Targeted Metabolomic Biomarkers for Stroke Subtyping

BACKGROUND AND PURPOSE

Ischemic stroke is a heterogeneous disease with various etiologies. The current subtyping process is complicated, time-consuming, and costly. Metabolite-based biomarkers have the potential to improve classification and deliver optimal treatments. We here aimed to identify novel, targeted metabolomics-based biomarkers to discriminate between large-artery atherosclerosis (LAA) and cardioembolic (CE) stroke.

METHODS

We acquired serum samples and clinical data from a hospital-based acute stroke registry (ischemic stroke within 3 days from symptom onset). We included 346 participants (169 LAA, 147 CE, and 30 healthy older adults) and divided them into training and test sets. Targeted metabolomic analysis was performed using quantitative and quality-controlled liquid chromatography with tandem mass spectrometry. A multivariate regression model using metabolomic signatures was created that could independently distinguish between LAA and CE strokes.

RESULTS

The training set (n = 193) identified metabolomic signatures that were different in patients with LAA and CE strokes. Six metabolomic biomarkers, i.e., lysine, serine, threonine, kynurenine, putrescine, and lysophosphatidylcholine acyl C16:0, could discriminate between LAA and CE stroke after adjusting for sex, age, body mass index, stroke severity, and comorbidities. The enhanced diagnostic power of key metabolite combinations for discriminating between LAA and CE stroke was validated using the test set (n = 123).

CONCLUSIONS

We observed significant differences in metabolite profiles in LAA and CE strokes. Targeted metabolomics may provide enhanced diagnostic yield for stroke subtypes. The pathophysiological pathways of the identified metabolites should be explored in future studies.

Cardioembolism after thoracoscopic left atrial appendage clipping in a patient on oral anticoagulation therapy

Cardioembolism associated with atrial fibrillation is a major cause of ischemic stroke. Left atrial appendage occlusion in atrial fibrillation patients undergoing cardiac surgery reduces the risk of postoperative stroke. A 78-year-old man with a history of atrial fibrillation and severe mitral regurgitation underwent thoracoscopic mitral valve repair with left atrial appendage clipping and the cryo-maze procedure 4 years previously. He was taking a direct oral anticoagulant for stroke prevention because his atrial fibrillation had recurred. He presented with acute onset disturbed consciousness, omnidirectional gaze palsy, left facial palsy, severe dysarthria, bilateral limb ataxia, and sensory disturbance. National Institutes of Health Stroke Scale score was 16. Although non-contrast computed tomography showed no early ischemic changes, computed tomography angiography revealed occlusion of the basilar artery. Intravenous thrombolysis was performed, which resulted in recanalization. Transesophageal echocardiography showed left atrial spontaneous echo contrast and thrombus in the left atrial appendage. Contrast-enhanced chest computed tomography confirmed incomplete left atrial appendage occlusion. Cardioembolic stroke was diagnosed, and warfarin was initiated. Cardioembolism may occur after thoracoscopic left atrial appendage clipping despite direct oral anticoagulant therapy, particularly if appendage occlusion is incomplete. Occlusion status should be evaluated after thoracoscopic clipping.

Learning objective

To illustrate, incomplete left atrial appendage closure may increase the risk of ischemic stroke even after thoracoscopic left atrial appendage clipping is performed to prevent embolism.

Diagnosis of atrial fibrillation in young patients with ischemic stroke: A systematic review and meta-analysis

INTRODUCTION

The recommended cardiac rhythm evaluation to determine the etiology of ischemic stroke (IS) is similar in all patients regardless of their age and includes an electrocardiogram and at least a 24-hour heart rhythm monitoring. However, it is known that the main causes of IS vary according to patients' age. There is a higher preponderance of arterial dissections and patent foramen ovale in younger patients, while atrial fibrillation (AF) is more common in older patients.

AIMS

To determine the proportion of AF in young IS reported in the literature and determine if young IS patients found to have AF had known structural cardiac pathology.

METHODS

Systematic review of the literature searching PubMed and Embase for articles published since their inception to August 2020. Inclusion criteria were studies including at least 10 patients, aged 14-50 years-old, clinical or radiological diagnosis of IS and quantification of patients found to have AF. We conducted a meta-analysis using a random-effects model and calculated pooled proportions with 95% confidence intervals.

RESULTS

8331 articles were screened, 154 were selected for full-text review. 43 studies were included in our final analysis (902800 patients). The proportion of AF in young IS overall was 3.1% [95%CI 2.4-3.7], I2 93.88%. Sub-analysis revealed a proportion of AF of 3.8% [95% CI 0.3-7.3] in lower-middle-income economies, versus 5.4% [95% CI 3-7.9] in upper-middle-income economies, and 2.2% [95% CI 1.6-2.8] in high-income economies. Only 3 studies mentioned the proportion of patients with AF that had structural cardiac pathology.

CONCLUSION

The proportion of AF in young IS was low. More studies are needed to better understand if young IS patients diagnosed with AF had a priori known structural cardiac pathology that could increase the probability of finding AF. This could lead to a reevaluation of the need for 24 hours cardiac rhythm evaluation in young patients without cardiac pathology.

Recognizing blind spots on echocardiography: Incremental benefit of cardiac CT in investigating the source of systemic embolism

Transesophageal echocardiography is the gold-standard for evaluating potential central sources of thromboembolism. Despite its routine use and excellent safety profile, limitations exist in the ability to effectively assess the aortic arch and proximal descending aorta with this imaging modality. We herein present a case of a 59 year-old patient presenting with renal and splenic infarcts, without obvious cardioembolic source on echocardiography, who was found to have a large, mobile aortic thrombus on gated cardiac computed tomography.

Focal Anticoagulation by Somatic Gene Transfer: Towards Preventing Cardioembolic Stroke

Cardioembolic stroke (CS) has emerged as a leading cause of ischaemic stroke (IS); distinguished by thrombi embolising to the brain from cardiac origins; most often from the left atrial appendage (LAA). Contemporary therapeutic options are largely dependent on systemic anticoagulation as a blanket preventative strategy, yet this does not represent a nuanced or personalised solution. Contraindications to systemic anticoagulation create significant unmedicated and high-risk cohorts, leaving these patients at risk of significant morbidity and mortality. Atrial appendage occlusion devices are increasingly used to mitigate stroke risk from thrombi emerging from the LAA in patients ineligible for oral anticoagulants (OACs). Their use, however, is not without risk or significant cost, and does not address the underlying aetiology of thrombosis and CS. Viral vector-based gene therapy has emerged as a novel strategy to target a spectrum of haemostatic disorders, achieving success through the adeno-associated virus (AAV) based therapy of haemophilia. Yet, thrombotic disorders, such as CS, have had limited exploration within the realm of AAV gene therapy approaches-presenting a gap in the literature and an opportunity for further research. Gene therapy has the potential to directly address the cause of CS by localised targeting of the molecular remodelling that serves to promote thrombosis.

Detection of patent foramen ovale in patients with ischemic stroke on prospective ECG-gated cardiac CT compared to transthoracic echocardiography

BACKGROUND

Cardiac CT acquired during the acute stroke imaging protocol is an emerging alternative to transthoracic echocardiography (TTE) to screen for sources of cardioembolism. Currently, its diagnostic accuracy to detect patent foramen ovale (PFO) is unclear.

