In silico analysis of embolism in cerebral arteries using fluid-structure interaction method

Ischemic stroke, particularly embolic stroke, stands as a significant global contributor to mortality and long-term disabilities. This paper presents a comprehensive simulation of emboli motion through the middle cerebral artery (MCA), a prevalent site for embolic stroke. Our patient-specific computational model integrates major branches of the middle cerebral artery reconstructed from magnetic resonance angiography images, pulsatile flow dynamics, and emboli of varying geometries, sizes, and material properties. The fluid-structure interactions method is employed to simulate deformable emboli motion through the middle cerebral artery, allowing observation of hemodynamic changes in artery branches upon embolus entry. We investigated the impact of embolus presence on shear stress magnitude on artery walls, analyzed the effects of embolus material properties and geometries on embolus trajectory and motion dynamics within the middle cerebral artery. Additionally, we evaluated the non-Newtonian behavior of blood, comparing it with Newtonian blood behavior. Our findings highlight that embolus geometry significantly influences trajectory, motion patterns, and hemodynamics within middle cerebral artery branches. Emboli with visco-hyperelastic material properties experienced higher stresses upon collision with artery walls compared to those with hyperelastic properties. Furthermore, considering blood as a non-Newtonian fluid had notable effects on emboli stresses and trajectories within the artery, particularly during collisions. Notably, the maximum von Mises stress experienced in our study was 21.83 kPa, suggesting a very low probability of emboli breaking during movement, impact, and after coming to a stop. However, in certain situations, the magnitude of shear stress on them exceeded 1 kPa, increasing the likelihood of cracking and disintegration. These results serve as an initial step in anticipating critical clinical conditions arising from arterial embolism in the middle cerebral artery. They provide insights into the biomechanical parameters influencing embolism, contributing to improved clinical decision-making for stroke management.

Left atrial appendage occlusion for recurrent stroke while on oral anticoagulation: a case series

Background

Clinical practice guidelines recommend oral anticoagulation (OAC) for stroke prevention in selected patients with atrial fibrillation (AF). However, some patients still experience thrombo-embolic events despite adequate anticoagulation. The optimal management of these cases remains uncertain, leading to practice pattern variability. We present a series of three cases illustrating the use of left atrial appendage occlusion (LAAO) as an adjunctive stroke prevention strategy in AF patients with recurrent thrombo-embolic events despite adequate anticoagulation.

Case summary

Case one describes an 89-year-old female on apixaban who presented with a thrombus and underwent successful mechanical thrombectomy. Left atrial appendage occlusion was performed, and no subsequent thrombo-embolic events were reported. Case 2 involves a 72-year-old female on full-dose apixaban who experienced recurrent strokes despite adequate anticoagulation. Thrombectomy was performed twice, and complications arose during LAAO. The patient was discharged on warfarin + clopidogrel and remained event-free at the six-month follow-up. Case 3 features an 88-year-old female on rivaroxaban who experienced recurrent cerebral ischaemic events and gastrointestinal bleeding. Left atrial appendage occlusion using an Amplatzer Amulet™ device was successful, and the patient remained event-free at the one-year follow-up.

Discussion

This case series emphasizes the complexity of stroke prevention in AF patients and underscores the need for an individualized approach. Incorporating LAAO alongside OAC can provide additional stroke protection for patients with inadequate response to anticoagulation. Further randomized controlled trials are needed to evaluate the efficacy and safety of this approach. In light of the limited evidence available, these cases contribute to the growing body of knowledge on the potential role of LAAO in secondary stroke prevention in AF patients with recurrent thrombo-embolic events despite appropriate anticoagulation.

Multifocal strokes and vision loss from PDLLA filler injections

BACKGROUND

Poly-D, L-lactic acid (PDLLA) is increasingly used as a commercial dermal filler due to its lasting cosmetic properties. Consequently, PDLLA-related vascular complications are increasingly recognized and described. Herein, we describe the first known occurrence of multifocal strokes from the use of PDLLA as a cosmetic dermal filler, and discuss the mechanisms facilitating PDLLA's entry into the intracranial arterial system.

CASE PRESENTATION

A middle-aged female presented with acute vision loss of both eyes immediately after dermal injections of PDLLA to her nasolabial folds and infraorbital regions. There were no additional neurological deficits. Dilated fundal examination revealed retinal edema bilaterally, with deposition of filler material in the retinal arteries. Magnetic resonance imaging of her brain and orbits demonstrated multifocal strokes (left caudate head, right medial frontal lobe) and ischemia of the left optic nerve. The temporal proximity of the dermal injections to her symptoms, guided by fundal examination and neuroimaging findings, allowed us to attribute her strokes and ischemic optic neuropathy to PDLLA's entry into, and embolism within, the intracranial arterial system. She was treated with hyperbaric oxygen therapy and experience improvement to her right eye's vision, although poor vision persisted in her left eye.

CONCLUSION

While PDLLA is generally considered safe, its increasing use as a cosmetic filler renders it crucial for physicians to be cognizant of its vascular complications, especially when early recognition and treatment are essential in mitigating their devastating ramifications.

Effects of the New Thrombolytic Compound LT3001 on Acute Brain Tissue Damage After Focal Embolic Stroke in Rats

LT3001 is a novel synthetic small molecule with thrombolytic and free radical scavenging activities. In this study, we tested the effects of LT3001 as a potential alternative thrombolytic in focal embolic ischemic stroke rat model. Stroked rats received intravenous injection of 10 mg/kg LT3001 or tPA at 1.5, 3, or 4.5 h after stroke, respectively, and the outcomes were measured at different time points after stroke by performing multi-parametric MRI, 2,3,5-triphenyltetrazolium chloride (TTC) staining, and modified neurological severity score. Lastly, we assessed the effect of LT3001 on the tPA activity in vitro, the international normalized ratio (INR), and the serum levels of active tPA and plasminogen activator inhibitor-1 (PAI-1). LT3001 treated at 1.5 h after stroke is neuroprotective by reducing the CBF lesion size and lowering diffusion and T2 lesion size measured by MRI, which is consistent with the reduction in TTC-stained infarction. When treated at 3 h after stroke, LT3001 had significantly better therapeutic effects regarding reduction of infarct size, swelling rate, and hemorrhagic transformation compared to tPA. When treated at 4.5 h after stroke, tPA, but not LT3001, significantly increased brain swelling and intracerebral hemorrhagic transformation. Lastly, LT3001 did not interfere with tPA activity in vitro, or significantly alter the INR and serum levels of active tPA and PAI-1 in vivo. Our data suggests that LT3001 is neuroprotective in focal embolic stroke rat model. It might have thrombolytic property, not interfere with tPA/PAI-1 activity, and cause less risk of hemorrhagic transformation compared to the conventional tPA. Taken together, LT3001 might be developed as a novel therapy for treating thrombotic ischemic stroke.

Embolic stroke and misidentification candida species endocarditis: Case presentation and literature review

Fungal endocarditis is a rare but serious form of infective endocarditis associated with high morbidity and mortality. Among fungal pathogens, Candida species are the most frequently isolated and commonly found in individuals with predisposing factors, such as prosthetic heart valves. The clinical presentation of endocarditis is highly variable and nonspecific, often including symptoms and signs of embolization. In this paper, we present a case of fungal prosthetic valve endocarditis in which the initial presentation was an acute ischemic stroke. The initial misidentification of Candida famata was attributed to limitations in the presumptive methodology used through selective chromogenic culture identification. However, the surgical specimen underwent mass spectrometry, leading to the correct identification of Candida guilliermondii instead of Candida famata. Furthermore, we conducted a non-systematic narrative review of the literature on Candida endocarditis. Our findings underscore the importance of considering fungal endocarditis in the differential diagnosis of patients with possible extracardiac complications, particularly those with a history of heart valve replacement. Early diagnosis and a comprehensive treatment strategy tailored by species identification and antifungal susceptibility testing are crucial in improving patient outcomes.

Chagas disease stroke and associated risk factors: A case-control study

INTRODUCTION

The intricate relationship between Chagas disease and ischemic stroke remains unclear. Limited evidence exists concerning secondary prophylaxis, etiological diagnosis, and stroke-related determinants. This study aims to discern factors linked to stroke in Chagas disease by contrasting patients with and without a history of ischemic stroke.

