Different aspects of early and late development of atrial fibrillation during hospitalization in cryptogenic stroke

Overview and Future Direction of Embolic Stroke of Undetermined Source from the Insights of CHALLENGE ESUS/CS Registry

Cryptogenic stroke (CS) accounts for approximately one-fourth of acute ischemic strokes, with most cases derived from embolic etiologies. In 2014, embolic stroke of undetermined source (ESUS) was advocated and the efficacy of anticoagulant therapy was anticipated. However, 3 large-scale clinical trials failed to demonstrate the superiority of direct oral anticoagulants (DOACs) over aspirin, potentially due to the heterogeneous and diverse pathologies of ESUS, including paroxysmal atrial fibrillation (AF), arteriogenic sources such as nonstenotic carotid plaque and aortic complicated lesion (ACL), patent foramen oval (PFO), and nonbacterial thrombotic endocarditis (NBTE) related to active cancer.Transesophageal echocardiography (TEE) is one of the most effective imaging modalities for assessing embolic sources in ESUS and CS. The Mechanisms of Embolic Stroke Clarified by Transesophageal Echocardiography for Embolic Stroke of Undetermined Source/Cryptogenic Stroke (CHALLENGE ESUS/CS) registry is a multicenter registry that enrolled consecutive patients with CS who underwent TEE at 8 hospitals in Japan between April 2014 and December 2016. Their mean age was 68.7±12.8 years, and 455 patients (67.2%) were male. The median National Institutes of Health Stroke Scale (NIHSS) score was 2. Since 7 analyses have been conducted from each institution to date, novel and significant insights regarding embolic origins and pathophysiologies of ESUS and CS were elucidated from this multicenter registry. This review discusses the diagnosis and treatment of ESUS and CS, tracing their past and future directions. Meaningful insights from the CHALLENGE ESUS/CS registry are also referenced and analyzed.

Cardiac Blood-Based Biomarkers of Myocardial Stress as Predictors of Atrial Fibrillation Development in Patients With Embolic Stroke of Undetermined Source/Cryptogenic Stroke: A Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE

Undiagnosed atrial fibrillation (AF) is a major risk factor for stroke that can go unnoticed in individuals with embolic stroke of undetermined source (ESUS) or cryptogenic stroke (CS). Early detection is critical for stroke prognosis and secondary prevention. This study aimed to determine if blood biomarkers of myocardial stress can accurately predict AF in patients with ESUS/CS, which would allow the identification of those who would benefit from closer monitoring.

METHODS

In February 2023 we performed a systematic date-unrestricted search of three databases for studies on patients with ESUS/CS who were subsequently diagnosed with AF. We examined the relationships between AF and serum myocardial stress markers such as brain natriuretic peptide (BNP), N-terminal-pro-BNP (NT-proBNP), midregional proatrial natriuretic peptide, and troponin.

RESULTS

Among the 1,527 studies reviewed, 23 eligible studies involving 6,212 participants, including 864 with AF, were analyzed. A meta-analysis of 9 studies indicated that they demonstrated a clear association between higher NT-proBNP levels and an increased risk of AF, with adjusted and raw data indicating 3.06- and 9.03-fold higher AF risks, respectively. Lower NT-proBNP levels had a pooled negative predictive value of 91.7%, indicating the potential to rule out AF with an 8% false-negative rate.

CONCLUSIONS

Further research is required to fully determine the potential of biomarkers for AF detection after stroke, as results from previous studies lack homogeneity. However, lower NT-proBNP levels have potential in ruling out AF in patients with ESUS/CS. Combining them with other relevant biomarkers may enhance the precision of identifying patients who will not benefit from extended monitoring, which would optimize resource allocation and patient care.

High-risk patent foramen ovale and elderly in cryptogenic stroke

BACKGROUND

High-risk patent foramen ovale (PFO) could be pathological in cryptogenic stroke (CS), but its clinical characteristics have not been fully studied, especially in elderly patients.

METHODS

Patients with CS were enrolled in the CHALLENGE ESUS/CS registry, a multicenter registry of CS patients undergoing transesophageal echocardiography. Clinical characteristics were compared among three groups: high-risk PFO group, large shunt PFO (≥25 microbubbles) or PFO with atrial septal aneurysm (ASA); right-to-left shunt (RLS) group, RLS including PFO with <25 microbubbles or without ASA; and no-RLS group.

RESULTS

In total, 654 patients were analyzed: 91, 221, and 342 in the high-risk PFO, RLS, and no-RLS groups, respectively. In multinomial logistic regression analysis, the male sex (odds ratio [OR] 1.825 [1.067-3.122]) was independently associated with high-risk PFO, but hypertension (OR, 0.562 [0.327-0.967]), multiple infarctions (OR, 0.601 [0.435-0.830]), and other cardioaortic embologenic risks (OR, 0.514 [0.294-0.897]) were inversely associated with high-risk PFO compared with non-RLS. In 517 patients aged ≥60 years, multiple infarctions (OR, 0.549 [0.382-0.788]) and other cardioaortic embologenic risks (OR, 0.523 [0.286-0.959]) were inversely associated with high-risk PFO.

CONCLUSIONS

High-risk PFO had specific clinical characteristics and possible mechanistic associations, and this trend was consistent among CS patients aged ≥60 years.

CLINICAL TRIAL REGISTRATION INFORMATION

http://www.umin.ac.jp/ctr/ (UMIN000032957).

European Stroke Organisation (ESO) guideline on screening for subclinical atrial fibrillation after stroke or transient ischaemic attack of undetermined origin

We aimed to provide practical recommendations for the screening of subclinical atrial fibrillation (AF) in patients with ischaemic stroke or transient ischaemic attack (TIA) of undetermined origin. These guidelines are based on the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology. Five relevant Population, Intervention, Comparator, Outcome questions were defined by a multidisciplinary module working group (MWG).

Longer duration of cardiac rhythm monitoring increases the detection of subclinical AF, but the optimal monitoring length is yet to be defined. We advise longer monitoring to increase the rate of anticoagulation, but whether longer monitoring improves clinical outcomes needs to be addressed. AF detection does not differ from in- or out-patient ECG-monitoring with similar monitoring duration, so we consider it reasonable to initiate in-hospital monitoring as soon as possible and continue with outpatient monitoring for more than 48h. Although insertable loop recorders (ILR) increase AF detection based on their longer monitoring duration, comparison with non-implantable ECG devices for similar monitoring time is lacking. We suggest the use of implantable devices, if feasible, for AF detection instead of non- implantable devices to increase the detection of subclinical AF. There is weak evidence of a useful role for blood, ECG, and brain imaging biomarkers for the identification of patients at high risk of AF. In patients with patent foramen ovale, we found insufficient evidence from RCT, but prolonged cardiac monitoring in patients >55 years is advisable for subclinical AF detection. To conclude, in adult patients with ischaemic stroke or TIA of undetermined origin, we recommend longer duration of cardiac rhythm monitoring of more than 48h and if feasible with IRL to increase the detection of subclinical AF.