METHODS

This was a substudy of Mind the Heart, a prospective cohort in which consecutive adult patients with acute ischemic stroke underwent prospective ECG-gated cardiac CT during the initial stroke imaging protocol. Patients also underwent TTE. We included patients < 60 years who underwent TTE with agitated saline contrast (cTTE) and assessed sensitivity, specificity, negative and positive predictive value of cardiac CT for the detection of PFO using cTTE as the reference standard.

RESULTS

Of 452 patients in Mind the Heart, 92 were younger than 60 years. Of these, 59 (64%) patients underwent both cardiac CT and cTTE and were included. Median age was 54 (IQR 49-57) years and 41/59 (70%) were male. Cardiac CT detected a PFO in 5/59 (8%) patients, 3 of which were confirmed on cTTE. cTTE detected a PFO in 12/59 (20%) patients. Sensitivity and specificity of cardiac CT were 25% (95% CI 5-57%) and 96% (95% CI 85-99%), respectively. Positive and negative predictive values were 59% (95% CI 14-95) and 84% (95% CI 71-92).

CONCLUSION

Prospective ECG-gated cardiac CT acquired during the acute stroke imaging protocol does not appear to be a suitable screening method for PFO due to its low sensitivity. Our data suggest that if cardiac CT is used as a first-line screening method for cardioembolism, additional echocardiography remains indicated in young patients with cryptogenic stroke, in whom PFO detection would have therapeutic consequences. These results need to be confirmed in larger cohorts.

Effects of Direct Oral Anticoagulants' Nonrecommended Dose in Atrial Fibrillation: A Meta-Analysis

BACKGROUND

The efficacy and safety profiles of nonrecommended direct oral anticoagulant (DOAC) doses in patients with nonvalvular atrial fibrillation (NVAF) are still undefined.

SUMMARY

We searched for randomized controlled trials and observational studies that compared nonrecommended versus recommended doses of DOACs, published up to December 2021. Primary study outcomes were ischemic stroke/transient ischemic attack/systemic embolism (IS/TIA/SE) and major bleeding (MB). All-cause mortality was a secondary outcome. We determined pooled odds ratios (ORs) between groups of patients with a random-effect model. Twenty-three studies with 175,801 patients were included. Nonrecommended doses were associated with a higher risk of IS/TIA/SE and all-cause mortality, but not of MB as compared to recommended doses of DOACs (OR 1.25 [95% CI: 1.14-1.38], OR 1.69 [95% CI: 1.31-2.18] and OR 1.10 [95% CI: 0.93-1.31], respectively). The nonrecommended low dose was associated with an increased risk of IS/TIA/SE and all-cause death (OR 1.21 [95% CI: 1.05-1.39] and OR 1.66 [95% CI: 1.18-2.35], respectively) but not of MB (OR 1.01 [95% CI: 0.83-1.22] as compared to recommended doses. Subgroup analysis of nonrecommended low doses of DOACs showed a nonsignificant increase in IS/TIA/SE in Asians (OR 1.17 [95% CI: 0.89-1.54] vs. non-Asian (OR 1.21 [95% CI: 1.07-1.36]).

KEY MESSAGES

Compared with recommended doses, nonrecommended low doses of DOACs increase the risk of ischemic events without decreasing the risk of bleeding. For Asians, the efficacy of DOACs seemed preserved despite the nonrecommended low-dose prescription. Clinicians should carefully adhere to recommended DOAC prescription advice in managing NVAF patients.

The hypereosinophilic syndrome - an unusual cause of myocarditis and cardioembolic strokes

Hypereosinophilic syndrome is a rare disorder characterized by excessive peripheral eosinophilia and eosinophil associated end-organ damage. Clinical presentations are heterogenous and can involve skin, pulmonary, cardiac and neurologic dysfunction. Eosinophilic myocarditis is a life-threatening complication that increases the risk of cardiac microemboli, which can subsequently lead to embolic strokes. Secondary to changes in blood viscosity, impaired clearance of microemboli, impaired cerebral blood flow, and pro-thrombotic conditions in the setting of hypereosinophilia, infarcts often present in vascular border zone regions. Here we present two cases of cardioembolic strokes involving borderzone regions in the setting of hypereosinophilic syndrome.

Diagnostic And Prognostic Value Of Left Atrial Function In Identification Of Cardioembolism And Prediction Of Outcomes In Patients With Cryptogenic Stroke

BACKGROUND

Strokes of undetermined source, commonly termed cryptogenic stroke (CS), account for a significant proportion of ischemic stroke etiology and have high rates of stroke recurrence. The heterogeneous etiology of CS makes decisions regarding treatment for such patients challenging. We sought to evaluate the diagnostic and prognostic value of left atrial (LA) function in identification of cardioembolism and prediction of outcomes in patients with CS.

METHODS

Consecutive patients admitted to our tertiary institution with ischemic stroke or transient ischemic attack (TIA) who underwent transthoracic echocardiography were recruited with comprehensive evaluation of LA metrics including LA strain. Ischemic strokes / TIAs were classified as non-cardioembolic, cryptogenic and cardioembolic. A total of 709 patients (66.0±15.1 years, 55% male) were recruited. 291 patients had CS, 189 had non-cardioembolic stroke and 229 had cardioembolic stroke. Patients with CS were followed for 20.0±13.8 months for recurrent ischemic stroke / TIA.

RESULTS

Receiver-operating characteristic curves showed LA reservoir (LASr) and contractile (LASct) strains to be strong discriminators of cardioembolic strokes and log rank tests showed both measures to be significantly associated with the distribution of time to recurrent ischemic stroke / TIA in patients with CS. Multivariable hazards models showed LASr and LASct to be independent predictors of recurrent ischemic stroke / TIA in CS patients in addition to eGFR and active smoking.

CONCLUSIONS

LASr and LASct were strong discriminators of cardioembolic stroke and independently predicted recurrent ischemic stroke / TIA in patients with CS. Use of LA strain may improve risk stratification and decision-making in patients with CS, with particular regards to prolonged ambulatory heart rhythm monitoring and/or empiric anticoagulation.

Classification of cardioembolic stroke based on a deep neural network using chest radiographs

BACKGROUND

Although chest radiographs have not been utilised well for classifying stroke subtypes, they could provide a plethora of information on cardioembolic stroke. This study aimed to develop a deep convolutional neural network that could diagnose cardioembolic stroke based on chest radiographs.

METHODS

Overall, 4,064 chest radiographs of consecutive patients with acute ischaemic stroke were collected from a prospectively maintained stroke registry. Chest radiographs were randomly partitioned into training/validation (n = 3,255) and internal test (n = 809) datasets in an 8:2 ratio. A densely connected convolutional network (ASTRO-X) was trained to diagnose cardioembolic stroke based on chest radiographs. The performance of ASTRO-X was evaluated using the area under the receiver operating characteristic curve. Gradient-weighted class activation mapping was used to evaluate the region of focus of ASTRO-X. External testing was performed with 750 chest radiographs of patients with acute ischaemic stroke from 7 hospitals.

FINDINGS

The areas under the receiver operating characteristic curve of ASTRO-X were 0.86 (95% confidence interval [CI], 0.83-0.89) and 0.82 (95% CI, 0.79-0.85) during the internal and multicentre external testing, respectively. The gradient-weighted class activation map demonstrated that ASTRO-X was focused on the area where the left atrium was located. Compared with cases predicted as non-cardioembolism by ASTRO-X, cases predicted as cardioembolism by ASTRO-X had higher left atrial volume index and lower left ventricular ejection fraction in echocardiography.