METHODS

Retrospective data from all outpatient Chagas disease patients from two Brazilian hospitals - one Chagas center and one stroke clinic - were examined. Descriptive analyses were conducted to identify stroke-associated factors. Variables were compared between patients with and without ischemic stroke history.

RESULTS

Among 678 subjects, 72 had experienced stroke. Univariate associations with stroke included male gender, heart failure, prior or ongoing alcoholism, electrocardiographic features (non-sinus rhythm, left bundle branch, right bundle branch block, left anterosuperior fascicular block, atrial fibrillation), as well as echocardiographic findings indicative of reduced left ventricular ejection fraction and segmental abnormalities. After logistic regression (multivariate analysis), congestive heart failure, right bundle branch block, left anterosuperior divisional block, and atrial fibrillation retained independent associations.

CONCLUSION

In this study, cardiac involvement emerged as the predominant factor correlated with stroke in Chagas disease. While atherosclerosis-related risk factors were prevalent, their influence on ischemic stroke in Chagas disease appeared limited.

Silent Embolic Infarction after Neuroform Atlas Stent-Assisted Coiling of Unruptured Intracranial Aneurysms

OBJECTIVE

There is still controversy regarding whether neck remodeling stent affects the occurrence of silent embolic infarction (SEI) after aneurysm coiling. Thus, the aim of the present study is to investigate the incidence of SEI after stent-assisted coiling (SAC) using Neuroform Atlas Stent (NAS) and possible risk factors. This study also includes a comparison with simple coiling group during the same period to estimate the impact of NAS on the occurrence of SEI.

METHODS

This study included a total of 96 unruptured intracranial aneurysms in 96 patients treated with SAC using NAS. Correlations of demographic data, aneurysm characteristics, and angiographic parameters with properties of SEI were analyzed. The incidence and characteristics of SEI were investigated in 28 patients who underwent simple coiling during the same period, and the results were compared with the SAC group.

RESULTS

In the diffusion-weighted imaging obtained on the 1st day after SAC, a total of 106 SEI lesions were observed in 48 (50%) of 96 patients. Of these 48 patients, 38 (79.2%) had 1-3 lesions. Of 106 lesions, 74 (69.8%) had a diameter less than 3 mm. SEI occurred more frequently in older patients (≥60 years, p=0.013). The volume of SEI was found to be significantly increased in older age (≥60 years, p=0.032), hypertension (p=0.036), and aneurysm size ≥5 mm (p=0.047). The incidence and mean volume of SEI in the SAC group (n=96) were similar to those of the simple coiling group (n=28) during the same period.

CONCLUSION

SEIs are common after NAS-assisted coiling. Their incidence in SAC was comparable to that in simple coiling. They occurred more frequently at an older age. Therefore, the use of NAS in the treatment of unruptured intracranial aneurysm does not seem to be associated with an increased risk of thromboembolic events if antiplatelet premedication has been performed well.

Central Retinal Artery Occlusion: Visual Outcomes from a Large Northern California Cohort

PURPOSE

To assess visual acuity (VA) outcomes in a large cohort of patients diagnosed with nonarteritic central retinal artery occlusion (CRAO), and to ascertain whether time from symptom onset to presentation, presenting VA, or conservative treatment delivery (anterior chamber paracentesis, ocular massage, intraocular pressure lowering drugs, hyperventilation, or some combination of those) impacted ultimate VA outcomes.

DESIGN

Retrospective cohort study.

SUBJECTS

The study included 794 patients who presented with CRAO between 2011 and 2020. Within this cohort, 484 individuals presented within 30 days of symptom onset and had comprehensive documentation regarding the details of their presentation, management, and follow-up ≥ 90 days postdiagnosis.

METHODS

Retrospective chart review was conducted for all patients with a diagnosis of CRAO initially identified via International Classification of Diseases coding, followed by confirmation of diagnosis by 2 retina specialists. Cases of arteritic CRAO were excluded.

MAIN OUTCOME MEASURES

Visual acuity recovery, defined as improvement from ≤ 20/200 or worse at presentation to ≥ 20/100 ≥ 90 days after diagnosis.

RESULTS

Of the 794 identified patients, 712 (89.7%) presented with VA of ≤ 20/200. Similarly, 447 (92.4%) of the 484-patient subset that presented within 30 days and had comprehensive documentation presented with VA ≤ 20/200. Of the 441 of those patients with documented follow-up, 380 (86.2%) remained at that level. Of the 244 patients who presented within 4.5 hours of symptom onset, 227 (93%) presented ≤ 20/200 and 201 (92.6%) of the 217 of those with follow-up data did not improve beyond that threshold. There was no significant difference (P < 0.05) in final VA between patients presenting before versus after 4.5 hours from time of vision loss. There was also no significant difference (P < 0.05) in VA outcomes between patients who did or did not receive conservative treatment.

CONCLUSIONS

This large retrospective study further highlights the poor visual prognosis for patients with CRAO. Earlier time to presentation did not seem to impact final VA outcome, nor did conservative treatment efforts. Efficacious evidence-based treatment options are needed for this patient population.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Transient ischemic attack and minor stroke as "surgeons affairs": a narrative review

OBJECTIVE

The scope of this paper is to review the subtypes of transient ischemic attack (TIA) and minor stroke (mS) in which a surgical treatment is needed, discussing the importance and the timing of a multidisciplinary approach, in order to achieve an optimized management and prevent major strokes or other critical complications.

MATERIALS AND METHODS

The keywords "transient ischemic attack," "minor stroke," "surgical treatment," "vascular surgery," "heart surgery," "neurosurgery," and "multidisciplinary" were searched using MEDLINE, EMBASE, and Scopus. Relevant search results were discussed by the authors for references inclusion.

RESULTS

Notwithstanding that best medical therapy is usually the first choice for the most part of cases, there are specific but recurrent etiologies that must be properly recognized because of a potential surgical approach, even in urgency. In fact, symptomatic carotid stenosis, or particular cases of hemodynamic cerebrovascular events, should be promptly referred to vascular surgeon, since increasing evidences highlighted a benefit from an early artery revascularization. In addition, beyond arrhythmic causes, cardioembolic events due to bacterial endocarditis and atrial myxoma should be quickly diagnosed, possibly in emergency department, because they are a presumptive urgency for heart surgery. In addition to the above-mentioned conditions, in patients suffering from vertebrobasilar TIA or mS, clinicians should keep in mind the Bow Hunter disease, because surgical artery decompression can represent the only suitable treatment in selected cases.

CONCLUSIONS

TIA and mS require a multidisciplinary in order to discuss therapeutic options, comparing risks and benefits and determining the best timing for an optimized management.

Endovascular treatment of acute ischemic stroke in childhood: A comprehensive literature review based on the experience of a single center

Acute ischemic stroke (AIS) in childhood is a relatively rare but significant condition that can result in long-term disabilities. There is a lack of standardized strategies for diagnosing and treating pediatric AIS due to limited evidence-based data on thrombolytic and endovascular treatments in children. This comprehensive literature review focuses on the experience of a single center in Italy and aims to highlight the main peculiarities of endovascular treatment (EVT) for AIS in childhood. The review covers the diagnostic workup, the endovascular procedures, and the need for a specific thrombectomy program for pediatric AIS. The review discusses the indications and considerations for thrombectomy in children, including the risk of complications and the challenges of extrapolating results from adult studies. The diagnostic protocols for pediatric AIS are also discussed, emphasizing the use of MRI to avoid X-ray and contrast medium exposure in children. The combination of intravenous thrombolysis and mechanical thrombectomy has been examined, considering the differences between pediatric and adult thrombi. Technical considerations related to the size of pediatric patients are addressed, including the use of large bore catheters and potential concerns with access points. The organization of a thrombectomy program for pediatric AIS is discussed, emphasizing the need for specialized facilities and expertise. Although evidence for EVT in the pediatric population is based on case series, the importance of specialized centers and the lack of validated guidelines are evident.

Identifying Atrial Fibrillation With Sinus Rhythm Electrocardiogram in Embolic Stroke of Undetermined Source: A Validation Study With Insertable Cardiac Monitors

BACKGROUND AND OBJECTIVES

Paroxysmal atrial fibrillation (AF) is a major potential cause of embolic stroke of undetermined source (ESUS). However, identifying AF remains challenging because it occurs sporadically. Deep learning could be used to identify hidden AF based on the sinus rhythm (SR) electrocardiogram (ECG). We combined known AF risk factors and developed a deep learning algorithm (DLA) for predicting AF to optimize diagnostic performance in ESUS patients.

