPG based wrist-worn wearables and intend to initiate market evaluation or clinical studies with one or more wearables in 2024.

The Zio Watch has not been commercially launched.

We are evaluating potential opportunities to leverage our PPG algorithms and ZEUS System with other PPG-based wearables, and we intend to further pursue development opportunities on a wearable platform in the future.

The iRhythm Difference

We believe there are strong benefits offered by our 14-day wear time, by the diagnostic yield possibly achieved through our technology, and by the clinical accuracy of our Zio report as enabled by our proprietary deep-learned artificial intelligence that can help to reduce inaccuracies in computerized ECG interpretations and improve the efficiency of expert human ECG interpretation.

This is supported by more than 125 original scientific research manuscripts and a robust, growing body of clinical evidence by third-party researchers.

A retrospective study by Turakhia et al, published in The American Journal of Cardiology in August 2013, analyzed data from 26,751 patients using the Zio XT System for the first time between January 1, 2011, and December 31, 2011.

The study results showed that among the 16,142 patients with detected, clinically relevant arrhythmias, over 50% of the first-diagnosed symptomatic arrhythmias occurred after 48 hours of monitoring, suggesting that these arrhythmias could have been missed by traditional Holter monitoring during the typical maximum prescribed monitoring time.

This data suggests that detection of infrequent arrhythmias requires longer monitoring times and ECG signal of consistent quality.

For the Zio XT System, other published clinical literature has routinely reflected a high level of compliance with 14-day wear time and a high percentage of analyzable time (i.e., the proportion of the ECG signal recording which is free from artifact and of sufficient fidelity to enable rhythm analysis).

Mean or median patient wear times have ranged for the Zio XT patch reported in the literature, and Kaura et al.

reported that the majority of 56 subjects randomized to the Zio XT System achieved the full 14-day wear time.

Publications which include assessment of percentage analyzable time report rates between 94% and 99.6% (i.e., mean or median percent analyzable data across all subjects).

Our Zio Services utilize advanced FDA-cleared artificial intelligence (“AI”) with a deep-learned algorithm to detect arrhythmias.

As published in Nature Medicine in 2019, Hannun et al.

used data from the Zio XT Service to develop a deep-neural network capable of diagnosing arrhythmias at a high diagnostic performance similar to that of expert cardiologists.

The deep-neural network model met or exceeded the performance of cardiologists for 12 types of arrhythmia classes and recapitulated the misclassifications made by cardiologists.

In clinical settings, this approach could reduce the amount of misdiagnosed computerized ECG interpretations and improve the efficiency of expert human ECG interpretation by accurately triaging or prioritizing the most urgent conditions.

Among this compendium of clinical evidence are multiple studies which demonstrate significant increases in arrhythmia detection through a 14-day monitoring time such as with Zio LTCM Services, as compared to shorter-term 24- to 48-hour monitoring, such as performed as with standard Holter devices.

Longer monitoring times with a consistent ECG signal of consistent quality permit detection of infrequent arrhythmias.

Other publications illustrate high patient compliance with a 14-day prescribed wear time and low ECG signal artifact, with wear times routinely above 13 days and percent analyzable time above 95%.

Additionally, data from the Zio LTCM Service has been used in development of proprietary artificial intelligence, including a deep-learned neural network model which has been shown to meet or exceed the performance of cardiologists in detection of 12 arrhythmia types.

In clinical settings, we believe that this approach could reduce the number of misdiagnosed computerized ECG interpretations and improve the efficiency of expert human ECG interpretation by accurately triaging or prioritizing the most urgent conditions.

Long-term, continuous monitoring maximizes diagnostic yield 1

2 Turakhia, M.

1, Turakhia et al.

Diagnostic Utility of a Novel Leadless Arrhythmia Monitoring Device.

The American Journal of Cardiology , 2013.

3 Tsang, J.P.

Benefits of monitoring patients with mobile cardiac telemetry (MCT) compared with the Event or Holter monitors.

Medical Devices:

Evidence and Research, 2014.

Taken together, we believe that these elements are differentiators for the Zio Systems in the diagnosis and treatment of cardiac arrhythmias and can lead to improved clinical outcomes, enhanced patient experience, high physician and healthcare staff satisfaction, and reduced cost of care to healthcare systems.

This was demonstrated by the results from the Cardiac Ambulatory Monitor EvaLuation of Outcomes and Time to Events (“CAMELOT”) study that were published in the American Heart Journal in December 2023.

The largest ever real-world evidence study of ambulatory cardiac monitoring, it revealed that the Zio long-term continuous monitoring service (the “Zio LTCM service”) using the Zio XT System was independently associated with the highest yield of clinical arrhythmia encounter diagnosis, lowest likelihood of retest, and the lowest incremental healthcare resource utilization of all strategies examined.

Using claims data from the full Medicare fee-for-service database (inclusive of part A, part B and part D claims), the authors performed a retrospective analysis of patients with first-time ambulatory cardiac monitoring between 2017 and 2018.

Within long-term continuous monitoring, they identified use of the Zio LTCM service from National Provider Identifier codes.

The authors evaluated 90-day diagnostic yield (arrhythmia diagnosis), 180-day retest (use of an additional ambulatory cardiac monitor) and 90-day health care utilization among a cohort of 287,789 patients.

