Irhythm Holdings, Inc.NASDAQ: IRTC

New Data From iRhythm Reinforce the Utility of Long-Term Ambulatory Cardiac Monitoring for Increased Diagnostic Yield and Improved Diagnostic Accuracy of Actionable Arrhythmias

· Issued by iRhythm Holdings, Inc. via GlobeNewswire

Clinical studies presented at Heart Rhythm 2023 build on the totality of clinical evidence that continue to highlight the value of iRhythm’s Zio products and services across a wide range of patient populations

SAN FRANCISCO, May 22, 2023 (GLOBE NEWSWIRE) -- Rhythm Technologies, Inc. (NASDAQ:IRTC), a leading digital health care company focused on creating trusted solutions that detect, predict, and prevent disease, announced today the presentation of four studies at the Heart Rhythm Society’s annual meeting, Heart Rhythm 2023, in New Orleans, LA. These new data reinforce the body of clinical evidence that long-term ambulatory cardiac monitoring of up to 14 days with Zio® XT increases diagnostic yield and improves diagnostic accuracy of ventricular arrhythmias across a wide range of patient populations.

These new scientific data from iRhythm build on the totality of clinical evidence – including real-world comparative effectiveness and head-to-head studies – that continue to highlight the value of iRhythm’s Zio products and services.

Life-threatening ventricular arrhythmias, specifically ventricular tachycardia and ventricular fibrillation, cause about 300,000 deaths per year in the US and account for almost half of deaths from cardiac causes. Early detection and diagnosis are crucial to treating these arrhythmias and preventing adverse health outcomes.

“These studies thematically showcase the value of iRhythm’s Zio products and services — in particular for identifying ventricular arrhythmias for risk stratification and disease management,” said Mintu Turakhia, MD, MAS, iRhythm’s chief medical officer, chief scientific officer and executive vice president, product innovation. “The findings have important clinical and scientific implications, and they further demonstrate the strength of our technology across the complete range of clinical arrhythmias.”

Extended Ambulatory ECG Monitoring Enhances Identification of Higher-risk Patients With Hypertrophic Cardiomyopathy

The EXAMINE-HCM study found that in patients with hypertrophic cardiomyopathy (HCM) – a disease of the heart affecting 1 in 500 people in the U.S. that can lead to an increased risk of sudden cardiac death – long-term monitoring of up to 14 days with the Zio XT service substantially improves diagnostic yield of non-sustained ventricular tachycardia (NSVT). This may be highly consequential for assessing risk of arrhythmias and defining treatment pathways in these patients.

Key findings:

  • Diagnostic yield for detecting NSVT was substantially increased using 14 days of monitoring, with 48 hours of monitoring missing nearly two-thirds of patients with high-risk NSVT episodes that may impact risk stratification and treatment.
  • Diagnostic yield of detecting NSVT was 18% during the first 48 hours of monitoring compared to 48% at 14 days, with 63% of the initial NSVT episodes occurring after the first 48 hours.
  • Diagnostic yield of detecting high-risk NSVT episodes was 8% during the first 48 hours as compared to 24% at 14 days, with 64% of the initial high-risk NSVT runs occurring after the first 48 hours.

The PVC Burden Analysis study: Premature Ventricular Complexes (PVC): Assessing Burden Density in a Large National Cohort Population to Better Define Optimal ECG Monitoring Duration

The PVC Burden Analysis study of 106,705 patients shows increased monitoring through at least seven to 10 days duration is associated with improved accuracy in categorization of patients by PVC burden level. The findings are important, as misclassification could impact clinical decision-making.

Key findings:

  • 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, performed by the Zio service, was necessary to achieve >95% accuracy in burden categorization.

The Non-sustained VT Prognostic study: Practice Variation After Ambulatory ECG Detection of Non-sustained Ventricular Tachycardia in the Non-Cardiac Patient

In the Non-sustained VT Prognostic study, a retrospective study from the Veterans Health Administration, the largest integrated health care system in the United States, nearly one-third of the 58,279 patients who received long-term ambulatory ECG monitoring of up to 14 days with Zio had NSVT. Findings highlight the opportunity to create risk models and integrated care pathways following ambulatory ECG monitoring.