METHODS

A DLA was developed to identify AF using SR 12-lead ECG with the database consisting of AF patients and non-AF patients. The accuracy of the DLA was validated in 221 ESUS patients who underwent insertable cardiac monitor (ICM) insertion to identify AF.

RESULTS

A total of 44,085 ECGs from 12,666 patient were used for developing the DLA. The internal validation of the DLA revealed 0.862 (95% confidence interval, 0.850-0.873) area under the curve (AUC) in the receiver operating curve analysis. In external validation data from 221 ESUS patients, the diagnostic accuracy of DLA and AUC were 0.811 and 0.827, respectively, and DLA outperformed conventional predictive models, including CHARGE-AF, C2HEST, and HATCH. The combined model, comprising atrial ectopic burden, left atrial diameter and the DLA, showed excellent performance in AF prediction with AUC of 0.906.

CONCLUSIONS

The DLA accurately identified paroxysmal AF using 12-lead SR ECG in patients with ESUS and outperformed the conventional models. The DLA model along with the traditional AF risk factors could be a useful tool to identify paroxysmal AF in ESUS patients.

Embolic stroke and atrioesophageal fistula as complications of atrial ablation

OBJECTIVES

Atrioesophagel fistula (AEF) is a rare, but potentially deadly complication of atrial ablation procedures. We present a case of a patient with cardioembolic cerebral infarcts and sepsis secondary to an atrioesophageal fistula, which likely developed after an atrial ablation procedure for atrial fibrillation.

CASE PRESENTATION

A 66-year-old man initially presented to an emergency department with diarrhea and sepsis, but his subsequent course was complicated by development of multiple, major cerebral infarcts. Despite high suspicion of septic embolism, extensive workup was required before the diagnosis of an atrioesophageal fistula was made.

CONCLUSIONS

Though rare, atrioesophageal fistula represents a high mortality complication of common atrial ablation procedures. A high index of suspicion is needed for timely diagnosis and to initiate appropriate treatment.

Early hyperbaric oxygen therapy is associated with favorable outcome in patients with iatrogenic cerebral arterial gas embolism: systematic review and individual patient data meta-analysis of observational studies

BACKGROUND

Iatrogenic cerebral arterial gas embolism (CAGE) caused by invasive medical procedures may be treated with hyperbaric oxygen therapy (HBOT). Previous studies suggested that initiation of HBOT within 6-8 h is associated with higher probability of favorable outcome, when compared to time-to-HBOT beyond 8 h. We performed a group level and individual patient level meta-analysis of observational studies, to evaluate the relationship between time-to-HBOT and outcome after iatrogenic CAGE.

METHODS

We systematically searched for studies reporting on time-to-HBOT and outcome in patients with iatrogenic CAGE. On group level, we meta-analyzed the differences between median time-to-HBOT in patients with favorable versus unfavorable outcome. On individual patient level, we analyzed the relationship between time-to-HBOT and probability of favorable outcome in a generalized linear mixed effects model.

RESULTS

Group level meta-analysis (ten studies, 263 patients) shows that patients with favorable outcome were treated with HBOT 2.4 h (95% CI 0.6-9.7) earlier than patients with unfavorable outcome. The generalized linear mixed effects model (eight studies, 126 patients) shows a significant relationship between time-to-HBOT and probability of favorable outcome (p = 0.013) that remains significant after correcting for severity of manifestations (p = 0.041). Probability of favorable outcome decreases from approximately 65% when HBOT is started immediately, to 30% when HBOT is delayed for 15 h.

CONCLUSIONS

Increased time-to-HBOT is associated with decreased probability of favorable outcome in iatrogenic CAGE. This suggests that early initiation of HBOT in iatrogenic CAGE is of vital importance.

Stroke with postoperative visual loss as the first clinical manifestation of antiphospholipid antibody syndrome: Case report

INTRODUCTION

Postoperative visual loss (POVL) is a rare and devastating complication. Its incidence in nonophthamologic surgeries varies from 0.056 % to 1.3 %. Autoimmune rheumatic diseases with a predisposition to thrombotic events, such as antiphospholipid antibody syndrome (APS), may constitute an important risk factor for this complication.

PRESENTATION OF CASE

A 34-year-old female patient, who was a former smoker and had no other comorbidities. She underwent orthopedic surgery and presented with bilateral POVL associated with the loss of secondary muscle strength and intraoperative venous and arterial cerebral thrombosis. She was thoroughly investigated regarding the etiology of her condition, and high levels of antiphospholipid antibodies were found.

DISCUSSION

APS is an autoimmune disease that predisposes the patient to thrombotic events. Among these, stroke is one of the main causes of POVL secondary to ischemia of the cortical territory, or also known as "cortical blindness."

CONCLUSION

The rare incidence of POVL in nonophthalmological surgeries and the consequence and preservation in the literature on the subject, explain the limitations of its pathophysiology, and especially the development of guidelines focused on the prevention of patients with risk factors for this condition. Thus, this case report warns about the risks and anesthetic care that patients with risk factors should have when undergoing nonophthalmological surgeries.

Use of the insertable Holter with remote detection in the etiological diagnosis of cryptogenic stroke: Analysis of 73 patients

INTRODUCTION

Cryptogenic stroke constitutes 25% of all ischemic strokes, of which 20-30% are due to atrial fibrillation (AF). With the aim of increasing the detection rate, implantable long-term monitoring devices have emerged. The study of the profile of the ideal candidate subsidiary to such monitoring would provide a better understanding of the mechanisms underlying this subtype of stroke.

OBJECTIVE

To determine which variables are related and can predict the detection of silent AF in patients with cryptogenic stroke.

PATIENTS AND METHODS

This is a longitudinal cohort with recruitment from March 2017 to May 2022. They are patients with an implantable monitoring device and cryptogenic stroke with a minimum monitoring of one year.

RESULTS

The total number of patients included was 73, with a mean age of 58.8 years, 56.2% were male. AF was detected in 21 patients (28.8%). The most frequent cardiovascular risk factors were hypertension (47.9%) and dyslipidemia (45.2%). The most frequent topography was cortical (52%). Regarding the echocardiographic parameters, 22% had a dilated left atrium, 19% had a patent foramen ovale, and 22% had high-density supraventricular tachycardia (>1%) on Holter monitoring. In the multivariate analysis, the only variable that predicts AF is the presence of high-density supraventricular tachycardia, with an area under the curve of 0.726 (CI 0.57-0.87, p=0.04), sensitivity of 47.6%, specificity of 97.5%, positive predictive value of 90.9%, negative predictive value of 78.8%, and accuracy of 80.9%.

CONCLUSIONS

The presence of high-density supraventricular tachycardia can be indicative for predicting silent AF. No other variables have been observed that allow us to predict detection of AF in these patients.

Association of non-sustained atrial tachycardia and its duration in 24-h Holter monitoring with embolic stroke of unknown source

BACKGROUND AND PURPOSE

Although supraventricular ectopic beats (SVE), including premature atrial contractions (PACs) and non-sustained atrial tachycardia (NSAT), are frequent in the general population, some study results indicate that they are pathologic. SVE may predict undiagnosed atrial fibrillation or be associated with the embolic pattern of ischemic stroke. The aim of this study was to identify the indicators most associated with embolic stroke among the parameters that suggest the burden of SVE.

METHODS

A total of 1920 consecutive acute ischemic stroke (AIS) patients were enrolled from two university hospitals. We defined embolic stroke of unknown source (ESUS) and small vessel occlusion (SVO) etiologies using stricter criteria than the existing conventional criteria.

RESULTS

We enrolled 426 (SVO: 310 vs. ESUS: 116) patients who met the inclusion criteria. In the 24-h Holter monitoring parameters, total number of PACs and PAC-to-total beat ratio were not significantly different between the two groups. However, NSATs were more frequent, and the duration of the longest NSAT was longer in the ESUS group. Multivariate logistic regression revealed that high brain natriuretic peptide levels, presence of NSAT, history of previous stroke, and the longest NSAT duration significantly correlated with the ESUS etiology.