Patients with Zio LTCM service had the highest diagnostic yield (adjusted odds ratio of new diagnosis for Holter vs.

Zio LTCM reference:

0.50 [0.47-0.53], p < 0.001) and lowest retest (adjusted odds ratio of retest for Holter vs.

Zio LTCM reference 1.35 [1.20-1.52], p < 0.001), even when compared to other long-term continuous monitoring or MCT.

As a category, long-term continuous monitoring was associated with the lowest one-year incremental health care expenditures (mean Δ$10,159), followed by Holter ($10,755), ambulatory event monitors ($11,462), and MCT ($12,532).

The largest ever real-world evidence study of ambulatory cardiac monitoring, it revealed that the Zio LTCM Service using the Zio XT System was independently associated with the highest yield of clinical arrhythmia encounter diagnosis, lowest likelihood of retest, and the lowest incremental healthcare resource utilization of all strategies examined.

Results of the CAMELOT study 1-4

4 Reynolds, M.

Comparative effectiveness and healthcare utilization for ambulatory cardiac monitoring strategies in Medicare beneficiaries, American Heart Journal, 2023.

Opportunities in Monitoring for Asymptomatic Afib Patients

1, Reynolds et al.

Comparative effectiveness and healthcare utilization for ambulatory cardiac monitoring strategies in Medicare beneficiaries.

2024;269:25–34.

A specified arrhythmia refers 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.

Opportunities in Monitoring for Undiagnosed Arrhythmias

Currently, the Zio Services are generally ordered by physicians for patients that are experiencing symptoms, with limited provision of these services for the estimated one-third of the U.S.

population that may be experiencing asymptomatic Afib, which is sometimes referred to as “silent Afib”.

We see a future opportunity in supporting physicians in the proactive assessment of the approximately 12 million patients who are at high risk of asymptomatic Afib or other clinically-actionable arrhythmia to identify those with the illness.

To that end, iRhythm has established the “Know Your Rhythm” program with the goal of increasing proactive screening of undiagnosed arrhythmias in the asymptomatic population.

We are offer the Know Your Rhythm program with the Zio Monitor System to patients that meet specified risk criteria.

We intend to initiate commercial pilots and gather additional data in 2024 for the Know Your Rhythm program with the aim to validate our belief that these screenings may be able to reduce certain healthcare costs over time.

We believe this opportunity is clinically appropriate and economically supported, as informed by our interpretation of several key studies:

Home-based Screening for Early Detection of Atrial Fibrillation (“SCREEN-AF”), a study examining early detection of Afib using the Zio XT System in high-risk patients, was published in the Journal of the American Medical Association (“JAMA”) Cardiology in February 2021.

This randomized control trial recruited 856 participants 75 years or older with hypertension and no known Afib from 48 primary care clinics across Canada and Germany between 2015 and 2019.

The intervention group included remote screening for Afib for two weeks with the Zio Service utilized at baseline and again at three months, in addition to standard care for six months.

The results showed Afib was newly diagnosed in the screening group in 5.3% of subjects at six months compared to 0.5% in the standard of care control group.

A secondary outcome showed oral anticoagulant therapy was prescribed for 75% of participants who had screen-detected Afib.

We believe that proactive screening and monitoring using the Zio Services could increase Afib detection 10-fold over standard of care, potentially prompting oral anticoagulant use.

The mHealth Screening to Prevent Strokes (“mSToPS”) study, led by researchers at the Scripps Research Translational Institute in collaboration with Aetna Inc., Healthagen LLC, Janssen Research and Development, LLC, and Johnson & Johnson, utilized a web-based platform to remotely recruit 5,214 eligible patients from the Aetna Commercial Fully Insured and Medicare Advantage programs.

Women over the age of 65 and men over 55 with certain risk factors were selected to participate based on information derived from claims data that placed them at a potentially increased risk of undiagnosed asymptomatic Afib.

Four peer-reviewed articles were published on the mSToPS study between 2018 and 2023.

The study design was published in the JAMA in July 2018 while the one-year results were published in Heart Rhythm O2 in December 2020 and the three-year follow-up analysis was published in PLOS One in October 2021.

Additionally, cost-effectiveness data of the study was published in Circulation:

Cardiovascular Quality and Outcomes in November 2023.

The results showed that, at one year, Afib was newly diagnosed in 6.6% of patients who were actively monitored by the Zio Service versus 2.4% in the observational control group receiving routine care.

In addition to this primary endpoint to evaluate the difference in new Afib diagnoses, active monitoring in an asymptomatic, moderate-risk population with the Zio Service was associated with an increase in cardiology outpatient visits but also significantly lower rates of emergency department visits and hospitalizations over the one year following monitoring.

At three years, screening for AFib was associated with a lower rate of clinical events and improved outcomes relative to the matched cohort.

Over the three years following the initiation of screening, AFib was newly diagnosed in 11.4% of screened participants versus 7.7% of observational controls, and for individuals whose Afib was first diagnosed clinically, 6.6% experienced a stroke, 10.2% were newly diagnosed with heart failure, 9.2% had a myocardial infarction, and 1.5% had systemic emboli.

