Embolic Strokes of Unknown Source and Cryptogenic Stroke: Implications in Clinical Practice

Prevalence of right-to-left shunt in stroke patients with cancer

BACKGROUND AND OBJECTIVES

Cancer is associated with an increased risk of acute ischemic stroke (AIS) and venous thromboembolism. The role of a cardiac right-to-left shunt (RLS) as a surrogate parameter for paradoxical embolism in cancer-related strokes is uncertain. We sought to investigate the relationship between the presence of an RLS and cancer in AIS patients.

METHODS

We included consecutive AIS patients hospitalized at our tertiary stroke center between January 2015 and December 2020 with available RLS status as detected on transesophageal echocardiography (TEE). Active cancers were retrospectively identified and the association with RLS was assessed with multivariable logistic regression and inverse probability of treatment weighting to minimize the ascertainment bias of having a TEE obtained.

RESULTS

Of the 2236 AIS patients included, 103 (4.6%) had active cancer, of whom 24 (23%) were diagnosed with RLS. An RLS was present in 774 out of the 2133 AIS patients without active cancer (36%). After adjustment and weighting, the absence of RLS was associated with active cancer (adjusted odds ratio (aOR) 2.29; 95% confidence interval (CI), 1.14-4.58). When analysis was restricted to patients younger than 60 years of age or those with a high-risk RLS (Risk of Paradoxical Embolism Score ⩾ 6), there was no association between RLS and cancer (aOR, 3.07; 95% CI, 0.79-11.88 and aOR, 0.56; 95% CI, 0.10-3.10, respectively).

CONCLUSION

RLS was diagnosed less frequently in AIS patients with cancer than in cancer-free patients, suggesting that arterial sources may play a larger role in cancer-related strokes than paradoxical venous embolization. Future studies are needed to validate these findings and evaluate potential therapeutic implications, such as the general indication, or lack thereof, for patent foramen ovale (PFO) closure in this patient population.

Antiphospholipid Syndrome and Antibodies Associated With Malignancy and Older Age: A Retrospective Study

BACKGROUND

Antiphospholipid syndrome (APLS) is an established cause of thrombosis and hypercoagulability. However, the clinical characteristics of those with APLS or patients with positive antiphospholipid antibodies (APLA) in the embolic stroke of undetermined source (ESUS) have not been well studied.

METHODS

A retrospective analysis was conducted between January 1, 2010, and December 31, 2020, across all three Mayo Clinic sites. Patients who were included in the study were tested for APLA and had a diagnosis of ESUS. Baseline characteristics, radiographic parameters, and outcome data were collected and compared between those who tested positive for APLS or had positive APLA and those who were negative.

RESULTS

A total of 206 patients were included in the study. Eight (4%) patients were diagnosed with APLS, and 21 (10%) patients had positive APLA. On comparing those with a diagnosis of APLS and those without, patients with APLS were found to be significantly older (75 years old ± 9 vs. 58 years old ± 14, p = 0.001) and were more likely to have a history of cancer (50% vs. 13%, p = 0.012). Those with positive APLA had similar findings of being older (67 years old ±13 vs. 58 years old ± 14 p = 0.003) and more likely to have a history of cancer (29% vs. 8.4% p = 0.027). Radiographically, those with APLS had a higher white matter disease burden (Fazekas score median 2 (IQR 1.5-3) vs. median 1 (IQR 1-2), p = 0.028).

CONCLUSION

Both APLS and positive APLA are associated with older age and a history of malignancy. These findings highlight the importance of considering a hypercoagulable evaluation even in the elderly ESUS population.

Left Atrial Septal Pouch (LASP) and cryptogenic stroke risk: An updated systematic review and meta-analysis of observational studies

BACKGROUND

The left atrial septal pouch (LASP) is a small anatomical septal recess in the heart that has been linked with cardioembolic events. A systematic appraisal of the existing literature is necessary to establish a better understanding of the risk as studies continue to indicate a correlation between LASPs and cryptogenic strokes.

OBJECTIVES

To determine the level of association between the presence of LASP and the risk of developing cryptogenic stroke.

METHODS

We searched PubMed, EMBASE and Scopus for studies comparing the prevalence of LASP in patients with cryptogenic stroke against non-cryptogenic stroke control groups from inception till December, 2023. The Newcastle Ottawa scale was used for quality assessment and Comprehensive Meta-Analysis Version 3.3 was used for data analysis with odds ratio (OR) as the effect measure.

RESULTS

Our review included a total of 10 retrospective, observational studies published between 2010 to 2022. A total of 683 cases of cryptogenic strokes were identified, out of which 33.1 % (n = 271) were associated with a LASP. Among the non-cryptogenic stroke controls (n = 2641), LASP was present in 20.6 % cases (n = 476). The aggregate OR for cryptogenic stroke was 1.618 times greater than non-cryptogenic stroke (p < 0.001) among LASP cases, CONCLUSION: The presence of a septal pouch in the left atrium is significantly linked to a higher risk of developing cryptogenic strokes. As a potential site of thrombus formation and subsequent dislodgement, further large-scale studies are necessary to establish the guidelines for management and prophylaxis to prevent embolic events.

Arterial Hypertension and Its Consequences Are the Main Predictors of Embolic Stroke of Undetermined Source

Methods

We performed a hospital-based prospective cohort study with 1,317 enrolled participants. We compared patients and healthy volunteers according to the main demographic, anthropometric parameters, stroke risk factors, comorbidities, and data of clinical and instrumental examination. In order to balance the study and the control groups for age and sex, the propensity score matching was performed. In order to generate the overall predictive model, a multivariate analysis was performed using the binary logistic regression method.

Results

The following predictors of ESUS were identified in current study: arterial hypertension (AH); increased heart rate and pulmonary arterial systolic pressure (PASP); the presence of conduction disturbance; the enlargement of left, right atrium, and left ventricle end-systolic length; increased intima-media thickness (IMT) in right and left common carotid artery (CCA); lowered Montreal Cognitive Assessment (MoСA) cognitive scale score; the presence of subcortical microbleeds; central brain atrophy; the larger size of third ventricle; and the higher medial temporal lobe atrophy (MTA) score. The following risk factors were included in the final predictive model: the presence of AH (p < 0.0005; OR = 12.98 (95% CI: 4.53-37.21)) and PASP (p=0.018; OR = 1.13 (95% CI: 1.02-1.25)) and male sex (p=0.046; OR = 2.771 (95% CI: 1.017-7.555)). The Nagelkerke's pseudo-R-squared value was 0.404 and the significance of the Hosmer-Lemeshow test was 0.733, which indicate the goodness of the final logistic regression model.

Conclusions

We propose that AH and its consequences are the main predictors of ESUS. The results of this study emphasize the importance of AH control for primary and secondary prevention of ESUS.

Embolic Stroke Associated With a Pulmonary Arteriovenous Fistula: An Unignorable Rare Causes of Stroke

INTRODUCTION

Here, we described a patient with ischemic stroke due to embolism, through an isolated pulmonary arteriovenous fistula (PAVF). Our case could be a paradigm of embolic stroke of undetermined source (ESUS) with an uncommon cause, providing an etiologic investigation process in addition to diagnostic pitfalls and pearls, eventually raising neurologists' ability to treat ESUS.

CASE REPORT

A 37-year-old right-handed woman presented to our emergency department with sudden onset left upper limb and lower limb weakness. She denied a past medical history of hypertension, diabetes, heart diseases, and other cerebrovascular disease risk factors, and she is without a family history of stroke, previous trauma, toxic exposure, or drug use. On admission, her physical and neurological examinations were negative, except for left-sided hemiparesis. Her routine evaluations, serum autoantibody testing, and digital subtraction angiography were negative. Subsequent diffusion-weighted brain magnetic resonance imaging demonstrated acute infarction in the right frontoparietal lobe. To find the etiology of this case, more detailed examinations were performed. Finally, she was diagnosed with ESUS, which was caused by the PAVF.

