Cryptogenic stroke. Part 2: paradoxical embolism

Studies of the biomarkers of atrial cardiopathy seem to be promising for identifying patients with cryptogenic stroke (CS), in which an intensive search for atrial fibrillation is indicated. Nevertheless, the diagnostic value of these markers and their threshold values require clarification. Objective : to present the characteristics of echocardiographic markers for atrial cardiopathy and the serum concentration of N-terminal pro-Btype natriuretic peptide (NT-proBNP) in embolic CS versus cardioembolic stroke (CES) and non-cardioembolic stroke (non-CES) to determine the threshold values of parameters with the highest sensitivity and specificity in differentiating CES and non-CES. Patients and methods . A total of 259 patients with ischemic stroke were examined. The standard examination additionally involved calculation of the parameters that reflected left atrial LA) function (LAF): LA emptying fraction (LAEF), and LA functional index (LAFI). The serum NT-proBNP concentration was also determined in 75 patients. Results and discussion . The patients with CES versus those with CS and non-CES were characterized by a considerable increase in LA diameter (4.3 [3.5; 4.5] cm vs 3.7 [3.4; 4.0] cm vs 3.7 [3.4; 3.9] cm; p=0.005 and p=0.009, respectively), LAVI (35.7 [30.5; 39.9] ml/m 2 vs 28.5 [25.6; 34.6] ml/m 2 vs 27.1 [24.5; 31.2] ml/m 2 ; p< 0.001) and NT-proBNP level (559 [409; 1144] pg/ml vs 164 [65; 308] pg/ml vs 191 [63; 446] pg/ml; p=0.002 and p=0.019, respectively), as well as by a lower LAEF value [50.3 [48.5; 51.1]% vs 54.7 [51.6; 56.6]% vs 54.9 [52.5; 56.8]%; p< 0.001). The only parameter that showed significant differences between all the three groups (CES, CS, and nonCES) was LAFI (0.24 [0.2; 0.32] units vs 0.37 [0.3; 0.47] units vs 0.40 [0.34; 0.47] units; p<0.00 1), while maintaining the differences in the values for the two groups (CS and non-CES) (p=0.004). The following threshold values of biomarkers were obtained for CES and nonCES; these were a LA diameter of 41.5 mm (p< 0.001), a LAVI of 36.3 ml/m 2 (p< 0.001), a LAEF of 51.8% (p< 0.001), a LAFI of 0.28 units (p< 0.001), and an NT-proBNP of 316 pg/ml (p< 0.001). Analysis of the ROC curves and the area under the curve (AUC) revealed that the most informative criteria for sensitivity and specificity were LAEF (79 and 88%, AUC 0.89), NT-proBNP (67 and 91%, AUC 0.89) and LAFI (93 and 72%, AUC 0.81). Conclusion . The CS group and non-CES one are comparable in the echocardiographic manifestations of atrial cardiopathy and in serum NTproBNP values. LAEF and NT-proBNP concentrations are promising biomarkers to classify CS patients into potential arterio- and cardioembolic types.

/pdf/biomarkers-of-atrial-cardiopathy-in-patients-with-different-2m0xa6rx9d.pdf

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

Patent foramen ovale (PFO) is detectable in more than 25% of the adult population and is generally clinically insignificant. However, it can be a cause of paradoxical embolism in some cases. Randomized trials indicate that endovascular PFO closure in patients with a history of cryptogenic stroke is an effective method for the secondary prevention of catastrophic brain damage. Objective : to study the safety and efficiency of endovascular PFO closure in young patients with a history of cryptogenic stroke. Patients and methods . Sixty-two patients, including (22 males and 40 females) women, underwent percutaneous PFO closure in May 2018 to March 2020. The patients' mean age was 37.4±7.6 years. The inclusion criteria were a prior cryptogenic ischemic stroke lasting less than 12 months and PFO with a high risk for paradoxical embolism (PFO concurrent with atrial septal aneurysm or hypermobility; PFO, ≥2 mm size; the presence of the Chiari network and/or the Eustachian valve). Results and discussion . The technical success of the operation was achieved in all cases. In 50 (80.6%) patients, the right chamber of the heart was completely isolated from the left one in the first 3 months. During the first year, the atria were also completely isolated in 10 (16.1%) patients. A left-to-right shunt persisted in 2 (3.2%) patents 12 months later. Two patients were found to have main procedural complications: one had perioperative atrial fibrillation and the other had pseudoaneurysm formation at the puncture site. Conclusion . Endovascular PFO closure is a safe and effective operation for the secondary prevention of recurrent ischemic stroke. In our study, blood shunting through the PFO was stopped in 96.6% of patients at less than 6 months after surgery, which suggests that there is a rapid and effective reduction in the risk of paradoxical embolism.

/pdf/safety-and-efficacy-of-endovascular-patent-foramen-ovale-17lymspjk2.pdf

Safety and efficacy of endovascular patent foramen ovale closure: the first results of a Russian multicenter study

The epidemiology of cervical artery dissection (CAD), which is often not thought to be the cause of ischemic stroke and transient ischemic attack (TIA), is discussed. The pathomorphology and pathogenesis of CAD, the key feature of which is the development of intramural hematoma, as well as predisposing conditions, triggers and associated conditions, in particular migraine, are reviewed. The clinical picture of diseases — local symptoms (headache and/ or neck pain, Horner’s syndrome, caudal cranial nerve involvement, cervical radicular syndrome, pulsatile tinnitus) and ischemic events (ischemic stroke or TIA) is presented. Modern approaches to urgent neuro- and angioimaging in CAD are reﬂected, including the possibilities of CT angiography (direct and indirect signs) and fat sat MRI (crescent symptom). Issues of reperfusion therapy (intravenous thrombolysis, thrombectomy and stenting) are discussed. The course of disease and secondary antithrombotic prophylaxis are analyzed.

