Algorithm Improvements in an Insertable Cardiac Monitor Reduce False Positives and Episode Review Burden

INTRODUCTION: The use of insertable cardiac monitors (ICM) for arrhythmia monitoring continues to grow steadily. However, ICM performance remains less than perfect, and the volume of transmitted data poses a challenge to clinics. Here, we evaluate the impact of three improvements implemented in the LUX-Dx II+ ICM for atrial fibrillation (AF), pause, and bradycardia detection. METHODS: Enhanced AF and pause algorithms were evaluated using real-world ECG data and compared against the predecessor LUX-Dx algorithms. Optimized nighttime (11 p.m.-7 a.m.) programming settings were simulated on LUX-Dx data to evaluate the reduction of non-actionable nocturnal bradycardia (>30 bpm) and pause (98% sensitivity relative to the legacy algorithm. False positive reduction and relative sensitivity were even higher (74% and 100%, respectively) in a subset of patients with more sensitive AF programming settings. The enhanced pause algorithm reduced false positives by 62.5% in the training set and 48.6% in the test set, while maintaining 100% relative sensitivity. Application of adjusted nocturnal detection thresholds reduced the number of nighttime bradycardia and pause episodes by 98% and 90%, corresponding to an overall episode reduction of 75% and 56%, respectively. CONCLUSION: The enhanced ICM algorithms and programming settings substantially reduced false positive AF and pause detections as well as non-actionable nighttime bradycardia and pause detections. These enhancements are expected to improve ICM performance and workflow in the device clinic.