CONCLUSIONS

This case raises the awareness of a potential important emboligenic mechanism, the existence of an isolated PAVF as a right-to-left shunt in patients with a stroke of unknown origin should not be overlooked, even if a PAVF is not suggested by the initial physical findings or chest x-ray.

Does left atrial appendage morphology and dimension differ amongst etiological stroke subtypes in patients without known atrial fibrillation? Results from the left atrial appendage morphology and dimension assessment by TEE in patients with stroke without known atrial fibrillation (LAMDA-STROKE) study

CONTEXT

Complex left atrial appendage (LAA) morphology is increasingly associated with cryptogenic ischemic stroke as compared to cardioembolic stroke due to atrial fibrillation (AF). However, data on such an association in patients with other etiological stroke subtypes in the absence of AF is limited.

AIM

The study aimed to assess the LAA morphology, dimension and other echocardiographic parameters by transesophageal echocardiography (TEE) in patients with embolic stroke of undetermined source (ESUS) and compare it with other etiological stroke subtypes without known AF.

METHODS

This was a single-Centre, observational study involving comparison of echocardiographic parameters including LAA morphology and dimension in ESUS patients (group A; n = 30) with other etiological stroke subtypes i.e., TOAST (Trial of Org 10172 in Acute Stroke Treatment) class I-IV without AF (group B; n = 30).

RESULTS

Complex LAA morphology was predominant in group A (18 patients in group A versus 5 patients in group B, p-Value = 0.001). Mean LAA orifice diameter (15.3 + 3.5 mm in group A versus 17 + 2.0 mm in group B, p-Value = 0.027) and LAA depth were significantly lower in group A (28.4 + 6.6 mm in group A versus 31.7 + 4.3 mm in group B, p-Value = 0.026). Out of these three parameters only complex LAA morphology was found to be independently associated with ESUS [OR = 6.003, 95% CI {1.225-29.417}, p = 0.027].

CONCLUSION

Complex LAA morphology is a predominant feature in ischemic stroke patients with ESUS and may contribute to an increased risk of stroke in these patients.

Is Composition of Brain Clot Retrieved by Mechanical Thrombectomy Associated with Stroke Aetiology and Clinical Outcomes in Acute Ischemic Stroke?—A Systematic Review and Meta-Analysis

Background: Brain clots retrieved following endovascular thrombectomy in acute ischemic stroke patients may offer unique opportunities to characterise stroke aetiology and aid stroke decision-making in select groups of patients. However, the evidence around the putative association of clot morphology with stroke aetiology is limited and remains inconclusive. This study aims to perform a systematic review and meta-analysis to delineate the association of brain clot composition with stroke aetiology and post-reperfusion outcomes in patients receiving endovascular thrombectomy. Methods: The authors conducted a systematic literature review and meta-analysis by extracting data from several research databases (MEDLINE/PubMed, Cochrane, and Google Scholar) published since 2010. We used appropriate key search terms to identify clinical studies concerning stroke thrombus composition, aetiology, and clinical outcomes, in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Results: The authors identified 30 articles reporting on the relationship between stroke thrombus composition or morphology and aetiology, imaging, or clinical outcomes, of which 21 were included in the meta-analysis. The study found that strokes of cardioembolic origin (SMD = 0.388; 95% CI, 0.032–0.745) and cryptogenic origin (SMD = 0.468; 95% CI, 0.172–0.765) had significantly higher fibrin content than strokes of non-cardioembolic origin. Large artery atherosclerosis strokes had significantly lower fibrin content than cardioembolic (SMD = 0.552; 95% CI, 0.099–1.004) or cryptogenic (SMD = 0.455; 95% CI, 0.137–0.774) strokes. Greater red blood cell content was also significantly associated with a thrombolysis in cerebral infarction score of 2b–3 (SMD = 0.450; 95% CI, 0.177–0.722), and a positive hyperdense middle cerebral artery sign (SMD = 0.827; 95% CI, 0.472–1.183). No significant associations were found between red blood cell, platelet, or white blood cell content and aetiology, or between clot composition and bridging thrombolysis. Conclusions: This meta-analysis found that fibrin composition is significantly higher in strokes of cardioembolic and cryptogenic origin, and that red blood cell content is positively associated with the hyperdense middle cerebral artery sign and better reperfusion outcomes. Important advances to stroke clinical workup can be derived from these findings, in which many aspects of stroke workflow remain to be optimised. As data are still limited in terms of the association of various thrombus components with stroke aetiology as well as a standardised method of analysis, further studies are required to validate these findings to guide their use in clinical decision-making.

Association of Vertebral Artery Hypoplasia and Vertebrobasilar Cerebrovascular Accident

Background and Objectives: Vertebral artery hypoplasia (VAH) is a controversial risk factor for cerebral infarction. The aim of this study was to analyze the prevalence of vertebral artery hypoplasia and to evaluate its association with vertebrobasilar cerebrovascular accidents. Materials and Methods: The study was conducted in the Neurology Departments of the Republican Vilnius University Hospital from 2015 to 2020. Data of 742 subjects (133 patients with posterior circulation infarction or vertebral artery syndrome (PCI/VAS), 80 patients with anterior circulation infarction (ACI) and 529 control subjects with no symptoms of cerebrovascular accident) were analyzed. Ultrasound examination of the extracranial internal carotid and vertebral arteries (VA) was performed, risk factors were recorded. Results: The mean age of the subjects was 64.51 ± 13.02 years. In subjects with PCI/VAS the diameter of VA was smaller, and the prevalence of VAH was higher compared to those in subjects with ACI and in the control group. A higher degree of VAH in subjects younger than 65 years of age increased the risk of PCI/VAS. Subjects with non-dominant VA diameter of 2.7–2.9 mm had 2.21 times higher risk of PCI/VAS, subjects with non-dominant VA diameter of 2.5–2.6 mm had 2.36 times higher risk of PCI/VAS, and subjects with non-dominant VA diameter of 2.2–2.4 mm had 4.12 times higher risk of PCI/VAS compared with subjects with non-dominant VA diameter of ≥3 mm. Among patients with PCI/VAS those with VAH had lower rates of ischemic heart disease compared with patients with normal VA diameter. There was no difference in the rates of other risk factors between PCI/VAS patients with and without VAH. Conclusions: Vertebral artery hypoplasia is not a rare finding in individuals without symptoms of cerebrovascular accident, but more frequent in patients with vertebrobasilar cerebral infarction or vertebrobasilar artery syndrome. Vertebral artery hypoplasia can be considered a risk factor for posterior circulation infarction in subjects under 65 years of age.