INTERPRETATION

ASTRO-X, a deep neural network developed to diagnose cardioembolic stroke based on chest radiographs, demonstrated good classification performance and biological plausibility.

FUNDING

Grant No. 14-2020-046 and 08-2016-051 from the Seoul National University Bundang Research Fund and NRF-2020M3E5D9079768 from the National Research Foundation of Korea.

A case report of takotsubo syndrome complicated by ischaemic stroke: the clinical dilemma of anticoagulation

Background

Takotsubo syndrome (TTS) is an acute and transient heart failure syndrome due to reversible myocardial dysfunction characterized by a wide spectrum of possible clinical scenarios. About one-fifth of TTS patients experience adverse in-hospital events. Thromboembolic complications, especially stroke, have been reported, albeit in a minority of patients.

Case summary

A 69-year-old woman presented to our emergency department for dyspnoea after a family quarrel. Electrocardiogram revealed ST-segment elevation in anterolateral leads and laboratory exams showed a slight elevation of high-sensitivity cardiac troponin. The patient was treated according to current guidelines on ST-elevation myocardial infarction and referred to the cath lab. Urgent coronary angiography revealed normal coronary arteries. Based on the patient profile and instrumental findings, a diagnosis of TTS was hypothesized. After 6 days, the patient developed dysarthria and right hemiparesis under therapy with aspirin, whilst low molecular weight heparin had been previously withdrawn. Transthoracic echocardiography (TTE) revealed persisting apical akinesia and a subtle intraventricular thrombus. Head computed tomography and magnetic resonance imaging detected focal areas of ischaemic necrosis resembling diffuse cardioembolic lesions. Anticoagulation therapy was started and regular TTE showed complete recovery of myocardial systolic function and absence of ventricular thrombi at 1-month follow-up. The patient fully recovered speech after 5 months.

Discussion

This challenging case reinforces current recommendations to administer antithrombotic therapy in TTS patients with extensive apical dysfunction up to complete or near-complete recovery of myocardial contractility, regardless of the presence of atrial fibrillation, and highlights the importance of close TTE monitoring during the acute phase.

Blood biomarkers to detect new-onset atrial fibrillation and cardioembolism in ischemic stroke patients

BACKGROUND

Accumulating data suggest blood biomarkers could inform stroke etiology.

OBJECTIVE

The purpose of this study was to investigate the performance of multiple blood biomarkers in elucidating stroke etiology with a focus on new-onset atrial fibrillation (AF) and cardioembolism.

METHODS

Between January and December 2017, information on clinical and laboratory parameters and stroke characteristics was prospectively collected from ischemic stroke patients recruited from the National University Hospital, Singapore. Multiple blood biomarkers (N-terminal pro-brain natriuretic peptide [NT-proBNP], d-dimer, S100β, neuron-specific enolase, vitamin D, cortisol, interleukin-6, insulin, uric acid, and albumin) were measured in plasma. These variables were compared with stroke etiology and the risk of new-onset AF and cardioembolism using multivariable regression methods.

RESULTS

Of the 515 ischemic stroke patients (mean age 61 years; 71% men), 44 (8.5%) were diagnosed with new-onset AF, and 75 (14.5%) had cardioembolism. The combination of 2 laboratory parameters (total cholesterol ≤169 mg/dL; triglycerides ≤44.5 mg/dL) and 3 biomarkers (NT-proBNP ≥294 pg/mL; S100β ≥64 pg/mL; cortisol ≥471 nmol/l) identified patients with new-onset AF (negative predictive value [NPV] 90%; positive predictive value [PPV] 73%; area under curve [AUC] 85%). The combination of 2 laboratory parameters (total cholesterol ≤169 mg/dL; triglycerides ≤44.5 mg/dL) and 2 biomarkers (NT-proBNP ≥507 pg/mL; S100β ≥65 pg/mL) identified those with cardioembolism (NPV 86%; PPV 78%; AUC 87%). Adding clinical predictors did not improve the performance of these models.

CONCLUSION

Blood biomarkers could identify patients with increased likelihood of cardioembolism and direct the search for occult AF.

Comparisons of Characteristics and Outcomes after Mechanical Thrombectomy for Vertebrobasilar Occlusion with Cardioembolism or Atherosclerotic Brain Infarction: Data from the Tokyo-Tama-Registry of Acute Endovascular Thrombectomy (TREAT)

BACKGROUND

Some reports suggest the efficacy of mechanical thrombectomy (MT) for acute vertebrobasilar artery (VBA) occlusion. The major causes of VBA occlusion include cardioembolism (CE) and large-artery atherosclerosis (LAA). However, the clinical characteristics of each cause remain unclear, and they might be important for decision making related to the indications and strategy of MT.

OBJECTIVE

This study aimed to compare functional outcomes and factors affecting outcomes between patients with CE and LAA with acute VBA occlusion.

METHODS

This was a retrospective and prospective observational study using data from TREAT (Tokyo-Tama-Registry of Acute Endovascular Thrombectomy), a multicenter registry of MT for acute large-vessel occlusion in the Tokyo metropolitan area. Patients with VBA occlusion classified into CE and LAA groups were analyzed. The primary outcome was a modified Rankin Scale score of 0-2 at 90 days.

RESULTS

Seventy-nine patients (57 with CE and 22 with LAA) were eligible from January 2015 to March 2020. Despite significantly shorter puncture-to-recanalization and onset-or-last-well-known-to-recanalization times in the CE group, the primary outcome was not significantly different between the 2 groups (CE, 31.6% vs. LAA, 45.5%; P = 0.248). In the subgroup analysis, patients with CE had worse clinical outcomes in the onset-or-last-well-known-to-door time ≥180 minutes, onset-or-last-well-known-to-door time ≥300 minutes, and low posterior circulation Alberta Stroke Program Early CT Score (≤7) subgroups.

CONCLUSIONS

Functional outcomes of VBA occlusion were not significantly different between CE and LAA. Based on the subgroup analysis, patients with CE might have poorer collateral status than do patients with LAA, and earlier recanalization might therefore be desired.

Cardiovascular magnetic resonance imaging and its role in the investigation of stroke: an update

Recent advances in complementary diagnostic exams have helped to clarify stroke etiology, not only by helping to confirm established stroke causes but also by unveiling new possible stroke mechanisms. Etiological investigation for cardioembolic stroke has benefited in the last years from information provided by studies analysing serum biomarkers, heart rhythm monitoring and imaging methods like cardiovascular magnetic resonance (CMR) imaging. CMR has been particularly important for the characterization of possible new cardioembolic stroke mechanisms including atrial cardiomyopathy, silent myocardial infarction and cardiomyopathies.

CT Angiography of the Heart and Aorta in TIA and Ischaemic Stroke: Cardioembolic Risk Sources and Clinical Implications

BACKGROUND

Cardiac emboli are important causes of (recurrent) ischaemic stroke. Aorta atherosclerosis might also be associated with an increased risk of stroke recurrence. This study aimed to evaluate the yield and clinical implications of CT-angiography (CTA) of the heart and aorta in the diagnostic workup of transient ischaemic attack (TIA) or ischaemic stroke.

