Arrhythmias & electrophysiologyCohort study
Accuracy of Implantable Loop Recorders
- multicenter, multivendor database
- random sample selected based on a prospectively determined power analysis
- alerts independently adjudicated by trained physicians
- 25 centers
Authors' conclusion
ILRs demonstrate variable accuracy in arrhythmia detection, with a substantial burden of false-positive alerts across all vendors despite artificial intelligence-based and other algorithmic enhancements. Further improvement of alert algorithms to reduce clinic burdens is needed.
Study context
- Population
- Patients with implantable loop recorders (medtronic (MDT) LINQ II, BSX LUX-Dx, Biotronik (BIO) Biomonitor III, Abbott (ABT) Confirm Rx), January 2022 to March 2023random sample (∼283 per device) from a database of 437,351 electrocardiogram-verified episodes from 6,756 patients
- Participants
- 1,140 patients
- Exposure
- arrhythmia detection accuracy among currently used implantable loop recorders (ILRs)
Main finding
As reported in the abstract
Total alerts
total alerts
25,826
alerts per patient
median of 5 alerts (IQR: 2-14)
Observational data: associations, not effects.
Further findings
Atrial tachycardia/AF alerts (share of alerts)
PPV
| Outcome | MDT | BSX | BIO | ABT |
|---|---|---|---|---|
| PPV after adjudication | 0.56 | 0.73 | 0.23 | 0.51 |
| Bradycardia detection PPV · MDT primarily due to undersensing | 0.36 | 0.96 | Not reported in the abstract | Not reported in the abstract |
| Pause detection PPV | Not reported in the abstract | 0.70 | Not reported in the abstract | 0.01 |
| Tachycardia alert PPV | 0.29 | 0.61 | 0.62 | 0.27 |
- Pause detection PPV: ABT 79.8% due to undersensing
Causes of false-positive atrial tachycardia/atrial fibrillation (AF) alerts with BIO devices
- ectopy
- 75.8%
- combined ectopy with oversensing/noise
- 5.3%
- isolated oversensing
- 5.2%
- sinus arrhythmias
- 3.9%
- indeterminate reason
- 3.7%
- noise
- 3.6%
- bradycardia
- 2.5%
Original publication
Accuracy of Implantable Loop Recorders. JACC Clin Electrophysiol. Published 13 February 2026. doi:10.1016/j.jacep.2025.12.039
Summarised from the published abstract; every number is checked against it