Transesophageal echocardiography for the evaluation and management of patients with cerebral ischemia

The Utility of Echocardiogram in the Workup of Ischemic Stroke Patients

BACKGROUND

Cardiac sources of emboli can be identified by transthoracic echocardiogram (TTE). The Canadian Best Practice Guidelines recommend routine use of TTE in the initial workup of ischemic stroke when an embolic source is suspected. However, TTEs are commonly ordered for all patients despite insufficient evidence to justify cost-effectiveness. We aim to evaluate the TTE ordering pattern in the initial workup of ischemic stroke at a regional Stroke Center in Central South Ontario and determine the proportion of studies which led to a change in management and affected length of stay (LOS).

METHODS

Hospital records of 520 patients with a discharge diagnosis of TIA or ischemic stroke between October 2016 and June 2017 were reviewed to gather information.

RESULTS

477 patients admitted for TIA or ischemic stroke met inclusion criteria. 67.9% received TTE, out of which 6.0% had findings of cardiac sources of emboli including left ventricular thrombus, atrial septal aneurysm, PFO, atrial myxoma, and valvular vegetation. 2.5% of all TTE findings led to change in medical management. The median LOS of patients who underwent TTE was 2 days longer (p < 0.00001).

CONCLUSION

TTE in the initial workup of TIA or ischemic stroke remains common practice. The yield of TTEs is low, and the proportion of studies that lead to changes in medical management is minimal. TTE completion was associated with increased LOS and may result in increased healthcare spending; however, additional factors prolonging the LOS could not be excluded.

A lower left atrial appendage peak emptying velocity in the acute phase of cryptogenic stroke predicts atrial fibrillation occurrence during follow-up

BACKGROUND

Silent atrial fibrillation is a frequent etiology of cryptogenic stroke. Spontaneous conversion of atrial fibrillation to sinus rhythm results in atrial stunning.

OBJECTIVE

To evaluate if the presence of a lower left atrial appendage peak emptying velocity (LAAV) after a cryptogenic stroke is associated with the occurrence of atrial fibrillation (AF).

METHODS

We retrospectively selected consecutive patients with an acute ischemic stroke that had a transoesophageal echocardiogram (TEE) performed in the first 30 days of the acute event. Documented AF or potential cardioembolic sources in the TEE were considered exclusion criteria. We assessed the LAAV. During follow-up, we evaluated the occurrence of new-onset AF and the combined endpoint of death or new ischemic stroke.

RESULTS

We studied 73 consecutive patients, during a mean follow-up period of 54.9 ± 19.3 months. Seven developed AF, and 13 had the combined endpoint. LAAV was independently associated with AF occurrence (HR: 0.93, 95% CI: 0.88-0.99; P = .016). Patients with a LAAV ≤ 46.5 cm/s (AUC: 0.766, 95% CI: 0.579-0.954; P = .021) had a lower survival rate free from AF occurrence (Log-rank, P < .001) and free from the combined endpoint of death or ischemic stroke (Log-rank, P = .010).

CONCLUSION

A lower LAAV was associated with AF occurrence and the combined endpoint of death or ischemic stroke after an initial episode of cryptogenic stroke. Patients with this finding could eventually benefit from long-term cardiac rhythm monitoring.

Cardio-embolic stroke: Lessons from a single centre in Sub-Saharan Africa

BACKGROUND

Limited information is available about cardio-embolic stroke (CES) in sub-Saharan Africa. The aim of this study was to describe the epidemiology, clinical features, etiology, the management and outcome of CES in our setting.

METHODS

A retrospective cohort study was carried out in the Douala General Hospital (DGH), using files of ischemic stroke patients admitted in the Neurological Unit and the Intensive Care Unit. Socio-demographic, clinical and paraclinical data were collected. After hospitalization, follow-up was performed with focus on mortality, stroke recurrence and the functional outcome assessed with Barthel score. Multivariate analysis was performed to determine the factors associated with death.

RESULTS

Of the 704 stroke cases included, 368 were ischemic with 86 (23.4%) of them being cardio-embolic. The mean age of patient with CES was 67±13.3 years. The main etiologies of CES were: atrial fibrillation (82.1%), dilated cardiomyopathy (12.8%), and rheumatic mitral stenosis (5.1%). Anti-platelet agents were the most prescribed anti-thrombotic drugs (50.7%). The in-hospital mortality rate was 23.3% with lesion in both internal carotid arteries [OR=110.3; 95% CI: 1.2-1040.7; P=0.043] and heart disease [OR=46.9; 95% CI: 1.2-1789.9; P=0.038] appeared to be predictive of this. Stroke recurrence was observed in 8 patients (12.1%) and the survival probability in 5 years was 10%. Functional outcome was progressively worse with the systolic blood pressure>140mmHg (P=0.025) been the associated factor.