CONCLUSION

The presence of NSAT and its duration are more important indicators of embolic stroke than the frequency of PACs is. Therefore, considering secondary prevention in AIS patients with ESUS, 24-h Holter monitoring parameters, such as the presence of NSAT and its duration, could be considered as potential sources of cardio-embolism.

Results of a focused cardiac ultrasound program conducted by neurologists within a stroke care network with cardiac imaging units

INTRODUCTION AND OBJECTIVES

Recently, neurologists have begun to perform focused cardiac ultrasound for the detection of a cardiac source of embolism in stroke patients, requiring them to undergo a prior accredited training process. We designed a prospective study to analyze the incidence of heart disease detected by a focused cardiac ultrasound program within a stroke care network with cardiac imaging units and to identify the outcomes of detected structural heart disease at 1 year of follow-up.

METHODS

We included patients admitted to a university hospital for ischemic stroke or a transient ischemic attack between 2017 and 2021 who were evaluated by focused cardiac ultrasound. We studied the presence of structural heart disease and cardioembolic sources. We analyzed cardiovascular events (CVE) during the first year of follow-up.

RESULTS

Focused cardiac ultrasound was performed in 706 patients. Structural heart disease was detected in 52.1% and a cardioembolic source in 31.9%. Adverse CVE occurred in 5.49% of the patients in the first year of follow-up. The presence of de novo structural heart disease was independently associated with a higher probability of adverse CVE (HR, 1.72; 95%CI, 1.01- 2.91; P=.046).

CONCLUSIONS

Focused cardiac ultrasound within a stroke care network with cardiac imaging units is an accessible technique with high diagnostic yield. Its use allows clinical and therapeutic actions in the prevention of stroke recurrences and other CVEs in this group of patients.

Microembolic signals and antiplatelet therapy in Moyamoya angiopathy

BACKGROUND

Embolism as a cause of stroke is widely neglected in Moyamoya angiopathy (MMA), and recommendations for use of antiplatelet therapy (APT) vary. We examined the presence of microembolic signals (MES) during transcranial Doppler (TCD) monitoring and assessed the effects of APT on the occurrence of MES in MMA.

PATIENTS AND METHODS

We retrospectively analysed patients with MMA treated at our centre between 2011 and 2021. TCD was performed at first presentation and at most visits, while number of visits varied between individual patients. TCD was performed for 30 min bilaterally. Patient demographics, vascular risk factors, and antiplatelet treatment were collected from each clinic visit and ischemic and haemorrhagic episodes were captured as recorded during follow-up visits.

RESULTS

209 patients were included in the analysis (mean age 38.7 ± 15.3, 28% male). 21 patients with 27 MES-positive TCD examinations were identified (10%). Patient characteristics were similar in MES-positive and MES-negative groups. However, recent ischemic events were detected at a significantly higher rate in MES-positive patients (42.9% vs 4.8%, p < 0.001). After MES detection, change of antiplatelet drug regime was performed, leading to loss of MES in all cases. Dual APT was preferably used in the MES-positive group (p < 0.001) but no significant difference of haemorrhage during follow-up-visits was observed. Reduction of APT before bypass-surgery triggered MES in four patients.

CONCLUSION

APT is required in patients with MMA. MES monitoring may help to identify risk patients in need of intensified APT.

Atrial cardiomyopathy: from cell to bedside

Atrial cardiomyopathy refers to structural and electrical remodelling of the atria, which can lead to impaired mechanical function. While historical studies have implicated atrial fibrillation as the leading cause of cardioembolic stroke, atrial cardiomyopathy may be an important, underestimated contributor. To date, the relationship between atrial cardiomyopathy, atrial fibrillation, and cardioembolic stroke remains obscure. This review summarizes the pathogenesis of atrial cardiomyopathy, with a special focus on neurohormonal and inflammatory mechanisms, as well as the role of adipose tissue, especially epicardial fat in atrial remodelling. It reviews the current evidence implicating atrial cardiomyopathy as a cause of embolic stroke, with atrial fibrillation as a lagging marker of an increased thrombogenic atrial substrate. Finally, it discusses the potential of antithrombotic therapy in embolic stroke with undetermined source and appraises the available diagnostic techniques for atrial cardiomyopathy, including imaging techniques such as echocardiography, computed tomography, and magnetic resonance imaging as well as electroanatomic mapping, electrocardiogram, biomarkers, and genetic testing. More prospective studies are needed to define the relationship between atrial cardiomyopathy, atrial fibrillation, and embolic stroke and to establish a prompt diagnosis and specific treatment strategies in these patients with atrial cardiomyopathy for the secondary and even primary prevention of embolic stroke.

Abdominal aortic aneurysm rupture presenting with focal weakness and altered mental status: a case report

Background

Abdominal aortic aneurysms (AAA) can present asymptomatically and may be found through routine screening or seen incidentally on imaging. Rupture due to weaking of the aortic wall is the main complication of an AAA and leads to approximately 200,000 deaths annually worldwide. Clinically, AAA rupture most frequently presents with abdominal and/or back pain, pulsatile abdominal mass, and hypotension. Here, we present an unusual presentation of embolic cerebrovascular accident associated with an AAA rupture.

Case presentation

A 58-year-old African American man transported to the emergency department via ambulance presents with altered mental status and unilateral extremity weakness. The initial presentation was concerning for acute cerebrovascular accident, acute kidney injury, severe sepsis, and urinary tract infection. Several hours after the initial presentation, the patient’s abdomen began to appear distended and he became hypotensive. An abdominal CT was ordered which showed a large AAA rupture with a retroperitoneal bleed. The patient was transferred to a higher-level medical center for surgical repair.

Conclusion

Abdominal aortic aneurysm rupture can rarely present due to an acute cerebrovascular accident with altered mental status and focal neurologic deficits.

Acute Hyperglycemia Exacerbates Hemorrhagic Transformation after Embolic Stroke and Reperfusion with tPA: A Possible Role of TXNIP-NLRP3 Inflammasome

OBJECTIVES

Acute hyperglycemia (HG) exacerbates reperfusion injury after stroke. Our recent studies showed that acute HG upregulates thioredoxin-interacting protein (TXNIP) expression, which in turn induces inflammation and neurovascular damage in a suture model of ischemic stroke. The aim of the present study was to investigate the effect of acute HG on TXNIP-associated neurovascular damage, in a more clinically relevant murine model of embolic stroke and intravenous tissue plasminogen activator (IV-tPA) reperfusion.

MATERIALS AND METHODS

HG was induced in adult male mice, by intraperitoneal injection of 20% glucose. This was followed by embolic middle cerebral artery occlusion (eMCAO), with or without IV-tPA (10 mg/kg) given 3 h post embolization. Brain infarction, edema, hemoglobin content, expression of matrix metalloproteinase (MMP-9), vascular endothelial growth factor A (VEGFA), tight junction proteins (claudin-5, occluding, and zonula occludens-1), TXNIP, and NOD-like receptor protein3 (NLRP3)-inflammasome activation were evaluated at 24 h after eMCAO.

RESULTS

HG alone significantly increased TXNIP in the brain after eMCAO, and this was associated with exacerbated hemorrhagic transformation (HT; as measured by hemoglobin content). IV-tPA in HG conditions showed a trend to decrease infarct volume, but worsened HT after eMCAO, suggesting that HG reduces the therapeutic efficacy of IV-tPA. Further, HG and tPA-reperfusion did not show significant differences in expression of MMP-9, VEGFA, junction proteins, and NLRP3 inflammasome activation between the groups.

CONCLUSION

The current findings suggest a potential role for TXNIP in the occurrence of HT in hyperglycemic conditions following eMCAO. Further studies are needed to understand the precise role of vascular TXNIP on HG/tPA-induced neurovascular damage after stroke.

Postural instability revealing infective endocarditis secondary to severe mitral stenosis: A case report with literature review

Introduction and importance

Infective endocarditis is a severe infection of the endocardial surface of the heart. One or more heart valves can be infected. However infective endocarditis complicating mitral stenosis is rare. It can be revealed by several and various symptoms such as fever and cardiac murmurs but also by complications such as focal neurological complaints

Case presentation

We report a case of a febrile postural instability as the primary presentation of an infective endocarditis secondary to a severe mitral stenosis in a young patient with a history of mitral stenosis for which he benefited from percutaneous mitral dilation. The diagnosis was based on the modified Duke criteria. In this case, the treatment was based mainly on antibiotic therapy. The outcome was favorable; with a clinical, biological and radiological improvement. The patient was subsequently referred to the cardiovascular department for surgical treatment of his valve disease.

