Large vessel occlusion is independently associated with atrial fibrillation detection

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.

Validation of the prehospital stroke scales as a tool for in-hospital large vessel occlusion stroke: whether we satisfied?

BACKGROUND

Prehospital stroke severity scales have been widely used to identify whether community stroke patients presented with large vessel occlusion (LVO) or not. However, whether these scales are also applicable to in-hospital stroke patients remains unknown.

PURPOSE

We aim to validate and compare the predictive capability of these scales for these patients.

MATERIAL AND METHODS

From January 2016 to October 2020, a total of 243 patients who activated in-hospital stroke alerts, were included in this study. The area under the curve (AUC) was used to assess the predictive ability of five scales (Field Assessment Stroke Triage for Emergency Destination [FAST-ED], Rapid Arterial Occlusion Evaluation [RACE], Los Angeles Motor Scale [LAMS], Cincinnati Prehospital Stroke Severity Scale [CPSSS], and Prehospital Acute Stroke Severity scale [PASS]) for LVO. In addition, multivariable logistic analysis was adopted to determine the predictors of LVO in our patients cohort.

RESULTS

Finally, 94 (38.7%) patients were confirmed presence of persistent LVO. The AUC for the FAST-ED, RACE, LAMS, CPSSS, and PASS scales to predict the presence of LVO in patients activating in-hospital stroke alerts were 0.82, 0.89, 0.86, 0.81, and 0.79, respectively. After multivariable analysis, baseline NIHSS (adjusted odds ratio [OR] = 1.160, 95% confidence interval [CI] = 1.110-1.212; P < 0.001) atrial fibrillation (adjusted OR = 2.940, 95% CI = 1.387-6.230; P = 0.005) and cardiac/pulmonary procedure (adjusted OR = 6.861, 95% CI = 2.437-19.315; P < 0.001) remained independent predictors of LVO.

CONCLUSION

The prehospital stroke scales also showed good predictive capabilities in discriminating LVO among inpatients who activated stroke alerts. However, given that inpatients' history is more readily available, a specifically designed in-hospital stroke scale that combines stroke severity and history is warranted.

In young patients with stroke of undetermined etiology, large vessel occlusions are less frequent in the group with high-risk patent foramen ovale

INTRODUCTION

Patent foramen ovale (PFO) is present in a significant proportion of young patients with stroke of undetermined etiology, but is not always causal. Therefore, classifications (RoPE, PASCAL) have been developed to determine the probability that PFO is the stroke cause. However, the presence of an initial arterial occlusion as a prediction factor was not studied when these classifications were built. Our aim was to evaluate the presence of arterial occlusion in young patients with stroke of undetermined etiology with/without high-risk PFO.

METHODS

From a prospectively-built monocentric database, we identified patients aged≥18 to<60-years with strokes of undetermined etiology and complete etiological work-up, including transesophageal echocardiography. We divided patients in two groups: (i) with high-risk PFO [i.e. PFO with large interatrial shunt (>30 microbubbles) or associated with atrial septal aneurysm] and (ii) with low-risk/without PFO. We recorded the presence of arterial occlusion and large vessel occlusion (LVO) in the acute phase.

RESULTS

We included 96 patients; 55 (57%) had high-risk PFO. Their median age was 48 (40-52) years, and 28 (29%) were women. The percentages of patients with arterial occlusion and with LVO were lower in the high-risk PFO group than in the low-risk/without PFO group: 11 (20%) versus 19 (46%) (P=0.008), and 5 (9%) versus 15 (37%) (P=0.002), respectively. There was no difference in the median RoPE score between groups (P=0.30).

CONCLUSION

The presence of LVO could represent a "red flag" of PFO causality in stroke of undetermined etiology, and could be implemented in future PFO-related stroke classifications.

Effect of edaravone on symptomatic intracranial hemorrhage in patients with acute large vessel occlusion on apixaban for non-valvular atrial fibrillation

BACKGROUND

Edaravone administration was associated with lower incidence of symptomatic intracranial hemorrhage (sICH) in patients with acute large vessel occlusion (LVO). However, its protective effect on sICH in patients with LVO who receive direct oral anticoagulants for non-valvular atrial fibrillation (NVAF) is uncertain.

OBJECTIVES

To explore the effect of edaravone administration on the incidence of sICH in patients with acute LVO receiving apixaban for NVAF.