For those diagnosed via screening, none experienced a stroke, myocardial infarction or systemic emboli in the period surrounding their AF diagnosis, and only 1 person (2.3%) had a new diagnosis of heart failure.

Finally, as demonstrated in the cost-effectiveness analysis published in November 2023, assessing the health economic value over the lifetime of the patient showed that proactive monitoring for Afib in individuals prescribed Zio patch monitors over the three-year period was associated with high economic value based on willingness to pay thresholds.

We also hope that additional informative data will be generated in the GUARD-AF study.

In November 2019, we announced our participation in the “ReducinG stroke by screening for UndiAgnosed atRial fibrillation in elderly inDividuals” (“GUARD-AF”) study, a randomized, controlled study sponsored by the Bristol-Myers Squibb-Pfizer Alliance.

This ongoing study seeks to determine if earlier detection of Afib through screening in previously undiagnosed men and women ultimately impacts the rate of stroke compared to usual standard medical care.

The GUARD-AF study population includes men and women at least 70 years of age visiting their primary care physician for usual follow-up care, and the screening arm utilizes the Zio XT Service.

Though trial enrollment was limited to 11,931 participants due to the impact of the COVID-19 pandemic on enrollment, GUARD-AF is the largest randomized trial in Afib screening to use a long-term continuous patch ECG monitor.

The primary outcome measures will be stroke and bleeding events leading to hospitalization.

The trial is designed to identify outcome events using insurance claims from a healthcare claims database, which is subject to certain limitations, and is expected to provide evidence on health outcomes associated with Afib detection intervention that may help inform future clinical practice guidelines.

Initial findings from the 5,713 patients who wore the Zio XT patch in the GUARD-AF study were presented at The American College of Cardiology’s 71st Annual Scientific Session & Expo in April 2022 and the trial’s design and rationale were published by Singer et al.

in the American Heart Journal in July 2022.

Initial findings demonstrated that in the older primary care population, 0.5% of screened participants had persistent Afib and 4% had paroxysmal Afib (“PAF”) detected within two weeks of monitoring.

In those with PAF, the average Afib burden was low but more than 25% had an episode of ≥4.6 hours of continuous Afib, suggesting increased stroke risk.

In addition to the primary outcome measures, the study is designed to generate important information to inform clinical decisions regarding the need for stroke-preventive interventions – including anticoagulants – for screen-detected PAF.

population that may be experiencing undiagnosed arrhythmias, including Afib.

Because Afib is associated with increased risk of clinical outcomes such as stroke and heart failure, we see a future opportunity in supporting physicians in the proactive assessment of the approximately 12 million patients who are at high risk of undiagnosed Afib or other clinically actionable arrhythmias to identify those with the illness, enabling initiation of appropriate therapies which may reduce risks.

To that end, iRhythm established the “Know Your Rhythm” program with the goal of enabling population health management strategies to identify undiagnosed arrhythmias in a defined patient population by using data-driven risk stratification, early disease identification, and targeted interventions.

What was initially conceived as our ‘Know Your Rhythm’ program for payor channels has been instead organically adopted by innovative, value-based care organizations to encapsulate proactive monitoring strategies.

Early success of the Zio Services within this paradigm has been the culmination of several factors iRhythm has been driving over the past few years.

The known increases in health care utilization and costs have been met with a focus on serving patients in lower cost settings of care.

The ease of use for physicians and patients alike of our Zio Monitor System, together with iRhythm’s clinical evidence demonstrate the Zio Services' ability to identify undiagnosed arrhythmias and the cost-effectiveness of a proactive arrhythmia monitoring approach.

To this end, we intend to utilize a precision artificial intelligence approach to better apply risk factor-based monitoring for atrial fibrillation and other arrhythmias in targeted patient populations — many that would not be identified with conventional criteria.

In 2024, the European Society for Cardiology updated their practice guidelines for management of Afib to include recommended screening in all patients 75 years and older and for those 65 and older with additional risk factors.

We have participated in multiple clinical studies, including SCREEN-AF, GUARD-AF, and mHealth Screening to Prevent Strokes ("mSToPS") which have demonstrated significant increases in Afib detection using Zio LTCM Services versus routine clinical care.

During a three-year follow-up period in the mSToPS study, Afib screening with the Zio LTCM Service was associated with a reduction in the rate of the combined endpoint of stroke, death, systemic emboli, and myocardial infarction as compared to an observational cohort that did not participate in active screening.

In patients who have suffered an ischemic stroke, identification of the underlying cause is important in prevention of recurring strokes and to improve patient outcomes.

The 2024 American College of Cardiology expert consensus decision statement on arrhythmia monitoring after stroke now recommends ambulatory cardiac monitoring of 14 or more days as the primary modality for use in detection of Afib in cases of stroke of unknown origin.

The Zio LTCM Service was shown to be superior to Holter monitoring for detection of Afib in post-stroke patients as part of the Early Prolonged Ambulatory Cardiac Monitoring in StrokeTrial.

Utility of Zio Long-term Continuous Monitoring in Ventricular Rhythms

Recently published literature has also demonstrated the value of 14-day long-term continuous monitoring in assessment of ventricular rhythms, including ventricular tachycardia and premature ventricular contractions (“PVC”).

