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.

Chronic ischemic lesions and presence of patent foramen ovale in young adults with embolic stroke of undetermined source: Results of the young ESUS patient registry

BACKGROUND

Chronic ischemic lesions (CILs) are frequent findings in patients with acute ischemic stroke, but their phenotypes and relevance in young adults with embolic stroke of undetermined source (Y-ESUS) remains uncertain. We aimed to compare Y-ESUS patients with CIL to those without CIL and assessed the association of CIL and its phenotypes with the presence of patent foramen ovale (PFO).

METHODS

This prospective longitudinal, multicenter cohort study enrolled consecutive patients 50 years and younger with ESUS from October 2017 to October 2019 in 41 stroke research centers in 13 countries. Local investigators adjudicated presence and phenotypes of CIL on routine brain imaging (either magnetic resonance imaging (MRI) or computed tomography (CT)).

RESULTS

Overall, 535 patients were enrolled (mean age = 40.4 (standard deviation (SD) = 7.3) years, 238 (44%) female). CILs were present in 76/534 (14.2%) patients with a median count CIL count of 1.0 (interquartile range (IQR) = 1-2), 42/76 (55%) had at least one cortical phenotype and 38/76 (50%) at least one non-cortical phenotype. Y-ESUS with CIL were less often female (32% vs 47% in non-CIL Y-ESUS), were older (mean 43 vs 40 years), had more often hypertension (42% vs 19%), diabetes (17% vs 7%), and hyperlipidemia (34% vs 18%). CIL Y-ESUS were independently associated with lower stroke recurrence (relative risk (RR) = 0.17 (0.05-0.61)). In Y-ESUS with PFO, CILs were less frequent in probable pathogenic PFO than with probable non-pathogenic PFO (6.1% vs 30% p< 0.001).

CONCLUSION

One in seven Y-ESUS patients has additional CIL. CILs were associated with several vascular risk factors, lower probability of a pathogenic PFO, and lower stroke recurrence.

Tumor Embolic Stroke: The Importance of Pathological Assessment of Clots after Thrombectomy

While tumor emboli are a rare cause of stroke in cancer patients, they highlight the importance of gross observations and pathological assessments in the evaluation of clots. In this case report, a 70-year-old male with type 2 diabetes mellitus and coronary artery disease presented with acute left-sided weakness. He was clinically diagnosed with stroke and given alteplase at 1.5 h from last known normal. He then underwent CT angiography that showed right internal carotid artery occlusion and immediate thrombectomy. The recovered clot was white and lipid-like; due to its atypical appearance, it was sent for pathological assessment, where it was shown to bear features of malignancy. Subsequent imaging identified masses indicating malignancy in the left gluteus, right pleural hilum, and spine. Tumor embolic stroke is a rare pathology. Embolic diseases such as strokes and pulmonary embolisms are common in patients with cancer. Embolic stroke of undetermined source (ESUS) represents a significant portion of cancer strokes. Tumor emboli, though rare, may be an underappreciated source of ESUS in cancer patients. We intend for this case to demonstrate the value of pathological assessment for atypical thrombi as well as highlight the etiology of tumor embolic strokes.

Magnetic resonance imaging for diagnostic workup of embolic stroke of undetermined source: A systematic review

BACKGROUND

Embolic stroke of undetermined source (ESUS) refers to ischemic stroke where the underlying cause of thromboembolism cannot be found despite the recommended diagnostic workup. Unidentified source of emboli hinders clinical decision-making and patient management with detrimental consequences on long-term prognosis. The rapid development and versatility of magnetic resonance imaging (MRI) make it an appealing addition to the diagnostic routine of patients with ESUS for the assessment of potential vascular and cardiac embolic sources.

AIMS

To review the use of MRI in the identification of cardiac and vascular embolic sources in ESUS and to assess the reclassification value of MRI examinations added to the conventional workup of ESUS.

SUMMARY OF REVIEW

We reviewed the use of cardiac and vascular MRI for the identification of a variety of embolic sources associated with ESUS, including atrial cardiomyopathy, left ventricular pathologies, and supracervical atherosclerosis in carotid and intracranial arteries and in distal thoracic aorta. The additional reclassification after MRI examinations added to the workup of patients with ESUS ranged from 6.1% to 82.3% and varied depending on the combination of imaging modalities.

CONCLUSION

MRI techniques allow us to identify additional cardiac and vascular embolic sources and may further decrease the prevalence of patients with the diagnosis of ESUS.

Left atrial strain, embolic stroke of undetermined source, and atrial fibrillation detection

BACKGROUND

Atrial cardiopathy is a proposed mechanism of embolic stroke of undetermined source (ESUS). Left atrial (LA) strain may identify early atrial cardiopathy prior to structural changes. We aim to study the associations between LA strain, ESUS, and atrial fibrillation (AF) detection in ESUS.

METHODS

The study population included patients with ESUS and noncardioembolic (NCE) stroke presenting to the Rhode Island Hospital Stroke Center between January 2016 and June 2017 who underwent transthoracic echocardiography. Speckle tracking echocardiography (STE) was used to measure the three phases of LA strain (reservoir, conduit, and contractile). Binary logistic regression analysis was performed to determine the associations between LA strain and stroke subtype (ESUS vs. NCE) as well as follow-up detection of AF in ESUS patients.

RESULTS

We identified 656 patients, 307 with ESUS and 349 with NCE. In binary logistic regression, the lowest tertiles of LA reservoir (adjusted OR 1.944, 95% CI 1.266-2.986, p = .002), contractile (aOR 1.568, 95% CI 1.035-2.374, p = .034), and conduit strain (aOR 2.288, 95% CI 1.448-3.613, p = .001) were more likely to be significantly associated with ESUS compared to NCE stroke. Among all ESUS patients, the lowest tertiles of LA reservoir strain (OR 2.534, 95% CI 1.029-6.236, p = .043), contractile strain (OR 2.828, 95% CI 1.158-6.903, p = .022), and conduit strain (OR 2.614, 95% CI 1.003-6.815, p = .049) were significantly associated with subsequent detection of AF.

CONCLUSION

Reduced LA strain is associated with ESUS occurrence and AF detection in ESUS patients. Therefore, quantification of LA strain in ESUS patients may improve risk stratification and guide secondary prevention strategies.

Effectiveness of statins on outcomes of patients with Embolic Stroke of Undetermined Source (ESUS)

BACKGROUND

Statins are highly recommended as a secondary prevention strategy after a stroke. Embolic Stroke of Undetermined Source (ESUS) accounts for up to one fifth of cases of ischemic stroke. There is a lack of studies investigating the effectiveness of statins in this subgroup of patients.

METHODS

We designed a longitudinal cohort study involving patients properly diagnosed with ESUS. Data about statin therapy included information about the time of initiation of the treatment, pre-stroke statin use, statin withdrawal, and the type and dosage of the statin prescribed. Patients were followed for 48 months after the index stroke. The primary endpoints included stroke recurrence, major cardiovascular events, and death from all causes. The secondary endpoint was the functional outcome, assessed in a standardized and systematic way using the modified Rankin Scale (mRS).

RESULTS

Patients who were not taking any statin after ESUS have significantly increased odds of stroke recurrence (OR = 3.29, 95% CI 1.27 - 8.55) or presenting the composite outcome of stroke recurrence, major cardiovascular events, and death (OR = 3.70, 95% CI 1.44 - 9.50) in the multivariate analysis. No statin therapy was directly associated with the functional outcome as well (OR = 3.32, 95% CI = 1.58 - 6.96). The early initiation of the statin therapy was estimated to reduce the risk of a second stroke and the composite outcome by 89% and 87%.

CONCLUSIONS

Our pioneering study provides evidence that patients with ESUS may benefit from statin therapy, especially if prescribed early and at higher dosages.

Atrial fibrillation in embolic stroke of undetermined source: role of advanced imaging of left atrial function

AIMS

Atrial fibrillation (AF) is detected in over 30% of patients following an embolic stroke of undetermined source (ESUS) when monitored with an implantable loop recorder (ILR). Identifying AF in ESUS survivors has significant therapeutic implications, and AF risk is essential to guide screening with long-term monitoring. The present study aimed to establish the role of left atrial (LA) function in subsequent AF identification and develop a risk model for AF in ESUS.

METHODS AND RESULTS

We conducted a single-centre retrospective case-control study including all patients with ESUS referred to our institution for ILR implantation from December 2009 to September 2019. We recorded clinical variables at baseline and analysed transthoracic echocardiograms in sinus rhythm. Univariate and multivariable analyses were performed to inform variables associated with AF. Lasso regression analysis was used to develop a risk prediction model for AF. The risk model was internally validated using bootstrapping. Three hundred and twenty-three patients with ESUS underwent ILR implantation. In the ESUS population, 293 had a stroke, whereas 30 had suffered a transient ischaemic attack as adjudicated by a senior stroke physician. Atrial fibrillation of any duration was detected in 47.1%. The mean follow-up was 710 days. Following lasso regression with backwards elimination, we combined increasing lateral PA (the time interval from the beginning of the P wave on the surface electrocardiogram to the beginning of the A' wave on pulsed wave tissue Doppler of the lateral mitral annulus) [odds ratio (OR) 1.011], increasing Age (OR 1.035), higher Diastolic blood pressure (OR 1.027), and abnormal LA reservoir Strain (OR 0.973) into a new PADS score. The probability of identifying AF can be estimated using the formula. Model discrimination was good [area under the curve (AUC) 0.72]. The PADS score was internally validated using bootstrapping with 1000 samples of 150 patients showing consistent results with an AUC of 0.73.

