iRhythm presents new data on Zio long-term continuous ECG monitoring

iRhythm (IRTC) Technologies announced new data presented in a podium session at the 18th Asia Pacific Heart Rhythm Society and Japanese Heart Rhythm Society 2025 Joint Scientific Session in Yokohama, Japan, held November 12-15. The investigators, led by Dr. Hiro Kawata, compared device compliance, performance, arrhythmia detection, and repeat-testing rates between Asians and non-Asians in a large cohort of U.S. patients. The study, titled “Comparative Analysis of Arrhythmia Detection and Clinical Outcomes in Asian and Non-Asian Populations Using Ambulatory Cardiac Monitoring,” analyzed 408,470 U.S. patients monitored between 2018 and 2022 using iRhythm’s Zio long-term continuous ECG monitoring service for up to 14 days. The analysis evaluated whether monitoring performance differs between patient groups, given that racial and cultural differences, including factors such as skin type, skin preparation, device tolerability, and lifestyle, may impact compliance and effectiveness in ambulatory cardiac monitoring. Key Findings: Comparable performance across populations: Median wear time and analyzable ECG duration were consistent between Asian and non-Asian patients, with Asians representing 3.4% of the full cohort. Consistent diagnostic yield: Despite lower baseline prevalence of atrial fibrillation, heart failure, and coronary artery disease, patients of Asian race showed a similar AF detection rate. The total arrhythmia yield was also comparable for both groups. Low repeat testing: Repeat monitoring rates were low and similar among Asian and non-Asian groups. This finding is consistent with published CAMELOT2 and AVALON3 analyses, which showed lower repeat testing with Zio long-term continuous monitoring compared with other ambulatory monitoring services. The analysis leveraged Zio ECG data linked to medical claims data which enabled a comprehensive assessment of patient race, comorbidities, and outcomes across a large, diverse population. The findings demonstrate that racial and cultural characteristics-such as variations in skin type, daily activities, and device wear behaviors-were not associated with meaningful differences in wear time, analyzable time, or arrhythmia detection yield, supporting the consistency of long-term continuous ECG monitoring performance across diverse patient populations.