Hypertrophic cardiomyopathy (“HCM”) is among the most common genetic heart diseases and patients are at increased risk for ventricular tachycardia and sudden cardiac death.

A 2024 study conducted by Rowin et al.

assessed the incidence of ventricular tachycardia in 236 HCM patients and concluded that 14-day continuous monitoring with Zio LTCM Services identified three times as many patients with high-risk episodes as compared to Holter monitoring over 48 hours, the standard duration for Holter monitoring.

Additionally, a 2024 study conducted by Krumerman et al.

assessed 106,705 patients with elevated PVC burden and demonstrated reduced error in determining the burden of PVC with 14-day continuous monitoring as compared to short-term monitoring durations.

This enabled improved classification of patients with respect to burden level, which is associated with increased risk for reduced ejection fraction and heart failure.

We believe that these studies together illustrate that 14-day continuous monitoring with the Zio Services may improve sensitivity for risk identification in ventricular rhythms and provides additional data valuable in clinical decision-making, such as determining the need for the implantable cardioverter defibrillator implant to reduce risk of sudden cardiac death in HCM patients, or the use of ablation procedures to reduce heart failure risks in patients with elevated PVC burden.

Our mission is to boldly innovate to create trusted solutions that detect, predict, and prevent disease.

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We intend to expand our market penetration by targeting the large existing ambulatory cardiac monitoring market in the United States and driving broader awareness of its advantages.

We plan to leverage our portfolio of products, including the Zio Monitor System and Zio AT System, and position the Zio Service as providing certainty in a single test due to high patient compliance and superior quality of uninterrupted data.

We plan to leverage our portfolio of products, including the Zio Monitor System and Zio AT System, and position Zio Services as providing certainty in a single test due to high patient compliance and superior quality of uninterrupted data.

The Zio Monitor System, which provides continuous long-term ECG monitoring, is designed to be appropriate for the majority of patients that require ambulatory cardiac monitoring while the Zio AT System, which includes near real-time monitoring, is intended for more acute patients that require timely notification.

We estimate our current market penetration in the United States to be approximately 30%.

Marketing and education throughout the medical community are key to bringing awareness and communicating the strong clinical evidence backing the Zio Service.

In addition, we expect to continue developing and publishing clinical evidence to demonstrate the potential advantages of the Zio Service relative to legacy and competitive monitoring technologies.

Within existing accounts, we expect to continue to introduce our Zio Service beyond cardiology and electrophysiology into other departments, including primary care, neurology, and emergency room.

We estimate our current market penetration in the United States to be over 30%.

Marketing and education throughout the medical community are key to bringing awareness and communicating the strong clinical evidence backing Zio Services.

In addition, we expect to continue developing and publishing clinical evidence to demonstrate the potential advantages of Zio Services relative to legacy and competitive monitoring technologies.

Within existing accounts, we expect to continue to introduce our Zio Services beyond cardiology and electrophysiology into other departments, including primary care, neurology, and emergency room.

To enable this broader adoption within a hospital system, we have successfully interfaced the Zio ordering and report posting processes into a number of large health systems’ electronic health record (“EHR”) systems.

This seamless integration of Zio workflow processes has proven to be a key factor in spurring growth within existing and new accounts and is an important part of our ongoing market penetration strategy.

We believe there is potential to increase the core symptomatic total addressable market by moving further upstream in the care pathway to the primary care physician call point.

Furthermore, we believe there is potential to increase the core symptomatic total addressable market by moving further upstream in the care pathway to the primary care physician call point.

We estimate that 15 million patients in the United States visit a primary care physician annually with palpitations due to suspected cardiac disease.

By educating primary care physicians on the benefits of the Zio Service for this patient population, we believe we can expand the market and reach more patients that are candidates for ambulatory cardiac monitoring.

In addition to approaching primary care physicians directly, we also are able to leverage virtual cardiology providers as key partners to deliver clinical decisions.

By educating primary care physicians on the benefits of Zio Services for this patient population, we believe we can expand the market and reach more patients that are candidates for ambulatory cardiac monitoring.

• Pursuing international expansion opportunities.

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In September 2020, we were named a winner of the Artificial Intelligence in Health and Care Award run by the Accelerated Access Collaborate as part of the National Health Service (“NHS”) AI Lab.

This funding will bring the Zio Service to selected NHS sites over a three-year program measuring clinical, pathway, and economic outcomes.

We also received positive guidance from the National Institute for Health and Care Excellence (“NICE”) in December 2020 for the adoption of the Zio XT Service which may facilitate future support of the Zio Service through the MedTech Funding Mandate.

This funding brought Zio Services to selected NHS sites over a three-year program measuring clinical, pathway, and economic outcomes.

We are also conducting diligence and prioritizing other geographies based on market size, regulatory pathway, and reimbursement opportunity.

We are initiating market development and market access initiatives in multiple European countries in 2024 and pursuing regulatory clearance in Japan.

We initiated commercial launch of the Zio Monitor System and Zio Services in Austria, the Netherlands, Spain, and Switzerland in the third quarter of 2024 and were granted regulatory approval in Japan in September 2024.

We estimate the total addressable market in our initial selected countries of the UK, Japan, and prioritized European countries to be at least 5 million existing ambulatory monitoring tests annually.