METHODS

CTA of the heart and aortic arch was performed in TIA/ischaemic stroke patients, in addition to routine diagnostic workup. Occurrence of cardioembolic (CE) risk sources and complex aortic plaques were assessed. Implications of cardiac CTA for therapeutic management were evaluated RESULTS: Sixty-seven patients were included (TIA n = 33, ischaemic stroke n = 34) with a mean age of 68 years (range 51-89) and median NIHSS of 0 (interquartile range 0-2). CE risk sources were detected in 29 (43%) patients. An intracardiac thrombus was present in 2 patients (3%; TIA 0%; ischaemic stroke 6%). Medium/low-risk CE sources included mitral annular calcification (9%), aortic valve calcification (18%) and patent foramen ovale (18%). Complex aortic plaque was identified in 16 patients (24%). In two patients with an intracardiac thrombus, therapeutic management changed from antiplatelet to oral anticoagulation.

CONCLUSIONS

CTA of the heart and aorta has a high yield for detection of embolic risk sources in TIA/ischaemic stroke, with clinical consequences for 6% of ischaemic stroke patients. Implementation of CTA of the heart and aorta in the acute stroke setting seems valuable, but cost-effectiveness of this approach remains to be determined.

Planning and execution of catheter closure of a giant left atrial appendage aneurysm causing recurrent cardioembolism

Giant left atrial appendage aneurysms (LAAAs) are rare causes of recurrent cardioembolism and managed routinely by surgery. A first catheter closure of a giant LAAA is reported, when a recent cerebral infarct precluded immediate surgery. Planning included ostial measurement on multimodal imaging, echo navigation for septal puncture, rotational angiogram for profiling, overlay imaging for device placement, and cerebral embolic protection from thrombus debris.

Atrial Fibrillation After Ischemic Stroke Detected by Chest Strap-Style 7-Day Holter Monitoring and the Risk Predictors: EDUCATE-ESUS

Aim: This study aimed to investigate the diagnostic yield of 7-day Holter monitoring for detecting covert atrial fibrillation (AF) in patients with recent embolic stroke of undetermined source (ESUS) and to identify the pre-entry screening biomarkers that had significant associations with later detection of AF (clinicaltrials.gov. NCT02801708).

Methods: A total of 206 patients who have recent ESUS without previously documented AF underwent Holter electrocardiography using a chest strap-style monitor. External validation of biomarkers predictive of AF was performed using 83 patients with ESUS who were implanted with insertable cardiac monitors.

Results: The 7-day Holter monitoring started at a median of 13 days after the onset of stroke. AF was detected in 14 patients, and three of these showed a single AF episode lasting ＜2 min. The median time delay to the first documented AF was 50 h. Each of serum brain natriuretic peptide ≥ 66.0 pg/mL (adjusted odds ratio 5.23), atrial premature contractions (APCs) ≥ 345 beats (3.80), and APC short runs ≥ 13 (5.74) on 24-h Holter prior to the 7-day Holter showed a significant association with detection of AF, independent of age and physiological findings in this derivation cohort, and all of these showed a significant association in the validation cohort (adjusted odds ratio 6.59, 7.87, and 6.16, respectively).

Conclusions: In recent ESUS patients, the detection rate of AF using the 7-day Holter monitoring was 6.8% (95% CI 4.1%–11.1%). Brain natriuretic peptide, APC count, and APC short runs in the standard clinical workup seemed to be predictors of covert AF.

Cortical and Internal Watershed Infarcts Might Be Key Signs for Predicting Neurological Deterioration in Patients with Internal Carotid Artery Occlusion with Mild Symptoms

Background

Treatment for acute ischemic stroke due to large vessel occlusion (LVO) with mild symptoms is under discussion. Although most patients have good outcomes, some patients deteriorate and have unfavorable results. Imaging findings that predict the prognosis of LVO with mild symptoms are needed to identify patients who require treatment. In this study, we focused on watershed infarctions (WSIs), because this clinical phenomenon quite sensitively reflects changes in cerebral blood flow. The purpose of this study was to assess positive rates of WSI on MRI findings in patients with internal carotid artery (ICA) occlusion, and compare WSI-positive rates between patients divided according to their clinical course.

Methods

We retrospectively collected data of 1,531 patients who presented with acute ischemic stroke between June 2006 and July 2019. Among them, we chose symptomatic ICA occlusion patients with a past history of atrial fibrillation who were treated conservatively. We divided these patients into two groups, those with maintenance or improvement in their NIHSS score after hospitalization, and those whose NIHSS score worsened. We compared WSI-positive rates between these two groups.

Results

Thirty-seven of the 1,531 patients were included in this study. Of them, total NIHSS score was maintained or improved in 8 patients (group A), 3 of whom (37.5%) had internal watershed infarctions (IWIs). In group B, consisting of patients whose NIHSS score worsened by >2 at 7 days from symptom onset, 24 (82.8%) had IWIs. Group A thus had statistically lower IWI positivity rates than group B (p = 0.02). Three patients (37.5%) in group A had cortical watershed infarctions (CWIs), while 27 patients in group B (93.1%) had CWIs. Group A thus had a significantly lower CWI positivity rate than group B (p = 0.002).

Conclusion

In patients with mildly symptomatic ICA occlusion, CWIs and IWIs might be key signs for predicting neurological deterioration after hospitalization.

Paradoxical embolism through a patent foramen ovale from central venous catheter thrombosis: A potential cause of stroke

Paradoxical embolism refers to a potential condition in which an embolus arising from a venous source crosses into the systemic circulation through a right-to-left cardiac shunt causing an arterial embolism. A 39-year-old woman carrier of a central venous catheter (CVC) without evident risk factors for stroke, developed an acute right homonymous hemianopia during hemodialysis. On neuroimaging, an infarct in the territory of the left posterior cerebral artery was demonstrated. Transesophageal echocardiography revealed a patent foramen ovale (PFO) and a large fluctuating thrombus in the right atrium on the tip of the CVC, thus allowing a diagnosis of ischemic stroke from paradoxical embolism. Oral anticoagulation therapy was started and the PFO was closed. This case emphasizes the potential risk of paradoxical embolism in patients with CVCs and PFO. This condition should be prevented and identified in patients with specific risk factors, such as long-term catheterization and hemodialysis.

Relationship between Presence of Visceral Infarction and Functional Outcome among Patients with Acute Ischemic Stroke

INTRODUCTION

Evidence of visceral infarction is often found in patients with acute ischemic stroke. It remains uncertain whether there exists a relationship between visceral infarction and functional outcomes among patients with stroke.

OBJECTIVE

The aim of this study was to evaluate whether evidence of visceral infarction is associated with functional outcomes among patients with stroke.

METHODS

Among patients with acute ischemic stroke enrolled in the Cornell AcutE Stroke Academic Registry (CAESAR) from 2011 through 2016, we included those with a contrast-enhanced abdominal computed tomographic scan within 1 year of admission. Our outcome was ambulatory status at discharge from acute stroke hospitalization, categorized as walking without assistance, walking with assistance, and unable to walk. We used ordinal logistic regression to examine the association between visceral infarction and discharge ambulatory status after adjustment for demographics, stroke risk factors, stroke severity (NIH Stroke Scale), and stroke subtype.

RESULTS

Among 2,116 ischemic stroke patients registered in CAESAR from 2011 to 2016, 259 had contrast-enhanced abdominal computed tomographic imaging, of whom 48 (19%) had evidence of visceral infarction. After adjustment for demographics, stroke risk factors, stroke severity, and stroke subtype, the presence of visceral infarction was associated with a worse ambulatory status at discharge (global OR for better ambulatory status, 0.4; 95% CI, 0.2-1.0, p = 0.046).

CONCLUSIONS

We found that the presence of visceral infarction was associated with poor functional outcomes at the time of hospital discharge. These findings suggest that such findings are not necessarily benign and are at the least a marker of poor outcomes.