METHODS

A Japanese multicenter registry of apixaban on clinical outcome of the patients with LVO or stenosis (ALVO study) included patients who were admitted within 24 h after stroke onset and were received apixaban within 14 days of stroke onset. Patients were divided into two groups according to edaravone administration (Edaravone and No-Edaravone groups). The incidence of sICH within one year and infarct growth before apixaban administration were compared between these groups.

RESULTS

Of the 686 enrolled patients, 622 were included and edaravone was administered to 407 (65.4%). The incidences of sICH in Edaravone and No-Edaravone groups were 1.3% and 5.0%, respectively (p = 0.01). The inverse probability of treatment-weighting (IPTW) hazard ratio (HR) (95% confidence interval [CI]) of Edaravone group for sICH within one year was 0.36 (0.15-0.80) compared to No-Edaravone group. The incidences of infarct growth in Edaravone and No-Edaravone groups were 35.3% and 42.0%, respectively (p = 0.13). IPTW HR (95% CIs) for infarct growth was 0.76 (0.60-0.97).

CONCLUSIONS

Edaravone administration was associated with a lower incidence of sICH in patients with LVO and NVAF who administrated apixaban.

Arrhythmic syncope: From diagnosis to management

Syncope is a concerning symptom that affects a large proportion of patients. It can be related to a heterogeneous group of pathologies ranging from trivial causes to diseases with a high risk of sudden death. However, benign causes are the most frequent, and identifying high-risk patients with potentially severe etiologies is crucial to establish an accurate diagnosis, initiate effective therapy, and alter the prognosis. The term cardiac syncope refers to those episodes where the cause of the cerebral hypoperfusion is directly related to a cardiac disorder, while arrhythmic syncope is cardiac syncope specifically due to rhythm disorders. Indeed, arrhythmias are the most common cause of cardiac syncope. Both bradyarrhythmia and tachyarrhythmia can cause a sudden decrease in cardiac output and produce syncope. In this review, we summarized the main guidelines in the management of patients with syncope of presumed arrhythmic origin. Therefore, we presented a thorough approach to syncope work-up through different tests depending on the clinical characteristics of the patients, risk stratification, and the management of syncope in different scenarios such as structural heart disease and channelopathies.

Sex Differences in Intensity of Care and Outcomes After Acute Ischemic Stroke Across the Age Continuum

BACKGROUND AND OBJECTIVES

Sex differences in stroke care and outcomes have been previously reported, but it is not known whether these associations vary across the age continuum. We evaluated whether the magnitude of female-male differences in care and outcomes varied with age.

METHODS

In a population-based cohort study, we identified patients hospitalized with ischemic stroke between 2012 and 2019 and followed through 2020 in Ontario, Canada, using administrative data. We evaluated sex differences in receiving intensive care unit services, mechanical ventilation, gastrostomy tube insertion, comprehensive stroke center care, stroke unit care, thrombolysis, and endovascular thrombectomy using logistic regression and reported odds ratios (ORs) and 95% CIs. We used Cox proportional hazard models and reported the hazard ratios (HRs) and 95% CI of death within 90 or 365 days. Models were adjusted for covariates and included an interaction between age and sex. We used restricted cubic splines to model the relationship between age and care and outcomes. Where the p-value for interaction was statistically significant (p < 0.05), we reported age-specific OR or HR.

RESULTS

Among 67,442 patients with ischemic stroke, 45.9% were female and the median age was 74 years (64-83). Care was similar between both sexes, except female patients had higher odds of receiving endovascular thrombectomy (OR 1.35, 95% CI [1.19-1.54] comparing female with male), and these associations were not modified by age. There was no overall sex difference in hazard of death (HR 95% CI 0.99 [0.95-1.04] for death within 90 days; 0.99 [0.96-1.03] for death within 365 days), but these associations were modified by age with the hazard of death being higher in female than male patients between the ages of 50-70 years (most extreme difference around age 57, HR 95% CI 1.25 [1.10-1.40] at 90 days, p-interaction 0.002; 1.15 [1.10-1.20] at 365 days, p-interaction 0.002).

DISCUSSION

The hazard of death after stroke was higher in female than male patients aged 50-70 years. Examining overall sex differences in outcomes without accounting for the effect modification by age may miss important findings in specific age groups.

