Real-World Performance and Diagnostic Yield Gains of a Next Generation Patch-Based 14-day Uninterrupted Ambulatory ECG Monitor

Background The impact of device-specific differences in wear performance and analyzable ECG duration on arrhythmia yield has not been well characterized at a population level. We evaluated device performance and arrhythmia yield in a large post-market comparison of two long-term continuous monitors. Methods We performed a retrospective study comparing the post-market performance of an updated patch-based long-term continuous monitor (LTCM; iRhythm Technologies, San Francisco, CA) with its predecessor among patients prescribed 14-day monitoring. Both devices used the same FDA-cleared algorithm and technician review workflow. Outcomes included wear performance, analyzable ECG duration, arrhythmia yield (atrial fibrillation, supraventricular tachycardia, ventricular tachycardia, pauses, and atrioventricular block), skin irritation, and patient satisfaction. Results In 911,819 patients (age 61.8 ± 17.7 years, 53.7% female), the new LTCM (n=446,344) had longer wear time (mean 12.8 ± 2.6 vs. 12.1 ± 3.3 days, p<0.001) and fewer early discontinuations (1.0% vs. 2.3%, p<0.001) than its predecessor (n=465,475). After adjustment for age and sex, the new LTCM was associated with higher arrhythmia yield (78.5% vs. 76.9%; OR 1.14, 95% CI 1.12-1.15), with higher detection of actionable arrhythmias, AF, SVT, and VT. Across both devices, every additional 0.5 days of analyzable ECG duration was associated with a 6.6% increase in adjusted odds of arrhythmia detection (OR 1.066, 95% CI 1.065-1.067). Conclusions A new LTCM demonstrated fewer early wear discontinuations, longer wear duration, and higher arrhythmia yield than its predecessor. Modest increases in analyzable ECG duration were associated with higher arrhythmia yield, suggesting that small improvements in wear performance can have measurable population-level effects.