CONCLUSION

The novel PADS score can identify the risk of AF on prolonged monitoring with ILR following ESUS and should be considered a dedicated risk stratification tool for decision-making regarding the screening strategy for AF in stroke.

Prevalence of high-risk aortic arch atherosclerosis features on computed tomography angiography in embolic stroke of undetermined source

INTRODUCTION

Embolic stroke of undetermined source (ESUS) comprises a heterogenous group. There is a need to further identify etiologies within this group to guide management strategies. We examined the prevalence of aortic arch atherosclerosis (AAA) on CT angiography (CTA) in patients with embolic stroke of undetermined source (ESUS) to characterize high-risk plaque features.

METHODS

All patients from two prospective multicenter acute ischemic stroke studies (INTERRSeCT and PRove-IT) were included if the CTA adequately imaged the proximal aortic arch and the stroke etiology was recorded. Three readers blinded to stroke etiology analyzed the following AAA plaque features on baseline CTA at the time of stroke: 1) thickness in millimetres (mm); 2) morphology (none, smooth, ulcerated, or protruding); 3) location within the aortic arch (proximal, transverse, or distal); and 4) calcification (none, single small, multiple small, single large, or diffuse extensive).

RESULTS

We included 1063 patients, of which 293 (27.6%) had ESUS (mean age 67.5 years; 46.4% men; median NIHSS 12; 80.6% large vessel occlusion). Mean AAA thickness was significantly larger in ESUS patients (3.8 mm) compared to non-ESUS patients (3.0 mm; p<0.0001) and to a subgroup of patients with large artery atherosclerosis (2.9 mm; p=0.003). ESUS patients had a significantly higher proportion of ulcerated or protruding plaques (17.4% vs 10.3%; risk ratio 1.7, 95% C.I. 1.2-2.4, p=0.002). The location of AAA in the ESUS group was the ascending aorta in 37.9%, transverse arch in 42.3%, and descending aorta in 84.6%. Although AAA was mostly located in the distal aortic arch, ulcerated or protruding plaques were least common in the distal arch (p=0.002). There was no difference between ESUS and non-ESUS patients in plaque location (p=0.23) or calcification grade (p=0.092).

CONCLUSION

ESUS patients in our study had thicker AAA and a higher prevalence of ulcerated or protruding plaques located more proximally within the aortic arch. High-risk plaque features may suggest a causal role of AAA in the ESUS population with visible intracranial occlusions.

Predictors of Atrial Fibrillation in Patients with Embolic Stroke of Unknown Etiology and Implantable Loop Recorders-Further Insights of the TRACK AF Study on the Role of ECG and Echocardiography

Aims-Electrocardiography (ECG) and echocardiographic left atrial (LA) parameters may be helpful to assess the risk of atrial fibrillation (AF) in embolic stroke of unknown etiology (ESUS) and could therefore guide intensity of ECG monitoring. Methods-1153 consecutive patients with ischemic stroke or transient ischemic attack (TIA) were analyzed. An internal loop recorder (ILR) was implanted in 104 consecutive patients with ESUS. Multiple morphologic P-wave parameters in baseline 12-channel ECG and echocardiographic LA parameters were measured and analyzed in patients with and without ILR-detected AF. Using logistic regression, we evaluated the predictive value of several ECG parameters and LA dimensions on the occurrence of AF. Results-In 20 of 104 (19%) patients, AF was diagnosed by ILR during a mean monitoring time of 575 (IQR 470-580) days. Patients with AF were significantly older (72 (67-75) vs. 60 (52-72) years; p = 0.001) and premature atrial contractions (PAC) were more frequently observed (40% vs. 2%; p < 0.001) during baseline ECG. All morphologic P-wave parameters did not show a significant difference between groups. There was a non-significant trend towards a larger LA volume index (31 (24-36) vs. 29 (25-37) mL/m2; p = 0.09) in AF patients. Conclusions-Age and PAC are independently associated with incident AF in ESUS and could be used as markers for selecting patients that may benefit from more extensive rhythm monitoring or ILR implantation. In our consecutive cohort of patients with ESUS, neither morphological P-wave parameters nor LA size were predictive of AF.

Assessing atrial myopathy with cardiac magnetic resonance imaging in embolic stroke of undetermined source

BACKGROUND

Left atrial myopathy has been implicated in atrial fibrillation (AF)-related stroke and embolic stroke of undetermined source (ESUS).

OBJECTIVE

To use advanced cardiac magnetic resonance (CMR) imaging techniques, including left atrial (LA) strain and 4D flow CMR, to identify atrial myopathy in patients with ESUS.

METHODS

20 patients with ESUS and no AF or other cause for stroke, and 20 age and sex-matched controls underwent CMR with 4D flow analysis. Markers of LA myopathy were assessed including LA size, volume, ejection fraction, and strain. 4D flow CMR was performed to measure novel markers of LA stasis such as LA velocities and the LA residence time distribution time constant (RTDtc). These markers of LA myopathy were compared between the two groups.

RESULTS

There was no significant difference in: CMR-calculated LA velocities or LA total, passive or active ejection fractions between the groups. There was no significant difference in CMR-derived reservoir, conduit or contractile average longitudinal strain between the ESUS and control groups (22.9 vs 22.6%, p=0.379, 11.2 ± 3.5 vs 12.4 ± 2.6% p=0.224, 10.8 ± 3.2 vs 10.4 ± 2.3%, p=0.625 respectively). Similarly, RTDtc was not significantly longer in ESUS patients compared to controls (1.3 ± 0.2 vs 1.2 ± 0.2, p=0.1).

CONCLUSIONS

There were no significant differences in any CMR marker of atrial myopathy in ESUS patients compared to healthy controls, likely reflecting the multiple possible aetiologies of ESUS suggesting that the role LA myopathy plays in ESUS is smaller than previously thought.

Independent external validation of a stroke recurrence score in patients with embolic stroke of undetermined source

BACKGROUND

Embolic stroke of undetermined source (ESUS) accounts for a substantial proportion of ischaemic strokes. A stroke recurrence score has been shown to predict the risk of recurrent stroke in patients with ESUS based on a combination of clinical and imaging features. This study aimed to externally validate the performance of the ESUS recurrence score using data from a randomized controlled trial.

METHODS

The validation dataset consisted of eligible stroke patients with available magnetic resonance imaging (MRI) data enrolled in the PreDAFIS sub-study of the MonDAFIS study. The score was calculated using three variables: age (1 point per decade after 35 years), presence of white matter hyperintensities (2 points), and multiterritorial ischaemic stroke (3 points). Patients were assigned to risk groups as described in the original publication. The model was evaluated using standard discrimination and calibration methods.

RESULTS

Of the 1054 patients, 241 (22.9%) were classified as ESUS. Owing to insufficient MRI quality, three patients were excluded, leaving 238 patients (median age 65.5 years [IQR 20.75], 39% female) for analysis. Of these, 30 (13%) patients experienced recurrent ischaemic stroke or transient ischemic attack (TIA) during a follow-up period of 383 patient-years, corresponding to an incidence rate of 7.8 per 100 patient-years (95% CI 5.3-11.2). Patients with an ESUS recurrence score value of ≥ 7 had a 2.46 (hazard ratio (HR), 95% CI 1.02-5.93) times higher risk of stroke recurrence than patients with a score of 0-4. The cumulative probability of stroke recurrence in the low-(0-4), intermediate-(5-6), and high-risk group (≥ 7) was 9%, 13%, and 23%, respectively (log-rank test, χ2 = 4.2, p = 0.1).

CONCLUSIONS

This external validation of a published scoring system supports a threshold of ≥ 7 for identifying ESUS patients at high-risk of stroke recurrence. However, further adjustments may be required to improve the model's performance in independent cohorts. The use of risk scores may be helpful in guiding extended diagnostics and further trials on secondary prevention in patients with ESUS.

TRIAL REGISTRATION

Clinical Trials, NCT02204267. Registered 30 July 2014, https://clinicaltrials.gov/ct2/show/NCT02204267 .

Risk Stratification Tools to Guide a Personalized Approach for Cardiac Monitoring in Embolic Stroke of Undetermined Source

Current recommendations support a personalized sequential approach for cardiac rhythm monitoring to detect atrial fibrillation after embolic stroke of undetermined source. Several risk stratification scores have been proposed to predict the likelihood of atrial fibrillation after embolic stroke of undetermined source. This systematic review aimed to provide a comprehensive overview of the field by identifying risk scores proposed for this purpose, assessing their characteristics and the cohorts in which they were developed and validated, and scrutinizing their predictive performance. We identified 11 risk scores, of which 4 were externally validated. The most frequent variables included were echocardiographic markers and demographics. The areas under the curve ranged between 0.70 and 0.94. The 3 scores with the highest area under the curve were the Decryptoring (0.94 [95% CI, 0.88-1.00]), newly diagnosed atrial fibrillation (0.87 [95% CI, 0.79-0.94]), and AF-ESUS (Atrial Fibrillation in Embolic Stroke of Undetermined Source) (0.85 [95% CI, 0.80-0.87]), of which only the latter was externally validated. Risk stratification scores can guide a personalized approach for cardiac rhythm monitoring after embolic stroke of undetermined source.