Clinical discussion

Rheumatic heart disease is the main cause of mitral stenosis and its prevalence is higher in developing nations than in the rest of the world, yet only few articles have reported infective endocarditis as a complication of mitral stenosis.

Conclusion

Mitral stenosis is rarely complicated by infective endocarditis, but this diagnosis should not be excluded in developing countries, particularly because of its high prevalence. To that end, clinicians should recognize its symptoms and complications and act accordingly to allow early treatment.

•

Mitral stenosis is rarely complicated by infective endocarditis.

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Recognizing infective endocarditis at an early stage is essential.

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Antimicrobial therapy is the backbone therapy of infective endocarditis along with surgery management, in some cases of complicated IE.

Epicardial and periaortic fat characteristics in ischemic stroke: Relationship with stroke etiology and calcification burden

PURPOSE

We explored epicardial (EAT) and periaortic (PAT) adipose tissue characteristics in patients with acute ischemic stroke (AIS), and the relationship with stroke etiology, calcification burden, and inflammation.

METHOD

We included a retrospective cohort of consecutive patients admitted with AIS between 2015 and 2020 who underwent a chest computed tomography. We calculated volumes and attenuation of EAT and PAT, and coronary artery (CAC), and thoracic aortic (TAC) calcification. Admission's neutrophil/lymphocyte ratio (NLR) was recorded. Stroke severity was assessed using the National Institute of Health Stroke Scale (NIHSS), and patients were discriminated between cardioembolic (CE), non-CE, and embolic strokes of uncertain source (ESUS).

RESULTS

A total of 182 patients were included. EAT (non-CE 127.4 ± 47.1 cm3; CE 133.3 ± 56.7 cm3; ESUS 121.6 ± 63.5 cm3, p > 0.05) and PAT (non-CE 37.4 ± 18.6 cm3; CE 40.4 ± 17.2 cm3; ESUS 34.5 ± 14.1 cm3, p > 0.05) volumes were similar between stroke etiologies. Patients with CE stroke had higher PAT attenuation (PAT = non-CE -84.4 ± 7.0 HU; CE -78.1 ± 9.9 HU; ESUS -82.3 ± 9.3 HU, p < 0.001). Using multiple linear regression, albeit weak, we found a significant relationship between NLR and PAT attenuation [Beta 0.24; (95% CI 0.04-0.51), p < 0.05). Despite similar volume, PAT attenuation was higher (p < 0.01) among demised patients.

CONCLUSION

In this study, we identified higher periaortic fat attenuation, despite similar fat volume, in patients with CE stroke.

Ischemic post-conditioning is neuroprotective even at delayed tPA administration after embolic stroke in female rats

Objectives

Delayed tissue plasminogen activator (tPA) thrombolysis is accompanied by different complications in stroke patients. Studies reported sex differences in stroke therapy. Ischemic postconditioning (PC) unveils neuroprotection in stroke models. In this study, we investigate the combined effect of delayed tPA therapy and PC procedure during an embolic stroke experimental model in female rats.

Materials and Methods

Female Wistar rats were randomly divided into control (saline), tPA, PC, and tPA+PC groups after stroke induction via clot injection to the middle cerebral artery. tPA treatment was initiated 6 hr after stroke, and PC procedure was performed 6.5 hr post-ischemia induction (occlusion: 10 sec; reopening: 30 sec; 5 cycles). The cerebral blood flow (CBF) was recorded up to 60 min from IV tPA injection time. The parameters of brain edema, infarct volume, disruption of the blood-brain barrier (BBB), behavioral tests, and matrix metalloproteinases-9 (MMP-9) were evaluated.

Results

This study revealed that PC conduction prevents excessive CBF increase by tPA and played a protective role in infarct volume reduction (P<0.05). The combination of PC and tPA reduced the infarct volume, brain edema, and protected BBB. tPA+PC could alleviate neurobehavioral disorders compared with control or tPA. Moreover, PC had the capability of MMP-9 reduction when combined with delayed tPA (P<0.05).

Conclusion

Conduction of PC not only alleviated some stroke complications but also enhanced the therapeutic time window of tPA in female rats under embolic stroke.

Simultaneous mechanical thrombectomy for bilateral acute internal carotid artery occlusion

Acute bilateral internal carotid occlusion was a very rare disease with a very poor prognosis. Clinical case reports according to the literature showed that mechanical thrombectomy was the most optimal treatment. We reported a clinical case of successful treatment with simultaneous thrombectomy in both occluded carotid arteries. A 62-year-old woman was admitted at our hospital within three hours of stroke onset secondary to an acute simultaneously bilateral carotid artery occlusion. On admission, her NIHSS (National Institutes of Health Stroke Scale) was 32. Non-contrast computed tomography right after that showed hyperacute infarction lesions in both hemispheres with right inferior temporal and insular cortex (Alberta Stroke Program Early CT Score - ASPECTS 8) and left putamen (ASPECTS 9). Her medical history included paroxysmal atrial fibrillation, prior ischemic stroke, pacemaker due to sick sinus syndrome. Her pre-stroke modified Rankin Scale score was 0 that she was fully recovered from previous stroke 4 months ago thanks to successful thrombectomy of the right internal carotid arteries (ICA). This time, the patient underwent again the simultaneous bilateral mechanical thrombectomy of both occluded ICA. The complete recanalization achieved on both sides with recanalization level of TICI-3 (thrombolysis in cerebral infarction) only in 38 mins after the groin puncture. She showed dramatic recovery and was discharged on day 28 with a Rankin Scale score of 2. Mechanical thrombectomy on bilateral ICA performed simultaneously will helps shorten the reperfusion time compared to the alternative one and thus, provides a better prognosis in acute ischemic stroke.

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

BACKGROUND AND PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Septal myectomy complicated by an embolic stroke in a patient with hypertrophic cardiomyopathy: a case report

Background

Hypertrophic cardiomyopathy is estimated to affect 1 out of every 500 adults in the USA. One of its main complications is left ventricular outflow obstruction, which may require surgical septal myectomy in severe cases. We report a rare complication of postoperative septal akinesis leading to thrombus formation presenting as an acute ischaemic stroke.

Case summary

A 48-year-old woman presented with acute stroke 2 years after surgical septal myectomy for hypertrophic obstructive cardiomyopathy. Diagnostic workup identified an intraventricular thrombus arising in the left ventricular outflow tract (LVOT). After comprehensive evaluation, it was determined that the thrombus development was a complication of the prior septal myectomy causing focal septal akinesis. Treatment with anticoagulation resulted in improvement of neurological symptoms and resolution of the intraventricular thrombus.

Discussion

This case illustrates the rarity and unusual presentation of an intracardiac thrombus that arises from septal myectomy site. A thrombus arising in the LVOT, which is characterized by high gradient laminar flow, is highly unusual. This suggests microscopic and macroscopic alteration in the ventricular septal wall structure, as evident by the septal wall akinesis seen on echocardiography. Recognition of this complication is critical to the selection of appropriate anticoagulation as secondary stroke prevention in these patients.

Stroke Etiology and Outcomes after Endovascular Thrombectomy: Results from the SITS Registry and a Meta-Analysis

BACKGROUND AND PURPOSE

The influence of stroke etiology on outcomes after endovascular thrombectomy (EVT) is not well understood. We aimed to investigate whether stroke etiology subgrouped as large artery atherosclerosis (LAA) and cardiac embolism (CE) influences outcomes in large artery occlusion (LAO) treated by EVT.

METHODS

We included EVT treated LAO stroke patients registered in the Safe Implementation of Treatment in Stroke (SITS) thrombectomy register between January 1, 2014 and September 3, 2019. Primary outcome was successful reperfusion (modified Treatment in Cerebral Infarction 2b-3). Secondary outcomes were symptomatic intracranial hemorrhage (SICH), 3-month functional independence (modified Ranking Scale 0-2) and death. Multivariable logistic regression models were used for comparisons. In addition, a meta-analysis of aggregate data from the current literature was conducted (PROSPERO, ID 167447).