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We intend to continue assessing the potential pathways for expanding indications and clinical use cases for our Zio Services and developing new systems for patient populations with unmet needs.

Leading with clinical and economical evidence, we are pursuing commercialization opportunities for our Know Your Rhythm by Zio program that is focused on patients at risk for undiagnosed arrhythmias.

With at least 12 million individuals in the United States estimated to be at risk for undiagnosed cardiac arrhythmias, we believe this could be a significant market opportunity.

Initial efforts to proactively monitor this population with the Zio Monitor System, including end-to-end care pathway pilots, are planned for 2024.

Leading with clinical and economical evidence, we are pursuing commercialization opportunities for proactive monitoring strategies that are focused on patients at risk for undiagnosed arrhythmias.

With at least 12 million individuals in the United States estimated to be at risk for undiagnosed cardiac arrhythmias, we believe this could be a significant market opportunity for which we believe Zio Services are uniquely positioned to succeed.

Initial efforts to proactively monitor this population with the Zio Monitor System were initiated in 2024 and will be continued into 2025.

In addition, we are actively exploring opportunities in adjacent markets beyond ambulatory cardiac monitoring.

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• Advancing our system portfolio and core technology offering .

We continue to invest in building a unique, innovative system portfolio and digital platform that addresses unmet needs in the ambulatory cardiac monitoring market and adjacent markets.

We continue to invest in building a unique, innovative system portfolio and digital platform that addresses unmet needs in the ACM market and adjacent markets.

We will continue to invest in research and development efforts to further differentiate our biosensor, data analytics and reporting, our information system, and our digital platform.

We intend to make improvements in Zio MCT Services during 2025, and we also intend to continue evaluating potential opportunities to leverage our PPG algorithms and ZEUS System with a PPG-based wearable platform in the future.

Additionally, in 2024 we entered into an exclusive license agreement with BioIntelliSense, Inc., a continuous health monitoring and clinical intelligence company, to develop and commercialize their patented pulse oximetry, accelerometry and trending non-invasive blood pressure technologies for use within the ACM market.

By incorporating medical grade, connected, multi-sensor capabilities, we believe iRhythm will be well positioned to deliver broad clinical insights within ACM that improve patient outcomes, enhance clinical and operational efficiency, and reduce costs to the healthcare system.

Sales and Marketing

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We market our Zio Services to a variety of physician specialties including general cardiologists, electrophysiologists, primary care physicians, neurologists, and other physician specialists who diagnose and manage care for patients with arrhythmias.

Focusing on sales to IDNs gives us the opportunity to conduct a holistic sale for health systems interested in making value-based purchasing decisions.

We have found success focusing on integrated delivery networks (“IDNs”), in which large networks of facilities and providers work together to offer a continuum of care to a specific geographic area or market, as well as with risk-bearing entities as our Zio Systems become a key tool in population health management.

Focusing on sales to these customer programs gives us the opportunity to conduct a holistic sale for health systems interested in making value-based purchasing decisions.

In January 2021, we established a small direct sales and clinical infrastructure in Bagshot, Surrey in England to service the UK market.

We have since focused efforts on the introduction of the Zio Services using the Zio XT System into new accounts and market access efforts, in particular through orders made by NHS Trusts and Hospitals.

In addition, we are exploring sales opportunities and market access in Japan, Switzerland, the Netherlands, and Spain.

Additionally, we have built a small sales force covering Switzerland, Austria, and the Netherlands.

In Japan and Spain, we intend to utilize distributor services.

We typically experience reduced revenue during the third quarter, as well as during the year-end holiday season.

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(acquired by Baxter International, Inc.) to offer remote cardiac monitoring technology and also function as diagnostic service providers.

We also compete with companies that sell traditional, 24-to-48-hour Holter monitors, including GE Healthcare, Philips Healthcare, Mortara Instrument, Inc., Spacelabs Healthcare Inc., and Welch Allyn Holdings, Inc.

(acquired by Hill-Rom Holdings, Inc.

which was acquired by Baxter International, Inc.).

We also compete with companies that sell traditional, 24-to-48-hour Holter monitors, including GE Healthcare, Philips Healthcare, and Spacelabs Healthcare Inc., as well as Mortara Instrument, Inc.

and Welch Allyn Holdings, Inc.

(both acquired by Hill-Rom Holdings, Inc.

now part of Baxter International, Inc.).

Many of our competitors have substantially greater financial, manufacturing, marketing, and technical resources than we do.

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These competitors have also developed patch-based cardiac monitors that have received FDA and foreign regulatory clearances.

We are also aware of some small start-up companies entering the patch-based cardiac monitoring market.

We are also aware of small start-up companies entering the patch-based cardiac monitoring market.

Large medical device companies may continue to acquire or form alliances with these smaller companies to diversify their product offering and participate in the digital health space.

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These suppliers are evaluated, approved, and monitored by our quality team to ensure conformity with the specifications, policies, and procedures applicable to our devices.

Our manufacturing operations are subject to regulatory requirements of FDA’s Quality System Regulation (“QSR”) for medical devices authorized for manufacturing and sale in the United States (set forth under 21 CFR Part 820), the Medical Devices Directive 93/42/EEC (“MDD”) and the Medical Devices Regulation 2017/745 of the European Parliament and of the Council (“EU MDR”), which is required for doing business in the EU, and the UK Medical Device Regulations 2002 (as amended) (“UK MDR”).