Incidence of Atrial Fibrillation in Large Vessel Occlusion and Large Embolic Stroke of Undetermined Source

INTRODUCTION

Large vessel occlusion (LVO) stroke is a common presentation of acute ischemic stroke and is often unknown or cryptogenic in etiology. There is a strong association between atrial fibrillation (AF) and cryptogenic LVO stroke, making it a unique stroke subgroup. Therefore, we propose that any LVO stroke meeting the criteria for an embolic stroke of an undetermined source (ESUS) be classified as large ESUS (LESUS). The purpose of this retrospective cohort study was to report the etiology of anterior LVO strokes that underwent endovascular thrombectomy.

METHODS

This was a single-center retrospective cohort study characterizing the etiology of acute anterior circulation LVO strokes that received emergent endovascular thrombectomy from 2011 to 2018. Patients with LESUS designation at hospital discharge were changed to cardioembolic etiology if AF was discovered during the two-year follow-up period.  Results: Overall, 155 (45%) of 307 patients in the study were found to have AF. New onset AF was discovered in 12 (23%) of 53 LESUS patients after hospitalization. Furthermore, eight (35%) of 23 LESUS patients who received extended cardiac monitoring were found to have AF.

CONCLUSION

Nearly half the patients with LVO stroke who received endovascular thrombectomy were found to have AF. With the use of extended cardiac monitoring devices after hospitalization, AF is frequently discovered in patients with LESUS and may change the secondary stroke prevention strategy.

Blood-Based Biomarkers to Search for Atrial Fibrillation in High-Risk Asymptomatic Individuals and Cryptogenic Stroke Patients

Background

Atrial fibrillation (AF) increases the risk of ischemic stroke in asymptomatic individuals and may be the underlying cause of many cryptogenic strokes. We aimed to test the usefulness of candidate blood-biomarkers related to AF pathophysiology in two prospective cohorts representative of those populations.

Methods

Two hundred seventy-four subjects aged 65–75 years with hypertension and diabetes from the AFRICAT cohort, and 218 cryptogenic stroke patients aged >55 years from the CRYPTO-AF cohort were analyzed. AF was assessed by 4 weeks of monitoring with a wearable Holter device (NuuboTM™). Blood was collected immediately before monitoring started. 10 candidate biomarkers were measured by automated immunoassays (Roche, Penzberg) in the plasma of all patients. Univariate and logistic regression analyses were performed in each cohort separately.

Results

Atrial fibrillation detection rate was 12.4% (AFRICAT cohort) and 22.9% (CRYPTO-AF cohort). 4 biomarkers were significantly increased in asymptomatic individuals with AF [Troponin-T, Angiopoietin-2 (Ang-2), Endocan, and total N-terminal pro-B type natriuretic peptide (NT-proBNP)] and 7 biomarkers showed significantly higher concentrations in cryptogenic stroke patients with AF detection [growth differentiation factor 15, interleukin 6, Troponin-T, Ang-2, Bone morphogenic protein 10, Dickkopf-related protein 3 (DKK-3), and total NT-proBNP]. The models including Ang-2 and total NT-proBNP [AUC 0.764 (0.665–0.863)], and Ang-2 and DKK-3 [AUC = 0.733 (0.654–0.813)], together with age and sex, showed the best performance to detect AF in high-risk asymptomatic individuals, and in cryptogenic stroke patients, respectively.

Conclusion

Blood-biomarkers, in particular, total NT-proBNP, DKK-3, and Ang-2, were associated with AF reflecting two mechanistically different pathways involved in AF pathophysiology (AF stretch and vascular changes). The combination of these biomarkers could be useful in AF screening strategies in the primary care setting and also for searching AF after cryptogenic stroke.

Impact of Neuroimaging Patterns for the Detection of a Trial Fibrillation by Implantable Loop Recorders in Patients With Embolic Stroke of Undetermined Source

Objectives

Atrial fibrillation (AF) is a well-known etiology of embolic stroke of undetermined source (ESUS), although the optimal detection strategy of AF was not been fully evaluated yet. We assessed AF detection rate by implantable loop recorder (ILR) in patients with ESUS and compared the clinical characteristics and neuroimaging patterns between the patients with AF and AF-free patients.

Methods

We reviewed clinical characteristics and neuroimaging patterns of consecutive patients with who were admitted to our comprehensive stroke center for ESUS and underwent ILR insertion between August 1, 2019, and January 31, 202. The inclusion criteria were (1) 18 years of age or older; (2) classified as having cryptogenic stroke extracted from the group with undetermined stroke according to ESUS International Working Group; and (3) underwent ILR insertion during or after admission due to index ischemic events. Ischemic stroke pattern was classified as (1) tiny-scattered infarction, (2) whole-territorial infarction, (3) lobar infarction and (4) multiple-territorial infarction. Interrogations of data retrieved from the ILR were performed by cardiologists in every month after the implantation.