RESULTS

Of 7,543 patients, 1,903 (25.2%) had LAA, 3,214 (42.6%) CE, and 2,426 (32.2%) unknown, other, or multiple etiologies. LAA patients were younger (66 vs. 74, P<0.001) and had lower National Institutes of Health Stroke Scale score at baseline (15 vs. 16, P<0.001) than CE patients. Multivariable analyses showed that LAA patients had lower odds of successful reperfusion (odds ratio [OR], 0.70; 95% confidence interval [CI], 0.57 to 0.86) and functional independence (OR, 0.74; 95% CI, 0.63 to 0.85), higher risk of death (OR, 1.44; 95% CI, 1.21 to 1.71), but no difference in SICH (OR, 1.09; 95% CI, 0.71 to 1.66) compared to CE patients. The systematic review found 25 studies matching the criteria. The meta-analysis did not find any difference between etiologies.

CONCLUSIONS

From the SITS thrombectomy register, we observed a lower chance of reperfusion and worse outcomes after thrombectomy in patients with LAA compared to CE etiology, despite more favorable baseline characteristics. In contrast, the meta-analysis did not find any difference between etiologies with aggregate data.

Monocyte-to-Lymphocyte Ratio in Clot Analysis as a Marker of Cardioembolic Stroke Etiology

The aim of the study was to find markers of high-risk cardioembolic etiology (HRCE) in patients with cryptogenic strokes (CS) through the analysis of intracranial clot by flow cytometry (FC). A prospective single-center study was designed including patients with large vessel occlusion strokes. The percentage of granulocytes, monocytes, lymphocytes, and monocyte-to-lymphocyte ratio (MLr) were analyzed in clots extracted after endovascular treatment (EVT) and in peripheral blood. Large arterial atherosclerosis (LAA) strokes and high-risk cardioembolic (HRCE) strokes were matched by demographics and acute reperfusion treatment data to obtain FC predictors for HRCE. Multilevel decision tree with boosting random forest classifiers was performed with each feature importance for HRCE diagnosis among CS. We tested the validity of the best FC predictor in a cohort of CS that underwent extensive diagnostic workup. Among 211 patients, 178 cases underwent per-protocol workup. The percentage of monocytes (OR 1.06, 95% CI 1.01-1.11) and MLr (OR 1.83, 95% CI 1.12-2.98) independently predicted HRCE diagnosis when LAA clots (n = 28) were matched with HRCE clots (n = 28). Among CS (n = 82), MLr was the feature with the highest weighted importance in the multilevel decision tree as a predictor for HRCE. MLr cutoff point of 1.59 yield sensitivity of 91.23%, specificity of 44%, positive predictive value of 78.79%, and negative predictive value of 68.75 for HRCE diagnosis among CS. MLr ≥ 1.6 in clot analysis predicted HRCE diagnosis (OR, 6.63, 95% CI 1.85-23.71) in a multivariate model adjusted for age. Clot analysis by FC revealed high levels of monocyte-to-lymphocyte ratio as an independent marker of cardioembolic etiology in cryptogenic strokes.

The Osteoporotic Condition as a Predictive Factor for Hemorrhagic Transformation in Acute Cardioembolic Stroke

Objective

Hemorrhagic transformation (HT) can be occurred after acute cerebral infarction. HT can worse symptoms in severe cases and adversely affect long-term prognosis. As bone and vascular smooth muscle are composed of type 1 collagen, we aimed to identify a potential relationship between bone mineral density (BMD) and HT after acute cardioembolic stroke.

Methods

As an indicator of BMD, we used mean frontal skull Hounsfield unit (HU) values on brain computed tomography (CT). Multivariative hazard ratios were calculated using Cox regression analysis to identify whether the osteoporotic condition was an independent predictor of HT after acute cardioembolic stroke.

Results

This 11-year analysis enrolled 506 patients who diagnosed as acute cardioembolic infarction. The first tertile of skull HU value was an independent predictor of HT development compared to the third tertile (hazard ratio, 2.12; 95% confidence interval, 1.13–3.98; p=0.020). We observed no interactions between age and skull HU with respect to HT statistically.

Conclusion

The results of this study revealed an association between osteoporotic conditions and HT development after acute cardioembolic stroke. A convenient method to measure the cancellous bone HU value of the frontal skull using brain CT images may be useful for predicting HT in patients with acute cerebral infarction.

Microbubble-mediated sonothrombolysis with BR38 of a venous full blood thrombus in a rat embolic stroke model

Background

Early recanalization of an occluded vessel is associated with a better clinical outcome in acute ischemic stroke. Intravenous thrombolysis using recombinant tissue plasminogen activator (rt-PA) is only available in a minority of patients and often fails to reopen the occluded vessel. Mechanical recanalization is more effective in this matter but only available for selected patients when a thrombectomy centre can be reached. Therefore, sonothrombolysis might represent an alternative or complementary approach. Here, we tested microbubble-mediated sonothrombolysis (mmSTL) in a thromboembolic stroke model for middle cerebral artery occlusion (MCAO) in rats.

Methods

Sixty-seven male Wistar rats underwent MCAO using an autologous full blood thrombus and were randomly assigned to four groups receiving rt-PA, mmSTL, a combination of both, or a placebo. Diagnostic workup included neurological examination, assessment of infarct size, and presence of intracerebral haemorrhage by magnetic resonance imaging (MRI) and presence of microbleedings in histological staining.

Results

Neurological examination revealed no differences between the treatment groups. In all treatment groups, there was a reduction in infarct size 24 hours after MCAO as compared to the placebo (P≤0.05), but there were no differences between the active treatment groups (P>0.05) (placebo 0.75±0.10 cm³; mmSTL 0.43±0.07 cm³; rt-PA 0.4±0.07 cm³; mmSTL + rt-PA 0.27±0.08 cm³). Histological staining displayed intracerebral microbleedings in all animals. The frequency of gross bleeding detected by MRI did not differ between the groups (placebo 3; mmSTL 4; rt-PA 2; mmSTL + rt-PA 2; P>0.05) and was not associated with worse performance in clinical testing (P>0.05). There were no statistical differences in the mortality between the groups (P>0.05).

Conclusions

Our study showed the efficacy and safety of mmSTL with or without rt-PA in an embolic rat stroke model using a continuous full blood thrombus. Sonothrombolysis might be useful for patients who need to be transported to a thrombectomy centre or for those with distal vessel occlusion.

In vivo analysis of the origin and characteristics of gaseous microemboli during catheter-mediated irreversible electroporation

Aims 

Irreversible electroporation (IRE) ablation is a non-thermal ablation method based on the application of direct current between a multi-electrode catheter and skin electrode. The delivery of current through blood leads to electrolysis. Some studies suggest that gaseous (micro)emboli might be associated with myocardial damage and/or (a)symptomatic cerebral ischaemic events. The aim of this study was to compare the amount of gas generated during IRE ablation and during radiofrequency (RF) ablation.

Methods and results

In six 60–75 kg pigs, an extracorporeal femoral shunt was outfitted with a bubble-counter to detect the size and total volume of gas bubbles. Anodal and cathodal 200 J IRE applications were delivered in the left atrium (LA) using a 14-electrode circular catheter. The 30 and 60 s 40 W RF point-by-point ablations were performed. Using transoesophageal echocardiography (TOE), gas formation was visualized. Average gas volumes were 0.6 ± 0.6 and 56.9 ± 19.1 μL (P < 0.01) for each anodal and cathodal IRE application, respectively. Also, qualitative TOE imaging showed significantly less LA bubble contrast with anodal than with cathodal applications. Radiofrequency ablations produced 1.7 ± 2.9 and 6.7 ± 7.4 μL of gas, for 30 and 60 s ablation time, respectively.

Conclusion 

Anodal IRE applications result in significantly less gas formation than both cathodal IRE applications and RF applications. This finding is supported by TOE observations.

Recurrent embolisms despite adequate anticoagulant therapy in a patient with prosthetic heart valves and atrial fibrillation: a case report

Background

Antithrombotic management in patients with atrial fibrillation (AF) that have undergone heart valve surgery may be challenging, especially in the context of thromboembolic events during follow-up. The combination of pharmacological therapies with modern transcatheter interventions allows these more complex cases to be overcome.