Predicting risk of AF in ischaemic stroke using sinus rhythm ECG abnormalities: A meta-analysis

OBJECTIVE

To identify ECG changes in sinus rhythm that may be used to predict subsequent development of new AF.

METHOD

We identified prospective and retrospective cohort or case control studies evaluating ECG patterns from a 12-lead ECG in sinus rhythm taken in hospital or community predicting subsequent development of new AF. For each identified ECG predictor, we then identify absolute event rates and pooled risk ratios (RR) using an aggregate level random effects meta-analysis.

RESULTS

We identified 609,496 patients from 22 studies. ECG patterns included P wave terminal force V1 (PTFV1), interatrial block (IAB) and advanced interatrial block (aIAB), abnormal P wave axis (aPWA), PR prolongation and atrial premature complexes (APCs). Pooled risk ratios reached significance for each of these; PTFV1 RR 1.48 (95% CI 1.04-2.10), IAB 2.54 (95% CI 1.64-3.93), aIAB 4.05 (95% CI 2.64-6.22), aPWA 1.89 (95% CI 1.25-2.85), PR prolongation 2.22 (95% CI 1.27-3.87) and APCs 3.71 (95% CI 2.23-6.16). Diabetes reduced the predictive value of PR prolongation.

CONCLUSION

APC and aIAB were most predictive of AF, while IAB, PR prolongation, PTFV1 and aPWA were also significantly associated with development of AF. These support their use in a screening tool to identify at risk cohorts who may benefit from further investigation, or following stroke, with empirical anticoagulation.

Echocardiography in cardioembolic stroke prevention

Stroke is a leading cause of mortality and disability, and cardiac embolism accounts for one-third of all ischaemic strokes. Thirty per cent of strokes are cryptogenic. In this setting, echocardiography is essential in the diagnosis, treatment, and prevention of embolic stroke of undetermined source since it is a widely available, safe, and inexpensive tool. Transthoracic echocardiography and transoesophageal echocardiography, furthermore, are proven to change therapeutic management leading to initiation of anti-coagulation, anti-microbial therapy, patent foramen ovale (PFO) closure, or cardiac tumour resection. The most common cardioembolic sources include left atrial appendage thrombus, left ventricular thrombus, vegetations in endocarditis, paradoxical embolization in PFO, prosthesis thrombosis, and intracardiac tumours. Although the presence of a cardioembolic source only represents a risk factor for an ischaemic stroke, it could not assure the certain or the unique cause of the event. The purpose of this review is to underline the importance of echocardiography and overview the main sources of cardiac embolism and the echocardiographic features.

Non-stenosing carotid artery plaques in embolic stroke of undetermined source: a retrospective analysis

BACKGROUND

We aim to identify the association between high-risk carotid plaques and their laterality to stroke in ESUS patient population. We also discuss recurrent stroke events and their laterality to the index stroke.

METHODS

This was a retrospective study. We reviewed data for patients with ESUS between June 20, 2016, and June 20, 2021. Using computed tomography angiography, we analyzed plaque features that are associated with ESUS, and then, we identified the recurrent stroke events and characterized lateralization to the index stroke.

RESULTS

Out of 1779 patients with cryptogenic ischemic stroke, we included 152 patients who met the criteria for ESUS. High-risk plaque features were found more often ipsilateral to the stroke side when compared contralaterally: plaque ulceration (19.08% vs 5.26%, p < .0001), plaque thickness > 3 mm (19.08% vs 7.24%, p = 0.001), and plaque length > 1 cm (13.16% vs 5.92%, p = 0.0218). There was also a significant difference in plaque component in which both components (soft and calcified) and only soft plaques were more prevalent ipsilaterally (42.76% vs 23.68% and 17.76% vs 9.21%, respectively, p < .0001). Of the 152 patients, 17 patients were found to have a recurrent stroke event, and 47% (n = 8) had an ipsilateral stroke to the index event. Moreover, stroke was bilateral in 41% of the patients (n = 7), and contralateral in 12% (n = 2).

CONCLUSION

High-risk plaque features studied here were more prevalent ipsilaterally to the stroke side in ESUS than contralaterally. Multicenter studies are needed to form precise prediction models and scoring systems to help guide treatment, i.e., choice of medical therapy and/or revascularization.

Atrial cardiomyopathy: Diagnosis, clinical implications and unresolved issues in anticoagulation therapy

Atrial cardiomyopathy (AC) is an evolving pathophysiological entity that has expanded our understanding regarding the atrium and its role in arrhythmogenesis and cardiac thromboembolism. The pathological myocardium in AC promotes arrhythmogenesis through mechanical dysfunction (hypocontractility, fibrosis), adverse alterations of the endothelium and secretion of prothrombotic factors (IL-6, IL-8, TNF-a). 'Red flags', indicative of AC, can be recognized either non-invasively by electrocardiography, echocardiography and cardiac magnetic resonance imaging or invasively by high-density electroanatomical mapping as low bipolar voltage areas of the affected myocardium. Signs of AC have been strongly associated with an increased risk of ischemic stroke, even embolic strokes of undetermined source, regardless of the coexistence of atrial fibrillation (AF). The underlying existence of AC has been negatively correlated with the success rate of catheter ablation of AF. The clinical value of AC is the provision of a novel pathway regarding the potential mechanisms of cerebrovascular events of cardiac thromboembolic origin. In addition, AC may serve as a risk stratification tool to predict the long-term responders of AF catheter ablation.

Advanced interatrial block predicts recurrence of embolic stroke of undetermined source

BACKGROUND

Advanced interatrial block (IAB) is an independent risk factor for ischaemic stroke. This study aimed to analyse whether advanced IAB predicts recurrence of embolic stroke of undetermined source (ESUS).

METHODS

104 patients with a confirmed diagnosis of ESUS were followed up for a median period of 15 months (interquartile range, 10-48). We recorded data on clinical variables, P-wave characteristics, and presence of IAB on the electrocardiogram. Electrocardiogram findings were interpreted by a blinded, centralised rater at (XXXX2). ESUS recurrence was the primary outcome variable.

RESULTS

Median age was 47 years (range, 19-85); 50% of patients were women. IAB was detected in 36 patients (34.6%); IAB was partial in 29 cases (27.9%) and advanced in 7 (6.7%). Sixteen patients (15.4%) presented stroke recurrence; of these, 5 had partial and 4 had advanced IAB (P = .01; odds ratio [OR] = 9.44; 95% confidence interval [CI], 1.88-47.46; relative risk [RR] = 4.62; 95% CI, 2.01-10.61). Median P-wave duration was longer in patients with stroke recurrence (P = .009). The multivariate logistic regression analysis identified the following independent risk factors for stroke recurrence: advanced IAB (P < .001; OR = 10.86; 95% CI, 3.07-38.46), male sex (P = .028; OR = 4.6; 95% CI, 1.18-17.96), and age older than 50 years (P = .039; OR = 3.84; 95% CI, 1.06-13.88). In the Cox proportional hazards model, the risk variables identified were age older than 50 years (P = .002; hazard ratio, 7.04; 95% CI, 2.06-23.8) and P-wave duration (per ms) (P = .007; hazard ratio, 1.02; 95% CI, 1.01-1.04).

CONCLUSIONS

Advanced IAB and age older than 50 years predict ESUS recurrence.

Long-Term Cardiac Monitoring After Embolic Stroke of Undetermined Source: Search Longer, Look Harder

Embolic stroke of undetermined source (ESUS) represents a heterogeneous subgroup of patients with cryptogenic stroke, in which despite an extensive diagnostic workup the cause of stroke remains uncertain. Identifying covert atrial fibrillation among patients with ESUS remains challenging. The increasing use of cardiac implanted electronic devices (CIED), such as pacemakers, implantable defibrillators, and implantable loop recorders (ILR), has provided important information on the burden of subclinical atrial fibrillation. Accumulating evidence indicate that long-term continuous monitoring, especially in selected patients with ESUS, significantly increases the possibility of atrial fibrillation detection, suggesting it may be a cost-effective tool in secondary stroke prevention. This review summarizes available evidence related to the use of long-term cardiac monitoring and the use of implantable cardiac monitoring devices in patients with ESUS.

Utility of P-wave abnormalities for distinguishing embolic stroke from non-embolic stroke

BACKGROUND

Our aim was to analyze the incidence of P-wave abnormalities in embolic and non-embolic strokes, and evaluate its clinical usefulness for predicting stroke etiology.

METHODS

We included 376 consecutive patients hospitalized for acute ischemic stroke from January 2015 to September 2021. Among the patients in sinus rhythm at admission, 31 had ischemic stroke due to atrial fibrillation (AF)-related embolism, 59 had embolic stroke of unknown source (ESUS), and 143 had non-embolic stroke. P-wave abnormalities were defined as 1. P-wave axis abnormality (PWAA); 2. P-wave terminal force in V₁ (PTFV1) ≤ -4000 μV*ms; 3. advanced inter-atrial block (A-IAB).