Our manufacturing operations are subject to regulatory requirements of FDA’s Quality System Regulation (“QSR”), the Medical Devices Regulation 2017/745 of the European Parliament and of the Council (“EU MDR”), the UK Medical Device Regulations 2002 (“UK MDR”), and the Japanese medical device Quality Management System ("QMS").

We are also subject to applicable requirements relating to the environment, waste management, and health and safety matters, including measures relating to the release, use, storage, treatment, transportation, discharge, disposal, sale, labeling, collection, recycling, treatment, and remediation of hazardous substances.

See “Regulation” below for further information.

We purchase certain components and materials used in manufacturing from single sources due to quality considerations, costs, or constraints resulting from regulatory or other requirements.

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For the year ended December 31, 2024, we received approximately 84% of our revenue through third-party payors, which includes approximately 24% of our total revenue from the Medicare program.

As we continue to contract with more commercial payors and the patient population ages into eligibility for the Medicare Advantage program, we believe more of our revenue will convert to commercial payer billing.

Our clinical centers are enrolled in the Medicare program as IDTFs, which allows us to bill CMS directly for our Zio Services.

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• Advancing our technology offering.

Our product portfolio includes patch-based solutions (utilized in the Zio Monitor System, Zio AT System, and Zio XT System) and the FDA-cleared Zio Watch that combine continuous monitoring for extended periods with accelerated notification of significant events through mobile transmission capabilities.

Our product portfolio includes patch-based solutions (utilized in the Zio Monitor System, Zio AT System, and Zio XT System) and the FDA-cleared Zio Watch (not yet commercially available) that combine continuous monitoring for extended periods with accelerated notification of significant events through mobile transmission capabilities.

• Customer workflow optimization .

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Our research and development activities consist of software development, algorithm and product development, regulatory affairs, and clinical research.

Our research and development expenses were $60.2 million, $46.6 million, and $38.7 million for the years ended December 31, 2023, 2022, and 2021, respectively.

Collaboration with Verily

On September 3, 2019, we entered into a Development Collaboration Agreement with Verily Life Sciences LLC, an Alphabet Company (“VLS”) and Verity Ireland Limited (“VIL,” and together with VLS, “Verily”) (such Development Collaboration Agreement, as amended by Amendment No.1 dated April 26, 2021 and Amendment No.2 dated January 24, 2022, the “Development Agreement”).

The Development Agreement involves collaboration development and production of intellectual property between us and Verily.

Each party has primary responsibility for certain aspects of development and approval, with all processes to be performed at each respective party’s own cost.

The parties agreed to develop certain next-generation Afib screening, detection, or monitoring products pursuant to the Development Agreement, which products will involve combining Verily’s and our technology platforms and capabilities.

Under the terms of the Development Agreement, we paid Verily an upfront fee of $5.0 million in 2019.

In addition, we agreed to make additional milestone payments to Verily up to an aggregate of $12.75 million upon achievement of various development and regulatory milestones over the term of the Development Agreement.

We have achieved milestones tied to payments totaling $11.0 million to date and expect to make additional payments over the term of the Development Agreement of $1.75 million, subject to the achievement of specified milestones.

The Development Agreement provides each party with licenses to use certain intellectual property of the other party for development activities in the field of Afib screening, detection, or monitoring, together with perpetual non-exclusive licenses to certain shared know-how (which licensed shared know-how excludes certain technology or intellectual property, such as patent rights).

Ownership of developed intellectual property is allocated to us or Verily depending on the subject matter of the underlying developed intellectual property, and, for certain subject matter, is jointly owned.

Our research and development expenses (excluding in-process research and development) were $71.5 million, $60.2 million, and $46.6 million for the years ended December 31, 2024, 2023, and 2022, respectively.

Technology License Agreement with BioIntelliSense, Inc.

On August 30, 2024, we entered into a Technology License Agreement (the “License Agreement”) with BioIntelliSense, Inc.

(“BioIS”), pursuant to which (i) we will receive a perpetual fully paid up license to certain of BioIS’ intellectual property, technology and products for research, development and commercialization of potential next generation products and services in certain fields of use, including an exclusive license to develop and commercialize pulse oximetry, accelerometry, and trending non-invasive blood pressure technologies for use within our ambulatory cardiac monitoring products and services, and (ii) each party agreed to negotiate in good faith a supply agreement for pulse oximetry hardware.

Under the terms of the License Agreement, we paid BioIS an upfront fee of $15.0 million in cash consideration in acceptance of the initial transfer of certain licensed technologies and data following the execution of the License Agreement.

In connection with the License Agreement, we also purchased an aggregate of $40.0 million of convertible promissory notes from BioIS (the “Convertible Notes”), of which $20.0 million (“Milestone Notes”) were designated for satisfaction of our regulatory milestone payment obligations.

The Milestone Notes, plus accrued and unpaid interest, if any, shall be cancelled, if outstanding, upon the achievement of the regulatory milestones up through December 31, 2026.

Additionally, BioIS is eligible to receive low single digit royalty payments on annual net sales of certain products that include licensed rights in the home sleep testing field of use, subject to certain adjustments specified in the License Agreement.