Results

In this study, 41 ESUS patients who received an ILR implantation were enrolled (mean age, 64 years; male sex, 65.9%). The rate of AF detection at 6 months was 34% (14 patients), and the mean time from ILR insertion to AF detection was 52.5 days [interquartile range (IQR), 45.0–69.5]. The median initial NIH stroke scale scores were significantly greater in patients with AF than those without AF (6.5 vs. 3.0, p = 0.019). Whole-territorial infarction pattern was significantly more frequent in patients with AF than in those without AF (64.3% vs.11.1%, p = 0.002).

Conclusions

Higher covert AF detection rates within the ESUS patients were most often associated with higher NIHSS and whole-territorial infarction patterns on brain imaging.

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.

Hyperdense Artery Sign in Patients With Acute Ischemic Stroke-Automated Detection With Artificial Intelligence-Driven Software

Background

Hyperdense artery sign (HAS) on non-contrast CT (NCCT) can indicate a large vessel occlusion (LVO) in patients with acute ischemic stroke. HAS detection belongs to routine reporting in patients with acute stroke and can help to identify patients in whom LVO is not initially suspected. We sought to evaluate automated HAS detection by commercial software and compared its performance to that of trained physicians against a reference standard.

Methods

Non-contrast CT scans from 154 patients with and without LVO proven by CT angiography (CTA) were independently rated for HAS by two blinded neuroradiologists and an AI-driven algorithm (Brainomix®). Sensitivity and specificity were analyzed for the clinicians and the software. As a secondary analysis, the clot length was automatically calculated by the software and compared with the length manually outlined on CTA images as the reference standard.

Results

Among 154 patients, 84 (54.5%) had CTA-proven LVO. HAS on the correct side was detected with a sensitivity and specificity of 0.77 (CI:0.66–0.85) and 0.87 (0.77–0.94), 0.8 (0.69–0.88) and 0.97 (0.89–0.99), and 0.93 (0.84–0.97) and 0.71 (0.59–0.81) by the software and readers 1 and 2, respectively. The automated estimation of the thrombus length was in moderate agreement with the CTA-based reference standard [intraclass correlation coefficient (ICC) 0.73].

Conclusion

Automated detection of HAS and estimation of thrombus length on NCCT by the tested software is feasible with a sensitivity and specificity comparable to that of trained neuroradiologists.

Proteins and pathways in atrial fibrillation and atrial cardiomyopathy underlying cryptogenic stroke

Background

Atrial fibrillation (AF) is one of the most prevalent causes of cryptogenic stroke. Also, apart from AF itself, structural and remodelling changes in the atria might be an underlying cause of cryptogenic stroke. We aimed to discover circulating proteins and reveal pathways altered in AF and atrial cardiomyopathy, measured by left atrial volume index (LAVI) and peak atrial longitudinal strain (PALS), in patients with cryptogenic stroke.

Methods

An aptamer array (including 1310 proteins) was measured in the blood of 20 cryptogenic stroke patients monitored during 28 days with a Holter device as a case-control study of the Crypto-AF cohort. Protein levels were compared between patients with (n = 10) and without AF (n = 10) after stroke, and the best candidates were tested in 111 patients from the same cohort (44 patients with AF and 67 without AF). In addition, in the first 20 patients, proteins were explored according to PALS and LAVI values.

Results

Forty-six proteins were differentially expressed in AF cases. Of those, four proteins were tested in a larger sample size. Only DPP7, presenting lower levels in AF patients, was further validated. Fifty-seven proteins correlated with LAVI, and 270 correlated with PALS. NT-proBNP was common in all the discovery analyses performed. Interestingly, many proteins and pathways were altered in patients with low PALS.

Conclusions

Multiple proteins and pathways related to AF and atrial cardiomyopathy have been revealed. The role of DPP7 as a biomarker for stroke aetiology should be further explored. Moreover, the present study may be considered hypothesis-generating.