RESULTS

The prevalence of each type of abnormality was consistently lower in patients with non-embolic stroke than in those with AF-related embolism (AF-related vs. ESUS vs. non-embolic; PWAA, 45% vs. 20% vs. 14%; PTFV1, 36% vs. 37% vs. 15%; and A-IAB, 55% vs. 31% vs. 13%, respectively). The identification of at least one type of P-wave abnormality improved the sensitivity compared to using a single abnormality parameter (sensitivity 72%, specificity 62%), while at least two types of abnormality had low sensitivity, but high specificity (sensitivity 29%, specificity 95%). Multivariate regression analysis revealed that identification of at least one type of P-wave abnormality was independently associated with embolic stroke (odds ratio 3.11, 95%CI 1.46-6.63).

CONCLUSIONS

The incidence of each type of P-wave abnormality was significantly lower in patients with non-embolic stroke. A combination of PWAA, PTFV1, and A-IAB parameters could be useful for distinguishing embolic from non-embolic stroke.

Interventional compared with medical management of symptomatic carotid web: A systematic review

BACKGROUND

Carotid web (CaW) is non-atheromatous, shelf-like intraluminal projection, generally affecting the posterolateral wall of the proximal internal carotid artery, and associated with embolic stroke, particularly in younger patients without traditional stroke risk factors. Treatment options for symptomatic CaWs include interventional therapy with carotid endarterectomy or carotid stenting versus medical therapy with antiplatelet or anticoagulants. As safety and efficacy of these approaches have been incompletely delineated in small-to-moderate case series, we performed a systematic review of outcomes with interventional and medical management.

METHODS

Systematic literature search was conducted and data analyzed per PRISMA guidelines (Preferred Reporting Items for Systemic Reviews and Meta-Analyses) from January 2000 to October 2021 using the search strategy: "Carotid web" OR "Carotid shelf" OR "Web vessels" OR "Intraluminal web". Patient-level demographics, stroke risk factors, technical procedure details, medical and interventional management strategies were abstracted across 15 series. All data were analyzed using descriptive statistics.

RESULTS

Among a total of symptomatic 282 CaW patients across 14 series, age was 49.5 (44-55.7) years, 61.7% were women, and 76.6% were black. Traditional stroke risk factors were less frequent than the other stroke causes, including hypertension in 28.6%, hyperlipidemia 14.6%, DM 7.0%, and smoking 19.8%. Thrombus adherent to CaW was detected on initial imaging in 16.2%. Among 289 symptomatic CaWs across 15 series, interventional management was pursued in 151 (52.2%), carotid artery stenting in 87, and carotid endarterectomy in 64; medical management was pursued in 138 (47.8%), including antiplatelet therapy in 80.4% and anticoagulants in 11.6%. Interventional and medical patients were similar in baseline characteristics. The reported time from index stroke to carotid revascularization was median 14 days (IQR 9.5-44). In the interventional group, no periprocedural mortality was noted, major periprocedural complications occurred in 1/151 (0.5%), and no recurrent ischemic events were observed over follow-up range of 3-60 months. In the medical group, over a follow-up of 2-55 months, the recurrence cerebral ischemia rate was 26.8%.

CONCLUSION

Cumulative evidence from multiple series suggests that carotid revascularization is a safe and effective option for preventing recurrent ischemic events in patients with symptomatic carotid webs.

A score to predict the stroke recurrence of patients with embolic stroke of undetermined source

AIM

We aimed to develop a score and validate it in a prospective cohort to identify the patients with ESUS at high risk for stroke recurrence.

METHODS

We assessed the stroke recurrence in ESUS patients of the Third China National Stroke Registry. We performed multivariable logistic regression analysis to identify predictors of stroke recurrence in the derivation cohort. Based on the coefficient of each covariate of the fitted multivariable model, we generated an integer-based point scoring system. We validated the score in the validation cohort assessing its discrimination and calibration.

RESULTS

2415 patients were included: 1611 in the derivation and 804 in the validation sample. We developed a scoring system (0-15 points) by assigning 2 points for hypertension, 3 points for diabetes mellitus, 4 points for multiple stage infarction, 2 points for watershed involved infarction, 1 points for left atrial diameter index (per increasing 2.5 mm/m2) and 3 points for without statin at discharge. The rate of stroke recurrence was 5.9% per year (95% CI 4.2-7.6%) in patients with low risk(a score of 0-5), 9.4% (7.3-11.5%) in patients with intermediate risk (6-10), and 26.8% (16.5-37.1%) in patients with high risk (11-15). The AUC (area under curve of receiver operator characteristic curve) of the score in the derivation cohort and validation cohort was, respectively, 0.60 (0.55-0.65) and 0.63 (0.56-0.70). The score was well calibrated both in the derivation cohort (p = 0.36) and validation cohort (p = 0.26) with the Hosmer-Lemeshow test.

CONCLUSION

The developed score can improve risk stratification after ESUS in secondary care settings.

Markers of Atrial Cardiopathy in Severe Embolic Strokes of Undetermined Source

Background and Purpose

The current definition of embolic strokes of undetermined source (ESUS) seems to be too broad, including strokes due to heterogeneous mechanisms, such as atrial cardiopathy and other occult cardiac conditions, aortic arch plaques, and non-stenosing atherosclerosis, that can be differently associated with clinical stroke severity at the time of presentation. The aim of our study was to assess the possible association between neurological deficit severity and presence of markers of atrial cardiopathy in ESUS.

Methods

We retrospectively reviewed the medical records of a cohort of 226 ESUS patients (105 M, 121 F), that were divided into two groups according to the severity of neurological deficit (99 mild strokes with NIHSS ≤ 5 and 127 severe strokes with NIHSS >5). The following indices of atrial cardiopathy were evaluated: P wave dispersion, P wave max, P wave min, P wave mean, P wave index, P wave axis, left atrial size.

Results

Patients with severe ESUS were significantly older (74 ± 12 vs. 67 ± 14 years, P < 0.001) and female sex was prevalent (67 vs. 36%, P > 0.001); they had higher values of P-wave-dispersion (51 ± 14 vs. 46 ± 13, P = 0.01), P-wave-max (131 ± 20 vs. 125 ± 15 ms, P = 0.01), P-wave-index (16 ± 5 vs. 15 ± 5 ms, P = 0.01), left atrial size (20 ± 6 vs. 18 ± 4 cm², P = 0.01), left atrial volume index (31 ± 14 vs. 27 ± 11 ml/m², P = 0.04), in comparison with mild ESUS. An abnormal P wave axis was detected more frequently in severe ESUS (21 vs. 9%, P = 0.01). Furthermore, multivariate logistic regression showed that age (OR = 1.21 for each 5-year increase, 95% CI 1.09–1.35), sex (OR = 3.24 for female sex, 95% CI 1.82–5.76) and PWD (OR = 1.32 for each 10-ms increase, 95% CI 1.07–1.64) were the best subset of associated variables for severe ESUS.

Conclusions

Our findings shed light on specific clinical characteristics of severe ESUS including the presence of atrial cardiopathy that could play a pathogenic role in this subgroup of patients. Searching for atrial fibrillation in these patients is especially important to perform the most appropriate therapy.

Ipsilateral Carotid Plaque Presence is Inversely Associated with Patent Foramen Ovale in Cryptogenic Stroke: A Multicenter CohortStudy

BACKGROUND

Embolic stroke of undetermined source (ESUS) accounts for up to 20% of all strokes. Potential contributors to ESUS include patent foramen ovale (PFO) and non-stenotic plaque (<50%, NSP) of the ipsilateral internal carotid artery (ICA). To better differentiate these as unique mechanisms, we explored the prevalence of each in a multicenter observational cohort.

METHODS

A retrospective multicenter cohort of consecutive patients with ESUS was queried (2015-2021). Patients with unilateral, anterior circulation ESUS who had a computed tomography angiography neck scan and a transthoracic echocardiogram (TTE) and/or transesophageal echocardiogram (TEE) with adequate visualization of a PFO were included. Patients with prior carotid stent, endarterectomy or alternative etiologies were excluded from the study. Descriptive statistics were used to characterize patients with and without PFO, with multivariable logistic regression used to predict the presence of a PFO based on clinicoradiographic factors as well as degree of luminal stenosis and ipsilateral plaque thickness >3mm, based on previously published thresholds of clinical relevance.

RESULTS

Of the 234 included patients with unilateral anterior ESUS and adequate TTE or TEE, 17 (7.3%) had a PFO and 64 (27.4%) had ≥3mm of ipsilateral ICA plaque. Patients with PFO had significantly less NSP and less ipsilateral cervical ICA stenosis (0% [IQR 0-0%] vs. 0% [IQR 0-50%], p=0.03; Table). After adjustment for all predictors of PFO in multivariable regression (p<0.1: Hispanic ethnicity and ipsilateral plaque thickness), ipsilateral NSP was independently associated with a 62% lower odds of harboring a PFO (OR_adj per 1cm of plaque 0.48, 95%CI 0.25-0.94). No patients with a PFO had ≥3mm of ipsilateral ICA plaque.

CONCLUSION

Ipsilateral NSP is more common in ESUS patients without a PFO. While this study is limited by the small PFO event rate, it supports the notion that NSP and PFO may be independent contributors to ESUS.

Potential Embolic Sources Differ in Patients With Embolic Stroke of Undetermined Source According to Age: A 15-Year Study

Introduction

Understanding the potential embolic source in young patients with ESUS may improve the diagnosis and treatment of such patients.

Hypothesis

Potential embolic sources (PES) differ in young vs. older patients with ESUS, and, therefore, not all patients with ESUS have the same risk profile for stroke recurrence.