Characteristics of aged ischemic stroke patients indicative of cardioembolism

The treatment of ischemic stroke has recently witnessed dramatic developments. However, there are limited data on ischemic stroke characteristics in aged patients. As part of the South Tochigi Acute Ischemic Stroke Registry, we prospectively enrolled 636 consecutive acute ischemic stroke patients (within 7 days after the onset) who were ≥ 60 years of age and who were admitted to two independent institutes from April 1, 2016 to February 28, 2019. We analyzed three groups divided by age: early-aged (60-69 years), middle-aged (70-79 years), and oldest-aged (≥ 80 years). From the 636 subjects, 194 were early-aged, 215 were middle-aged, and 227 were oldest-aged. There were significant differences in the ischemic stroke subtypes in each aging group (p < 0.01). The proportion of cardioembolism was 22.2% in early-aged, 27.4% in middle-aged, and 41.4% in the oldest-aged patients. The proportion of patients with a modified Rankin Scale of 0-2 at 1 year after onset decreased to 42.2% in middle-aged and 17.8% in oldest-aged with cardioembolic ischemic stroke. The proportion of patients receiving anticoagulation therapy before admission was 25.6% (36.7% of atrial fibrillation [AF]) in early-aged, 39.0% (52.3% of AF) in middle-aged, and 18.1% (21.0% of AF) in oldest-aged patients (p < 0.001). Our study reports characteristics of clinical ischemic stroke in an aging population. The assessment of cardiogenic embolism is important for an aging population.

Diagnostic accuracy of acute infarcts in multiple cerebral circulations for cardioembolic stroke: Literature review and meta-analysis

OBJECTIVE

To determine the diagnostic value of acute infarcts in multiple cerebral circulations (AIMCC) on MRI diffusion-weighted imaging (DWI) for cardioembolism (CE) stroke subtype in adult patients hospitalized with acute ischemic stroke, we conducted a systematic literature review and meta-analysis.

METHODS

MEDLINE was searched via PubMed for articles reporting patients hospitalized with acute ischemic stroke with MRI DWI categorized as AIMCC vs other and use of Trial of Org 10172 in Acute Stroke Treatment (TOAST) Criteria for cardioembolism subtype. Measures of diagnostic accuracy were calculated from the retrieved studies.

RESULTS

Seven eligible articles comprised 5813 patients. Bivariate random effects models estimated sensitivity 0.19 (95% CI, 0.13 to 0.27), specificity 0.89 (0.86 to 0.91), positive predictive value 0.37 (0.30 to 0.45), negative predictive value 0.76 (0.7 to 0.82), positive likelihood ratio 1.70 (1.13 to 2.57) and negative likelihood ratio 0.91 (0.83 to 1).

INTERPRETATION

The pattern of AIMCC on DWI is of limited diagnostic value. It is not sufficiently accurate to exclude cardiac pathology by a negative test nor does a positive test indicate a major increase in the probability of identifying a potential cardioembolic source.

Chronic Small Cortical Cerebellar Infarctions on MRI are Associated with Patent Foramen Ovale in Young Cryptogenic Stroke

BACKGROUND

In acute infarction patients, small cortical cerebellar infarctions (SCCI) on MRI (assessed on diffusion-weighted imaging, with SCCI often chronic and asymptomatic) are associated with acute cardioembolic infarction. In young cryptogenic stroke patients, patent foramen ovale (PFO) is thought to be a potential source of cardioembolic infarction. We hypothesize that SCCI on MRI would be associated with PFO in young cryptogenic stroke patients.

METHODS

A total of 321 consecutive young (≤50 years) stroke patients admitted between January 2015 and July 2019 were screened. Of these patients, 287 patients had diagnostic work-up including early-phase MRI, intra- and extracranial vessel imaging, contrast transoesophageal or contrast transthoracic echocardiography, and ≥24 h ECG-monitoring. We retrospectively analyzed MRI scans of the 112 patients with cryptogenic stroke, including 63 with and 49 without PFO. Between both groups, we compared baseline characteristics (including cardiovascular risk factors and history of stroke), MRI characteristics of acute symptomatic infarction (cortical/subcortical localization, arterial territory, lesion number, and lesion size in case of subcortical infarction), atrial septum aneurysm (ASA) presence, and acute and chronic SCCI and non-SCCI lesions assessed on diffusion-weighted imaging.

RESULTS

Groups with and without PFO were comparable in regard to performed vessel imaging and echocardiography modalities, baseline characteristics, and acute infarction characteristics, except for more frequent current smoking (67 vs. 44%, p = 0.022) and multiterritorial infarction (14 vs. 0%, p = 0.0024) and less frequent ASA (10 vs. 48%, p < 0.001) in the group without PFO. Risk of Paradoxal Embolism score was >6 in 76% of patients with PFO. SCCI was more frequent in patients with than without PFO (33 vs. 10%, p = 0.0061; OR 4.4, 95% CI 1.5-12.7), with chronic and asymptomatic SCCI in the vast majority of cases. No difference was observed for non-SCCI lesions.

CONCLUSIONS

Chronic SCCI are strongly associated with PFO in young cryptogenic stroke patients. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT04043559.

Small obliquely oriented cortical cerebellar infarctions are associated with cardioembolic stroke

Background

A revised classification of cerebellar infarctions (CI) may uncover unrecognized associations with etiologic stroke subtypes. We hypothesized that obliquely oriented small cortical cerebellar infarction (SCCI) representing end zone infarctions on MRI would be associated with cardiac embolism.

Methods

We retrospectively analyzed consecutive stroke patients recruited between January–December 2016 in our center. Analyzed baseline characteristics: sex, age, cardiovascular risk factors, history of stroke or atrial fibrillation (AF). TOAST classification was used for determining stroke subtype. Acute infarction location (anterior/posterior/mixed anterior-posterior circulation), acute uni- or multiterritorial infarction, and acute or chronic CI/SCCI/non-SCCI were assessed by MRI, and vertebrobasilar stenosis/occlusion by vessel imaging. Pre-specified analysis was also performed in patients without known high cardioembolic risk (known AF history or acute multiterritorial infarction).

Results

We included 452 patients (CI in 154, isolated SCCI in 55, isolated non-SCCI in 50, and mixed SCCI/non-SCCI in 49). Both SCCI and non-SCCI were associated with AF history (SCCI, p = 0.021; non-SCCI, p = 0.004), additional acute posterior circulation infarction (p < 0.001 both CI-subtypes), multiterritorial infarctions (SCCI, p = 0.003; non-SCCI, p < 0.001) and cardioembolic more frequent than large-artery atherosclerosis origin (p < 0.001 for both CI-subtypes). SCCI was associated with older age (p < 0.001), whereas non-SCCI was associated with stroke history (p = 0.036) and vertebrobasilar stenosis/occlusion (p = 0.002). SCCI were older (p = 0.046) than non-SCCI patients, had less frequently prior stroke (p < 0.001), and more frequent cardioembolic infarction (p = 0.025).

In patients without known high cardioembolic risk (n = 348), SCCI was strongly associated with subsequent cardioembolism diagnosis (OR 3.00 [CI 1.58–5.73, p < 0.001]). No such association was present in non-SCCI.

Conclusions

Acute or chronic SCCI are strongly associated with a cardioembolic origin.

