Diagnostic Yield of TEE in Patients with Cryptogenic Stroke and TIA with Normal TTE: A Systematic Review and Meta-Analysis

Emergency medicine updates: Transient ischemic attack

INTRODUCTION

Transient ischemic attack (TIA) is a condition commonly evaluated for in the emergency department (ED). Therefore, it is important for emergency clinicians to be aware of the current evidence regarding the diagnosis and management of this disease.

OBJECTIVE

This paper evaluates key evidence-based updates concerning TIA for the emergency clinician.

DISCUSSION

TIA is a harbinger of ischemic stroke and can result from a variety of pathologic causes. While prior definitions incorporated symptoms resolving within 24 h, modern definitions recommend a tissue-based definition utilizing advanced imaging to evaluate for neurologic injury and the etiology. In the ED, emergent evaluation includes assessing for current signs and symptoms of neurologic dysfunction, appropriate imaging to investigate for minor stroke or stroke risk, and arranging appropriate disposition and follow up to mitigate risk of subsequent ischemic stroke. Imaging should include evaluation of great vessels and intracranial arteries, as well as advanced cerebral imaging to evaluate for minor or subclinical stroke. Non-contrast computed tomography (CT) has limited utility for this situation; it can rule out hemorrhage or a large mass causing symptoms but should not be relied on for any definitive diagnosis. Noninvasive imaging of the cervical vessels can also be used (CT angiography or Doppler ultrasound). Treatment includes antithrombotic medications if there are no contraindications. Dual antiplatelet therapy may reduce the risk of recurrent ischemic events in higher risk patients, while anticoagulation is recommended in patients with a cardioembolic source. A variety of scoring systems or tools are available that seek to predict stroke risk after a TIA. The Canadian TIA risk score appears to have the best diagnostic accuracy. However, these scores should not be used in isolation. Disposition may include admission, management in an ED-based observation unit with rapid diagnostic protocol, or expedited follow-up in a specialty clinic.

CONCLUSIONS

An understanding of literature updates concerning TIA can improve the ED care of patients with TIA.

Comparative diagnostic accuracy of transcranial Doppler and contrast-enhanced transthoracic echocardiography for the diagnosis of patent foramen ovale and atrial septal defect

BACKGROUND

Recognition of right-to-left shunt is crucial in the work-up of patients with suspected patent foramen ovale (PFO) or atrial septal defect (ASD). While transesophageal echocardiography (TEE) remains the gold standard diagnostic tool for the anatomic assessment of PFO/ASD, transcranial Doppler (TCD) and contrast-enhanced transthoracic echocardiogram (CE-TTE) hold the promise of providing minimally invasive yet accurate clinical details. Their comparative accuracy remains however debated.

METHODS

We conducted a retrospective observational study leveraging our extensive institutional experience with systematic TCD and CE-TTE in patients with suspected PFO/ASD. Several measures of diagnostic test accuracy were computed, with point estimates and 95% confidence intervals, when applicable.

RESULTS

A total of 1358 patients were included, with age 48±14 years and 772 (58%) women. Tests were performed for diagnostic purposes in 797 (58.6%) and during follow-up in 740 (54.5%). A PFO was eventually diagnosed in 1038 (77.9%) patients, and an ASD in 60 (4.5%). Agreement between TCD and CE-TTE occurred in 1309 (85.2%) cases, with TCD yielding worse findings than CE-TTE in 91 (5.9%) patients, and vice versa in 137 (8.9%), yielding a Cohen kappa of 78.6% (95% CI: 76.3-81.1%) and a highly significant P value at McNemar test (P<0.001). After dichotomization, and using TCD as benchmark, CE-TTE yielded sensitivity 96.9%, specificity 95.1%, area under the curve 92.1%, and P=0.249. Similar findings were obtained when focusing only on diagnostic tests or follow-up ones (Cohen kappa respectively 74.0% [70.2-77.1%], P<0.001 and 80.3% [76.4-84.3%], P<0.001). Notably, Valsalva was necessary to disclose the presence of shunt during TCD in 487 (31.7%) patients and during CE-TTE in 482 (31.4%) cases. Finally, performance of TCD and CE-TTE in a subset of patients eventually undergoing TTE was quite similar.

CONCLUSIONS

The diagnostic accuracy of CE-TTE appears favorable, and this imaging test may identify patients who may be missed if only TCD is used to screen patients with suspected PFO/ASD. Accordingly, CE-TTE is recommended as an adjunct diagnostic modality for all patients with a high pre-test probability of PFO/ASD and right-to-left shunt.

Diagnostic Evaluation of Stroke Etiology

OBJECTIVE

Precise therapies require precise diagnoses. This article provides an evidence-based approach to confirming the diagnosis of ischemic stroke, characterizing comorbidities that provide insights into the pathophysiologic mechanisms of stroke, and identifying targets for treatment to optimize the prevention of recurrent stroke.

LATEST DEVELOPMENTS

Identifying the presence of patent foramen ovale, intermittent atrial fibrillation, and unstable plaque is now routinely included in an increasingly nuanced workup in patients with stroke, even as ongoing trials seek to clarify the best approaches for treating these and other comorbidities. Multicenter trials have demonstrated the therapeutic utility of patent foramen ovale closure in select patients younger than age 60 years. Insertable cardiac monitors detect atrial fibrillation lasting more than 30 seconds in about one in ten patients monitored for 12 months following a stroke. MRI of carotid plaque can detect unstable plaque at risk of being a source of cerebral embolism.

ESSENTIAL POINTS

To optimize the prevention of recurrent stroke, it is important to consider pathologies of intracranial and extracranial blood vessels and of cardiac structure and rhythm as well as other inherited or systemic causes of stroke. Some aspects of the stroke workup should be done routinely, while other components will depend on the clinical circumstances and preliminary testing results.

Clinical Study of Clopidogrel Combined with Huoxue Tongluo Prescription in Improving Transient Ischemic Attack and the Effect on MMP-9, Hcy, and CRP

Background. This study aimed to explore the clinical study of clopidogrel combined with Huoxue Tongluo prescription in improving transient ischemic attack (TIA) and the effect on MMP-9, Hcy, and CRP. Methods. A total of 84 patients with TIA admitted to our hospital from December 2019 to February 2021 were selected. The patients were divided into the control group (42 cases: not treated with Huoxue Tongluo prescription) and study group (42 cases: treatment with Huoxue Tongluo prescription). The clinical efficacy, adverse reactions, the levels of blood pressure and lipid, blood rheology and cerebral hemodynamics, neurological function-related indicators, MMP-9, Hcy, and CRP of the two groups were compared. Results. The total effective rate in the study group was higher than the control group. Compared with before treatment, the levels of SBP and DBP in both groups decreased memorably after treatment, and those in the study group decreased more particularly than the control group. The levels of LDL, HDL, TC, and TG in the study group were significantly better than those in the control group. The plasma viscosity, whole blood high shear viscosity, whole blood low shear viscosity, and hematocrit of patients in the study group were lower than those in the control group, and the maximum blood flow velocity, minimum blood flow velocity, average blood flow velocity, and average blood flow were higher than those in the control group. The levels of NSE, MBP, and S100β in the study group were more memorably lower than those in the control group. After treatment, the levels of MMP-9, Hcy, and CRP in the study group were significantly lower than those in the control group. There was no obvious difference in the incidence of adverse reactions between the study group and control group. Conclusion. Clopidogrel combined with Huoxue Tongluo prescription can significantly improve the therapeutic effect and reduce the levels of MMP-9, Hcy, and CRP in patients with TIA.