ESC Working Group on e-Cardiology Position Paper: accuracy and reliability of electrocardiogram monitoring in the detection of atrial fibrillation in cryptogenic stroke patients : In collaboration with the Council on Stroke, the European Heart Rhythm Association, and the Digital Health Committee

The role of subclinical atrial fibrillation as a cause of cryptogenic stroke is unambiguously established. Long-term electrocardiogram (ECG) monitoring remains the sole method for determining its presence following a negative initial workup. This position paper of the European Society of Cardiology Working Group on e-Cardiology first presents the definition, epidemiology, and clinical impact of cryptogenic ischaemic stroke, as well as its aetiopathogenic association with occult atrial fibrillation. Then, classification methods for ischaemic stroke will be discussed, along with their value in providing meaningful guidance for further diagnostic efforts, given disappointing findings of studies based on the embolic stroke of unknown significance construct. Patient selection criteria for long-term ECG monitoring, crucial for determining pre-test probability of subclinical atrial fibrillation, will also be discussed. Subsequently, the two major classes of long-term ECG monitoring tools (non-invasive and invasive) will be presented, with a discussion of each method's pitfalls and related algorithms to improve diagnostic yield and accuracy. Although novel mobile health (mHealth) devices, including smartphones and smartwatches, have dramatically increased atrial fibrillation detection post ischaemic stroke, the latest evidence appears to favour implantable cardiac monitors as the modality of choice; however, the answer to whether they should constitute the initial diagnostic choice for all cryptogenic stroke patients remains elusive. Finally, institutional and organizational issues, such as reimbursement, responsibility for patient management, data ownership, and handling will be briefly touched upon, despite the fact that guidance remains scarce and widespread clinical application and experience are the most likely sources for definite answers.

Embolic stroke of undetermined source: beyond atrial fibrillation

INTRODUCTION

Embolic stroke of undetermined source (ESUS) accounts for 25% of all cerebral infarcts; only 30% are associated with paroxysmal atrial fibrillation (AF). Various biochemical, electrocardiographic, and echocardiographic findings may suggest left atrial damage and increased risk of embolism in the absence of clinically documented AF or atrial flutter. In this review, we analyse the available evidence on atrial cardiopathy or atrial disease, its involvement in ESUS, and its identification through electrocardiographic, echocardiographic, and serum markers and its possible therapeutic implications.

DEVELOPMENT

A systematic search was conducted on MEDLINE (PubMed) using the following MeSH terms: MeSH [ESUS]+[atrial cardiopathy]+[atrial fibrillation]+[interatrial block]+[treatment]. We selected what we considered to be the most useful original prospective or retrospective studies and systematic reviews. We then read the full texts of the articles and checked the references cited in each article. We analyse epidemiological and demographic variables of patients with ESUS, as well as recent evidence related to presentation and prognosis and factors associated with recurrence and mortality. We review the contribution of atrial cardiopathy diagnosis prior to the detection of AF and the clinical, electrocardiographic, and echocardiographic variables and the biochemical markers associated with its development and its potential contribution to cerebral embolism.

CONCLUSIONS

The systematic search of biochemical and electrocardiographic, and echocardiographic alterations can be useful to identify ESUS patients at higher risk of recurrence.

Embolic stroke of undetermined source: Beyond atrial fibrillation

INTRODUCTION

Embolic stroke of undetermined source (ESUS) accounts for 25% of all cerebral infarcts; only 30% are associated with paroxysmal atrial fibrillation (AF). Various biochemical, electrocardiographic, and echocardiographic findings may suggest left atrial damage and increased risk of embolism in the absence of clinically documented AF or atrial flutter. In this review, we analyse the available evidence on atrial cardiopathy or atrial disease, its involvement in ESUS, and its identification through electrocardiographic, echocardiographic, and serum markers and its possible therapeutic implications.

DEVELOPMENT

A systematic search was conducted on MEDLINE (PubMed) using the following MeSH terms: MeSH [ESUS]+[atrial cardiopathy]+[atrial fibrillation]+[interatrial block]+[treatment]. We selected what we considered to be the most useful original prospective or retrospective studies and systematic reviews. We then read the full texts of the articles and checked the references cited in each article. We analyse epidemiological and demographic variables of patients with ESUS, as well as recent evidence related to presentation and prognosis and factors associated with recurrence and mortality. We review the contribution of atrial cardiopathy diagnosis prior to the detection of AF and the clinical, electrocardiographic, and echocardiographic variables and the biochemical markers associated with its development and its potential contribution to cerebral embolism.

CONCLUSIONS

The systematic search of biochemical and electrocardiographic, and echocardiographic alterations can be useful to identify ESUS patients at higher risk of recurrence.

Left atrial appendage closure during cardiac surgery for atrial fibrillation: A meta-analysis

BACKGROUND

Left atrial appendage closure (LAAC) during cardiac surgery in atrial fibrillation (AF) patients has been investigated in multiple studies with variable safety and efficacy results.

METHODS

A comprehensive review was performed of all studies comparing LAAC and placebo arm during cardiac surgery in AF patients. A random-effect model was used to calculate risk ratios, mean differences, and 95% confidence intervals.

RESULTS

Five randomized controlled trials and 22 observational studies were included with a total of 540,111 patients. The LAAC group had significantly decreased postoperative stroke/embolic events as compared to the no LAAC group with all cardiac surgeries (3.74% vs 4.88%, p = 0.0002), isolated valvular surgery (1.95% vs 4.48%, p = 0.002). However, CABG insignificantly favored the LAAC group for stroke/embolic events (6.72% vs 8.30%, p = 0.07). There was no difference between both groups in all-cause mortality in the perioperative period (p = 0.42), but was significantly lower in the LAAC arm after two years (14.1% vs 18.3%, p = 0.02). There was no difference in major bleeding, all-cause rehospitalizations, or cross-clamp time between both groups (p = 0.53 and p = 0.45). The bypass and the cross-clamp time were longer in the LAAC group (4 and 9 min, respectively).

CONCLUSION

In AF patients, LAAC during cardiac surgery had a decreased risk of stroke and long-term all-cause mortality. Additionally, there was no difference in major bleeding, all-cause rehospitalizations, or cross-clamp time.

A Combined Computational Fluid Dynamics and Arterial Spin Labeling MRI Modeling Strategy to Quantify Patient-Specific Cerebral Hemodynamics in Cerebrovascular Occlusive Disease

Cerebral hemodynamics in the presence of cerebrovascular occlusive disease (CVOD) are influenced by the anatomy of the intracranial arteries, the degree of stenosis, the patency of collateral pathways, and the condition of the cerebral microvasculature. Accurate characterization of cerebral hemodynamics is a challenging problem. In this work, we present a strategy to quantify cerebral hemodynamics using computational fluid dynamics (CFD) in combination with arterial spin labeling MRI (ASL). First, we calibrated patient-specific CFD outflow boundary conditions using ASL-derived flow splits in the Circle of Willis. Following, we validated the calibrated CFD model by evaluating the fractional blood supply from the main neck arteries to the vascular territories using Lagrangian particle tracking and comparing the results against vessel-selective ASL (VS-ASL). Finally, the feasibility and capability of our proposed method were demonstrated in two patients with CVOD and a healthy control subject. We showed that the calibrated CFD model accurately reproduced the fractional blood supply to the vascular territories, as obtained from VS-ASL. The two patients revealed significant differences in pressure drop over the stenosis, collateral flow, and resistance of the distal vasculature, despite similar degrees of clinical stenosis severity. Our results demonstrated the advantages of a patient-specific CFD analysis for assessing the hemodynamic impact of stenosis.

HRS White Paper on Clinical Utilization of Digital Health Technology

This collaborative statement from the Digital Health Committee of the Heart Rhythm Society provides everyday clinical scenarios in which wearables may be utilized by patients for cardiovascular health and arrhythmia management. We describe herein the spectrum of wearables that are commercially available for patients, and their benefits, shortcomings and areas for technological improvement. Although wearables for rhythm diagnosis and management have not been examined in large randomized clinical trials, undoubtedly the usage of wearables has quickly escalated in clinical practice. This document is the first of a planned series in which we will update information on wearables as they are revised and released to consumers.