Key finding:

  • There was a wide site-level variation in diagnostic testing and treatment in the VA Health Care System after detection of NSVT, such as in the proportion of patients with echocardiograms, coronary angiograms, stress testing, cardiology care, and use of cardiovascular medications in the 90 days following ambulatory monitoring.

The Flec-ARVC study: Randomized Placebo-controlled Trial of Flecainide in Patients With Arrhythmogenic Right Ventricular Cardiomyopathy

The Flec-ARVC study, conducted at the University of Rochester, the Johns Hopkins ARVC Program and other institutions outside of iRhythm, is the first randomized clinical trial evaluating flecainide in arrhythmogenic right ventricular cardiomyopathy (ARVC). ARVC is an inherited heart disorder that carries a high risk of ventricular tachycardia and sudden death, often in young persons. Although implantable cardioverter defibrillators (ICD) can prevent sudden cardiac death, recurrent ventricular arrhythmias can be a significant clinical challenge, and there is limited trial data on the efficacy of antiarrhythmic therapy for ventricular arrhythmia suppression. The use of Zio services highlights Zio’s PVC burden measurement capabilities and more broadly, the opportunity to use the Zio service in clinical trials and research.

Key finding:

  • In this randomized, placebo-controlled, crossover trial of 41 patients that received Zio XT ambulatory ECG monitoring for seven days, Flecainide significantly reduced PVC burden.

About the “Extended Ambulatory ECG Monitoring Enhances Identification of Higher-risk Patients With Hypertrophic Cardiomyopathy” studyAuthors: Ethan J. Rowin, MD; Gaurav Das, MD; Christopher Madias, MD; Mike Hsu, PhD; Lori Crosson, PhD; Barry J. Maron, MD; Mintu P. Turakhia, MD, MAS; Martin S. Maron, MD

The study authors evaluated 236 hypertrophic cardiomyopathy (HCM) patients (49 ± 12 years; 72% male) without primary prevention implantable cardioverter defibrillators judged previously to be at low or intermediate sudden death (SD) risk with 14-day continuous ambulatory monitoring through Zio XT. Episodes of NSVT were evaluated during the initial 48 hours of monitoring and compared to NSVT identified in subsequent two to 14 days. NSVT episodes with ≥1 of the following criteria were considered higher risk as a SD marker: ≥ 200 bpm, ≥ eight beats, ≥ three runs within a consecutive 48 hour period. Among the 236 patients, 114 (48%) had ≥ one runs of NSVT, with a median of two runs (IQR: 1-4) during the complete monitoring period, including 86 patients with ≤ four runs (36%), 13 with five through nine runs (6%), and 15 with ≥10 runs (7%). Diagnostic yield of detecting NSVT was 18% during the first 48 hours of monitoring compared to 48% at 14 days, with 63% of the initial NSVT episodes occurring after the first 48 hours (72 of 114). Similarly, diagnostic yield of detecting high risk NSVT episodes was 8% during the first 48 hours as compared to 24% at 14 days, with 64% of the initial high-risk NSVT runs occurring after the first 48 hours (36 of 56).

About the “Premature Ventricular Complexes: Assessing Burden Density in a Large National Cohort Population to Better Define Optimal ECG Monitoring Duration” studyAuthors: Andrew Krumerman, MD; Luigi Di Biase, MD, PhD; Jay J. Chudow, MD; Ardit Kacorri, MD; Lori Crosson, PhD; Alan Wilk, BS; Kevin J. Ferrick, MD

Patients with a PVC burden ≥5%, age ≥18 and a ≥13-day wear period were analyzed between June 2011 to April 2022. Patient demographics were reported, and the mean absolute error in PVC burden was calculated at baseline (