Machine Learning-Based Model for Predicting Incidence and Severity of Acute Ischemic Stroke in Anterior Circulation Large Vessel Occlusion

Objectives: Patients with anterior circulation large vessel occlusion are at high risk of acute ischemic stroke, which could be disabling or fatal. In this study, we applied machine learning to develop and validate two prediction models for acute ischemic stroke (Model 1) and severity of neurological impairment (Model 2), both caused by anterior circulation large vessel occlusion (AC-LVO), based on medical history and neuroimaging data of patients on admission.

Methods: A total of 1,100 patients with AC- LVO from the Second Hospital of Hebei Medical University in North China were enrolled, of which 713 patients presented with acute ischemic stroke (AIS) related to AC- LVO and 387 presented with the non-acute ischemic cerebrovascular event. Among patients with the non-acute ischemic cerebrovascular events, 173 with prior stroke or TIA were excluded. Finally, 927 patients with AC-LVO were entered into the derivation cohort. In the external validation cohort, 150 patients with AC-LVO from the Hebei Province People's Hospital, including 99 patients with AIS related to AC- LVO and 51 asymptomatic AC-LVO patients, were retrospectively reviewed. We developed four machine learning models [logistic regression (LR), regularized LR (RLR), support vector machine (SVM), and random forest (RF)], whose performance was internally validated using 5-fold cross-validation. The performance of each machine learning model for the area under the receiver operating characteristic curve (ROC-AUC) was compared and the variables of each algorithm were ranked.

Results: In model 1, among the included patients with AC-LVO, 713 (76.9%) and 99 (66%) suffered an acute ischemic stroke in the derivation and external validation cohorts, respectively. The ROC-AUC of LR, RLR and SVM were significantly higher than that of the RF in the external validation cohorts [0.66 (95% CI 0.57–0.74) for LR, 0.66 (95% CI 0.57–0.74) for RLR, 0.55 (95% CI 0.45–0.64) for RF and 0.67 (95% CI 0.58–0.76) for SVM]. In model 2, 254 (53.9%) and 31 (37.8%) patients suffered disabling ischemic stroke in the derivation and external validation cohorts, respectively. There was no difference in AUC among the four machine learning algorithms in the external validation cohorts.

Conclusions: Machine learning methods with multiple clinical variables have the ability to predict acute ischemic stroke and the severity of neurological impairment in patients with AC-LVO.

Cardiac monitoring for patients with palpitations

Palpitations are one of the most common reasons for medical consultation. They tend to worry patients and can affect their quality of life. They are often a symptom associated with cardiac rhythm disorders, although there are other etiologies. For diagnosis, it is essential to be able to reliably correlate the symptoms with an electrocardiographic record allowing the identification or ruling out of a possible rhythm disorder. However, reaching a diagnosis is not always simple, given that they tend to be transitory symptoms and the patient is frequently asymptomatic at the time of assessment. In recent years, electrocardiographic monitoring systems have incorporated many technical improvements that solve several of the 24-h Holter monitor limitations. The objective of this review is to provide an update on the different monitoring methods currently available, remarking their indications and limitations, to help healthcare professionals to appropriately select and use them in the work-up of patients with palpitations.

ASCOD Phenotyping of Stroke With Anterior Large Vessel Occlusion Treated by Mechanical Thrombectomy

BACKGROUND AND PURPOSE

Determining the mechanism of large vessel occlusion related acute ischemic stroke is of major importance to initiate a tailored secondary prevention strategy. We investigated using the atherosclerosis, small vessel disease, cardiac source, other cause, dissection (ASCOD) classification the distribution of the causes of large vessel occlusion related acute ischemic stroke treated by mechanical thrombectomy.

METHODS

This was a predefined substudy of the FRAME (French Acute Multimodal Imaging to Select Patient for Mechanical Thrombectomy). Each patient underwent a systematic etiological workup including brain and vascular imaging, electrocardiogram monitoring lasting at least 24 hours and routine blood tests. Stroke mechanisms were systematically evaluated using the atherosclerosis, small vessel disease, cardiac source, other cause, dissection grading system at 3 months. We defined single potential cause by one cause graded 1 in a single domain, possible cause as a cause graded 1 or 2 regardless of overlap, and no identified cause without grade 1 nor 2 causes.

RESULTS

A total of 215 patients (mean age 70±14; 50% male) were included. A single potential cause was identified in 148 (69%). Cardio-embolism (53%) was the most frequent, followed by atherosclerosis (9%), dissection (5%) and other causes (1%). Atrial fibrillation accounted for 88% of C1. Overlap between grade 1 causes was uncommon (3%). Possible causes were identified in 168 patients (83%) and 16 (7%) had no cause identified after the initial evaluation.

