P0383 - Diagnostic Accuracy and Safety of Confirm RxTM Insertable Cardiac Monitor in Pediatric Patients

Title: Diagnostic Accuracy and Safety of Confirm RxTM Insertable Cardiac Monitor in Pediatric Patients

Purpose: ICMs are efficacious in establishing symptom-rhythm correlation in cases of infrequent and unpredictable symptoms. Confirm RxTM devices recently were upgraded with SharpSenseTM – an algorithm for detecting arrhythmias. The purpose of this study is to assess the diagnostic capabilities of the Confirm RxTM device pre- and post-implementation of SharpSenseTM, and evaluate the effectiveness of customization strategies to improve specificity in pediatric patients.

Methods: A single center, IRB-approved, retrospective chart review of patients ≤ 21 years s/p implantation of Confirm RxTM ICMs from 2017-2020. Data included demographics, procedural details, indications, complications, R-wave amplitude and presence of P-wave at implantation and follow-up, rate of patient- and device-initiated transmissions, and false-positive rate in device transmissions pre- and post-SharpSenseTM. All transmissions were reviewed by an electrophysiologist. Recurrent false-positive transmissions resulted in device reprogramming.

Results: Confirm RxTM ICMs were implanted in 29 patients (median age: 8 years, 59% females). Mean follow-up was 9.8 months (0-24 months). P-waves were identified in all patients at implant. Mean R-wave at implant was 0.85mV (0.26 – 1.03mV). No significant difference in R-wave amplitude based on size (BSA1.5 m2: 0.76mV, <1.5 m2: 0.91mV), congenital heart disease (+CHD: 0.86mV, -CHD: 0.85mV), and at follow-up (BSA1.5 m2: 0.76mV, <1.5 m2: 0.91mV). 9 dysrhythmias were identified: wide complex tachycardia (1), supraventricular tachycardia (4), sinus pause and bradycardia (3), premature ventricular contraction (1). Of the 21 pre-SharpSenseTM, 10 (48%) had false-positive arrhythmia detection and 6 (29%) required reprogramming. A single false-positive in 8 patients with SharpSense TM. Average inappropriate transmissions/month decreased from 1.9 to 0.06 post-SharpSenseTM - a 97% reduction.

Conclusions: Confirm RxTM is a safe and effective tool for the detection of dysrhythmias in pediatric patients. There was no correlation between patient age, BSA, and the presence of CHD and average R-wave amplitude. Device-detected false-positive arrhythmias are dramatically reduced (1.9 to 0.06 transmissions/month) with SharpSenseTM technology.