Relationship between the Angle of the Posterior Inferior Cerebellar Artery and Cardioembolic Stroke

BACKGROUND

In patients with unilateral posterior inferior cerebellar artery (PICA) territory infarction, the absence of relevant vessel stenosis may make it difficult to determine the etiology of the infarction. The incidence of cardioembolic (CE) infarction and the factors associated with infarction in such patients remains largely unknown. We hypothesized that the PICA angle would affect the flow direction of embolic sources. Thus, we analyzed the association between high-risk CE sources and the PICA angle.

METHODS

Patients with an isolated unilateral PICA territory infarction without relevant vessel stenosis who were admitted between 2014 and 2017 were included from the Korea University Stroke Registry, which includes data from 3 university hospitals. We classified patients according to the presence of CE sources. For each case, we measured the angle between the vertebral artery (VA) and the proximal PICA.

RESULTS

In all, 71 patients met the final study entry criteria. Multivariable analysis showed that the PICA angle was independently associated with the risk of a CE source. The optimal cut-off value using Youden's index was 89°. We classified the PICA shape based on the optimal cut-off value. A CE source was identified in 83.3% of cases in which the PICA angle exceeded 89°.

CONCLUSIONS

The angle between the PICA and VA was an independent predictor of unilateral PICA stroke with high-risk CE sources without relevant artery stenosis, suggesting that an angle greater than 89° could be a new image marker for determining the stroke subtype.

Effects of mechanical thrombectomy for acute stroke patients with etiology of large artery atherosclerosis

AIMS

Atherosclerosis is more prevalent in Asian population. This distinct etiology of stroke might disadvantage Asian patients when applying. mechanical thrombectomy (MT). The purpose of this research was to evaluate the efficacy and safety of MT in a cohort of Chinese patients with acute ischemic stroke. due to large artery atherosclerosis (LAA).

METHODS AND RESULTS

A total of 649 patients treated with MT were included. Patients were classified according to etiology of stroke as LAA and cardioembolism ones. Successful revascularization was defined as modified Thrombolysis in Cerebral Infarction (mTICI) grade ≥ 2b. Favorable outcome was defined as modified Rankin Scale (mRS) score ≤ 2 at 90 days. Logistic regression was used to identify predictors for functional outcomes. The patients with stroke of LAA etiology had significantly higher rate of favorable functional outcome (50.2% vs 36.5%, p < .001) and good collateral (grade of ASITN/SIRI: 2-3) (58.8% versus 43.2%, p < .001), and lower median baseline National Institutes of Health Stroke Scale score (NIHSS) (15.6 versus 18.2, p < .001), compared to patients with stroke of cardioembolism etiology. There was no significant difference in the rate of successful postprocedural mTICI between groups (84.5% versus 83.2%, p = .671). Rates of symptomatic intracranial hemorrhage (20.0% versus 11.7%, p = .004) and mortality (31.8% versus 18.8%, p < .001) within 3 months were notably higher in the cardioembolism group than that in the LAA group.

CONCLUSION

Mechanical thrombectomy may be more efficacious in treating acute ischemic stroke of LAA etiology than that of cardioembolism etiology.

Updates on Prevention of Cardioembolic Strokes

Cardiac embolism continues to be a leading etiology of ischemic strokes worldwide. Although pathologies that result in cardioembolism have not changed over the past decade, there have been significant advances in the treatment and stroke prevention methods for these conditions. Atrial fibrillation remains the prototypical cause of cardioembolic strokes. The availability of new long-term monitoring devices for atrial fibrillation detection such as insertable cardiac monitors has allowed accurate detection of this leading cause of cardioembolism. The non-vitamin K antagonist oral anticoagulants have improved our ability to prevent strokes for many patients with non-valvular atrial fibrillation (NVAF). Advances in left atrial appendage closure and the U.S. Food and Drug Administration approval of the WATCHMAN (Boston Scientific) device for stroke prevention in NVAF patients who have an appropriate rationale for a nonpharmacological alternative, have revolutionized the field and provided a viable option for patients at higher hemorrhagic risk. The role of patent foramen ovale closure for secondary prevention in selected patients experiencing cryptogenic ischemic strokes at a relatively young age has become clearer thanks to the very recent publication of long-term outcomes from three major studies. Advances in the management of infective endocarditis, heart failure, valvular diseases, and coronary artery disease have significantly changed the management of such patients, but have also revealed new concerns related to assessment of ischemic versus hemorrhagic risk in the setting of antithrombotic use. The current review article aims to discuss these advances especially as they pertain to the stroke neurology practice.

Patent foramen ovale and stroke

A patent foramen ovale (PFO) is a highly prevalent finding in cryptogenic ischaemic stroke, particularly in young adults. A common challenge in clinical practice is to distinguish between incidental and pathogenic PFO. Some clinical features and tools such as the Risk of Paradoxical Embolism score may help determining the probability of a stroke-related PFO. Nonetheless, the best therapeutic option to reduce stroke recurrence after a cryptogenic stroke with PFO has been a matter of debate for a long time. We review the mechanisms of stroke-related PFO, together with its clinical features and diagnostic criteria. In addition, we focus on the methodological details and results from new studies in the field of secondary prevention. In contrast to prior evidence, the data from three recent clinical trials and an updated meta-analysis favour PFO closure over medical treatment after cryptogenic stroke/TIA for the prevention of stroke recurrence. The PFO closure device procedure is not associated with higher mortality or cardiovascular events, except for a small increase in the occurrence of transient atrial fibrillation. Furthermore, the benefit of PFO closure was higher among those with atrial septal aneurysm and PFO with large right-to-left shunt. Future studies should address pending issues such as the option for anticoagulants or antiplatelet in patients not undergoing closure, the duration of antiplatelet treatment after PFO closure and the role of PFO closure in patients older than 60.

ECG markers associated with ischemic stroke at young age - a case-control study

INTRODUCTION

Certain electrocardiographic (ECG) abnormalities are associated with ischemic stroke (IS), especially cardioembolic subtype. Besides atrial fibrillation, markers of left ventricular hypertrophy (LVH) or atrial pathology also reflect elevated risk. We studied the association of ECG markers with IS in young adults.

METHODS

We performed a case-control study including 567 consecutive IS patients aged 15-49 years (inclusion period: 1994-2007) and one or two age- and sex-matched control subjects enrolled during 1978-1980 (n = 1033), and investigated also the stroke aetiologic subgroups. We studied ECGs of all participants for markers of atrial abnormality, i.e. P-terminal force (PTF) on lead V1, interatrial blocks (IAB; P-wave duration ≥110 ms), and LVH. Conditional logistic regression analyses were used.

RESULTS

IAB (hazard ratio [HR]: 1.57, 95% confidence interval [CI]: 1.16-2.13) and PTF combined with LVH (HR: 6.83, 95% CI: 1.65-28.31), were independently associated with IS. LVH, abnormal P-wave (HR: 6.87, 95% CI: 1.97-135.29), PTF, IAB, and combinations of these P-wave abnormalities with LVH - were associated with cardioembolic subtype. Abnormal P-wave and IAB were associated with cryptogenic stroke subtype. In unadjusted analysis, LVH was associated with small-vessel disease subtype.

CONCLUSION

P-wave abnormalities on ECG were associated with cardioembolic but also with a cryptogenic subtype of IS. Key messages ECG patterns associated with atrial pathology are markers of increased risk of ischemic stroke in young adults. The ECG markers reflecting atrial pathology were seen in patients with cardioembolic and cryptogenic subtypes of ischemic stroke.