Methods

Young patients (age 18-49) with ESUS, who were admitted to our stroke center from 2006 to 2019, were identified retrospectively and matched with next consecutive older patients (age 50-99) with ESUS by admission date. PES were categorized as atrial cardiopathy, AFib diagnosed during follow-up, left ventricular disease (LVD), cardiac valvular disease (CVD), PFO or atrial septal aneurysm (ASA), and arterial disease. Patients, who had cancer or thrombophilia, were excluded. The type and number of PES and stroke recurrence rates were determined and compared between young and older patients.

Results

In young patients (55.3% women, median age 39 years), the most common PES was PFO/ASA, and the rate of other PES was low (2-7%). Half of the young patients (54.1%) had a single PES, only 10% had multiple PES, and 35.3% of young patients did not have any PES identified. In older patients (41.7% women, median age 74 years), the 3 most common PES were atrial cardiopathy (38.1%), LVD (35.7%), and arterial disease (23.8%). Nearly half of older patients (42.9%) had multiple PES. The rate of stroke recurrence tended to be lower in young patients as compared to older patients (4.9 vs. 11.4%, p = 0.29). During a median follow-up of 3 years, only 3 young patients (4.9%) had a recurrent stroke, and two of them had unclosed PFO. There were no recurrent strokes among young patients with no PES identified.

Conclusions

It was noted that PES differ in patients with ESUS according to age and differences in recurrence. PFO is the only common PES in young patients with ESUS. Future studies prospectively evaluating PES in both age groups are needed.

From cryptogenic to ESUS: Toward precision medicine?

Cryptogenic infarctions are infarctions without a defined cause, despite a complete work-up. They differ from infarctions of undetermined causes, which may involve overlapping causes or an incomplete investigation. It is also different from uncommon heritable and non-heritable causes. The term embolic stroke of undetermined source (ESUS) proposed in 2014 is defined as a non-lacunar brain infarct without proximal arterial stenosis or cardioembolic sources. The major advantage of this definition compared to cryptogenic definition is the proposition of a specific work-up. In a general population, frequent potential sources of embolism in patients with ESUS have been suggested since a long time and include: patent foramen ovale (PFO), covert atrial fibrillation (AF), complex aortic arch atheroma, large vessel atheroma with stenosis<50%, carotid web, atrial cardiomyopathy, thrombophilia associated with cancer. It took almost 30 years to show, in patients under 60 with a cryptogenic stroke and a PFO, that PFO occlusion was superior to medical treatment alone for recurrent stroke. PFO under 60 is therefore no longer a cryptogenic cause of infarction. The concept of cryptogenic stroke and its refinement in ESUS have been fruitful for the identification of PFO associated as a cause. Covert AF can be detected by different techniques but its risk significance for recurrent stroke might be different from the simple electrocardiographic detection of AF. With the development of direct oral anticoagulants (DOAs), randomized studies in patients with ESUS, were run for stroke prevention but no difference was observed between patients treated by DOA compared to aspirin. These studies showed however the heterogeneity of ESUS patients. Further ESUS classification should be considered as a tool to identify homogeneous groups. We propose to further split the ESUS group into different subgroups: ESU-PFO>60-year-old, ESUS-ATH with stenosis<50%, ESUS-AF (covert AF & atrial cardiomyopathy), ESUS-cancer and others. Precision medicine is the ability to make targeted healthcare decisions based on the specific risks of individual patients. One preliminary stage is therefore to identify homogeneous groups suitable in the future for new therapeutic trials and, at the end, for new specific treatments.

Management of Patients with Embolic Stroke of Unknown Source: Interpreting the Evidence in the Light of Clinical Judgement

PURPOSE OF REVIEW

To assess the validity of the belief that anticoagulation is not beneficial in patients with embolic stroke of unknown source (ESUS), and to asssess the benefits and safety of direct-acting oral anticoagulants (DOACs).

RECENT FINDINGS

The failure of randomized trials to show benefit of anticoagulation in ESUS is probably due to misclassification of large artery atherosclerosis (LAA) as ESUS, as defined by a stenosis ≥ 50%. There are important differences among DOACs. There are a number of problems with dabigatran, and rivaroxaban and edoxaban are not suitable for once-daily dosing. Recent evidence from real-world practice indicates that apixaban is more effective and safer than rivaroxaban. Plaque burden should be included in the definition of LAA. Patients in whom a cardioembolic source is strongly suspected should be anticoagulated; antiplatelet agents are not significantly safer than DOACs, and are not effective in cardioembolic stroke.

Rivaroxaban versus aspirin on functional and cognitive outcomes after embolic stroke of undetermined source: NAVIGATE ESUS trial

BACKGROUND

The effect of interventions on functional impairment is an important outcome in stroke prevention trials and should be considered as an adjunct to counting discrete events. In the NAVIGATE-ESUS trial, 7213 patients with recent embolic strokes of undetermined source were randomized to rivaroxaban (15 mg once daily) or aspirin (100 mg daily). After 11 months there was no effect on the prevention of recurrent stroke.

AIMS

To determine the effect of rivaroxaban compared to aspirin on functional and cognitive outcomes.

METHODS

Function and cognition were measured at baseline, 1 year, and study end using the Standard Assessment of Global Everyday Activities (SAGEA), a 15-item scale assessing cognitive, instrumental, and basic activities of daily living as well as mobility, and the Montreal Cognitive Assessment (MoCA). Changes in scores were calculated by subtracting either study end or 1-year scores from baseline, and differences in distributions were compared using the Mann-Whitney U test. SAGEA and MoCA scores were also correlated with recurrent stroke.

RESULTS

Follow-up SAGEA scores were available in 6378 (88%) participants. There was no difference in change in function for those allocated to rivaroxaban compared to aspirin (Mann-Whitney U test, p = 0.8), with both distributions having a median (25p,75p) change of 0 (-2,1). Overall, more of those who experienced a recurrent stroke (n=247; mostly minor ischemic), reported functional difficulty at study end versus entry, compared with those who did not (51% versus 30%, chi-square test, p< 0.001), and this was consistent across global regions. There was no difference in the change in cognition by treatment group, nor were recurrent strokes associated with a change in cognition.

CONCLUSIONS

Rivaroxaban, compared to aspirin, was not associated with changes in functional or cognitive status in patients with recent ESUS. The SAGEA scale detected changes in functional status associated with recurrent strokes in an international stroke population.

Functional Abilities of an International Post-Stroke Population: Standard Assessment of Global Everyday Activities (SAGEA) Scale

BACKGROUND AND OBJECTIVES

Function is an important outcome after stroke; traditional assessments may not capture functional deficits important to patients. We examined the validity of the Standard Assessment of Global Everyday Activities (SAGEA), a patient-reported outcome that assesses activities important to patients and for use in international clinical trials.

METHODS

The NAVIGATE-ESUS trial evaluated rivaroxaban compared to aspirin in preventing recurrent stroke in 7213 participants. The Modified Rankin Scale (mRS), the National Institutes of Health Stroke Scale (NIHSS), and the SAGEA were collected at entry. Chi square tests were used to compare proportions and Spearman rank correlations were used to compare between measures. SAGEA was compared to the Modified Frailty Index (MFI) and the occurrence of infarct to examine criterion validity RESULTS: Participants were 67 years, 2/3 were male, and at baseline 30% had no disability and 58% had slight disability according to mRS scores. SAGEA was weakly correlated with the mRS (r=0.37), the NIHSS (r=0.29) and the MFI (r=0.30). Of the 2154 with an mRS score of 0, 61% reported difficulty on the SAGEA. The largest discrepancies between SAGEA and other measures were because of cognitive functional deficits detected by the SAGEA that were not identified on other assessments. A larger number of MRI identified infarcts (acute and covert) were associated with a higher SAGEA score (p=0.007).

CONCLUSIONS

The SAGEA is a simple, globally applicable measure of cognitive and functional abilities that identifies issues that other commonly used assessments of disability and function do not capture.

Cardiac Papillary Fibroelastoma: A Rare Cause of Cardioembolic Stroke

BACKGROUND

Cardiac fibroelastomas are exceedingly rare etiologies of stroke, increasingly recognized with better diagnostic modalities. Surgical excision is the only curative option; however, timing of heparinization for cardiac bypass remains a challenging decision.

OBJECTIVE

We present a case of a 56-year-old female, diagnosed with multiple posterior circulation strokes and a left atrial mass, who successfully underwent anticoagulation and resection in 1 week.

MATERIAL AND METHODS

MRI of the brain demonstrated numerous embolic-looking posterior circulation strokes. Transthoracic echo was negative for atrial pathology; a transesophageal echo revealed a left atrial mass, histologically consistent with papillary fibroelastoma.

RESULTS

Resection was delayed for up to 1 week to allow safe heparinization. We present a unique case of embolic stroke of undetermined source (ESUS) arising from a histologically rare tumor.

CONCLUSION

We make the case for extensive workup for evaluation of posterior circulation strokes, including TEE, as well as timely resection of cardiac tumors.

Rivaroxaban versus aspirin for prevention of covert brain infarcts in patients with embolic stroke of undetermined source: NAVIGATE ESUS MRI substudy

Background

Covert brain infarcts are associated with important neurological morbidity. Their incidence in patients with embolic stroke of undetermined source (ESUS) is unknown.