CONCLUSIONS

Cardio-embolism, especially atrial fibrillation, was the major cause of large vessel occlusion related acute ischemic stroke. This finding emphasizes the yield of paroxysmal atrial fibrillation detection in those patients. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03045146.

Prediction of large vessel occlusion for ischaemic stroke by using the machine learning model random forests

BACKGROUNDS

The timely identification of large vessel occlusion (LVO) in the prehospital stage is extremely important given the disease morbidity and narrow time window for intervention. The current evaluation strategies still remain challenging. The goal of this study was to develop a machine learning (ML) model to predict LVO using prehospital accessible data.

METHODS

Consecutive acute ischaemic stroke patients who underwent CT or MR angiography and received reperfusion therapy within 8 hours from symptom onset in the Computer-based Online Database of Acute Stroke Patients for Stroke Management Quality Evaluation-II dataset from January 2016 to August 2021 were included. We developed eight ML models to integrate National Institutes of Health Stroke Scale (NIHSS) items with demographics, medical history and vascular risk factors to identify LVO and validate its efficiency.

RESULTS

Finally, 15 365 patients were included in the training set and 4215 patients were included in the test set. On the test set, random forests (RF), gradient boosting machine and extreme gradient boosting presented area under the curve (AUC) of 0.831 (95% CI 0.819 to 0.843), which were higher than other models, and RF presented the highest specificity (0.827). In addition, the AUC of RF was higher than other scales, and the accuracy of the model was improved by 6.4% compared with NIHSS. We also found the top five items of identifying LVO were total NIHSS score, gaze deviation, level of consciousness (LOC), LOC commands and motor left leg.

CONCLUSIONS

Our proposed model could be a useful screening tool to predict LVO based on the prehospital accessible medical data.

TRIAL REGISTRATION NUMBER

NCT04487340.

Novel Prehospital Triage Scale for Detecting Large Vessel Occlusion and Its Cause

Background

Patients with large vessel occlusion stroke (LVOS) need to be rapidly identified and transferred to comprehensive stroke centers. However, current prehospital evaluation and strategies still remain challenging.

Methods and Results

We retrospectively reviewed our prospectively collected database of patients with acute ischemic stroke (AIS). Based on the items of National Institutes of Health Stroke Scale and medical history that had a strong association with LVOS, we designed the 4‐item Stroke Scale (4I‐SS) and validated it in multi‐centers. The 4I‐SS incorporated gaze, level of consciousness, arm weakness, and atrial fibrillation. Receiver operating characteristic analysis was used to compare the 4I‐SS with previously established prehospital prediction scales. Finally, 1630 and 11 440 patients were included in the derivation and validation cohort, respectively. In the validation cohort, Youden Index, area under the curve, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the 4I‐SS≥4 to predict LVOS were 0.494, 0.800, 0.657, 0.837, 0.600, 0.868, and 0.788, respectively, and that of the 4I‐SS≥7 to predict basilar artery occlusion were 0.200, 0.669, 0.229, 0.971, 0.066, 0.974, and 0.899, respectively. Youden Index and area under the curve were higher than previously published scales for predicting LVOS. Further analysis showed that for predicting whether cardiogenic embolism was the cause, its accuracy was 0.922 when the 4I‐SS score, including atrial fibrillation, was ≥6, and its accuracy of predicting the occluded vessel was intracranial internal carotid artery or M1 segment of the middle cerebral artery when it was ≥7 was 0.590.

Conclusions

The 4I‐SS is an effective and simple tool that can identify LVOS and its cause.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03317639.

Combined Omic Analyzes of Cerebral Thrombi: A New Molecular Approach to Identify Cardioembolic Stroke Origin

[Figure: see text].