Guidelines for the Use of Echocardiography in the Evaluation of a Cardiac Source of Embolism

Embolism from the heart or the thoracic aorta often leads to clinically significant morbidity and mortality due to transient ischemic attack, stroke or occlusion of peripheral arteries. Transthoracic and transesophageal echocardiography are the key diagnostic modalities for evaluation, diagnosis, and management of stroke, systemic and pulmonary embolism. This document provides comprehensive American Society of Echocardiography guidelines on the use of echocardiography for evaluation of cardiac sources of embolism. It describes general mechanisms of stroke and systemic embolism; the specific role of cardiac and aortic sources in stroke, and systemic and pulmonary embolism; the role of echocardiography in evaluation, diagnosis, and management of cardiac and aortic sources of emboli including the incremental value of contrast and 3D echocardiography; and a brief description of alternative imaging techniques and their role in the evaluation of cardiac sources of emboli. Specific guidelines are provided for each category of embolic sources including the left atrium and left atrial appendage, left ventricle, heart valves, cardiac tumors, and thoracic aorta. In addition, there are recommendation regarding pulmonary embolism, and embolism related to cardiovascular surgery and percutaneous procedures. The guidelines also include a dedicated section on cardiac sources of embolism in pediatric populations.

Ischemic Stroke after Heart Transplantation

Cerebrovascular complications after orthotopic heart transplantation (OHT) are more common in comparison with neurological sequelae subsequent to routine cardiac surgery. Ischemic stroke and transient ischemic attack (TIA) are more common (with an incidence of up to 13%) than intracranial hemorrhage (2.5%). Clinically, ischemic stroke is manifested by the appearance of focal neurologic deficits, although sometimes a stroke may be silent or manifests itself by the appearance of encephalopathy, reflecting a diffuse brain disorder. Ischemic stroke subtypes distribution in perioperative and postoperative period after OHT is very different from classical distribution, with different pathogenic mechanisms. Infact, ischemic stroke may be caused by less common and unusual mechanisms, linked to surgical procedures and to postoperative inflammation, peculiar to this group of patients. However, many strokes (40%) occur without a well-defined etiology (cryptogenic strokes). A silent atrial fibrillation (AF) may play a role in pathogenesis of these strokes and P wave dispersion may represent a predictor of AF. In OHT patients, P wave dispersion correlates with homocysteine plasma levels and hyperhomocysteinemia could play a role in the pathogenesis of these strokes with multiple mechanisms increasing the risk of AF. In conclusion, stroke after heart transplantation represents a complication with considerable impact not only on mortality but also on subsequent poor functional outcome.

Device-Detected Atrial Fibrillation-Perils and Pitfalls: An Update

Stroke and thromboembolism are catastrophic complications of atrial fibrillation (AF). Cardiac implantable electronic devices (CIED) with an atrial lead can reliably detect atrial high-rate events (AHRE). However, this correlation may be imperfect because of oversensing and undersensing of atrial signals and spurious arrhythmias. The critical duration, frequency, or overall burden of AHRE that increases stroke risk is still unknown; thus, the threshold level of AHRE (duration and frequency) that warrants anticoagulation in patients with CIED-detected AHRE is still unclear. This article reviews current literature on the risk of stroke with CIED-detected AHRE and raises questions that need further clarification.

Resting 12-lead electrocardiogram reveals high-risk sources of cardioembolism in young adult ischemic stroke. Int J Cardiol. 2015;198:196-200. [PMID: 26163917 DOI: 10.1016/j.ijcard.2015.06.095]

BACKGROUND

The diagnostic work-up to reveal etiology in a young ischemic stroke (IS) patient includes evaluation for high-risk source of cardioembolism (HRCE), since this subtype associates with high early recurrence rate and mortality. We investigated the association of ECG findings with a final etiologic subgroup of HRCE in a cohort of young patients with first-ever IS.

METHODS

The Helsinki Young Stroke Registry includes IS patients aged 15 to 49 years admitted between 1994 and 2007. Blinded to other clinical data, we analyzed a 12-lead resting ECG obtained 1-14 days after the onset of stroke symptoms in 690 patients. We then compared the ECG findings between a final diagnosis of HRCE (n=78) and other/undetermined causes (n=612). We used multivariate logistic regression to study the association between ECG parameters and HRCE.

RESULTS

Of our cohort (63% male), 35% showed ECG abnormality, the most common being T-wave inversion (16%), left ventricular hypertrophy (14%), prolonged P-wave (13%), and prolonged QTc (12%). 3% had atrial fibrillation (AF), and 4% P-terminal force (PTF). Of the continuous parameters, longer QRS-duration, QTc, and wider QRS-T-angle independently associated with HRCE. After AF, PTF had the strongest independent association with HRCE (odds ratio=44.32, 95% confidence interval=[10.51-186.83]), followed by a QRS-T angle >110° (8.29 [3.55-19.32]), T-wave inversion (5.06, 2.54-10.05), and prolonged QTc (3.02 [1.39-6.56]).

CONCLUSION

Routine ECG provides useful information for directing the work-up of a young IS patient. In addition to AF, PTF in particular showed a strong association with etiology of HRCE.

Unfavorable Outcome of Thrombolysis in Chinese Patients with Cardioembolic Stroke: a Prospective Cohort Study

BACKGROUND

Thrombolysis with alteplase is an effective and safe treatment for acute ischemic stroke (AIS). It is controversial whether the outcome of thrombolysis in cardioembolic stroke is different from that of other stroke subtypes. This study compares the outcomes at 3 months postthrombolysis in Chinese patients with AIS secondary to cardioembolism (CE) to the outcomes of those with large-artery atherosclerosis (LAA).

METHODS

Using the Thrombolysis Implementation and Monitoring of Acute Ischemic Stroke in China (TIMS-China) cohort, we prospectively followed 827 patients treated within 4.5 h of onset symptoms with alteplase as an intravenous thrombolytic agent. CE and LAA were defined according to TOAST criteria. We compared symptomatic intracerebral hemorrhage (SICH), mortality, and functional outcome at 3 months using multivariables logistic regression analysis.

RESULTS

In this cohort, 221 (19.6%) had CE and 606 (53.7%) had LAA. Approximately 2/3 of patients with CE had atrial fibrillation. Symptoms at onset were more severe in patients with CE than in those with LAA (NIHSS, 15.0 vs. 11.0; P < 0.0001); increased rate of SICH (5.9% vs. 0.8%; P < 0.0001); higher mortality (18.6% vs. 10.3%; P = 0.0015); and reduced functional independence (43.6% vs. 55.9%; P = 0.0018) at 3-month follow-up. After adjustment for baseline variables, the clinical outcome of patients with CE was worse than that of patients with LAA (OR, 0.62; 95% CI, 0.39 to 0.97, P = 0.0378).

CONCLUSIONS

Patients with cardioembolic stroke had more SICH after thrombolysis, and worse clinical outcome at 3-month follow-up compared with those with LAA. This emphasizes the importance of preventing cardioembolism.

Isolated hippocampal infarcts: Vascular and neuropsychological findings

BACKGROUND AND PURPOSE

The hippocampus plays a role in the verbal and spatial memory processing, learning, and emotions. The purpose of this study was to determine clinical, etiological, and radiological features of isolated hippocampal infarcts.

METHODS

We reviewed, 6800 patients with first-ever ischaemic stroke included in our Stroke Registry between 2004 and 2014. Among them we studied 19 patients with an acute isolated hippocampal infarct confirmed by MRI.