CONCLUSION

CES accounted for 1/4 of ischemic stroke with a high risk of early death and long-term recurrence. Atrial fibrillation was the leading cause of CES. The association of VKA and anti-platelet agent should be avoided to reduce early death during acute stroke.

[Clinical and neuroimaging signs of cardioembolic stroke in children]

AIM

To study clinical and neuroimaging signs of cardioembolic stroke (CES) in children.

MATERIAL AND METHODS

A group of 100 patients with arterial ischemic stroke (AIS), aged from 1 month to 15 years, was stratified into the main group (10 patients with CES) and the comparison group (90 patients with other subtypes of AIS). CT and MRI, MR-angiography, ultrasound study as well as assessment of clinical symptoms on PedNIHSS were performed. The duration of follow-up was from 2 month to 14 years. The follow-up allowed the assessment of occurrence of secondary strokes, severity of residual neurological symptoms on the PSOM and fatal outcomes. Special attention was drawn to the use of CASSADE criteria for CES.

RESULTS AND CONCLUSION

Clinical features that help to diagnose CES, even in the absence of adequate neuroimaging, in patients with heart disease, which is a potential high risk factor for cardioembolia, were established. These factors include early disease onset, acute development and progression of neurological deficit to the maximal level in the first 5 min., marked severity of the acute period (PedNIHSS > 15), early recovery of neurological functions, significant residual neurological symptoms (PSOM > 2). These symptoms should be used in addition to the CASCADE criteria in the diagnosis of CES of AIS type in children.

[Clinical and neuroimaging signs of cardioembolic stroke laboratory in children]

AIM

To study clinical and neuroimaging signs of cardioembolic stroke (CES) in children.

MATERIAL AND METHODS

Ten children (mean age 3.5±3.5 years) were examined. Eight children met the diagnostic criteria of CES CASCADE, two children were diagnosed with CES based on the complex of symptoms. A comparison group consisted of 90 children with other subtypes of ischemic stroke (IS). The diagnosis was confirmed by MRI and magnetic-resonance angiography; symptom severity was assessed with PedNIHSS and PSOM.

RESULTS AND CONCLUSION

The PedNIHSS score in the acute stage of CES was higher (18.4±9.34) compared to patients with other subtypes of IS (12.6±6.2; p=0.0065). Six patients had large cerebral infarctions with the involvement of basal ganglia, internal capsule, white matter and cerebral cortex. In two patients, the infarction affected the cerebral cortex and underlying white matter, in one patient it affected the cortex from one side and the basal ganglia from the other. A damage of the cortex was noted in one patient. The frequency of recurrent CES was 30%, of fatal cases 20%. Recurrent IS and severe residual neurological deficit were more frequent in CES.

CONCLUSION

Early disease onset, acute development and progression of neurological deficit up to the maximal level in the first 5 min, marked severity of the acute stage (PedNIHSS score >15), early onset of neurological function recovery, marked residual neurological deficit (PSOM score >2) are the additional signs of CES.

Etiologic classification of ischemic stroke: Where do we stand?

Despite major technological advances in ischemic stroke diagnostic techniques, our current understanding of stroke mechanisms and etiology continues to remain unclear in a significant percent of patients. As a result, several etiological ischemic stroke classifications have emerged during the last two decades but their reliability and validity is far from perfect and further world-wide research is needed in order to achieve the so much needed "standard reference language". An ideal ischemic stroke classification should both comprise all underlying pathologies that could potentially concur to an index event and emphasize the most likely etiological and pathophysiological mechanism. Currently available approaches to ischemic stroke classification are either phenotypic or causative in nature, a multitude of criteria being published by different authors. Phenotypic classifications are targeted towards describing the concurring underlying pathologies, without highlighting the most probable ischemic stroke etiology, while causative classifications focus on establishing the most likely cause, neglecting other associated diseases. A judicious use of this two different concepts might improve clinical research as well as daily clinical practice.

The Role of Patent Foramen Ovale in Cryptogenic Stroke

INTRODUCTION

Almost one-third of ischemic strokes has an unknown etiology and are classified as cryptogenic stroke. Paradoxical embolism because of a patent foramen ovale (PFO) is detected in 40%-50% of these patients. Recently, PFO has been reported as a risk factor for patients of all age groups.

