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Largest Ever Real-World Evidence Study of Ambulatory Cardiac Monitoring Demonstrates Clinical Superiority of iRhythm's Zio Long-Term Continuous Monitoring Service

  • Findings published in the American Heart Journal show higher clinical diagnostic yield and lower odds of retesting with Zio long-term continuous monitoring service (LTCM) compared to other LTCM and ambulatory cardiac monitoring (ACM) products
  • LTCM was associated with lower incremental health care utilization and cost

SAN FRANCISCO, Jan. 05, 2024 (GLOBE NEWSWIRE) -- (NASDAQ:IRTC) today announced that the results from the Cardiac Ambulatory Monitor EvaLuation of Outcomes and Time to Events (CAMELOT) study have been published in the American Heart Journal (AHJ).

The peer-reviewed manuscript, titled “Comparative Effectiveness and Healthcare Utilization for Ambulatory Cardiac Monitoring (ACM) Strategies in Medicare Beneficiaries,” reveals that the Zio long-term continuous monitoring service (LTCM), which features up to 14 continuous days of monitoring, was independently associated with the highest yield of clinical arrhythmia encounter diagnosis and lowest likelihood of retest. The retrospective study of almost 300,000 patients makes CAMELOT the largest published real-world comparative effectiveness analysis of ambulatory cardiac monitoring.

“Our findings reveal significant variation in selection of monitoring devices, which can be influenced by patient characteristics and other factors. However, long-term continuous monitoring — and iRhythm’s Zio LTCM in particular — was independently associated with a higher probability of an arrhythmia diagnosis being documented and a lower probability of repeat testing," said Matthew Reynolds, MD, MSc, a cardiac electrophysiologist at Lahey Hospital & Medical Center and the study's lead author. “LTCM also minimized subsequent health care spending, compared to traditional Holter monitors or non-continuous event monitors. We believe these findings may be useful for clinicians in choosing the best type of monitor for different clinical scenarios.”

Higher Diagnostic Yield and Lower Likelihood of Retest

The investigators sought to determine the impact of choice of monitoring service and strategy on a range of clinical and health economic outcomes. Using the full (100%) sample of Medicare beneficiaries, the investigators identified 287,789 patients who had previously not received cardiac monitoring or arrhythmia diagnosis in the 12 months prior to the index date (baseline period).

The study found that in diagnostic-naïve Medicare patients, Zio LTCM was associated with a higher diagnostic yield, ascertained by medical claims, compared to all other ACMs when looking at specified arrhythmias. The presence of an encounter diagnosis of an arrhythmia within the first 90 days was highest for the LTCM (33.8%) followed by the mobile cardiac telemetry (MCT) (27.1%), external ambulatory event monitoring (AEM) (24.6%), and Holter (22.7%). Holter, AEM, MCT, and non-iRhythm LTCM were 50%, 42%, 33%, and 23% less likely to achieve clinical arrhythmia encounter diagnosis compared to the Zio LTCM service, respectively.

The study also found that in diagnostic-naïve Medicare patients, the Zio LTCM had a lower adjusted odds of retesting within 180 days compared to other ACM modalities, including LTCMs from other service providers in the same extended monitoring category. Non-iRhythm LTCMs were 3.7 times more likely to result in a retest than the Zio LTCM service. Zio LTCM also outperformed other ACM categories: even after accounting for baseline patient differences, Holter, MCT monitoring and AEM were 1.4, 3.0, and 4.3 times more likely to result in retesting as compared to the Zio LTCM, respectively.

“These are really important findings to consider when we recommend cardiac monitoring to our patients. We now have clear evidence that the short-term Holter monitors still used by many are less likely to provide a diagnosis and more likely to require repeat testing — both of which impact patient care,” said Rod Passman, MD, MSCE, cardiac electrophysiologist and professor of medicine at Northwestern University. “We also learned that not all LTCMs are equivalent and choosing the right device can make a big difference in how we find and treat abnormal cardiac rhythms.”

Lower Increase in Health Care Utilization and Costs

The study also found that LTCM were associated with the lowest increase in health care resource utilization and costs — including fewer emergency department visits. AEM and MCT monitoring services were associated with statistically significantly higher costs of $1,317 and $2,372 more per patient, respectively.

“These real-world findings show how our innovation — including the patient experience with a single uninterrupted 14-day monitor, the clinician experience with our integrated tools, along with our advanced AI and ECG technicians — all translate into superior clinical outcomes,” said Mintu Turakhia, MD, MAS, chief medical officer, chief scientific officer and executive vice president, product innovation at iRhythm. “CAMELOT unequivocally shows that all monitoring is not the same. Compared to the field, long-term continuous monitoring with the Zio service is more likely to prevent retesting and get to a diagnosis — which is important for patients, clinicians, health systems and payers.”

To access the manuscript, go to the “Comparative Effectiveness and Healthcare Utilization for Ambulatory Cardiac Monitoring (ACM) Strategies in Medicare Beneficiaries” published in the AHJ.

The research reinforces the findings of the National Association of Managed Care Physicians (NAMCP), which, in an independent third-party review, found that Zio LTCM service value proposition claims are credible and objective and demonstrate high value around clinical utility and payer economics, noting that iRhythm is the first manufacturer of cardiac monitors that have conducted and published real-world comparative economic and outcome data. Since the CAMELOT study presentation at the American College of Cardiology's 2023 Annual Scientific Sessions, these data have resulted in several health insurers updating their respective policies, ultimately removing access barriers for patients and prescribers — updates that could positively impact nearly 17 million covered lives in the US.

Visit to learn more about iRhythm and its portfolio of Zio products and services.

About the CAMELOT Study
Authors: Matthew R. Reynolds MD MSc, Rod Passman MD, Jason Swindle PhD, Iman Mohammadi PhD, Brent Wright RN DrPH, Kenneth Boyle DC, Mintu P. Turakhia MD MS, Suneet Mittal MD

Objective data comparing the diagnostic capabilities and subsequent outcomes of various ACMs has been lacking.

The CAMELOT study aimed to fill the void by assessing variations in monitoring strategies, clinical outcomes, and health care utilization among patients undergoing ambulatory monitoring without a pre-existing arrhythmia diagnosis, and to provide critical insights that could significantly impact cardiac care and diagnostic precision.

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 ACM in 2017-2018. Within LTCM, 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 ACM) and 90-day health care utilization. The cohort included 287,789 patients [age 76 ±7 years, 61% female; 10% AEM, 54% Holter, 13% LTCM, 23% mobile cardiac telemetry (MCT)]. Patients with Zio LTCM service had the highest diagnostic yield (adjusted odds ratio versus Holter: 1.95 [1.90-2.00, p < 0.001]) and lowest retest (adjusted odds ratio versus Holter 0.74 [0.72-0.77, p < 0.001]), even when compared to other LTCM or MCT. As a category, LTCM was associated with the lowest one-year incremental health care expenditures (mean Δ$10,159), followed by Holter ($10,755), AEM ($11,462), and MCT ($12,532).

The CAMELOT study was funded by iRhythm Technologies, Inc; statistical analysis was independently performed by Inovalon. The manuscript and supplemental materials, which includes the full list of specified arrhythmias ascertained, can be accessed here.

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.

Investor Relations Contact:
Stephanie Zhadkevich
(919) 452-5430

iRhythm Media Contact:
Saige Smith
(262) 289-7065

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