Implantable cardiac monitors to detect atrial fibrillation after cryptogenic stroke: a systematic review and economic evaluation

BACKGROUND

Cryptogenic stroke is a stroke for which no cause is identified after standard diagnostic tests. Long-term implantable cardiac monitors may be better at diagnosing atrial fibrillation and provide an opportunity to reduce the risk of stroke recurrence with anticoagulants.

OBJECTIVES

The objectives were to assess the diagnostic test accuracy, clinical effectiveness and cost-effectiveness of three implantable monitors [BioMonitor 2-AF™ (Biotronik SE & Co. KG, Berlin, Germany), Confirm Rx™ (Abbott Laboratories, Lake Bluff, IL, USA) and Reveal LINQ™ (Medtronic plc, Minneapolis, MN, USA)] in patients who have had a cryptogenic stroke and for whom no atrial fibrillation is detected after 24 hours of external electrocardiographic monitoring.

DATA SOURCES

MEDLINE, EMBASE, The Cochrane Library, Database of Abstracts of Reviews of Effects and Health Technology Assessment databases were searched from inception until September 2018.

REVIEW METHODS

A systematic review was undertaken. Two reviewers agreed on studies for inclusion and performed quality assessment using the Cochrane Risk of Bias 2.0 tool. Results were discussed narratively because there were insufficient data for synthesis. A two-stage de novo economic model was developed: (1) a short-term patient flow model to identify cryptogenic stroke patients who have had atrial fibrillation detected and been prescribed anticoagulation treatment (rather than remaining on antiplatelet treatment) and (2) a long-term Markov model that captured the lifetime costs and benefits of patients on either anticoagulation or antiplatelet treatment.

RESULTS

One randomised controlled trial, Cryptogenic Stroke and underlying Atrial Fibrillation (CRYSTAL-AF) (Sanna T, Diener HC, Passman RS, Di Lazzaro V, Bernstein RA, Morillo CA, et al. Cryptogenic stroke and underlying atrial fibrillation. N Engl J Med 2014;370:2478-86), was identified, and no diagnostic test accuracy study was identified. The CRYSTAL-AF trial compared the Reveal™ XT (a Reveal LINQ predecessor) (Medtronic plc) monitor with standard of care monitoring. Twenty-six single-arm observational studies for the Reveal devices were also identified. The only data for BioMonitor 2-AF or Confirm Rx were from mixed population studies supplied by the companies. Atrial fibrillation detection in the CRYSTAL-AF trial was higher with the Reveal XT than with standard monitoring at all time points. By 36 months, atrial fibrillation was detected in 19% of patients with an implantable cardiac monitor and in 2.3% of patients receiving conventional follow-up. The 26 observational studies demonstrated that, even in a cryptogenic stroke population, atrial fibrillation detection rates are highly variable and most cases are asymptomatic; therefore, they probably would not have been picked up without an implantable cardiac monitor. Device-related adverse events, such as pain and infection, were low in all studies. The de novo economic model produced incremental cost effectiveness ratios comparing implantable cardiac monitors with standard of care monitoring to detect atrial fibrillation in cryptogenic stroke patients based on data for the Reveal XT device, which can be related to Reveal LINQ. The BioMonitor 2-AF and Confirm RX were included in the analysis by making a strong assumption of equivalence with Reveal LINQ. The results indicate that implantable cardiac monitors could be considered cost-effective at a £20,000-30,000 threshold. When each device is compared incrementally, BioMonitor 2-AF dominates Reveal LINQ and Confirm RX.

LIMITATIONS

The cost-effectiveness analysis for implantable cardiac monitors is based on a strong assumption of clinical equivalence and should be interpreted with caution.

CONCLUSIONS

All three implantable cardiac monitors could be considered cost-effective at a £20,000-30,000 threshold, compared with standard of care monitoring, for cryptogenic stroke patients with no atrial fibrillation detected after 24 hours of external electrocardiographic monitoring; however, further clinical studies are required to confirm their efficacy in cryptogenic stroke patients.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42018109216.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 5. See the NIHR Journals Library website for further project information.

Aortic Sources of Embolism

Aortic arch atheroma is a frequent finding in ischemic stroke patients. Its role as a source of cerebral emboli or a marker of atherosclerosis is unclear. Transesophageal echography is considered the gold standard for its detection, whereas computed tomography angiography is a good alternative; magnetic resonance and positron emission tomography could be proposed to better analyze plaque vulnerability. Despite the interest in this condition, the optimal antithrombotic treatment remains uncertain, while intensive lipid-lowering therapy should be recommended. This review aims to offer guidance on patients with aortic arch atheroma, about its causal role in stroke, diagnosis, and treatment based on current available evidence.

The Utility of the Markers of Coagulation and Hemostatic Activation Profile in the Management of Embolic Strokes of Undetermined Source

BACKGROUND

Potential causes of embolic stroke of undetermined source (ESUS) include occult malignancy, venous thrombosis (VTE) with paradoxical embolism, and hypercoagulable disorders. Given the association of markers of coagulation and hemostatic activation (MOCHA) with these causes, the objective of this study was to validate the utility of the MOCHA profile in identifying the underlying cause of stroke.

METHODS

We prospectively identified ESUS patients from January 1, 2017 to December 1, 2019 who underwent MOCHA profile (plasma d-dimer, prothrombin fragment 1.2, thrombin-antithrombin complex, fibrin monomer) testing. Abnormal MOCHA profile was defined as ≥ 2 abnormal markers. New diagnoses of malignancy, VTE, hypercoagulable disorders and recurrent stroke were identified during routine clinical follow-up.

RESULTS

Of 236 ESUS patients, 104 (44%) patients had an abnormal MOCHA profile. In multivariable analyses the number of MOCHA abnormalities was significantly associated with malignancy, VTE, and hypercoagulable disorders (OR 2.59, CI 95% 1.78-3.76, p<0.001). Sensitivity, specificity, positive predictive value, and negative predictive value of an abnormal MOCHA profile for the combined outcome of malignancy, VTE, and hypercoagulability was 96%, 62%, 23%, and 99% respectively.

DISCUSSION

The MOCHA profile was able to identify ESUS patients more likely to have malignancy, VTE, and hypercoagulable disorders during follow-up. Our results show that a normal MOCHA profile in ESUS patients can effectively rule out these potential causes of ESUS.

Cervical Carotid Plaque MRI : Review of Atherosclerosis Imaging Features and their Histologic Underpinnings

Magnetic resonance (MR) imaging is considered the gold standard for non-invasive evaluation of carotid artery plaque morphology and composition. A number of studies have demonstrated the clinical utility of MR plaque imaging in the risk stratification of carotid atherosclerotic disease, determination of stroke etiology, and identification of surgical and endovascular candidates for carotid revascularization procedures. The MR plaque imaging also provides researchers and clinicians with valuable insights into the pathogenesis, natural history and composition of carotid atherosclerotic disease. Nevertheless, the field of MR plaque imaging is complex, and requires a thorough knowledge of the histologic basis for how various plaque features appear on imaging. This article details the pathogenesis and histology of atherosclerosis, reviews the expected appearance of different plaque components, and describes how MR imaging features may be related to symptomatology or predict future ischemic events.

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.

Biomarkers of atrial cardiopathy in patients with different pathogenetic subtypes of ischemic stroke

Studies of the biomarkers of atrial cardiopathy seem to be promising for identifying patients with cryptogenic stroke (CS), in which an intensive search for atrial fibrillation is indicated. Nevertheless, the diagnostic value of these markers and their threshold values require clarification.

Objective: to present the characteristics of echocardiographic markers for atrial cardiopathy and the serum concentration of N-terminal pro-Btype natriuretic peptide (NT-proBNP) in embolic CS versus cardioembolic stroke (CES) and non-cardioembolic stroke (non-CES) to determine the threshold values of parameters with the highest sensitivity and specificity in differentiating CES and non-CES.