Intellectual Property

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We hold patents and pending patent applications in the United States and other parts of the world which, in aggregate, we believe to be of importance in the operation of our business.

As of December 31, 2023, we owned, or retained an exclusive license to, forty-two issued patents from the U.S.

Patent Office (“USPTO”), ten issued patents from the Japanese Patent Office, three issued patents from the Australian Patent Office, four issued patents from the Canadian Patent Office, six issued patents from the European Patent Offices, five issued patents from the Korean Patent Office, and two issued patents from the Chinese Patent Office.

As of December 31, 2024, we owned, or retained an exclusive license to, 46 issued patents from the U.S.

Patent Office (“USPTO”), 13 issued patents from the Japanese Patent Office, 4 issued patents from the Australian Patent Office, 5 issued patents from the Canadian Patent Office, 7 issued patents from the European Patent Offices, 6 issued patents from the Korean Patent Office, two issued patents from the Chinese Patent Office, and 1 issued patent from the Indian Patent Office.

issued patents as of December 31, 2024 are set to expire over a range of years, from November 2028 to August 2041, subject to any extensions.

As of December 31, 2023, we had forty-eight pending patent applications globally, including eleven in the United States, seven in the European Patent Office, seven in Japan, two Patent Cooperation Treaty ("PCT") international applications, six in Australia, four in each of Korea, China, and India, and three in Canada.

As of December 31, 2024, we had 50 pending patent applications globally, including 14 non-provisional applications and 2 design applications in the United States, 7 in the European Patent Office, 8 in Japan, 1 Patent Cooperation Treaty ("PCT") international application, 5 in Korea, 4 each in Australia and China, 3 in India, and 2 in Canada.

Our patents and patent applications seek to protect aspects of our core technologies and our product concepts for ambulatory cardiac monitoring.

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trademark registrations for the marks MyZIO, ZIO, ZIO SUITE, ZIO AT, and IRHYTHM and pending U.S.

trademark applications for the marks KNOW YOUR RHYTHM BY ZIO, KNOW YOUR RHYTHM, ZIO and ZIO MCT.

trademark applications for the marks KNOW YOUR RHYTHM BY ZIO, KNOW YOUR RHYTHM, and ZIO MCT.

It also contained registered trademarks for the mark IRHYTHM in Australia, the EU, Austria, Canada, China, Denmark, Finland, France, Germany, Japan, Italy, Norway, Sweden, Switzerland, and the UK.

It further contained trademark registrations for the mark ZIO in Australia, Canada, China, the EU, Japan, Norway, and Switzerland.

It further contained trademark registrations for the mark ZIO in Australia, Canada, China, the EU, Japan, Norway, Switzerland, and the UK.

It also contained trademark registrations for the mark MYZIO in Canada, the UK, and the EU, trademark registrations for the mark ZIO MCT in the UK and the EU, and trademark registrations for the mark ZIOSUITE in the UK and the EU.

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After clearance, changes made to devices must be evaluated on an ongoing basis and may trigger the need for additional 510(k) clearances or – depending on the nature of the change – might require a higher level of FDA review (through the de novo premarket approval or (“PMA”) process).

To date, our product changes have been managed within the 510(k) framework and we have not been required to provide clinical data to support these 510(k) submissions and clearances.

To date, our product changes have been managed within the 510(k) framework.

After a device is placed on the market, numerous regulatory requirements continue to apply.

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• criminal prosecution.

For further details on these risks, see “Risk Factors” below.

Privacy and Security Regulation

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European Union and United Kingdom

The Zio XT patch is currently regulated in the EU as a Class IIa medical device pursuant to the MDD.

The MDD sets out the basic regulatory framework for medical devices in the EU.

In May 2021, the EU MDR, a more comprehensive regulatory framework, replaced the MDD.

The system of regulating medical devices operates by way of a certification for each medical device.

Each certified device is marked with the CE mark which shows that the device has a certificate of conformance under the MDD or EU MDR.

National competent authorities (the “Competent Authorities”) in each member state oversee the implementation of the MDD and EU MDR within their jurisdiction, typically through so-called notified bodies which are certification organizations designated by a member state to conduct third-party conformity assessments (the “Notified Bodies").

In the European Union, the system of regulating medical devices operates by way of a certification for each medical device.

Each certified device is marked with the CE mark which shows that the device has a certificate of conformance under the EU MDR.

Since May 2021, the EU MDR has been the relevant regulatory framework for devices in the EU, replacing the prior Medical Device Directive.

The Zio Monitor System and the Zeus System are currently marked in the EU under our CE mark under the EU MDR issued by the British Standards Institution ("BSI") in December 2023.

National competent authorities in each member state of the EU oversee the implementation of the EU MDR within their jurisdiction, typically through so-called notified bodies which are certification organizations designated by a member state to conduct third-party conformity assessments (the “Notified Bodies”).

The means for achieving the requirements for the CE mark vary according to the nature of the device.

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The CE mark is contingent upon continued compliance with the applicable regulations and the quality system requirements of the ISO 13485 standard.

