Summary
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 CHA2DS2-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.
Key words
Atrial fibrillation - embolic stroke of undetermined source - implantable - loop-recorder
- remote monitoring - stroke