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Advanced Neurology ESUS, atrial fibrillation, and recurrence

1. Introduction in patients with ESUS, for predicting the probability of
detecting SAF during prolonged ECG monitoring. 12
The rate of stroke recurrence in the embolic stroke of
undetermined source (ESUS) patients is approximately Once SAF is detected, a consequent appropriate
5%, even with secondary prevention using single or dual treatment should be prescribed for secondary prevention.
antiplatelet therapy, which remains the recommended first- In strokes related to atrial fibrillation, oral anticoagulant
1,2
choice preventive option. Indeed, randomized clinical therapy (OAC) is recognized as the first choice for
trials have thus far failed to demonstrate the advantage of secondary prevention, owing to its superior efficacy and
13
direct oral anticoagulants (DOACs) over antiplatelets in safety profile compared with antiplatelets. In this context,
preventing stroke recurrence in ESUS patients. The majority DOACs are preferred over vitamin K antagonists (VKAs). 13
3
of stroke recurrences in ESUS patients are attributed to However, despite this established knowledge, there
ESUS or cardioembolic subtypes, especially when ESUS remains a dearth of literature on the follow-up management
is associated with large vessel occlusion and/or large brain of patients with ESUS, particularly when SAF is detected
ischemic lesions. The outcome of ESUS recurrence is and OAC is prescribed for secondary prevention with the
4-6
more severe than that of the index stroke. 4-6 aim of reducing the risk of stroke recurrence. Therefore, our
Subclinical atrial fibrillation (SAF) is a non-symptomatic study aimed to provide evidence regarding the 12-month
arrhythmia, mainly of short duration, primarily detectable rate of stroke recurrence in ESUS patients receiving OAC
in patients with electronic cardiac devices. SAF represents after SAF detection.
the main etiology underlying an ESUS. SAF can be
7,8
detected by using prolonged electrocardiogram (ECG) 2. Methods
monitoring during hospitalization or post-discharge 2.1. Procedures
using non-implantable or implantable devices for ECG We conducted a retrospective analysis of clinical,
monitoring. The rate of SAF detection increases steadily radiographic, and echocardiographic data from patients
with the duration of ECG monitoring. Using implantable
loop recorder ECG, the rate of SAF in ESUS patients ranges diagnosed with ESUS and admitted to the Stroke Unit at San
9
from 15% at 6 months to 43% at 3 years. Recommendations Giuseppe Hospital, Empoli, Italy. These patients underwent
for SAF detection in this context have been provided in post-discharge prolonged ECG monitoring using a non-
implantable external event recorder (Spider Flash-t , Sorin
TM
recent years. The AF-SCREEN International Collaboration
recommends, as a first step, ECG monitoring lasting at least Group, US) from January 1, 2017, to August 31, 2022. The
72 h. Patients with non-diagnostic 72-h ECG monitoring external ECG monitoring duration was 2 weeks. Episodes of
10
and high SAF risk should undergo prolonged ECG SAF, regardless of duration (even those lasting less than 30
monitoring using non-implantable or implantable tools. s), were considered diagnostic. For all patients, demographic
10
characteristics (age and sex), pre-event and 90-day post-
A similar approach has been proposed by the European
Society of Cardiology, which recommends evaluating stroke modified Rankin scale (mRS), risk factors for SAF, the
the probability of SAF detection using clinical tools and CHA DS -VASc score, National Institute of Health Stroke Scale
2
2
tailoring the duration of ECG monitoring. The European (NIHSS) at stroke onset, any acute revascularization treatment
11
by systemic thrombolysis and/or mechanical thrombectomy,
Stroke Organization (ESO) suggests an ECG monitoring of
at least 48 h in all ESUS patients over 55 years and, when size (<2.5 or >2.5 cm), location (cortical, cortical-subcortical,
feasible, a prolonged ECG monitoring using an implantable subcortical, supra- or sub-tentorial) and number (single or
loop recorder. However, in real-world clinical practice, multiple) of the ischemic lesions, presence or absence of large
9
only a minority of ESUS patients receive implantable loop vessel occlusion, left atrium size (with left atrial enlargement
2
recorders due to limited availability and the invasiveness defined as diameter ≥40 mm or area ≥20 cm ), presence of
of this monitoring option. Furthermore, in many cases, hemorrhagic transformation on 24 – 48-h brain computed
the time between the stroke event and prolonged ECG tomography, antithrombotic secondary prophylaxis at
monitoring may be prolonged, increasing the risk of stroke discharge and after ECG monitoring, the time between stroke
recurrence. Thus, pre-selection of ESUS patients with the onset and ECG monitoring, OAC prescription, and the rate of
highest SAF probability is crucial. In recent years, tools 12-month stroke recurrence were analyzed.
such as predictive scores aimed at tailoring the priority for All procedures performed in this study were in
prolonged ECG monitoring and reducing inappropriate accordance with the ethical standards of the institutional
costs have been proposed. A systematic review of the research ethics committee and with the 1964 Helsinki
literature by Masotti et al. identified eleven clinical scores, Declaration and its later amendments. Informed consent
eight derived in patients with cryptogenic stroke and three was obtained from all patients. The study was approved

Volume 3 Issue 1 (2024) 2 https://doi.org/10.36922/an.2287