Cervical dissection in emergency neurology: diagnostic and treatment algorithms

OBJECTIVE
To analyze clinical and instrumental characteristics of patients with ischemic stroke (IS) due to paradoxical embolism according to the data of hospital registers of Moscow and Perm.


MATERIAL AND METHODS
A comprehensive study of 114 patients, aged 18 to 55 years, with IS by the mechanism of paradoxical embolism was carried out. All patients underwent clarification of the cause of IS (electrocardiography, ultrasound scanning of the brachiocephalic arteries, CT or MRI of the brain, CT or MR angiography, transthoracic and/or transesophageal echocardiography). The presence of right-left shunt blood flow (RLS) was confirmed by transcranial dopplerography with a bubble test. The clinical significance of patent foramen ovale (PFO) was assessed according to The PFO-Associated Stroke Causal Likelihood Classification System (PASCAL).


RESULTS
Clinical and instrumental characteristics of patients with IS due to paradoxical embolism were obtained from two hospital registries. In both groups, the leading trigger for the development of IS was the Valsalva phenomen (>20%), the share of other provoking factors did not exceed 10%. Significant differences between the analyzed groups related to the ultrasonic characteristics of RLS/PFO: patients with a grade 4 shunt predominated in the Research Center of Neurology (RCN) population, while patients with a grade 3 shunt predominated in the City Clinical Hospital (CCH) №4 group. At the same time, there were twice as many patients with aneurysm of the interatrial septum in the CCH №4 group. In accordance with the PASCAL classification, in 93% of RCN patients, PFO can be considered as a probable cause of IS, while in the CCH No. 4 group, a probable causal relationship was traced only in 51% of cases, in 18% of patients, the role of an anomaly in the development of stroke was unlikely.


CONCLUSION
The analysis showed that the primary screening of RLS in a regional vascular center allows classifying PFO as a probable cause of IS in only half of the patients. For a more accurate selection of patients for whom endovascular occlusion of the PFO will be most effective, an in-depth examination in a specialized hospital is recommended.

[Ischemic stroke associated with patent foramen ovale: hospital database analysis].

Patent foramen ovale (PFO) is an important cause of embolic cryptogenic stroke (ECS) in young patients. The main mechanism in this case is paradoxical embolism (PE), the basis for which is a right-to-left (R-L) shunt. Objective: to comparatively characterize patients who have undergone ECS, with and without an R-L shunt, as evidenced by transcranial Doppler with the bubble test (TCD-BT). Patients and methods . In 40 patients with acute ECS, an R-L shunt was sought using TCD-BT, followed by transesophageal echocardiography (TEE). The left atrial volume index (LAVI) was additionally calculated. Brain damage was analyzed by probabilistic mapping of foci according to magnetic resonance imaging. Results and discussion. The mean age of the examined patients was 51.5 (39.5–60.0) years; of them there were 22 women and 18 men. An RL shunt was detected in 24 (60.0%) of patients with cryptogenic embolism that was mainly grades 2 and 3 (41.0 and 35.0%). TEE could visualize PFO (1.0 to 5.5 mm in size) in 16 (40%) patients and atrial septal aneurysm in 3 (7.5%). PFO was not found in 5 patients with positive results of TCD-BT, which may suggest that there is either a pulmonary shunt or a false-negative TEE. The patients with an R-L shunt versus those without an R-L-shunt showed lower LAVIs (23.9 and 26.5 mL/m2) (p=0.016). This fact may additionally confirm the causative role of PFO in the development of stroke, whereas higher LAVIs in the non R-L shunt subgroup should alert to the presence of atrial cardiopathy and initiate an appropriate diagnostic search for latent atrial fibrillation. According to the presence or absence of an R-L shunt, the groups did not significantly differ in gender, age, and clinical characteristics of the stroke. In patients with PFO, a lesion focus was most commonly localized in the middle cerebral artery bed (35.3%), cerebellum (23.5%), and posterior cerebral artery (17.6%). Five (29.0%) patients were ascertained to have several foci of acute stroke. There was a trend towards the larger size of cerebral infarction foci and their specific localization in the vertebrobasilar bed in PE, which determined the high (35.3%) incidence of ataxia with the onset of the disease. Conclusion. PE causes ECS in 60.0% of cases. The distinctive feature of patients with an R-L shunt is lower LAVIs and a trend towards the larger size of cerebral infarction foci and their specific localization in the vertebrobasilar bed.

/pdf/the-paradoxical-embolism-phenomenon-in-patients-with-embolic-1v871yon50.pdf

The paradoxical embolism phenomenon in patients with embolic cryptogenic stroke

A description of two cases of ischemic stroke with a progressive course on background of dissection of internal carotid artery (ICA) in young women is presented. In the fi rst observation patient developed headache, severe rightsided hemiparesis and sensorimotor aphasia. In digital subtraction angiography dissection subocclusion of left ICA was visualized, after that thrombectomy, intra-arterial thrombolysis and stenting were sequentially performed with achievement complete recanalization, accompanied by regress of paresis. In the second observation, mild leftsided hemiparesis developed, which grew after 4 days, hemianopsia and dysarthria appeared. Based on the results of emergency digital subtraction angiography, a dissection subocclusion of the right ICA was visualized. Using of tandem stenting, complete recanalization was achieved, accompanied by an increase in strength in the limbs and vision improvement. The literature review about the effi cacy and safety of stenting in dissection is presented.

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The paradoxical embolism phenomenon in patients with embolic cryptogenic stroke

Стентирование сонной артерии при цервикальной диссекции