METHODS

In this study, 1080 ischemic stroke patients admitted to our clinic (2011-2013) were retrospectively evaluated. Age, sex, risk factors, complete blood count, vasculitis, biochemical and hypercoagulability tests, magnetic resonance imaging, magnetic resonance angiography, transthoracic echocardiography, transeosophageal echocardiography (TEE) findings, and therapeutic approaches were evaluated.

RESULTS

The age range of the participants (seven male and four female patients) was 20-60 years (mean=43.09±11.13 years). Hemiparesis (n=10), diplopia (n=2), hemianopsia (n=2), and dysarthria (n=2) were the main findings of the neurological examinations. Patient medical history revealed hypertension (n=3), asthma (n=1), deep venous thrombosis (n=1), and smoking (n=4). Diffusion-weighted imaging showed middle cerebral artery (n=8) and posterior cerebral artery (n=3) infarctions. In one case, symptomatic severe carotid stenosis was detected. In eight cases, TEE showed PFO without any other abnormalities, but PFO was associated with atrial septal aneurysm in two cases, and in one case it was associated with ventricular hypokinesia and pulmonary arterial hypertension. Antiplatelet therapy was applied to nine patients and percutaneous PFO closure operation to two patients. In a 2-year follow-up, no recurrent ischemic stroke was recorded.

CONCLUSION

PFO, especially in terms of the etiology of cryptogenic stroke in young patients, should not be underestimated. We want to emphasize the importance of TEE in identifying potential cardioembolic sources not only in young but also in all ischemic stroke patients with unknown etiology; we also discuss the controversial management options of PFO.

Cardiac workup of ischemic stroke

Stroke is the leading cause of disability in developed countries and the third cause of mortality. Up to 15-30% of ischemic strokes are caused by cardiac sources of emboli being associated with poor prognosis and high index of fatal recurrence. In order to establish an adequate preventive strategy it is crucial to identify the cause of the embolism. After a complete diagnostic workup up to 30% of strokes remain with an undetermined cause, and most of them are attributed to an embolic mechanism suggesting a cardiac origin.There is no consensus in the extent and optimal approach of cardiac workup of ischemic stroke. Clinical features along with brain imaging and the study of the cerebral vessels with ultrasonography or MRI/CT based angiography can identify other causes or lead to think about a possible cardioembolic origin.Atrial fibrillation is the most common cause of cardioembolic stroke. Identification of occult atrial fibrillation is essential. Baseline ECG, serial ECG('s), cardiac monitoring during the first 48 hours, and Holter monitoring have detection rates varying from 4 to 8% each separately. Extended cardiac monitoring with event loop recorders has shown higher rates of detection of paroxysmal atrial fibrillation.Cardiac imaging with echocardiography is necessary to identify structural sources of emboli. There is insufficient data to determine which is the optimal approach. Transthoracic echocardiography has an acceptable diagnostic yield in patients with heart disease but transesophageal echocardiography has a higher diagnostic yield and is necessary if no cardiac sources have been identified in patients with cryptogenic stroke with embolic mechanism.

Guidelines for the primary prevention of stroke: a guideline for healthcare professionals from the American Heart Association/American Stroke Association

BACKGROUND AND PURPOSE

This guideline provides an overview of the evidence on established and emerging risk factors for stroke to provide evidence-based recommendations for the reduction of risk of a first stroke.

METHODS

Writing group members were nominated by the committee chair on the basis of their previous work in relevant topic areas and were approved by the American Heart Association (AHA) Stroke Council Scientific Statement Oversight Committee and the AHA Manuscript Oversight Committee. The writing group used systematic literature reviews (covering the time since the last review was published in 2006 up to April 2009), reference to previously published guidelines, personal files, and expert opinion to summarize existing evidence, indicate gaps in current knowledge, and when appropriate, formulate recommendations using standard AHA criteria (Tables 1 and 2). All members of the writing group had the opportunity to comment on the recommendations and approved the final version of this document. The guideline underwent extensive peer review by the Stroke Council leadership and the AHA scientific statements oversight committees before consideration and approval by the AHA Science Advisory and Coordinating Committee.

