Assessment of Variation in Ambulatory Cardiac Monitoring Among Commercially Insured Patients

Ambulatory cardiac monitors (ACMs) enable heart rhythm monitoring for various durations, including Holter monitors (0-48 hours), long-term continuous monitors (LTCMs; 3-14 days), and external ambulatory event monitors (AEMs; up to 30 days). These devices detect intermittent or asymptomatic arrhythmias that might go unnoticed with a standard electrocardiogram. Previous research has explored variations in ACM use among Medicare beneficiaries. This study assessed the incidence of clinical and economic outcomes among commercially insured patients who had never had an arrhythmia diagnosis and received their first ACM. Retrospective cohort study using a large commercial claims database focused on patients without prior arrhythmia diagnoses who received their first ACM between 2016 and 2023. Outcomes included new arrhythmia diagnoses, repeat ACM testing, cardiovascular (CV) events, and health care resource use and costs. Results were stratified by major ACM manufacturers using National Provider Identifiers. To minimize confounding, inverse probability of treatment weighting was used to balance covariates, and adjusted regression models were used to evaluate outcomes during follow-up. Of 428,707 patients meeting inclusion criteria, 36% used LTCMs, 36% used Holter monitors, and 27% used external AEMs. Adjusted analyses showed that a certain LTCM brand was associated with higher odds of a new arrhythmia diagnosis, fewer retests (except vs AEMs), lower odds of CV events, and less follow-up health care resource use and costs than other ACM types and manufacturers. Clinical and economic outcomes can vary by ACM type among commercially insured patients. A specific LTCM manufacturer demonstrated superior performance, with greater diagnoses of arrhythmia, fewer repeat tests, and fewer CV events compared with other ACM types and manufacturers.