Patients and methods. A total of 259 patients with ischemic stroke were examined. The standard examination additionally involved calculation of the parameters that reflected left atrial LA) function (LAF): LA emptying fraction (LAEF), and LA functional index (LAFI). The serum NT-proBNP concentration was also determined in 75 patients.

Results and discussion. The patients with CES versus those with CS and non-CES were characterized by a considerable increase in LA diameter (4.3 [3.5; 4.5] cm vs 3.7 [3.4; 4.0] cm vs 3.7 [3.4; 3.9] cm; p=0.005 and p=0.009, respectively), LAVI (35.7 [30.5; 39.9] ml/m2 vs 28.5 [25.6; 34.6] ml/m2 vs 27.1 [24.5; 31.2] ml/m2 ; p< 0.001) and NT-proBNP level (559 [409; 1144] pg/ml vs 164 [65; 308] pg/ml vs 191 [63; 446] pg/ml; p=0.002 and p=0.019, respectively), as well as by a lower LAEF value [50.3 [48.5; 51.1]% vs 54.7 [51.6; 56.6]% vs 54.9 [52.5; 56.8]%; p< 0.001). The only parameter that showed significant differences between all the three groups (CES, CS, and nonCES) was LAFI (0.24 [0.2; 0.32] units vs 0.37 [0.3; 0.47] units vs 0.40 [0.34; 0.47] units; p<0.00 1), while maintaining the differences in the values for the two groups (CS and non-CES) (p=0.004). The following threshold values of biomarkers were obtained for CES and nonCES; these were a LA diameter of 41.5 mm (p< 0.001), a LAVI of 36.3 ml/m2 (p< 0.001), a LAEF of 51.8% (p< 0.001), a LAFI of 0.28 units (p< 0.001), and an NT-proBNP of 316 pg/ml (p< 0.001). Analysis of the ROC curves and the area under the curve (AUC) revealed that the most informative criteria for sensitivity and specificity were LAEF (79 and 88%, AUC 0.89), NT-proBNP (67 and 91%, AUC 0.89) and LAFI (93 and 72%, AUC 0.81).

Conclusion. The CS group and non-CES one are comparable in the echocardiographic manifestations of atrial cardiopathy and in serum NTproBNP values. LAEF and NT-proBNP concentrations are promising biomarkers to classify CS patients into potential arterio- and cardioembolic types.

Clot composition of embolic strokes of undetermined source: a feasibility study

BACKGROUND

A number of emerging studies have evaluated clot composition in acute ischemic stroke. Studies of clot composition of embolic strokes of undetermined strokes are lacking.

OBJECTIVES

We sought to analyze the RBC to platelet ratios in clots and correlated our findings with stroke etiology.

METHODS

This was a prospective study analyzing clots retrieved by mechanical thrombectomy in acute ischemic stroke patients at our institution. All clots were stained and scanned at 200x magnification by using a Scanscope XT digital scanner (Apergio, Vista, California). Image-J software (National Institutes of Health, Bethesda, Maryland) was used for semi quantitative analysis of percentage RBC's and platelets. Unpaired t-test was used to compare means of RBC to Platelet ratios. Correlation of RBC to Platelet ratios with stroke etiology was performed.

RESULTS

A total of 33 clots from 33 patients were analyzed. Stroke etiology was undetermined in 6 patients, cardioembolic in 14, large vessel atherosclerosis (LVA) in 9, and carotid dissection in 4. The mean RBC to platelet ratio was 0.78:1 (+/- 0.65) in cardioembolic clots, 1.73:1 (+/- 2.38) in LVA and 1.4:1(+/- 0.70) in carotid dissections. Although patients with undetermined etiology had a similar clot composition to cardioembolic stroke (0.36:1+/- 0.33), (p = 0.19), it differed significantly from LVA and dissections respectively (p = 0.037, p = 0.01).

CONCLUSION

In our study, a low RBC to Platelet ratio was found among patients with embolic strokes of undetermined source, however shared similar characteristics with cardioembolic thrombi. Ongoing collection and analysis is needed to confirm these findings and its significance in evaluating stroke etiology.

Relationship between Lambl's excrescences and embolic strokes of undetermined source

Introduction

About one-fourth of ischaemic strokes are classified as embolic strokes of undetermined source. Lambl's excrescences are commonly seen on cardiac valves, and data are limited on whether they may be a source of embolization. We examined the relationship between Lambl's excrescences and embolic stroke of undetermined source.

Patients and Methods

We performed a case-control study of patients in the Cornell AcutE Stroke Academic Registry. Stroke aetiologies were adjudicated using the Trial of Org 10172 in Acute Stroke Treatment and embolic stroke of undetermined source criteria. We included patients with acute ischaemic stroke between 2011 and 2016 who underwent transthoracic or transoesophageal echocardiography within six months of hospitalisation. Cases were embolic stroke of undetermined source patients and controls were patients with an identified, non-cardioembolic stroke aetiology (i.e. small- or large-vessel strokes). Multiple logistic regression was used to evaluate the association between Lambl's excrescences and embolic stroke of undetermined source after adjustment for demographics, comorbidities and mode of echocardiography.

Results

A total of 923 patients met the criteria for this analysis, including 530 with embolic stroke of undetermined source and 393 with small- or large-vessel strokes. Lambl's excrescences were identified in 47 (8.9%) patients with embolic stroke of undetermined source and 11 (2.8%) patients with small- or large-artery strokes, but the majority (54/58) of Lambl's excrescences were visualised on transoesophageal echocardiogram and embolic stroke of undetermined source patients were more likely to undergo transoesophageal echocardiogram. After adjustment for demographics, comorbidities and mode of echocardiography, we found no association between the presence of Lambl's excrescences and embolic stroke of undetermined source (odds ratio 0.9; 95% confidence interval 0.4-2.3).

Conclusion

We found no association between Lambl's excrescences and embolic stroke of undetermined source. These results do not support the hypothesis that Lambl's excrescences are an occult cause of embolic stroke of undetermined source.

Ability of the number of territories involved on DWI-MRI to predict occult systemic malignancy in cryptogenic stroke patients

BACKGROUND

Lesions in multiple arterial territories is one of the typical features of malignancy patients with cryptogenic stroke. Hence, if patients with cryptogenic stroke display such feature, occult cancer could be predicted. The study aimed to analyze the predictive ability of the number of territories involved on DWI-MRI for occult systemic malignancy (OSM) in patients with cryptogenic stroke.

METHODS

We enrolled patients with cryptogenic stroke without a diagnosis of malignancy at stroke onset between January 2013 and November 2018. Clinical variables were analyzed between cryptogenic stroke patients with and without OSM through univariate and multiple logistic regression analyses. Points for OSM were generated by β-coefficients. The sensitivity and specificity of the risk score were assessed by the area under the receiver operating characteristic curve (AUROC). The cutoff value for predicting OSM was determined by the maximum Youden index.

RESULTS

Among 108 cyptogenic stroke patients, compared to patients without OSM (n = 96), patients with OSM (n = 12) had a lower nutrition status (P = 0.031), higher plasma D-dimer levels (P < 0.001) and more territories involved on DWI-MRI (P < 0.001). Multiple logistic regression analysis revealed that plasma D-dimer levels (OR, 3.54; 95% Cl, 1.62-7.76; P = 0.002) and the number of territories involved (OR, 4.45; 95% CI, 1.25-15.80; P = 0.021) independently predicted OSM. The predictive score system built upon the number of territories showed good discrimination with an AUROC of 0.84 (95% CI, 0.71-0.96). The cutoff value was 2 with a maximum Youden's index of 0.56, which means that patients with more than one territory involved on DWI-MRI may need extensive screening for OSM.

