Rates of therapeutic interventions in a large real-world cohort with insertable cardiac monitors

Abstract Background Insertable cardiac monitors (ICMs) provide up to several years of continuous monitoring and have demonstrated high diagnostic yields for arrhythmia detection. However, the rates of arrhythmia-related therapeutic interventions following ICM implant have not been comprehensively characterized across indicated patient populations. Purpose To quantify rates of arrhythmia therapies in a large, real-world U.S. cohort of ICM patients. Methods De-identified patients receiving a Reveal LINQ ICM between Oct 1, 2016 – Sept 30, 2020 with no prior cardiac implantable electronic devices (CIEDs) and ≥1 year of follow-up in the Optum Clinformatics® Data Mart claims database were identified (N=17,037). Patients were stratified by indication for ICM placement: N=431 (2.5%) of patients were indicated for AF ablation monitoring, 2,193 (12.9%) for AF management, N=4,852 (28.5%) Cryptogenic stroke, N=1,252 (7.3%) Palpitations, 1,346 (7.9%) Suspected AF, 6,716 (39.4%) Unexplained syncope, and 247 (1.4%) Ventricular tachycardia (VT). Each patient was followed in the claims database after ICM insertion until end of continuous claims enrollment, end of database, or death. Therapeutic interventions for arrhythmias were characterized during follow-up, including procedures (CIED implants, cardioversion, and ablation) and arrhythmia medication initiation (antiarrhythmics, rate-control medications, and oral anticoagulants). Results Mean(SD) follow-up in the claims database post ICM placement was 3.4(1.3) years; 52.4% of patients were female, and mean age was 70.8(11.9) years. Overall, 54.5% of patients received a therapeutic intervention during follow-up, with 25.0% of patients receiving a therapeutic procedure and 44.0% initiating an arrhythmia-related medication (table). The highest procedure rates included implantable pulse generator (IPG) implants in the Unexplained syncope population (21.4% of patients) and cardiac ablations in the populations receiving ICM for known AF (27.8% of AF ablation monitoring patients and 23.5% of AF management patients). Medication initiation rates were highest for oral anticoagulants in the Cryptogenic stroke population (31.0% of patients). The mean time from ICM insertion to therapeutic action was 13(13) months for procedures and 7(11) months for medication initiation. Conclusions In a large sample of real-world ICM patients, more than half received a therapeutic intervention after ICM placement. Time to intervention was lengthy and showed substantial variability amongst patients, underscoring the importance of long-term continuous monitoring to uncover clinically-relevant arrhythmia findings.