Treatment of cryptogenicstroke patients with atrial fibrillation detected by insertable cardiac monitors reduces recurrent stroke risk to background levels

Abstract

Abstract Background Atrial fibrillation (AF) is a well-known risk factor for ischemic stroke with a reported increased incidence range of 2.5 to 5-fold. However, it is not well established whether treatment of cryptogenic stroke patients with AF detected by insertable cardiac monitors (ICM) reduces the risk of recurrent stroke. Objective To compare recurrent stroke rates between cryptogenic stroke patients who have AF detected by ICMs and thus started on oral anticoagulation (OAC) treatment and those without detected AF. Methods We performed a retrospective analysis of consecutive patients who received an ICM for the purpose of AF monitoring following a cryptogenic stroke between July 2015 and March 2019. Patients with prior documented AF history were excluded. We calculated the rates of AF detection and OAC initiation. We also compared recurrent stroke rates between patients with and without AF detected. Results A total of 298 cryptogenic stroke patients receiving an ICM and home remote monitoring were studied (mean age: 77 SD: 11.7; Female/Male: 147 (49%)/151; virtual CHA2DS2-VASc: 4.96 SD: 1.28). AF was newly detected in 91 (29.6%) patients over a mean follow-up of 46 months. Of these patients 68 (72.4%) were started on OAC, 12 (15.3%) were already on OAC and 11 (12.2%) remained not anticoagulated. Of the total patients evaluated, 22 patients (7.3%) developed recurrent strokes for an annualized stroke rate of 1.926%. Of those, 8 occurred among the 91 patients with newly detected AF, for an annualized stroke rate of 1.72%. The remining 14 recurrent strokes occurred among the 207 patients without AF detected, for an annualized stroke rate of 1.76%; (p=0.87). One recurrent stroke occurred in an AF patient not anticoagulated due to a prior bleeding event. No hemorrhagic strokes were reported in the AF-OAC group. Conclusion Our study found that newly AF was detected by ICM in almost 1/3 (29%) of cryptogenic stroke patients (consistent with previous studies), and the vast majority of them (88%) accordingly received oral anticoagulation. There was not a significant difference in recurrent stroke rates among patients with AF detected on OAC and those without AF detected. This suggests that rigorous arrhythmia monitoring with ICMs can help identify cryptogenic stroke patients with new AF and initiate oral anticoagulation accordingly, to reduce their risk of recurrent stroke to background levels. Annualized Stroke Risk Funding Acknowledgement Type of funding source: None