CONCLUSIONS

The number of territories involved on DWI-MRI was a valid predictor for OSM in cryptogenic stroke patients who need to undergo further evaluations .

The Microbiota-Gut-Brain Axis Heart Shunt Part I: The French Paradox, Heart Disease and the Microbiota

It has been well established that a vegetarian and polyphenol-rich diet, including fruits, vegetables, teas, juices, wine, indigestible fiber and whole grains, provide health-promoting phytochemicals and phytonutrients that are beneficial for the heart and brain. What is not well-characterized is the affect these foods have when co-metabolized within our dynamic gut and its colonizing flora. The concept of a heart shunt within the microbiota-gut-brain axis underscores the close association between brain and heart health and the so-called “French paradox” offers clues for understanding neurodegenerative and cerebrovascular diseases. Moreover, oxidation-redox reactions and redox properties of so-called brain and heart-protective foods are underappreciated as to their enhanced or deleterious mechanisms of action. Focusing on prodromal stages, and common mechanisms underlying heart, cerebrovascular and neurodegenerative diseases, we may unmask and understanding the means to better treat these related diseases.

Incidence of Ischemic Stroke in Individuals With and Without Aortic Valve Stenosis: A Danish Retrospective Cohort Study

Background and Purpose- Aortic valve stenosis may lead to atrial and ventricular remodeling, predisposes to atrial fibrillation, and may also be an independent risk factor of ischemic stroke. However, information on stroke rates among persons with aortic valve stenosis are sparse. We aimed to determine the incidence rates and relative risks of ischemic stroke in individuals with diagnosed aortic valve stenosis compared with age- and sex-matched controls. Methods- All patients with incident aortic valve stenosis aged >18 years (n=79 310) and age- and sex-matched controls were identified using the Danish nationwide registries (1997-2017). Incidence rates per 1000 person-years (PY) and multivariable adjusted hazard ratios with 95% CIs were reported. Results- In total, 873 373 individuals (median age 77 years, 51.5% men, 9.1% with aortic valve stenosis) were included. Ischemic stroke occurred in 70 205 (8.0%) individuals during 4 880 862 PY of follow-up. Incidence rates of ischemic stroke were 13.3/1000 PY among the controls compared with 30.4/1000 PY in patients with aortic valve stenosis, corresponding to a hazard ratio of 1.31 (95% CI, 1.28-1.34). In all age-groups, the incidence rates and relative risks were significantly increased in patients with aortic valve stenosis compared with controls, but the relative risk was greater for younger individuals (eg, age group, 18-45 years: hazard ratio, 5.94 [95% CI, 4.10-8.36]). In patients with aortic valve stenosis above 65 years of age, the risk of ischemic stroke was markedly lower after aortic valve replacement (30.3 versus 19.6/1000 PY before and after valve replacement). Among people with atrial fibrillation the incidence rate of ischemic stroke was 1.5 times higher when aortic valve stenosis was present (33.0/1000 PY versus 49.9/1000 PY). Conclusions- People with aortic valve stenosis have a significantly increased risk of ischemic stroke compared with age- and sex-matched controls. Future studies are warranted to explore whether antithrombotic therapy may be beneficial in some individuals.

Cryptogenic stroke

The paper considers the epidemiology and general etiological characteristics of cryptogenic stroke (CS). It discusses the concept of embolic stroke with an unknown source of embolism. It also characterizes the most significant causes of CS, such as paroxysmal atrial fibrillation, atrial cardiopathy, aortic atheroma, non-stenotic cerebral atherosclerotic plaques, and malignant neoplasms. The paper describes approaches to the diagnosis and secondary prevention of CS and proposes etiological and neuroimaging diagnostic algorithms for CI. Clinical cases are also presented.

Beneficial effect of left atrial appendage closure during cardiac surgery: a meta-analysis of 280 585 patients

In non-rheumatic atrial fibrillation (AF), left atrial appendage (LAA) is thought to be the source of embolism in 90% of the strokes. Thus, as recent clinical trials have shown the non-inferiority of percutaneous LAA closure (LAAc) in comparison to medical treatment, and despite a IIb recommendation in the latest guidelines for concomitant surgical LAAc, we sought to investigate the beneficial effect of LAAc in the surgical population. A meta-analysis model was performed comparing studies including any cardiac surgery with or without concomitant surgical LAAc reporting stoke/embolic events and/or mortality, from inception to January 2019. Twenty-two studies (280 585 patients) were included in the model. Stroke/embolic events both in the perioperative period [relative risk (RR) 0.66, 95% confidence interval (CI) 0.53–0.82; P = 0.0001] and during follow-up of >2 years (RR 0.67, 95% CI 0.51–0.89; P < 0.005) were significantly reduced in patients who underwent surgical LAAc (RR 0.71, 95% CI 0.58–0.87; P = 0.001). Regarding the rate of preoperative AF, LAAc showed protective effect against stroke/embolic events in studies with >70% preoperative AF (RR 0.64, 95% CI 0.53–0.77; P < 0.00001) but no benefit in the studies with <30% of preoperative AF (RR 0.77, 95% CI 0.46–1.28; P = 0.31). Postoperative mortality was also significantly lower in surgical patients with LAAc at the mid- and long-term follow-up. (RR 0.72, 95% CI 0.67–0.78; P < 0.00001; I2 = 0%). Based on these findings, concomitant surgical LAAc is associated with lower rates of embolic events and stroke in the postoperative period in patients with preoperative AF and also improves postoperative mortality in the mid- and long-term follow-up.

Predictors of Atrial Fibrillation in Patients With Cryptogenic Stroke

Background and Purpose

Many patients diagnosed with cryptogenic stroke or transient ischemic attack are subsequently found to have atrial fibrillation (AF) on outpatient cardiac telemetry monitoring. Identification of predictive factors for the detection of AF could assist with patient selection to increase the yield of telemetry and hasten initiation of appropriate secondary stroke prevention.

Methods

This was a retrospective cross-sectional study of patients diagnosed with cryptogenic stroke at a comprehensive stroke center and referred for at least 21 days of prolonged outpatient telemetry. Telemetry reports and data from the patient's stroke hospitalization, including imaging studies, electrocardiogram (EKG), echocardiogram, vital signs, and laboratory data, were reviewed.

Results

Ten percent of the 121 patients included in the study were diagnosed with AF based on outpatient telemetry. There was a strong association between presence of premature atrial contractions (PACs) on admission EKG and subsequent detection of AF (P = .004). Large left atrial diameter on echocardiogram was correlated with AF detection in males (P = .024). However, there was no association between AF and other echocardiographic measurements. Thyroid-stimulating hormone (TSH) levels were significantly higher in patients with cryptogenic stroke having AF (P = .008), with a TSH greater than 4.20 mIU/L predictive of detection of AF (P < .001).

Conclusions

Atrial fibrillation was found by outpatient monitoring in a notable percentage of patients with cryptogenic stroke. Predictors of occult AF in our study population included PACs and higher TSH levels. Although an association between low TSH and AF has been well established, our results suggest that high TSH may be a predictive factor as well.

The value of STAF (Score for the Targeting of Atrial Fibrillation) in Patients with Cryptogenic Embolic Stroke

Introduction

The aim of the present study was to predict paroxysmal atrial fibrillation (PAF) in acute ischemic stroke patients with presumed cryptogenic embolic etiology.