Aims

To assess the incidence of covert brain infarcts and cerebral microbleeds using MRI in a prospective substudy of the NAVIGATE ESUS randomized trial and to evaluate the effects of antithrombotic therapies.

Methods

At 87 sites in 15 countries, substudy participants were randomly assigned to receive rivaroxaban 15 mg daily or aspirin 100 mg daily and underwent brain MRI near randomization and after study termination. The primary outcome was incident brain infarct (clinical ischemic stroke or covert brain infarct). Brain infarcts and microbleeds were ascertained centrally by readers unaware of treatment. Treatment effects were estimated using logistic regression.

Results

Among the 718 substudy participants with interpretable, paired MRIs, the mean age was 67 years and 61% were men with a median of 52 days between the qualifying ischemic stroke and randomization and a median of seven days between randomization and baseline MRI. During the median (IQR) 11 (12) month interval between scans, clinical ischemic strokes occurred in 27 (4%) participants, while 60 (9%) of the remaining participants had an incident covert brain infarct detected by MRI. Assignment to rivaroxaban was not associated with reduction in the incidence of brain infarct (OR 0.77, 95% CI 0.49, 1.2) or of covert brain infarct among those without clinical stroke (OR 0.85, 95% CI 0.50, 1.4). New microbleeds were observed in 7% and did not differ among those assigned rivaroxaban vs. aspirin (HR 0.95, 95% CI 0.52–1.7).

Conclusions

Incident covert brain infarcts occurred in twice as many ESUS patients as a clinical ischemic stroke. Treatment with rivaroxaban compared with aspirin did not significantly reduce the incidence of covert brain infarcts or increase the incidence of microbleeds, but the confidence intervals for treatment effects were wide.

Registration:https://www.clinicaltrials.gov. Unique identifier: NCT 02313909

Coexisting of aortic arch atheroma and atrial fibrillation for short-term recurrence and poor functional outcome in acute stroke

BACKGROUND AND PURPOSE

Multiple embolic sources are sometimes observed simultaneously in patients with embolic stroke. The present study investigated the effects of coexisting aortic arch atheroma ≥ 4 mm thick and atrial fibrillation (AF) on short-term stroke recurrence and functional outcome.

METHODS

Transesophageal echocardiography (TEE) was performed in consecutive embolic stroke patients, and 395 patients were classified into 4 groups according to the presence of aortic arch atheroma ≥ 4 mm thick and AF: AF - /ARCH - group, AF + /ARCH - group, AF - /ARCH + group, and AF + /ARCH + group. In accordance with these 4 groups, we evaluated stroke recurrence and all-cause death for 3 months after stroke onset, and also evaluated the 3-month functional outcome using the modified Rankin scale (mRS).

RESULTS

Among the 128 AF patients, 39.1% also had aortic arch atheroma ≥ 4 mm thick. Of the 395 enrolled cases, the AF + /ARCH + group showed the highest frequencies of stroke recurrence and all-cause death during 3 months after onset. On multivariate analysis, stroke recurrence or all-cause death during 3 months after onset was relatively more frequent in the AF + /ARCH + group than in the AF + /ARCH - group (OR, 2.34; 95% CI, 0.82-6.69; p = 0.11), but that was not statistically significant, and poor functional outcome (mRS score 3-6) at 3 months was significantly more frequent in the AF + /ARCH + group than in the AF + /ARCH - group (OR, 2.59; 95% CI, 1.08-6.24; p = 0.0339).

CONCLUSIONS

Aortic arch atheroma concomitant with AF is not rare and appears associated with increased risks of stroke recurrence and poor functional outcome.

Advanced interatrial block predicts recurrence of embolic stroke of undetermined source

BACKGROUND

Advanced interatrial block (IAB) is an independent risk factor for ischaemic stroke. This study aimed to analyse whether advanced IAB predicts recurrence of embolic stroke of undetermined source (ESUS).

METHODS

104 patients with a confirmed diagnosis of ESUS were followed up for a median period of 15 months (interquartile range, 10-48). We recorded data on clinical variables, P-wave characteristics, and presence of IAB on the electrocardiogram (ECG). ECG findings were interpreted by a blinded, centralised rater at (XXXX2). ESUS recurrence was the primary outcome variable.

RESULTS

Median age was 47 years (range, 19-85); 50% of patients were women. IAB was detected in 36 patients (34.6%); IAB was partial in 29 cases (27.9%) and advanced in 7 (6.7%). Sixteen patients (15.4%) presented stroke recurrence; of these, 5 had partial and 4 had advanced IAB (P = .01; odds ratio [OR] = 9.44; 95% confidence interval [CI], 1.88-47.46; relative risk [RR] = 4.62; 95% CI, 2.01-10.61). Median P-wave duration was longer in patients with stroke recurrence (P = .009). The multivariate logistic regression analysis identified the following independent risk factors for stroke recurrence: advanced IAB (P < .001; OR = 10.86; 95% CI, 3.07-38.46), male sex (P = .028; OR = 4.6; 95% CI, 1.18-17.96), and age older than 50 years (P = .039; OR = 3.84; 95% CI, 1.06-13.88). In the Cox proportional hazards model, the risk variables identified were age older than 50 years (P = .002; hazard ratio, 7.04; 95% CI, 2.06-23.8) and P-wave duration (per ms) (P = .007; hazard ratio, 1.02; 95% CI, 1.01-1.04).

CONCLUSIONS

Advanced IAB and age older than 50 years predict ESUS recurrence.

Statin treatment and outcomes after embolic stroke of undetermined source

The association of low-density lipoprotein cholesterol lowering with outcomes in embolic stroke of undetermined source (ESUS) patients is unclear. In these patients we aimed to assess the effect of statin on stroke recurrence, major adverse cardiovascular events (MACE) and death rates. Consecutive ESUS patients in the Athens Stroke Registry were prospectively followed-up to 10 years for stroke recurrence, MACE, and death. The Nelson-Aalen estimator was used to estimate the cumulative probability by statin allocation at discharge and cox-regression analyses to investigate whether statin at discharge was a predictor of outcomes. Among 264 ESUS patients who were discharged and followed for 4 years, 89 (33.7%) were treated with statin at discharge. Patients who were discharged on statin had lower rates of stroke recurrence (3.58 vs. 7.23/100 patient-years, HR: 0.48; 95% CI 0.26-0.90), MACE (4.98 vs. 9.89/100 patient-years, HR: 0.49; 95% CI 0.29-0.85), and death (3.93 vs. 8.21/100 patient-years, HR: 0.50; 95% CI: 0.28-0.89). In the multivariate analysis, statin treatment at discharge was an independent predictor of stroke recurrence (adjusted HR: 0.48; 95% CI 0.26-0.91), MACE (adjusted HR: 0.48; 95% CI 0.28-0.82), and death (adjusted HR: 0.50; 95% CI 0.27-0.93). Patients with ESUS discharged on statins have lower rates of stroke recurrence, MACE, and death compared to those not receiving statin therapy.

Partitioning risk factors for embolic stroke of undetermined source using exploratory factor analysis

Background

Embolic stroke of undetermined source (ESUS) accounts for up to 25% of strokes. Understanding risk factors associated with ESUS is important in reducing stroke burden worldwide. However, ESUS patients are younger and present with fewer traditional risk factors. Significant global variation in ESUS populations also exists making the clinical picture of this type of stroke unclear.

Methods and results

ESUS patients were pair matched for age, sex, and ethnicity with a group of all other strokes (both n = 331). Exploratory factor analysis was applied in both groups to 14 risk and clinical factors to identify latent factors. In ESUS patients, two latent factors emerged consisting primarily of heart-related variables such as left ventricular wall motion abnormalities, reduced ejection fraction, and increased left atrial volume index, as well as aortic arch atherosclerosis. This is in comparison to the all other strokes group, which was dominated by traditional stroke risk factors.

Conclusions

Our findings support the existence of a unique pattern of risk factors specific to ESUS. We show that LVWMA and corresponding changes in left heart function are a potential source of emboli in these patients. In addition, the clustering of aortic arch atherosclerosis with left heart factors suggests a causal link. Through the application of exploratory factor analysis, this work contributes to a further understanding of stroke mechanisms in ESUS.

Closure or medical therapy of patent foramen ovale in cryptogenic stroke: prospective case series

Background

Results of randomized controlled trials (RCT) do not provide definite guidance for secondary prevention after ischemic stroke (IS)/transient ischemic attack (TIA) attributed to patent foramen ovale (PFO). No recommendations can be made for patients > 60 years. We aimed to compare interventional and medical PFO-management in cryptogenic IS/TIA patients, including patients > 60 years.

Methods

Prospective case series including consecutive cryptogenic IS/TIA patients with PFO at Tuebingen university stroke unit, Germany. ‘PFO-closure’ was recommended in patients ≤70 years when featuring high-risk PFO (i.e., with atrial septal aneurysm, spontaneous, or high-grade right-to-left shunt during Valsalva). Primary (recurrent IS/intracranial hemorrhage) and secondary endpoints (e.g., disability) were assessed during ≥1-year follow-up; planned subgroup analyses of patients ≤60/> 60 years.