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

The detection of underlying atrial fibrillation (AF) has become increasingly possible by insertable cardiac monitoring (ICM). During hospitalization for cryptogenic stroke, factors related to the early and late development of AF have not been studied. CHALLENGE ESUS/CS is a multicenter registry of cryptogenic stroke patients undergoing transesophageal echocardiography. Twelve-lead electrocardiogram, continuous cardiac monitoring, and 24-h Holter electrocardiogram were all used for the detection of AF. Early and late detection of AF was determined with an allocation ratio of 1:1 among patients with AF. A total of 677 patients (68.7 ± 12.8 years; 455 men) were enrolled, and 64 patients developed AF during hospitalization. Four days after admission was identified as the approximate median day to classify early and late phases to detect AF: ≤ 4 days, 37 patients; > 4 days, 27 patients. Multiple logistic regression analysis showed that spontaneous echo contrast (SEC) (OR 5.91; 95% CI 2.19–15.97; p < 0.001) was associated with AF ≤ 4 days, whereas a large infarction > 3 cm in diameter (OR 3.28; 95% CI 1.35–7.97; p = 0.009) was associated with AF > 4 days. SEC and large infarctions were important predictors of in-hospital AF detection, particularly in the early and late stages, respectively; thus, they could serve as indications for recommending ICM.

Atrial Fibrillation and Stroke

Atrial fibrillation (AF) is the most common cardiac arrythmia and a major cause of stroke, heart failure, sudden death, and cardiovascular morbidity. AF increases risk of thromboembolic stroke via stasis in the left atrium and subsequent embolization to the brain. In patients with acute ischemic stroke, it is essential that clinicians undertake careful investigation to search for AF. In these patients, up to 23.7% eventually are found to have underlying AF. Oral anticoagulation is effective in prevention of strokes secondary to AF, reducing overall stroke numbers by approximately 64%. Left atrial appendage occlusion is promising for prevention of stroke in AF.

Paroxysmal Atrial Fibrillation in Cryptogenic Stroke Patients With Major-Vessel Occlusion

Background and Purpose: To determine whether acute major-vessel occlusion (MVO) predicts atrial fibrillation (AF) in cryptogenic stroke (CS) patients, we analyzed the association between acute MVO and AF detected by insertable cardiac monitoring (ICM).

Methods: We conducted a retrospective, multicenter, observational study of patients with CS who underwent ICM implantation between October 2016 and March 2018. In this analysis, we included follow-up data until June 2018. We analyzed the association of MVO with AF detected by ICM.

Results: We included 84 consecutive patients with CS who underwent ICM implantation. The proportion of patients with newly detected AF by ICM was higher in patients with MVO than in those without (41% [12/29] vs. 13% [7/55], p < 0.01) within 90 days of ICM implantation. The MVO was associated with AF after adjustment for each clinically relevant factor.

Conclusions: MVO was independently associated with AF detection in patients with CS, which suggests that MVO may be a useful predictor of latent AF. It is therefore essential to actively assess latent AF in patients with CS presenting with MVO.

B-type natriuretic peptide over N-terminal pro-brain natriuretic peptide to predict incident atrial fibrillation after cryptogenic stroke

BACKGROUND AND PURPOSE

B-type natriuretic peptide (BNP) and N-terminal pro-brain natriuretic peptide (NT-proBNP) are well-known surrogates of atrial fibrillation (AF) detection but studies usually present data on either BNP or NT-proBNP. The aim was to determine and directly compare the validity of the two biomarkers as a tool to predict AF and guide prolonged cardiac monitoring in cryptogenic stroke patients.

METHODS

Non-lacunar acute ischaemic stroke (<72 h) patients over 55 years of age with cryptogenic stroke after standard evaluation were included in the Crypto-AF study and blood was collected. BNP and NT-proBNP levels were determined by automated immunoassays. AF was assessed by 28 days' monitoring. Highest (optimizing specificity) and lowest (optimizing sensitivity) quartiles were used as biomarker cut-offs to build predictive models adjusted by sex and age. The integrated discrimination improvement index (IDI) and DeLong test were used to compare the performance of the two biomarkers.

RESULTS

From 320 patients evaluated, 218 were included in the analysis. AF was detected in 50 patients (22.9%). NT-proBNP (P < 0.001) and BNP (P < 0.001) levels were higher in subjects with AF and their levels correlated (r = 0.495, P < 0.001). BNP showed an increased area under the curve (0.720 vs. 0.669; P = 0.0218) and a better predictive capacity (IDI = 3.63%, 95% confidence interval 1.36%-5.91%) compared to NT-proBNP. BNP performed better than NT-proBNP in a specific model (IDI = 3.7%, 95% confidence interval 0.87%-6.5%), whilst both biomarkers performed similarly in the case of a sensitive model.

CONCLUSIONS

Both BNP and NT-proBNP were increased in cryptogenic stroke patients with AF detection. Interestingly, BNP outperforms NT-proBNP, especially in terms of specificity.