Methods

In this retrospective cohort study, demographics, blood tests, data of neuroimaging studies such as non-contrast computed tomography (NCCT), magnetic resonance imaging (MRI), standard 12-lead electrocardigraphy (ECG), 24-hour Holter ECG, echocardiography was collected. The diagnostic work-up to detect atrial fibrillation (AF) was either medical history of the patient or 12-lead ECG or 24-hour Holter ECG or continuous ECG monitoring. Score for the targeting of atrial fibrillation (STAF) was calculated for all patients. Cryptogenic ischemic stroke (CS) patients with and without documented AF were recorded.

Results

Between July 2014 and December 2015, a total of 133 of the 258 patients with CS were included in this study. Overall, 133 patients were enrolled and AF was detected in 30 (22.6%) patients. In univariate analysis gender (p<0.001), age (p=0.001), smoking habit (p=0.004), aortic and mitral valve insufficiency (p=0.014 and p=0.021), left ventricular systolic dysfunction (p=0.04), and left atrial dilatation (p=0.03) were predictors of AF but multivariate analysis showed that only gender and age were independent predictors of AF in patients with presumed cryptogenic ischemic stroke. According to ROC analysis, area under the curve was 70% and the sensitivity and specificity of STAF score of ≥5 was 86% and 71% respectively.

Conclusion

STAF score predicted with fair accuracy, and has a limited use for the risk of PAF in stroke patients.

Patent foramen ovale and embolic cryptogenic stroke

The paper considers the actual problem of cryptogenic stroke and patent foramen ovale (PFO). It highlights the issues of pathogenesis and role of paradoxical embolism in the development of cerebral circulation disorders. The features of clinical manifestations and neuroimaging pattern of stroke in the presence of PFO are described. Ultrasound diagnostic techniques used to verify a cardiac anomaly are characterized. Approaches to establishing a cause-and-effect relationship between the presence of PFO and the development of stroke are presented. The current possibilities of secondary prevention in this category of patients, in particular the results of studies of percutaneous PFO occlusion, are discussed.

Incidence, characteristics and outcomes in patients with embolic stroke of undetermined source: A population-based study

Embolic stroke of undetermined source (ESUS) represents a subgroup of cryptogenic ischemic stroke (CS) distinguished by high probability of an underlying embolic mechanism. There are scarce population-based data regarding the incidence, characteristics and outcomes of ESUS. Consecutive patients included with first-ever ischemic stroke of undetermined cause in the previously published population-based Evros Stroke Registry were further subdivided into ESUS and non-ESUS CS. Crude and adjusted [according to the European Standard Population (ESP), WHO and Segi population] incidence rates (IR) for ESUS and non-ESUS CS were calculated. Baseline characteristics, admission stroke severity (assessed using NIHSS-score), stroke recurrence and functional outcomes [determined by modified Rankin Scale (mRS) scores], were recorded during the 1-year follow-up period. We identified 21 and 242 cases with ESUS (8% of CS) and non-ESUS CS. The crude and ESP-adjusted IR for ESUS were 17.5 (95%CI: 10-25) and 16.6 (95%CI: 10-24) per 100,000 person-years. Patients with ESUS were younger (p < .001) and had lower median admission NIHSS-scores (p < .001). Functional outcomes were more favorable in ESUS at 28, 90 and 365 days. ESUS was independently (p = .033) associated with lower admission NIHSS-scores (unstandardized linear regression coefficient: -13.34;95%CI: -23.34, -3.35) on multiple linear regression models. ESUS was not related to 1-year stroke recurrence, mortality and functional improvement on multivariable analyses. In conclusion we found that ESUS cases represented 8% of CS patients in this population-based study. Despite the fact that ESUS was independently related to lower admission stroke severity, there was no association of ESUS with long-term outcomes.

Cryptogenic stroke - How to make sense of a non-diagnostic entity

Secondary preventive strategies in ischaemic stroke depend on the underlying aetiology. However, approximately one-third of ischaemic strokes remain unexplained, or 'cryptogenic'. There is a wide range of possible underlying causes in cryptogenic stroke, and the best approach to secondary prevention of these may differ. To date, though, the widely accepted and uniform secondary preventive strategy in this group consists of modification of vascular risk factors, and of treatment with a combination of antiplatelet therapy and antihypertensive and lipid-lowering medication. Among the potential causes for cryptogenic stroke are occult atrial fibrillation, patent foramen ovale, atrial cardiopathy, aortic arch atheroma and hypercoagulable states. While it is possible to diagnose these conditions, in individual patients there is often uncertainty over whether they have a directly causative role, are markers of disease, or are innocent bystanders. Similarly, even if the cause is found, the best secondary preventive strategies remain uncertain, which questions the benefit of extensive investigations in a clinical setting. More recently, the concept of "embolic stroke of unknown source (ESUS)" has been introduced, in the hope that anticoagulation may offer better secondary prevention than antiplatelet therapy, but trials so far have been negative. At present, there is little justification for introducing extensive new investigative strategies into the management of patients with cryptogenic stroke. Investigations should be targeted at identifying those high-risk conditions which lead to a change in management. Further investigations need to be tailored individually, according to clinical circumstances. This should include identifying patients for participation in clinical trials, as the significance and best management of many of the potential causes for cryptogenic stroke require further research.

Three Territory Sign: An MRI marker of malignancy-related ischemic stroke (Trousseau syndrome)

Background

Multiple acute cerebral territory infarcts of undetermined origin are typically attributed to cardioembolism, most frequently atrial fibrillation. However, the importance of 3-territory involvement in association with malignancy is under-recognized. We sought to highlight the "Three Territory Sign" (TTS) (bilateral anterior and posterior circulation acute ischemic diffusion-weighted imaging [DWI] lesions), as a radiographic marker of stroke due to malignancy.

Methods

We conducted a single-center retrospective analysis of patients from January 2014 to January 2016, who suffered an acute ischemic stroke with MRI-DWI at our institution, yielding 64 patients with a known malignancy and 167 patients with atrial fibrillation, excluding patients with both to eliminate bias. All DWI images were reviewed for 3-, 2-, and 1-territory lesions. Chi-square test of proportion was used to test significance between the 2 groups.

Results

We found an association between the groups (malignancy vs atrial fibrillation) and the number of territory infarcts (p < 0.0001). Pairwise comparisons using the Holm p value adjustment showed no difference between 1- and 2-territory patterns (p = 0.465). However, the TTS was 6 times more likely observed within the malignancy cohort as compared to patients with atrial fibrillation (23.4% [n = 15] vs 3.5% [n = 6]) and was different from both 1-territory (p < 0.0001) and 2-territory patterns (p = 0.0032).

Conclusion

The TTS is a highly specific marker and 6 times more frequently observed in malignancy-related ischemic stroke than atrial fibrillation-related ischemic stroke. Evaluation for underlying malignancy in patients with the TTS is reasonable in patients with undetermined etiology.

Succinate links atrial dysfunction and cardioembolic stroke

OBJECTIVE

To determine whether altered metabolic profiles represent a link between atrial dysfunction and cardioembolic (CE) stroke, and thus whether underlying dysfunctional atrial substrate may contribute to thromboembolism risk in CE stroke.

METHODS

A total of 144 metabolites were measured using liquid chromatography-tandem mass spectrometry in plasma samples collected within 9 hours of stroke onset in 367 acute stroke patients. Stroke subtype was assigned using the Causative Classification of Stroke System, and CE stroke (n = 181) was compared to non-CE stroke (n = 186). Markers of left atrial dysfunction included abnormal atrial function (P-wave terminal force in lead V1, PTFV₁ >4,000 μV·ms), left atrial enlargement on echocardiography, and frank atrial fibrillation on ECG. Stroke recurrence risk was assessed using CHADS₂ and CHA₂DS₂-VASc scores. Associations between metabolites and CE stroke, atrial dysfunction, and stroke recurrence risk were evaluated using logistic regression models.