RESULTS

Among 6800 patients, 19 patients (0.03%) showed ischaemic lesions in the hippocampal artery territory, allowing us to delineate 5 variant distributions; (1) anterior hippocampal infarcts (4 patients [21%]) were present with altered consciousness, transient visual vivid hallucinations, and transient global amnesia with episodic and verbal memory deficits. (2) Posterior hippocampal infarcts (3 patients [16%]) developed dizziness and dullness at stroke onset, confusion, episodic and procedural memory deficit and verbal learning deficit. (3) Unilateral complete hippocampal infarcts were present (4 patients [21%]) with confusion, object specific hallucinations, intense mood states changes as well as impulsivity or depressive behaviour. Memory dysfunctions were found in all patients. (4) Bilateral hippocampal infarcts (3 patients [16%]) had cognitive deficits and memory deficits in all patients. All patients had difficulties retrieving specific autobiographical events and retrieving recent memory, and disturbances of learning in verbal and visual task. Hippocampal dementia was observed in 2 patients with severe immediate, delayed verbal and visual memory deficits, dysexecutive syndrome, deficits in responding to feedback and error correction with dull and aimless appearance lasting several months. (5) Small circumscribed (punctiform) hippocampal infarcts (5 patients [26%]) showed dizziness or dullness sensation and difficulties finding words or objects that they use everyday. Cardioembolism (10; 53%) and large-artery disease of the vertebrobasilar system (6; 32%) were the main stroke mechanisms.

CONCLUSIONS

We described topographic patterns of hippocampal infarction with distinct manifestations and etiologies. We thought that different patterns of hippocampal infarcts are the result of variation in hippocampal arterial supply or reflect a source of embolism.

Clinical characteristics of cardioembolic transient ischemic attack: comparison with noncardioembolic transient ischemic attack

BACKGROUND

Previous studies show that 6%-31% of transient ischemic attacks (TIA) were caused by cardiogenic cerebral embolism (cardioembolic TIA). As prompt initiation of therapy is essential in TIA to prevent subsequent strokes, determining their cause is important. In this study, we aim to determine the features of cardioembolic TIA and to compare them with those of noncardioembolic etiology.

METHODS

We retrospectively reviewed patients with a tissue-defined TIA who were admitted to our hospital from April 2007 to August 2013. The etiology was categorized according to Trial of Org 10172 in Acute Stroke Treatment, and TIA of cardioembolic origin and cervicocerebrovascular etiology (noncardioembolic TIA) were included in this study. Those with 2 or more possible causes or undetermined etiologies were excluded. Age, sex, comorbidities, ABCD2 score, and CHADS2 score were assessed and compared between the 2 groups.

RESULTS

There were no significant differences in the neurologic symptoms and their duration, morbidities of hypertension, diabetes, and dyslipidemia between the 2 groups. Coronary and peripheral artery diseases were more common in the cardioembolic TIA group (18.4% vs. 6.9%). Incidences of prior stroke and cerebral infarction determined by MRI were similar between the 2 groups. The ABCD2 score showed a similar distribution, but the CHADS2 score was significantly different; the cardioembolic TIA group showed a higher score (P = .005).

CONCLUSIONS

Clinical features are similar in tissue-defined TIA of cardioembolic and noncardioembolic etiologies. The CHADS2 score can be useful in assessing the probability of cardioembolic TIA.

Is There a Role for Tissue Doppler Imaging in Infective Endocarditis?

An 87-year-old woman was admitted to our Cardiology Department with symptoms and signs of acute congestive heart failure and fever. She had a long history of hypertension and chronic atrial fibrillation. Transthoracic echocardiography showed a large (>10 mm) and mobile mitral valve vegetation, prolapsing into the left ventricular inflow tract, with severe mitral regurgitation due to a perforation in the posterior leaflet, in a mitral valve with fibro-calcific degeneration. Mitral regurgitation was hemodynamically significant and a moderate-to-severe pulmonary hypertension was observed. Tissue Doppler Imaging recorded at the level of the vegetation detected its incoherent motion and measured the peak antegrade velocity, which was found to be almost four times higher than that sampled at the lateral mitral annulus. Blood cultures were negative for both aerobic and anaerobic microbes. During hospitalization, the patient developed a sudden onset of left-side hemiplegia. Diffusion-weighted magnetic resonance imaging demonstrated multiple hyperintense lesions involving both hemispheres, suggestive of a cardioembolism. Diagnosis of fungal endocarditis was made and a treatment with fluconazole was started. Successive echocardiograms showed a decrease in the size and mobility of the mitral vegetation, and an increase in its echo intensity. However, in view of the systemic conditions severely affected, the patient was treated conservatively and died 3 months later. In our patient echocardiography played a key role for a better definition of the clinical course. In this context, Tissue Doppler Imaging might provide an adjunctive parameter for the prediction of embolic risk from endocardial vegetations: the peak antegrade velocity recorded at the level of the vegetation. However, before being adopted in clinical setting, this parameter should be validated by adequately powered prospective studies.

Greater stroke severity predominates over all other factors for the worse outcome of cardioembolic stroke

BACKGROUND

Cardioembolic (CE) strokes are more disabling and more fatal than non-CE strokes. Multiple prognostic factors have been recognized, but the magnitude of their relative contributions has not been well explored.

METHODS

Using a prospective stroke outcome database, we compared the 3-month outcomes of CE and non-CE strokes. We assessed the relative contribution of each prognostic factor of initial stroke severity, poststroke complications, and baseline characteristics with multivariable analyses and model fitness improvement using -2 log-likelihood and Nagelkerke R2.

RESULTS

This study included 1233 patients with acute ischemic stroke: 193 CE strokes and 1040 non-CE strokes. Compared with the non-CE group, CE group had less modified Rankin Scale (mRS) 0-2 outcomes (47.2% versus 68.5%; odds ratio [95% confidence interval], .41 [.30-.56]), less mRS 0-1 outcomes (33.7% versus 53.5%; .44 [.32-.61]), more mRS 5-6 outcomes (32.1% versus 10.9%; 3.88 [2.71-5.56]), and higher mortality (19.2% versus 5.2%; 4.33 [2.76-6.80]) at 3 months. When adjusting either baseline characteristics or poststroke complications, the outcome differences between the 2 groups remained significant. However, adjusting initial National Institute of Health Stroke Scale (NIHSS) score alone abolished all outcome differences except for mortality. For mRS 0-2 outcomes, the decrement of -2 log-likelihood and the Nagelkerke R2 of the model adjusting initial NIHSS score alone approached 70.2% and 76.7% of the fully adjusting model.

CONCLUSION

Greater stroke severity predominates over all other factors for the worse outcome of CE stroke. Primary prevention and more efficient acute therapy for stroke victims should be given top priorities to reduce the burden of CE strokes.

Hemorrhagic cardioembolic stroke secondary to a left ventricular thrombus: a therapeutic dilemma

Cardiogenic embolism is a major cause of stroke and often leads to significant morbidity and mortality. Despite the recent advances in our understanding of the pathophysiology of stroke and its risk factors, diagnosis and therapy; some case scenarios still present a real challenge for the treating physicians. We report a case of a 50 year old male patient presenting with multi-territory cerebral infarctions due to a left ventricular mobile thrombus complicated with hemorrhagic transformation at the time of presentation. Gradual introduction of anticoagulation coupled with a multidisciplinary team approach advocating careful daily clinical assessment of the patient and regular echocardiographic and neuroimaging studies have resulted in a better management and achievement of therapeutic goals.