RESULTS

Schemes for assessing a person's risk of a first stroke were evaluated. Risk factors or risk markers for a first stroke were classified according to potential for modification (nonmodifiable, modifiable, or potentially modifiable) and strength of evidence (well documented or less well documented). Nonmodifiable risk factors include age, sex, low birth weight, race/ethnicity, and genetic predisposition. Well-documented and modifiable risk factors include hypertension, exposure to cigarette smoke, diabetes, atrial fibrillation and certain other cardiac conditions, dyslipidemia, carotid artery stenosis, sickle cell disease, postmenopausal hormone therapy, poor diet, physical inactivity, and obesity and body fat distribution. Less well-documented or potentially modifiable risk factors include the metabolic syndrome, excessive alcohol consumption, drug abuse, use of oral contraceptives, sleep-disordered breathing, migraine, hyperhomocysteinemia, elevated lipoprotein(a), hypercoagulability, inflammation, and infection. Data on the use of aspirin for primary stroke prevention are reviewed.

CONCLUSIONS

Extensive evidence identifies a variety of specific factors that increase the risk of a first stroke and that provide strategies for reducing that risk.

Frequency of atrial septal aneurysm in patients with recent stroke: preliminary results from a multicenter study

BACKGROUND

The role of atrial septal aneurysm (ASA) as a risk factor for cerebral ischemia of unknown etiology is controversial. Recent studies have found an association between ASA and focal ischemic events, while results from other studies suggest a low incidence of embolism in patients with ASA.

HYPOTHESIS

The present study was designed to evaluate the frequency of ASA, a minor cardioembolic source, in patients with a recent stroke presenting with normal carotid arteries.

METHODS

In all, 394 patients with cerebral ischemic stroke were referred to our institutions. Patients underwent transthracic and transesophageal echocardiography and carotid artery ultrasound examination. The study population included 215 patients without significant arterial disease. Frequency and morphologic characteristics of ASA were evaluated.

RESULTS

Transthoracic examination showed ASA in 39 patients (18%), while transesophageal echocardiography showed ASA in 61 patients (28%). A patent foramen ovale was found in 47 patients (21.8%) and was associated with ASA in 40 patients (65.5%). We observed an increased thickness of the aneurysmatic wall (3.80 +/- 1.7 mm) in all patients with ASA.

CONCLUSIONS

The present study confirms the relationship between ASA and stroke in patients with normal carotid arteries. The most common abnormality associated with ASA was patent foramen ovale. We suggest that patients who have a stroke in the absence of significant carotid disease undergo transesophageal echocardiography to identify possible underlying septal abnormalities.

Improved aetiological diagnosis of ischaemic stroke in a Vascular Medicine Unit--the significance of transesophageal echocardiogram

BACKGROUND

The TOAST study estimates that 34% of ischaemic strokes are of undetermined aetiology. Improvements in the diagnosis of the pathogenetic mechanism of ischaemic stroke would translate into a better care, in analogy to other fields of vascular and internal medicine.

OBJECTIVE

To measure the reduction of undetermined aetiology strokes performing a set of additional diagnostic tests.

DESIGN

Consecutive case series with historical controls.

SETTING

Internal Medicine Ward with a stroke area (SA) admitting most stroke patients of a large hospital in Italy.

SUBJECTS

A total of 179 ischaemic stroke patients admitted to SA in 2004-2005 compared with 105 ischaemic stroke patients admitted to the whole department in 2001.

INTERVENTION

To perform more diagnostic tests, including transesophageal echocardiography (TEE), in the greatest possible number of ischaemic stroke inpatients admitted in SA of the Internal Medicine Department, in the years 2004-2005.

RESULTS

More diagnostic tests were performed during the study period than in 2001, especially TEE (56% of patients in 2004-2005 vs. 3% of patients in 2001). We observed a significant reduction of undetermined aetiology from 38% in 2001 to 16% in 2004-2005 (p < 0.0001), largely for an increased identification of cases of cardio-embolic mechanism (from 18% to 40%, p = 0.0002). In the years 2004-2005 the fraction of patients on anticoagulant treatment at discharge was 21% vs. 12% in 2001 (p = 0.041).

CONCLUSION

Performing more tests, particularly TEE, brought improvements in the aetiological diagnosis of stroke, increasing cardio-embolism diagnosis and anticoagulant treatment.

Patent foramen ovale and atrial septal aneurysm in cryptogenic stroke

Up to 40% of acute ischaemic strokes in young adults are cryptogenic in nature, that is, no cause is determined. In more than half of these patients, patent foramen ovale (PFO) is seen along with an increased incidence of atrial septal aneurysm. The commonest method of investigation is echocardiography (preferably transoesophageal echocardiography). On the basis of available evidence, low risk patients are treated with antiplatelet agents and high risk patients with warfarin. There are inconclusive data on the efficacy of PFO closure to prevent stroke recurrence. However, if there is recurrent stroke or intolerance to medical therapy, percutaneous closure is carried out.