Results

Among 236 patients with median age of 58 (range 18–88) years, 38.6% were females and median presenting National Institutes of Health Stroke Scale score was 1 (IQR 0–4). Mean follow-up was 2.8 ± 1.3 years. No intracranial hemorrhage was observed. Recurrent IS rate after ‘PFO-closure’ was 2.9% (95%CI 0–6.8%) and 7% (4–16.4) in high-risk PFO patients ≤60 (n = 103) and > 60 years (n = 43), respectively, versus 4% (0–11.5) during ‘medical therapy alone’ MTA (n = 28). 42 low-risk PFO patients treated with MTA experienced no recurrent IS/TIA.

Conclusions

In our real-world study, IS recurrence rate in ‘PFO-closure’ high-risk PFO patients ≤60 years was comparable to that observed in recent RCT. High-risk PFO patients > 60 years who underwent PFO-closure had similar IS recurrence rates than those who received MTA. MTA seems the appropriate treatment for low-risk PFO.

Trial registration

ClinicalTrials.gov, registration number: NCT04352790, registered on: April 20, 2020 – retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s42466-021-00114-3.

Recurrent Stroke Incidence and Etiology in Patients with Embolic Stroke of Undetermined Source and Other Stroke Subtypes

Aims: This study aimed at clarifying the incidence of recurrent stroke and its etiology in patients with embolic stroke of undetermined source (ESUS) and other stroke subtypes in both the acute and chronic periods.

Methods: A total of 645 patients who were admitted with acute ischemic stroke (IS) between March 2015 and August 2019 were enrolled. Among them, 511 patients with ESUS, cardioembolism (CE), large artery atherosclerosis (LAA), or small vessel disease (SVD) were analyzed in this study. After discharge, 391 patients who visited the outpatient clinic were followed up until August 2020. The outcome was stroke recurrence.

Results: In the acute admission, recurrence rates were 7.6%, 8.1%, 18.8%, and 2.2% in patients with ESUS, CE, LAA, and SVD, respectively, and there were significant differences between the groups. The subtype of recurrence was almost identical to that of the index stroke. In the outpatient clinic, the annual recurrence rates were 4.4%, 4.3%, 6.0%, and 2.9% in ESUS, CE, LAA, and SVD, respectively, and no difference was observed. Subtypes of recurrence in outpatients with ESUS included ESUS, intracerebral hemorrhage (ICH), and SVD. Patients with ESUS and SVD had a higher risk of ICH during follow-up.

Conclusions: Although the risk of recurrence was comparable between patients with ESUS and CE and intermediate between patients with LAA and SVD, in the acute admission unit, the risk in outpatients was similar among all subtypes. ESUS was the most recurrent stroke subtype in outpatients with ESUS. The risk of hemorrhagic stroke was significant in patients with SVD and ESUS.

Prevalence and predictors of atrial fibrillation in patients with embolic stroke of undetermined source: a real-life single-center retrospective study

INTRODUCTION

Up to one-third of ischemic strokes remained cryptogenic despite extensive investigations. Atrial fibrillation may be detected in a significant proportion of patients with embolic stroke of undetermined source, particularly after the introduction of implantable loop recorder in clinical practice.

METHODS

We retrospectively included all the consecutive patients with embolic stroke of undetermined source referred to our units in the period November 2013 to December 2018 and in which an implantable loop recorder was positioned within 6 months from stroke event. Prevalence and predictors of atrial fibrillation were investigated.

RESULTS

One hundred thirty-eight patients with embolic stroke of undetermined source fulfilling inclusion criteria were identified. The crude prevalence of atrial fibrillation at the end of observation period was of 45.7%. Incidence rates at 6, 12, 18, 24, and 36 months resulted, respectively, 31.8% (95% CI, 30.4-46.7), 38.0% (95% CI, 30.4-46.9), 42.6% (95% CI, 34.5-51.6), 46.6% (95% CI, 38.2-55.8), and 50.4% (95% CI, 41.6-59.9). On multivariate analysis, only excessive supraventricular electric activity and left atrial enlargement resulted to be significant predictors of atrial fibrillation (p = 0.037 and p < 0.0001, respectively).

CONCLUSIONS

Atrial fibrillation may be detected in a relevant proportion (up to 50%) of patients with embolic stroke of undetermined source if a careful and extensive diagnostic work-up is employed. Excessive supraventricular electric activity and left atrial enlargement are significant predictors of the occurrence of atrial fibrillation in these patients.

Prognostic impact of renal dysfunction on embolic stroke of undetermined source-Role beyond CHA2 DS2 -VASc score: Results from Taiwan Stroke Registry

BACKGROUND AND PURPOSE

The CHA₂ DS₂ -VASc score has immense prognostic value in patients with embolic stroke of undetermined source (ESUS). We aimed to determine the usefulness of advanced renal dysfunction and its addition to the CHA₂ DS₂ -VASc score in improving predictive accuracy.

METHODS

In total, 3775 ESUS patients were enrolled from a nationwide hospital-based prospective study. Advanced renal dysfunction was defined as estimated glomerular filtration rate <30 ml/min per 1.73 m² or patients under dialysis. Clinical outcomes included recurrent stroke and 1-year all-cause mortality. Poor functional outcome was defined as a modified Rankin Scale >2 at first-, third-, and sixth-month post-stroke. The renal (R)-CHA₂ DS₂ -VASc score was derived by including advanced renal dysfunction in the CHA₂ DS₂ -VASc score. Risk stratification improvement after including advanced renal dysfunction was assessed using C statistic, integrated discrimination improvement (IDI), and category-free net reclassification index (NRI).

RESULTS

After adjusting for confounding factors and CHA₂ DS₂ -VASc score, advanced renal dysfunction showed significant associations with all-cause mortality (HR: 2.88, 95% CI: 1.92-4.34) and poor functional outcome at third- (OR: 2.69, 95% CI: 1.47-4.94) and sixth-month post-stroke (OR: 2.67, 95% CI: 1.47-4.83). IDI and NRI showed that incorporating advanced renal dysfunction significantly improved risk discrimination over the original CHA₂ DS₂ -VASc score. R-CHA₂ DS₂ -VASc score ≥2 increased risk by 1.94-fold (95% CI: 1.15-3.27) for all-cause mortality, and ≥4 increased risk by 1.62-fold (95% CI: 1.05-2.50) of poor functional outcome at third-month post-stroke and by 1.81-fold (95% CI: 1.19-2.75) at sixth-month post-stroke.

CONCLUSIONS

Advanced renal dysfunction was significantly associated with clinical and functional outcomes in ESUS patients and may improve prognostic impact of the CHA₂ DS₂ -VASc score.

Routine surveillance of pelvic and lower extremity deep vein thrombosis in stroke patients with patent foramen ovale

Patent foramen ovale (PFO) is a potential conduit for paradoxical embolization to the systemic atrial circulation of a thrombus originating in the venous system. In a selected group of subjects, the prevalence of deep vein thrombosis (DVT) was assessed. Subjects were identified if they underwent magnetic resonance venography (MRV) pelvis and lower extremity doppler (LE-VDU) for assessment of DVT with PFO. The primary outcome measure was to report the number of patients with paradoxical embolization as their suspected etiology of stroke due to the presence of DVT, which then will be considered as determined stroke. Others with determined stroke diagnosis were reported using Treatment of Acute Stroke Trial (TOAST) criteria. At discharge, those without etiology of their stroke were grouped under embolic stroke of undetermined source (ESUS). We further analyzed the prevalence of DVT by age group, ≤ 60 years vs > 60 years to describe if the prevalence is higher with younger age and to evaluate if higher Risk of Paradoxical Embolism (ROPE) score will have higher number of DVTs compared to lower ROPE scores. Of the 293, 19 (7%) were strokes due to paradoxical embolism. At discharge, determined stroke were 54% vs ESUS were 46%. The overall prevalence of DVT was 19 (7%); MRV-pelvis 13 (4%), and LE-VDU was 9 (3%). No significant difference was noted using both modalities. However, in multivariable regression analysis, a trend suggested an association between pelvic thrombi and high ROPE score as the etiology of stroke; OR 3.56 (0.98, 12.93); p = 0.054. Detection of DVT was not associated with PFO, high ROPE scores or young age. Our data indicate an over-reliance of testing for DVT, particularly MRV pelvis with contrast, in patients with PFO. Clinical studies are needed to identify other factors predictive of DVT in patients with ischemic stroke and PFO.

Outcome after intravenous thrombolysis in embolic stroke of undetermined source compared to cardioembolic stroke

BACKGROUND

It is assumed that most cases of embolic stroke of undetermined source (ESUS) are of cardioembolic origin. The data about outcome after the treatment with intravenous thrombolysis (IVT) for this type of acute ischemic stroke (AIS) are limited. We aimed to compare clinical characteristics and outcomes after IVT for AIS between patients with ESUS and cardioembolic stroke (CS).

METHODS

This study was a single center retrospective analysis of stroke patients treated with IVT. The Trial of ORG 10172 in Acute Stroke Treatment criteria were used to establish stroke etiology subtype at 3 months, while ESUS was considered a subset of stroke of undetermined etiology, defined according to 2014 international criteria. Functional outcome was assessed at 3 months and defined as excellent (modified Rankin scale 0-1) and favorable (modified Rankin scale 0-2).