Case summary

We present the case of a 66-year-old female with a history of AF and mechanical aortic and mitral valve replacement, which was admitted to the hospital complaining of dizziness and unsteady gait. A computerized tomography scan of the brain confirmed the diagnosis of embolic stroke. Two years later, the patient complained of sudden onset of chest pain, accompanied by electrocardiographic abnormalities and elevated high-sensitivity troponin T. Emergency cardiac catheterization revealed embolic myocardial infarction with distal occlusion of the obtuse marginal artery. Again, 2 years later, the patient suffered a new cerebral embolic event. Given the adequate anticoagulation therapy throughout almost the entire clinical course, percutaneous left atrial appendage closure was proposed as an adjunct to vitamin K antagonist treatment. Notably, intraprocedural transoesophageal echocardiography revealed the presence of a previously undetected left atrial appendage thrombus, thus an embolic protection device was used during the procedure, which was successfully carried out without complications.

Discussion

This case report demonstrates the complexity of the antithrombotic management in patients with AF and prosthetic heart valves, and highlights the importance of an individualized approach, integrating new therapeutic strategies to achieve success, in patients that present thromboembolic events despite adequate anticoagulation therapy.

Atrial Cardiopathy Biomarkers and MRI-Based Infarct Patterns in Patients with Embolic Strokes of Undetermined Source

OBJECTIVES

The study aimed to investigate whether N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentration and/or left atrial volume index (LAVI), as atrial cardiopathy biomarkers, were associated with infarct patterns on diffusion-weighted imaging in patients with embolic strokes of undetermined source (ESUS).

MATERIALS AND METHOD

We retrospectively evaluated patient with ESUS from our stroke registry between January 2018 and November 2019. Cut-off values for atrial cardiopathy biomarkers were defined as >250 pg/mL for NT-proBNP and >34 mL/m² for LAVI. Eligible patients were then assigned to 3 groups and infarct patterns were compared according to their atrial cardiopathy markers: Group 1 (no atrial cardiopathy markers), Group 2 (one marker), and Group 3 (both markers).

RESULTS

Among 194 eligible patients with ESUS (76 women; mean age, 69.2 years), simultaneous increases of NT-proBNP concentration and LAVI were identified in 39 (20.1%). Group 3 had a significantly larger infarct volume, relative to Group 1 and Group 2 (P=0.043) Multivariable logistic regression analyses revealed that these patients (Group 3) were significantly more likely to have multi-territorial infarcts (adjusted odds ratio [aOR]: 3.03, 95% confidence interval [CI]: 1.05-8.72; P=0.04), a maximal lesion diameter >15mm (aOR: 4.51, 95% CI: 1.70-11.93; P=0.001), and large cortical infarctions (aOR: 4.17, 95% CI: 1.75-9.96; P=0.001).

CONCLUSION

We found that simultaneously increased values for NT-proBNP concentration and LAVI were independently associated with multi-territorial and large cortical infarct patterns in patients with ESUS. These findings suggest that NT-proBNP and LAVI may be useful biomarkers for identifying cardioembolic subtypes and guiding treatment selection in patients with ESUS.

Importance of Paroxysmal Atrial Fibrillation and Sex Differences in the Prevention of Embolic Stroke in Hypertrophic Cardiomyopathy

Background: Although atrial fibrillation (AF) is a well-known risk factor for embolic stroke in hypertrophic cardiomyopathy (HCM), there is a paucity of information derived from HCM patients who have experienced embolic stroke.

Methods and Results: From 141 consecutive HCM patients who had been hospitalized between 2000 and 2018, the clinical characteristics and management of 86 patients with AF were analyzed retrospectively. The incidence of embolic stroke was 36% (n=31 patients). The median (interquartile range) age of embolic stroke was younger in male than female HCM patients (71 [64–80] vs. 83 [77–87] years, respectively; P=0.009). The prevalence of paroxysmal AF (74%) was significantly higher than that of chronic AF (26%) in 31 patients with embolic stroke (P=0.007). The CHADS₂ score in patients with embolic stroke was not particularly useful in predicting the occurrence of embolic stroke.

Conclusions: One-third of HCM patients with AF developed embolic stroke, and male HCM patients were younger at the time of the embolic stroke than female HCM patients. The prevalence of paroxysmal AF was significantly higher than that of chronic AF in patients with AF and embolic stroke. Early introduction of anticoagulation therapy is recommended at the first documentation of paroxysmal AF.

Device closure for patent foramen ovale in patients with cryptogenic stroke: which patients should get it?

Patent foramen ovale (PFO) and cryptogenic stroke (CS) both have a high prevalence. The optimal treatment to reduce stroke recurrence after CS remains controversial. Results from clinical trials, meta-analyses, and position papers, support percutaneous PFO device closure and medical therapy compared to medical therapy alone. However, the procedure may be associated with cardiac complications including an increased incidence of new atrial fibrillation. The benefit/risk balance should be determined on a case-by-case basis with the greatest benefit of PFO closure in patients with atrial septal aneurysm and PFO with large shunts. Future studies should address unsolved questions such as the choice of medical therapy in patients not undergoing closure, the duration of antiplatelet therapy, and the role of PFO closure in patients over 60 years old.

Neurologic complications of brady-arrhythmias

Brady-arrhythmias are responsible for both overt as well as subtle neurologic signs and symptoms, from the seemingly benign and nonspecific symptoms associated with presyncope, to sudden focal neurologic deficits. A brief background on nodal and infra-nodal brady-arrhythmias is provided, followed by extensive discussion regarding neurologic complications of brady-arrhythmias. The multiple mechanisms of and associations between Brady-arrhythmias and transient ischemic attacks and ischemic stroke are discussed. Controversial associations between brady-arrhythmias and neurologic disease are discussed as well, such as potential roles of brady-arrhythmias in cognitive impairment and sequelae of chronotropic incompetence; and the contribution of brady-arrhythmias to syncope and associated injuries to the nervous system. The chapter is written to stand on its own, with guidance toward other pertinent sections of this text where appropriate for further reading.

Atrial Fibrillation and Stroke

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

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.

Carney complex syndrome manifesting as cardioembolic stroke: a case report and review of the literature

BACKGROUND

"Carney Complex (CNC) is a familial lentiginosis syndrome, caused by PRKAR1A mutations that lead to cyclic AMP-dependent protein kinase (PKA) signaling pathway abnormalities, predisposing to a variety of skin tumors, myxomas and endocrine tumors.

METHODS/RESULTS

We describe a Greek family diagnosed with CNC after recurrent embolic strokes, secondary to left-sided atrial myxomas. There are limited cases in the literature describing this type of presentation for CNC; typically, most cases present with an endocrine syndrome. Our case serves as a reminder of this rare, underdiagnosed syndrome and its wide phenotypic spectrum. It is followed by a review of the current literature on cases with cerebrovascular disease as a manifestation of CNC.

CONCLUSION

The co-occurrence of emboligenic cardiac myxomas and skin lesions should be an indication for screening for CNC.

Multiple embolic stroke on magnetic resonance imaging of the brain in a COVID-19 case with persistent encephalopathy

The pulmonary manifestations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or coronavirus disease 2019 (COVID-19) are well known. The literature on neurological manifestations and complications in patients with COVID-19 has been increasing but is still sparse. At present, there are only a few reported case reports and clinical studies on neurological manifestations of COVID-19, of which ischemic stroke is one of the most common ones. Coagulopathy and vascular endothelial dysfunction have been proposed as the complications of COVID-19 which can ultimately lead to ischemic stroke. In this case report, we present a case of multifocal ischemic stroke in a patient with COVID-19. This patient had persistent encephalopathy and dysarthria after recovering from hypoxic respiratory failure and subsequently developed ischemic stroke in multiple vascular territories during hospital admission.

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Hypercoagulopathy and vascular endothelial dysfunction have been proposed as complications of COVID 19 which can lead to stroke.

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Diagnoses of stroke in critically ill patients hospitalized with COVID-19 using MRI brain can be challenging due to multiple factors.

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Patient with COVID-19 with stroke in multiple vascular territories after he had persistent encephalopathy and dysarthria.

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MRI brain is more sensitive and specific modality to detect brain tissue that has been damaged by an ischemic stroke than a CT head.

Timing of Recognition for Perioperative Strokes Following Cardiac Surgery

INTRODUCTION

More than half of reported perioperative strokes following cardiac surgery are identified beyond postoperative day one. The objective of our study was to determine preoperative and intraoperative factors that are associated with stroke following cardiac surgery and to identify factors that may contribute delayed recognition of perioperative stroke.