RESULTS

Three tricarboxylic acid metabolites-succinate (odds ratio [OR] 1.71, 95% confidence interval [CI] 1.36-2.15, p = 1.37 × 10^-6), α-ketoglutarate (OR 1.62, 95% CI 1.29-2.04, p = 1.62 × 10^-5), and malate (OR 1.58, 95% CI 1.26-1.97, p = 2.57 × 10^-5)-were associated with CE stroke. Succinate (OR 1.36, 95% CI 1.31-1.98, p = 1.22 × 10^-6), α-ketoglutarate (OR 2.14, 95% CI 1.60-2.87, p = 2.08 × 10^-8), and malate (OR 2.02, 95% CI 1.53-2.66, p = 1.60 × 10^-7) were among metabolites also associated with subclinical atrial dysfunction. Of these, succinate was also associated with left atrial enlargement (OR 1.54, 95% CI 1.23-1.94, p = 1.06 × 10^-4) and stroke recurrence based on dichotomized CHADS₂ (OR 2.63, 95% CI 1.68-4.13, p = 3.00 × 10^-6) and CHA₂DS₂-VASc (OR 2.43, 95% CI 1.60-3.68, p = 4.25 × 10^-6) scores.

CONCLUSIONS

Metabolite profiling identified changes in succinate associated with CE stroke, atrial dysfunction, and stroke recurrence, revealing a putative underlying link between CE stroke and energy metabolism.

Stroke in the elderly

Stroke remains the second leading cause of death in the world, and its prevalence is projected to rise in the United States and globally. The main driver for increased stroke prevalence is aging of the population; however, best evidenced-based strategies for stroke treatment and prevention are not always followed for older patients. Furthermore, considerable gaps in knowledge exist for stroke prevention and treatment in elderly and very elderly patients. In this chapter, we discuss various aspects of stroke care in the elderly, including the evidence that guides stroke prevention and treatment. We focus on the challenges in managing stroke in the very elderly including the paucity of data to guide management. The sections span the continuum of stroke care, from primary prevention to management of stroke complications. Finally, we highlight the most significant unanswered questions regarding stroke care in the elderly.

Juvenile Stroke

BACKGROUND

So-called juvenile stroke, i.e., stroke in a person aged 18 to 55, affects approximately 30 000 persons per year in Germany and is thus an important cause of mortality and permanent morbidity. The spectrum of causes of stroke is broader in this age group than in older patients and is also differently distributed.

METHODS

This review is based on pertinent publications retrieved by a selective search in PubMed and on current guideline recommendations.

RESULTS

Juvenile strokes are often caused by cardiogenic emboli (ca. 25%) and by vascular dissection (ca. 20%). Approximately 10% are due to rare causes such as vasculitis or thrombophilia, 25-50% remain cryptogenic, and 20-30% meet the criteria for an embolic stroke of undetermined source (ESUS). A rational diagnostic algorithm should be applied that is based on the relative frequencies of the potential causes. The acute treatment of ischemic stroke is the same for patients of all ages: the patient must be transferred as soon as possible to a hospital where a vascular recanalization procedure can be performed. From age 40 onward, there is a steep rise in vascular risk factors and therefore also in the resulting macro- and microangiopathy, which lead, in turn, to stroke. Only 40% of patients with juvenile stroke are ever able to return to their original occupation, and approximately one-third remain permanently unable to work.

CONCLUSION

The high rates of cryptogenic stroke and ESUS among patients with juvenile stroke indicate that uncertainties remain in the diagnosis and treatment of this entity. The identification of rare causes of juvenile stroke requires a major diagnostic effort. Which diagnostic tests are useful or necessary in which patients is a matter that is currently decided on an individual basis. This is true, above all, of the indication for long-term cardiac monitoring.

Effect of Clot Stiffness on Recombinant Tissue Plasminogen Activator Lytic Susceptibility in Vitro

The lytic recombinant tissue plasminogen activator (rt-PA) is the only drug approved by the Food and Drug Administration for treating ischemic stroke. Less than 40% of patients with large vessel occlusions who are treated with rt-PA have improved blood flow. However, up to 6% of all patients receiving rt-PA develop intracerebral hemorrhage. Predicting the efficacy of rt-PA treatment a priori could help guide therapeutic decision making, such that rt-PA is administered only to those individuals who would benefit from this treatment. Clot composition and structure affect the lytic efficacy of rt-PA and have an impact on elasticity. However, the relationship between clot elasticity and rt-PA lytic susceptibility has not been adequately investigated. The goal of this study was to quantify the relationship between clot elasticity and rt-PA susceptibility in vitro. Human and porcine highly retracted and mildly retracted clots were fabricated in glass pipettes. The rt-PA lytic susceptibility was evaluated in vitro using the percent clot mass loss. The Young's moduli of the clots were estimated using ultrasound-based single-track-location shear wave elasticity imaging. The percent mass loss in mildly retracted porcine and human clots (28.9 ± 6.1% and 45.2 ± 7.1%, respectively) was significantly higher (p < 0.05) than in highly retracted porcine and human clots (10.9 ± 2.1% and 25.5 ± 10.0%, respectively). Furthermore, the Young's moduli of highly retracted porcine and human clots (5.33 ± 0.92 and 3.21 ± 1.97 kPa, respectively) were significantly higher (p < 0.05) than those of mildly retracted porcine and human clots (2.66 ± 0.55 and 0.79 ± 0.21 kPa, respectively). The results revealed an inverse relationship between the percent clot mass loss and Young's modulus. These findings motivate continued investigation of ultrasound-based methods to assess clot stiffness in order to predict rt-PA thrombolytic efficacy.

Different Clinical Phenotypes of Embolic Stroke of Undetermined Source: A Subgroup Analysis of 86 Patients

INTRODUCTION AND STUDY AIM

Embolic strokes of undetermined source (ESUS) represent a rather recent diagnostic entity under clinical research for relapse prevention in cryptogenic stroke patients. Despite strict diagnostic criteria, ESUS definition ignores major clinical and radiological aspects, so including heterogeneous cases and probably influencing trial results. This study researches clinically relevant phenotypes among ESUS patients.

PATIENTS AND METHODS

We evaluated ESUS patients admitted at Trento Stroke Unit over a 4-year period. Vascular risk factors (RFs), neurological deficit severity, presence of potential embolic sources, and ASCOD phenotype were recorded. Ischemic lesions were categorized considering their extension in 4 groups. Subgroup comparisons by predefined differences in age, amount of RFs, history of previous stroke, deficit severity, and stroke lesion extension were done.

RESULTS

ESUS cases were 86. Patients younger than 50 years old (n = 17) had a lower prevalence of RFs, left atrial enlargement, left ventricle diastolic dysfunction, a higher proportion of ASCOD score A0 (P < .05). Patients without RFs (n = 18) differed from those with greater than or equal to 3 RFs (n = 23) for a younger age and a lower prevalence of potential causes of embolism (P < .05). Patients without a previous stroke (n = 70) were younger, had a lower prevalence of RFs, left ventricle diastolic dysfunction, a higher prevalence of ASCOD score A0 (P < .05). No differences were observed comparing minor and major clinical and radiological strokes.

DISCUSSION AND CONCLUSIONS

ESUS patients can be distinguished in 2 opposite phenotypes defined by a lower and a higher load of atherosclerotic pathology. They may suggest possible underlying pathogenic mechanisms and support interpretation of ongoing trials results.