Detection of atrial fibrillation in patients with embolic stroke of undetermined source by prolonged monitoring with implantable loop recorders

Abstract

Recently, the clinical entity embolic stroke of undetermined source (ESUS) has been defined for patients with ischemic strokes, where neither a cardioembolic nor a non-cardiac source can be detected. These patients may suffer from asymptomatic atrial fibrillation (AF), terminating spontaneously and thus eluding detection. Implantable loop recorders (ILR) with automatic AF detection algorithms can detect short-lasting, subclinical AF. The aim of this study was to prospectively assess and predict AF detection in patients with ESUS using ILR with daily remote interrogation. Patients with acute ESUS received an ILR, were seen every 6 months and additionally interrogated their ILR daily using remote monitoring. The incidence of AF detection was assessed and parameters which might predict AF detection (clinical and from magnetic resonance tomography) were analysed. ILR implantation was performed in 123 patients on average 20 days after stroke. During a mean follow-up of 12.7±5.5 months, AF was documented and manually confirmed in 29 of 123 patients (23.6 %). First AF detection occurred on average after 3.6±3.4 months of monitoring. Patients with AF were on average older, had a higher CHADS-VASc score and more often cerebral microangiopathy. In conclusion, AF can be documented in approximately 25 % of patients with the diagnosis of ESUS after careful work-up within a year of monitoring by an ILR and daily remote interrogation. This had important therapeutic consequences (initiation of anticoagulation for secondary stroke prevention) in these patients.

Usefulness of P Wave Duration in Embolic Stroke of Undetermined Source

“…This study provides several important findings: (1) atrial electrical remodeling substrate assessed by P wave SAECG in patients with ESUS was equivalent to that of patients with clinically diagnosed paroxysmal AF; (2) we could predict SCAF through PWD assessed by SAECG, which is associated with atrial substrate, and consequently with the degree of intra-/interatrial conduction delay; (3) the standardized clinical follow-up allowed us to detect SCAF in approximately one-quarter of patients with ESUS, which is similar to the AF detection rate reported in a 1-year follow-up study using ILR in patients with ESUS [5]; (4) prolonged PWD (≥ 135 ms) predicts stroke recurrence more robustly than SCAF detection; (5) considering the stroke recurrence trend shown in this study, the current APT-based strategy is inadequate in preventing stroke recurrence in patients with ESUS ( Figure 4).…”

“…However, approximately 10-25% of ischemic strokes are still categorized as embolic strokes of undetermined source (ESUS) since they do not reveal any specific cause despite standard evaluation [1]. Prior analyses of patients with cardiac implantable electronic devices suggest that ESUS might be associated with subclinical atrial fibrillation (SCAF) and that continuous monitoring of electrocardiography (ECG) over a prolonged period is important to diagnose SCAF [2][3][4][5].…”

Newer technologies for detection of atrial fibrillation

“…The incidence of new atrial fibrillation detected by ILRs in cohort studies of patients at risk for stroke and patients with cryptogenic stroke or TIA varies widely,414243515253545556 which is likely because of differences in study population, duration of follow-up, definition of atrial fibrillation, and ILRs used (table 3 and table 4). The Cryptogenic Stroke and Underlying Atrial Fibrillation (CRYSTAL AF) trial, which enrolled 441 patients aged 40 or over with cryptogenic stroke or TIA, evaluated the Reveal XT (Medtronic, Minneapolis, MN, USA) in an RCT.…”

Continuous 4‐week ECG monitoring with adhesive electrodes reveals AF in patients with recent embolic stroke of undetermined source

“…Increasing monitoring length beyond 4 weeks (Silverman, 2016) or conducting multiple intermittent monitoring periods yielded only little addition compared to a shorter monitoring period. To our knowledge, so far only a single study enrolling ESUS patients has been conducted, reporting AF detection rate of 24% in 13 months with an implantable cardiac monitor (Israel et al, 2017). ECG devices using adhesive electrodes or belts with one to three lead ECG have been successfully used and with high patient compliance rates among various other groups of arrhythmia patients (Ackermans et al, 2012;Engel, Mehta, Fogoros, & Chavan, 2012;Rosenberg, Samuel, Thosani, & Zimetbaum, 2013).…”