RESULTS

Total of 394 patients were treated with IVT; 113 had a cardioembolism, 88 had undetermined stroke subtype, of which 62 met the ESUS criteria. Patients with ESUS were on average younger (63.7 years versus 69.7 years, p = 0.001), had a lower National Institutes of Health Stroke Scale (NIHSS) score on admission (12 versus 15, p = 0.002) and lower prevalence of antiplatelets use (27.4% versus 42.5%, p = 0.04) compared with CS patients. Favorable outcome was more likely in ESUS patients, at discharge (48.4% versus 24.0%, p = 0.002) and after 3 months (71.0% versus 37.2%, p < 0.001). Hemorrhagic transformation was less frequent (17.7% versus 33.6%, p = 0.03) in ESUS patients. Independent predictors of 3‑month favorable outcome were ESUS, the absence of leukoaraiosis on computed tomography (CT) and absence of diabetes as a risk factor.

CONCLUSION

Patients with ESUS had better outcome after IVT than patients with CS, which can be attributed to younger age and milder strokes in these patients.

Non-stenosing Carotid Atherosclerosis and Arterial Stiffness in Embolic Stroke of Undetermined Source

Background and Purpose: Recent findings suggested that non-stenosing atherosclerosis (NSA) may play an important pathogenic role, especially in cryptogenic strokes. Furthermore, arterial stiffness has been suggested to be a useful tool in identifying patients with embolic stroke of undetermined source (ESUS) with poor neurological prognosis. In this view, the aim of our study was to assess the association between carotid NSA and arterial stiffness in ESUS patients, in order to better define the cardiovascular risk profile of this subgroup of patients.

Methods: We enrolled 100 patients with ESUS (52 males, 48 females) and 48 patients with ischemic stroke from atherosclerosis. All patients underwent clinical and neuroimaging examination. A 24-h heart rate and blood pressure monitoring was performed in order to evaluate systolic, diastolic and mean blood pressure, pulse pressure, and arterial stiffness index (ASI).

Results: NSA was present in 48 patients. In comparison with non-NSA-ESUS, in NSA-ESUS the mean age was higher, neurological deficit was more severe, hypertension, and diabetes were more common; systolic blood pressure, pulse pressure, and ASI were higher. In particular NSA-ESUS had ASI levels similar to strokes due to atherosclerosis.

Conclusions: Our findings shed light on specific cardiovascular risk profiles underlying different subtypes of ESUS, suggesting the presence of increased arterial stiffness in NSA-ESUS patients with a risk factors profile similar to strokes due to atherosclerosis.

Left Heart Factors in Embolic Stroke of Undetermined Source in a Multiethnic Asian and North African Cohort

Background

Cardiac features diverge in Asians; however, it is not known how these differences relate to embolic stroke of unknown source (ESUS) in Southeast Asian and Eastern Mediterranean regions.

Methods and Results

A retrospective analysis of prospectively collected acute ischemic stroke data from 2014 to 2018 was performed. Stroke subtypes were noncardioembolic stroke (large‐vessel and small‐vessel disease; n=1348), cardioembolic stroke (n=532), and ESUS (n=656). Subtypes were compared by demographic, clinical, and echocardiographic factors. In multivariate logistic regression, patients with ESUS in comparison with noncardioembolic stroke were twice as likely to have left ventricular diastolic dysfunction (P=0.001), 3 times the odds of global hypokinesia (P=0.001), and >7 times the odds of left ventricular wall motion abnormalities (P=0.001). In the second model comparing ESUS with cardioembolic stroke, patients with ESUS were 3 times more likely to have left ventricular wall motion abnormalities (P=0.001) and 1.5 times more likely to have left ventricular diastolic dysfunction grade I (P=0.009), and 3 times more likely to have left ventricular diastolic dysfunction grades II and III (P=0.009), whereas age (P=0.001) and left atrial volume index (P=0.004) showed an inverse relation with ESUS. ESUS in patients ≥61 years old had higher levels of traditional risk factors such as coronary artery disease, but the coronary artery disease was not significantly different in ESUS age groups (P=0.80) despite higher left ventricular wall motion abnormalities (P=0.001).

Conclusions

Patients with ESUS and noncardioembolic stroke were younger than patients with cardioembolic stroke. While a third of the patients with ESUS >45 years old had coronary artery disease, it was unrecognized or underreported in the older ESUS age group (≥61 years old). In patients with ESUS from Southeast Asia and Eastern Mediterranean regions, left ventricular wall motion abnormalities and left ventricular diastolic dysfunction were related to ESUS.

Diagnosis and Treatment for embolic stroke of undetermined source: Consensus statement from the Taiwan stroke society and Taiwan society of cardiology

Cryptogenic stroke comprises about one-quarter of ischemic strokes with high recurrence rate; however, studies specifically investigating the features and treatment of this stroke subtype are rare. The concept of 'embolic stroke of undetermined source' (ESUS) may facilitate the development of a standardized approach to diagnose cryptogenic stroke and improve clinical trials. Since recent large randomized control trials failed to demonstrate a reduction in stroke recurrence with anticoagulants, anti-platelet agents remain the first-line treatment for ESUS patients. Nevertheless, patients with high risk of stroke recurrence (e.g., those with repeated embolic infarcts despite aspirin treatment) require a more extensive survey of stroke etiology, including cardiac imaging and prolonged cardiac rhythm monitoring. Anticoagulant treatments may still benefit some subgroups of high-risk ESUS patients, such as those with multiple infarcts at different arterial territories without aortic atheroma, the elderly, or patients with high CHA₂D₂-VASc or HOVAC scores, atrial cardiopathy or patent foramen ovale. Several important ESUS clinical trials are ongoing, and the results are anticipated. With rapid progress in our understanding of ESUS pathophysiology, new subcategorizations of ESUS and assignment of optimal treatments for each ESUS subgroup are expected in the near future.

Meta-Analysis of Secondary Prevention of Cryptogenic Stroke

BACKGROUND

Cryptogenic stroke and embolic stroke of undetermined source (ESUS) are a frequently encountered categories of ischemic stroke with an uncertain cause.

METHODS

We analyzed all randomized clinical trials (RCTs) that evaluated antithrombotic therapy and patent foramen ovale (PFO) closure in cryptogenic stroke and/or ESUS. We calculated aggregate hazard ratios (HRs) using direct and network meta-analysis. The primary outcome was recurrent ischemic stroke.

RESULTS

Ten RCTs with a total of 16,876 patients, randomizing 32,143 patient-years of follow-up (mean age 61.2 ± 13.5 with 39.2% female) were identified. Anticoagulation therapy was associated with significantly reduced recurrent ischemic stroke compared with antiplatelet therapy (HR = 0.66; [95% confidence interval (CI) = 0.47-0.94]). Meta-regression analysis showed significantly reduced recurrent stroke with longer duration of therapy, and significantly increased events with advanced age. Significant interactions were observed based on the presence of PFO, stroke type, and anticoagulant used. There were no significant differences with regard to the composite ischemic outcome, transient ischemic attack, any death, major bleeding, or intracranial bleeding. In the network meta-analysis, compared to antiplatelet therapy, warfarin (HR = 0.31; [95% credible interval (CrI) = 0.12-0.68]) and PFO closure (HR = 0.14; 95% CrI = 0.05-0.31]) were associated with significantly reduced recurrent ischemic stroke. In rank order, PFO closure was associated with the best outcome, followed by warfarin.

CONCLUSIONS

Among patients with cryptogenic stroke, anticoagulation therapy, as compared with antiplatelet therapy is associated with lower rate of recurrent stroke. The small sample size and high heterogeneity with regards to bleeding outcomes require further large trials. In patients with PFO, closure and warfarin are associated with the lowest rates of recurrent stroke.

Rivaroxaban versus aspirin for secondary prevention of ischaemic stroke in patients with cancer: a subgroup analysis of the NAVIGATE ESUS randomized trial

BACKGROUND AND PURPOSE

Cancer is a frequent finding in ischaemic stroke patients. The frequency of cancer amongst participants in the NAVIGATE ESUS randomized trial and the distribution of outcome events during treatment with aspirin and rivaroxaban were investigated.

METHODS

Trial participation required a recent embolic stroke of undetermined source. Patients' history of cancer was recorded at the time of study entry. During a mean follow-up of 11 months, the effects of aspirin and rivaroxaban treatment on recurrent ischaemic stroke, major bleeding and all-cause mortality were compared between patients with cancer and patients without cancer.

RESULTS

Amongst 7213 randomized patients, 543 (7.5%) had cancer. Of all patients, 3609 were randomized to rivaroxaban [254 (7.0%) with cancer] and 3604 patients to aspirin [289 (8.0%) with cancer]. The annual rate of recurrent ischaemic stroke was 4.5% in non-cancer patients in the rivaroxaban arm and 4.6% in the aspirin arm [hazard ratio (HR) 0.98, 95% confidence interval (CI) 0.78-1.24]. In cancer patients, the rate of recurrent ischaemic stroke was 7.7% in the rivaroxaban arm and 5.4% in the aspirin arm (HR 1.43, 95% CI 0.71-2.87). Amongst cancer patients, the annual rate of major bleeds was non-significantly higher for rivaroxaban than aspirin (2.9% vs. 1.1%; HR 2.57, 95% CI 0.67-9.96; P for interaction 0.95). All-cause mortality was similar in both groups.

CONCLUSIONS

Our exploratory analyses show that patients with embolic stroke of undetermined source and a history of cancer had similar rates of recurrent ischaemic strokes and all-cause mortality during aspirin and rivaroxaban treatments and that aspirin appeared safer than rivaroxaban in cancer patients regarding major bleeds. www.clinicaltrials.gov (NCT02313909).