Four Studies Demonstrate Clinical, Economic Value of iRhythm’s Product Portfolio

iRhythm Technologies Inc. is touting the results of four clinical studies that demonstrate the health, economic, and clinical value of its Zio AT and XT product lines for various diseases and clinical settings.
 
“The studies have important clinical implications,” iRhythm Chief Medical Officer and Chief Scientific Officer Dr. Mintu Turakhia said. “First, screening for atrial fibrillation, based on the mSToPS trial, is cost-effective and can provide high value. Next, extended ambulatory ECG monitoring from our products, compared to shorter monitoring, more accurately estimates the burden of a common type of ventricular arrhythmia, which is clinically consequential to patients and important to get right. We also found that atrial fibrillation was an unexpected and important finding in patients who receive monitoring for loss of consciousness, which we already know benefits from Zio’s 14-days of ambulatory ECG monitoring compared to other diagnostics. Finally, we showed the potential for partnered healthcare system research with EHR integration, in this case for tailored care pathways for diverse populations.”
 
The mSToPS health economic study evaluated the cost-effectiveness of screening for atrial fibrillation (AFib) with Zio XT. The analysis found that systematic screening for AFib in an at-risk population with the iRhythm Zio XT patch provided high value from a health economic perspective. Over three years, individuals prescribed Zio XT were more likely than unmonitored individuals to have outpatient visits—including to cardiologists—but less likely to require emergency department visits or hospitalization. The study demonstrated an incremental cost-effectiveness ratio (ICER) of $17,000 per quality-adjusted life year gained—substantially lower than accepted willingness-to-pay thresholds in the United States and other healthcare systems—and the authors conclude that screening for AFib using Zio XT provided high value.

The “Cost-Effectiveness of AF Screening with Two-Week Patch Monitors: The mHealth Screening to Prevent Strokes Study,” was written by Matthew R. Reynolds, M.D.; Amy B. Stein, Ph.D.; Evangelos Hytopoulos, Ph.D.; Xiaowu Sun, Ph.D.; Steven R. Steinhubl, M.D.; and David J. Cohen, M.D. The authors conducted a health economic analysis of AFib screening with Zio patch monitors using patient-level data from the mSToPS study. Clinical outcomes and costs from the payer perspective were obtained from enrollment through three years using Aetna claims data. Study group participants (mean age 74 years, 41% female, median CHA2DS2-VASC score 3) wore an average of 1.7 two-week patch monitors at an average cost of $601/person. Over three years, individuals prescribed Zio patch monitors were more likely than unmonitored individuals to have outpatient visits, including to cardiology, but less likely to require emergency department visits or hospitalization. Pharmacy costs over three years were similar between groups. Total adjusted three-year costs, including patch monitors, were slightly higher (difference $1,170, 95% CI -1,315 to 3,657) in the monitoring group. In patient-level projections, the monitoring group had slightly better total and quality-adjusted survival (11.91 vs. 11.82 life years, 9.38 vs. 9.30 QALYs) and slightly higher lifetime costs, resulting in an incremental cost-effectiveness ratio of $16,978/QALY gained. The investigators conclude that based on lifetime projections derived from the mSToPS study, AFib screening using two-week Zio XT patch monitoring provided high value from a health economic perspective.
 
The ventricular arrhythmia study was a >10-year study between 2011 and 2022 that analyzed PVC burden in 25,793 patients. The study sought to determine if extended ambulatory ECG monitoring increased accuracy for estimating burden of PVCs, which require accurate assessments for actionability. The data showed that a 48-hour estimation of PVCs misclassified PVC burden compared to 14-days of ambulatory ECG monitoring. At least seven days of continuous ambulatory ECG monitoring, which is performed by the Zio AT and XT product lines, was necessary to achieve >95% accuracy in burden categorization. The findings are important, as misclassification could impact clinical decision-making.

The “Assessing the Optimal Duration of ECG Monitoring Required to Accurately Establish Premature Ventricular Contraction (PVC) Burden in a Large National Database” study was written by Andrew K. Krumerman, M.D.; Luigi DiBiase, M.D.; Jay Chudow, M.D.; Ardit Kacorri, M.D.; Alan Wilk, B.S.; Lori Crosson, Ph.D.; and Kevin J. Ferrick, M.D. This retrospective multicenter analysis included patients undergoing ambulatory ECG monitoring with iRhythm’s Zio patch in the United States between June 2011 and April 2022 for any indication and overall PVC burden ≥5%. The mean absolute error (MAE) in PVC burden was calculated after 24 hours, 48 hours, and seven days. PVC density was more frequent in men than women and in patients age ≥ 65. The MAE calculated at 24 hours, 48 hours, and seven days were 2.96%, 2.56%, 1.34%, respectively, confirming the previously reported decrease in measurement variability with increased patch monitoring duration. The accuracy in categorization of PVC burden level increased from 89.2% at 24 hours to 95.1% at seven days. The findings underscore the importance of extended patch monitoring for accurate PVC burden assessment, which has important treatment implications.
 
