Age and Clinically Actionable Events in Patients With Implantable Loop Recorders: Analysis of Multicenter Loop...

Little is known about age and clinical intervention after implantable loop recorder (ILR) insertion. This study investigated the association between age and clinical intervention after ILR implantation.

Data were obtained from a multicenter registry of ILR in Korea (2017-2020, n = 795). ILRs were inserted with indications of unexplained syncope, recurrent palpitation, or cryptogenic stroke. The primary outcome was clinically actionable event that was a composite of the newly detected atrial fibrillation (AF), pacemaker or implantable cardioverter defibrillator (ICD) implantation, catheter ablation, and anticoagulation initiation. The mean age was 64.3 years, and the mean follow-up duration was 20.6 months. Clinically actionable events were observed in 322 (40.5%) patients. Compared to younger age (< 50 years), older age (≥ 50 years) showed higher prevalence of newly detected AF (3.7% vs. 15.8%; p = 0.001), pacemaker implantation (11.2% vs. 21.2%; p = 0.022), and initiation of anticoagulation (3.7% vs. 18.6%; p < 0.001). No significant differences were found in ICD implantation (1.9% vs. 1.3%; p = 0.996) or catheter ablation (3.8% vs. 6.0%; p = 0.512). The older age group more frequently experienced clinically actionable events compared to the younger age group (hazard ratio 2.52, 95% confidence interval: 1.86-3.41; p < 0.001). A significant association was found in the increase of age (per 1-year) and the risk of clinically actionable events (adjusted hazard ratio 1.03, 95% confidence interval 1.02-1.04; p < 0.001).

Advanced age is a significant risk factor for clinical intervention after ILR insertion. ILR should be considered more actively in older patients requiring prolonged rhythm monitoring.