Our CE mark for the Zio XT System was issued by the National Standards Authority of Ireland under the MDD and is replaced by our new CE mark under the EU MDR issued by the British Standards Institution (“BSI”) on December 15, 2023 for the Zio Monitor System and the Zeus System.

Due to UK’s departure from the EU, the MHRA has issued new requirements associated with the UK Conformity Assessed (“UKCA”) mark.

Due to UK’s departure from the EU, the MHRA has issued requirements associated with the UK Conformity Assessed (“UKCA”) mark.

The UKCA marking is a new UK product marking that is used for goods being placed on the market in Great Britain.

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The UKCA requirement became effective on January 1, 2021, and we have obtained a UKCA mark with the BSI, which also serves as our UK Approved Body, for the Zio XT System and the Zeus System.

We are also registered with the UK’s Care Quality Commission (“CQC”) to carry out diagnostic and screening procedures.

We are also registered with the UK’s Care Quality Commission to carry out diagnostic and screening procedures.

Additionally, the EU Notified Body and UK Approved Body regularly audit our manufacturing, design, and operational facilities to ensure ongoing ISO 13485 and EU MDR compliance and periodically audit technical design files in accordance with the EU MDR in order to maintain our CE mark or issue a CE mark or UKCA mark for new or updated devices.

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In accordance with these values, we believe that effectively managing environmental, social, and corporate governance (“ESG”) risks and opportunities drives business success and that, when fully integrated into the business, ESG can provide a competitive advantage.

In 2022, we set out on a journey to develop iRhythm’s approach to ESG by conducting an ESG Priority Assessment to identify the ESG priority topics that are important to internal and external stakeholders and operationalizing ESG within the organization by forming an ESG Steering Committee and multiple ESG Working Groups, which focus on specific ESG substantive areas or workstreams.

Additionally, in 2023, we established formal board oversight of ESG by revising the charters of two committees of our Board of Directors – the Nominating and Corporate Governance Committee and the Compensation and Human Capital Management Committee.

Our 2022 ESG report, issued in 2023 (available on our website), outlines these efforts and we continue to work within our organization to advance our strategic ESG roadmap by pursuing ESG workstreams.

We intend to update our ESG report in 2025.

During 2024, we refreshed our ESG priority assessment to ensure we are aligning with the issues that matter most to our business and stakeholders.

We made significant progress in many aspects of our ESG strategy, including:

• Expanded measurement of Greenhouse Gas Emissions to include Scope 3 in addition to Scope 1 and 2 measurements;

• Obtained ISO 14001:2015 Environmental Management System Certification for our manufacturing facility in Cypress, CA;

• Completed a Life Cycle Analysis to further assess the environmental impacts of our products;

• Published supplier code of conduct and conflict minerals policies on our website;

• Expanded patient access to Zio by launching commercially in Spain, Switzerland, Austria and The Netherlands;

• Added one new employee resource group for iRhythm employees to further build an inclusive culture that empowers and engages all employees.

Human Capital

As of December 31, 2024, we had approximately 2,000 employees globally.

While the COVID-19 pandemic initially disrupted how and where we work, our employees demonstrated resilience, flexibility, and camaraderie and we transitioned to a hybrid work model.

In our hybrid work model, our positive company culture has ensured that we performed well financially, long-term productivity was maintained, and employee engagement remained high.

The Compensation and Human Capital Management Committee of our Board of Directors has oversight of our culture and human capital management, including diversity, equity, and inclusion with respect to our employees.

Diversity, Equity, and Inclusion

We believe in creating a flexible, productive, and globally connected dispersed workforce.

Our work model is comprised of employees spanning remote, hybrid, and fully onsite work arrangements.

Work arrangements are determined based on the needs of the role, nature of work, and regulatory requirements.

Our approach is designed to empower our global workforce, fostering flexibility and productivity while maintaining a strong company culture.

The Compensation and Human Capital Management Committee of our Board of Directors has oversight of our culture and human capital management.

Inclusion and Belonging

We are committed to being an equal opportunity employer and we prohibit all forms of unlawful discrimination in accordance with applicable law.

We believe in the richness and quality of a working environment that is informed by people from all walks of life and strive to create a genuinely inclusive environment.

As of December 31, 2023, our workforce was comprised of more than 55% female employees and more than 44% of employees identified as ethnically diverse.

To further build on our commitment to diversity, equity, and inclusion (“DEI”), we have formed a DEI Counsel that is led by our Chief Risk Officer to support strategic initiatives, partnerships, advocacy, and educational programs to foster a more diverse, equitable, and inclusive culture.

We value our differences, recognizing that from those differences comes our strengths, and we are committed to continuing to build a culture of diversity, equity, and inclusion.

Over the course of 2023, we also launched three new Employee Resource Groups (“ERGs”).

These employee-led ERGs are reflective of employee demographics and interests and continue to cultivate a sense of inclusion and belonging.

To build on our commitment to inclusion and belonging, we have various initiatives led by our Chief Risk Officer to foster a work environment where everyone feels valued, respected, and empowered to contribute.

Board and Management Oversight

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Compared sentence by sentence after normalising whitespace, quotation marks, case and digits, so re-formatting and restated figures do not read as changed language. Wording changes appear as one removal and one addition. The current filing and the prior one are authoritative.

What changed 10-K

Item 1. Business