The study titled “Near-Real Time Extended Ambulatory ECG Monitoring in Patients With Syncope Unveils a Spectrum of Arrhythmias and High Incidence of Atrial Fibrillation” utilized iRhythm’s proprietary database containing arrhythmia findings of patients prescribed Zio AT mobile cardiac telemetry for the diagnosis of syncope, or loss of consciousness possibly from heart rhythm disorders. The study of over ten thousand patients found not only a high diagnostic yield (79%) with Zio AT, but an unexpectedly high burden of supraventricular arrhythmias (69%) and AFib (9.5%) that are generally not thought to be associated with syncope. Most patients with AFib met criteria for an MD notification, highlighting the value of iRhythm’s mobile cardiac telemetry. A subgroup of syncope-indicated patients had an unexpectedly high AFib burden — potentially requiring a different treatment pathway.

This study was written by Bobbi Lynn Hoppe, M.D.; Matthew R. Reynolds, M.D.; Mike Hsu, Ph.D.; Alan Wilk, B.S.; Lori Crosson, Ph.D.; and Marie-Noelle Langan, M.D. Data were retrospectively analyzed from 10,643 patients from U.S. institutions with a syncope indication for monitoring. Patients with recordings between July 2017 to December 2021 were analyzed. Arrhythmias were defined as: AFib, ≥30 seconds at any heart rate; SVT, ≥90 bpm for ≥4 S beats; Pause, ≥3 second; AV Block, any third or second degree AV Block (Mobitz I or II); VT, ≥100 bpm for ≥4 V beats or PVT, TdP, VF. Detected arrhythmias were characterized by duration, episode counts, rates, and/or burden (where applicable). Of the 10,643 patients studied (49% female, mean age 65.4 years, mean wear 11.9 ± 3.6 days), 8,442 (79%) had at least one arrhythmia detected, with 3,107 (29%) having two or more arrhythmia types. The most common arrhythmias detected in this patient population were SVT (69%; 7,365), VT (26%; 2,716), and AFib (9.5%; 1,015). AV blocks (3.6%; 382) and pauses (6.2%; 662) were not uncommon.
 
The electronic health record (EHR) integration study sought to determine the relationship of age, gender, and race for AFib detection in one of the largest U.S. private healthcare systems. In 6,293 Ascension patients linked to Zio XT data, the study found risk of detected AFib was highest in older, white, and male patients; female, diverse patients below age ≤ 65 had the lower risk of detected AFib. The study demonstrated that EHR-linkage is not only feasible but an important step to generate tailored care pathways within a healthcare system.
 
The “Ascension Health System Experience with Extended Ambulatory Electrocardiographic Monitoring: Implementation of a Novel Integrated Approach to Better Characterize Disparities in Healthcare” study was written by Robert A. Pickett, M.D.; Jeffrey T. Ellis, Ph.D.; Evangelos Hytopoulos, Ph.D.; Lori Crosson, Ph.D.; Mohammed N. Khan, M.D.; and Kristopher M. Heinzman, M.D. This retrospective cohort study included patients treated at 34 Ascension centers in six states between January 2020 and April 2022. Patient EHR data were linked to proprietary device-specific rhythm reports for analyses. Among 6,293 patients in whom EHR data were matched to Zio XT findings, the median (IQR) age was 63 (47, 73) years, 3,816 (60.6%) were female, and 1,038 (16.5%) were diverse. Median device wear time was 7.2 (5.0, 13.9) days. AFib was detected in 749 (11.9%) patients, including 326 (5.2%) with 100% AFib. Median AFib burden was 37.0% (3.4%, 100%). Older white males had the highest risk of AFib events, whereas younger diverse females had the lowest risk. Diverse subgroups demonstrated greater freedom from AFib compared to white populations. The trial demonstrates the potential of EHR linkage with device-specific outcomes to develop tailored care pathways.
 
iRhythm is a cardiovascular diagnostics and digital healthcare company that creates solutions to 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.