METHODS

Patients undergoing coronary artery bypass surgery or isolated valve surgery from January 2, 2015 to April 28, 2017 at an academic health system were identified from the Society of Thoracic Surgeons Registry. We determined preoperative and intraoperative factors associated with perioperative stroke. Two neurologists performed retrospective chart reviews on perioperative stroke patients to determine the last seen well time and the stroke cause.

RESULTS

During the study period, 2795 patients underwent coronary artery bypass surgery or isolated valve surgery (mean age 64 ± 11 years, 71% male, 72% Caucasian, 9% history of stroke), of which 43 (1.5%) had a perioperative stroke; 31 (72%) patients had an embolic mechanism of stroke based on neuroimaging. In multivariable analysis, perioperative strokes were independently associated with increasing age (OR 1.04, 95% 1.01-1.07), history of stroke (OR 2.73, 95% CI 1.47-5.06), and history of thoracic aorta disease (OR 3.36, 95% CI 1.16-9.71). Strokes were identified after postoperative day one in 32 (74%) patients of which 26 (81%) had a preoperative last seen well time.

CONCLUSION

Given the high frequency of preoperative last seen well time in perioperative stroke patients who are identified after postoperative day one, delayed stroke recognition may contribute to the bimodal distribution in timing of perioperative stroke. Frequent neurological monitoring within 24 hours after CABG or isolated valve surgery should be considered for all patients undergoing cardiac surgery, particularly elderly patients and those with a history of stroke or thoracic aorta disease, to improve early stroke recognition.

Inhibition of PI3Kγ by AS605240 plus low-dose tissue plasminogen activator (tPA) combination improves thrombolytic therapy in a rat model of embolic stroke

Our previous study showed that PI3Kγ inhibition with AS605240 plus a standard rat-dose tPA (10 mg/kg) combination attenuates delayed tPA-induced brain hemorrhage and ameliorates acute stroke injury 3 days after ischemic stroke in rats. The purpose of this study was to investigate whether combining AS605240 with tPA can enhance thrombolytic efficacy, so that lower doses of tPA can be applied to improve long-term outcome after ischemic stroke. The results showed that AS605240 plus low-dose tPA (5 mg/kg) combination therapy at 4 h after stroke onset significantly reduced infarct volume and neurological deficits at 24 h after stroke compared with saline, AS605240 or low-dose tPA alone group. Importantly, the combination therapy significantly reduced the delayed tPA-associated brain hemorrhage. Moreover, the combination therapy significantly decreased the size of the residual embolus within the middle cerebral artery, which was associated with a decrease in plasma plasminogen activator inhibitor-1 (PAI-1) activity compared with saline and tPA alone. Finally, AS605240 plus low-dose tPA combination improved long-term outcome for at least 35 days after stroke compared with the saline-treated group. Taken together, these findings suggest that PI3Kγ inhibition with AS605240 might act as an adjunct approach for enhancing tPA thrombolytic efficacy in acute ischemic stroke.

Paradoxical Embolism in a Case of Hereditary Hemorrhagic Telangiectasia: Case Report with Literature Review

Ischemic stroke involving multiple artery territory with normal vessels gives a clue for an embolic stroke. Paradoxical embolization is a recognized cause of ischemic stroke. We describe a 48-year-old male who presented with acute onset giddiness, mild dysarthria, right hemiparesis, and ataxia. Clinical examinations indicated left cerebellar signs with right hemiparesis. Additionally, the patient had significant clubbing and mild cyanosis. A strong family history of epistaxis and hemoptysis was noted. His Magnetic resonance imaging of the brain showed acute left cerebellar and left frontal cortical infarct with normal vessels. The routine stroke and cardiac workup were normal. Chest X-ray showed bilateral lower zone opacities. Contrast-enhanced computerized tomogram (CT) of the chest showed bilateral pulmonary arteriovenous malformation. Paradoxical embolism due to pulmonary arteriovenous malformation resulted in ischemic stroke in our patient. He fulfilled all of the four criteria for diagnosing definite hereditary hemorrhagic telangiectasia. Our case highlights the importance of a systematic search for paradoxical embolism in a cryptogenic stroke.

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.

Left Ventricular Thrombi and Embolic Events in Takotsubo Syndrome despite Therapeutic Anticoagulation

INTRODUCTION

Takotsubo syndrome (TTS) may be complicated by left-ventricular (LV) thrombus formation in 1.3-5.3% of patients. Risk factors for thrombi comprise apical TTS, elevated levels of C-reactive protein and troponine, thrombocytosis, persisting ST segment elevation and right-ventricular involvement. Embolic risk appears high, and anticoagulation is recommended.

CASE PRESENTATION

We present 3 females, aged 60-82 years, with TTS-associated LV thrombi and cerebral embolism despite therapeutic anticoagulation. Two patients showed apical and 1 patient midventricular ballooning. In 2 patients LV thrombi had not been present at the first echocardiographic examination. LV thrombi were multiple and highly mobile in 2 patients; 1 patient had a single immobile thrombus associated with spontaneous echocardiographic contrast (SEC). In each case, 3 of the described risk factors for LV thrombus formation were identified. The embolic stroke occurred 41-120 h after TTS symptom onset and 21-93 h after the initiation of therapeutic anticoagulation. Two patients were discharged with a neurological deficit, and 1 of them eventually died as a consequence of the stroke. LV thrombectomy to prevent embolism, which has been reported in a small number of cases, had not been considered in our patients.

CONCLUSION

At present, the management of patients with TTS-related thrombi is still unclear, and further studies are urgently needed to assess the best methods for imaging and anticoagulation and to determine the role of thrombolysis and cardiac surgery. Until these studies are available, we suggest the following approach: patients with a TTS-related thrombus should be monitored by echocardiography while receiving anticoagulation. In case of highly mobile LV thrombi, the heart team may consider cardiac surgery to prevent systemic embolism. The role of SEC in TTS remains to be determined.

Thrombocytopenia and endocarditis in a patient with Whipple's disease: case report

Background

Whipple’s disease (WD) is a rare multisystem infectious disorder that is caused by the actinomycete Tropheryma whipplei. It presents with joint pain followed by abdominal pain, diarrhea, malabsorption and finally failure to thrive. Diagnosis requires tissue sampling and histology with periodic acid-Schiff [PAS] staining. Thrombocytopenia associated with endocarditis associated with WD has been reported twice.

Case presentation

A 56 year old Caucasian male presented with years of steroid treated joint pain and recent onset diarrhea, weight loss and abdominal pain. Ultimately he was found to have a platelet count of 4000 with concomitant endocarditis and embolic stroke. Small bowel biopsy confirmed the diagnosis of WD approximately 1 year after his first visit. His platelets improved with antibiotic treatment but he eventually expired 16 months after his initial consult and 5 months after his definitive diagnosis.

Conclusion

WD can remain undiagnosed and untreated until late in the course of the illness. A high index of suspicion is recognized as necessary for early diagnosis to begin treatment. Critical thrombocytopenia associated with endocarditis is a rare and potentially poor prognostic sign in late stage Whipple’s disease.

Stroke after spontaneous intracranial hypotension: Not a single mechanism. Case report and review of literature

Spontaneous intracranial hypotension (SIH) is a rare syndrome, typically manifests as orthostatic headache. Sometimes considered asbenignillness, neurological complications are well described, in particular subdural hematoma and cerebral venous sinus thrombosis. Brain infarction as complication of SIH is rarely reported. The main mechanism supported in the literature is the stretching of arteries due to the sagging of the brain. We report a case of SIH followed with brain infarction, with a distinct presentation from previous literature, suggesting a different mechanism. A 35 year-old had severe orthostatic headache, responsible for prolonged bed rest. One month later, he had acute left hemiparesis secondary to stroke and right posterior cerebral artery occlusion. Stroke MRI showed arguments for intracranial hypotension (thickened meninges). He was successfully treated with intravenous rtPA thrombolysis. Headache were resolved after an epidural blood patch. A patent foramen ovale was detected. Clinical features of this description were compared with previous literature. This case suggest a different mechanism for cerebral infarction after intracranial hypotension. In case of prolonged lying down due to intracranial hypotension, the presence of patent foramen ovale could be a risk factor for embolic stroke.