Prevention of cardioembolic stroke

Temporal trends of sex differences in acute reperfusion therapy and early outcomes of acute ischemic stroke in South Korea: 10-year analysis of the nationwide stroke registry

BACKGROUND

Sex differences in stroke outcomes are notable, with women experiencing higher incidence rates, greater disability-adjusted life years, and poorer recovery compared to men, even after adjusting for age and comorbidities. Despite the disproportionate burden in women, studies have reported that women are less likely to receive appropriate stroke treatment than men.

AIM

This study investigated temporal trends of sex differences in acute reperfusion therapy and early outcomes in patients with acute ischemic stroke over 10 years in South Korea.

METHODS

A retrospective analysis of Korean Stroke Registry included patients with acute ischemic stroke from 2012 to 2021. The study outcomes were the temporal trends of acute reperfusion therapy and early outcomes over 10 years in men and women, respectively. In addition, this study analyzed the temporal trends of sex differences in these parameters during the same period. Early outcomes include the proportions of favorable functional outcomes at discharge, discharge patterns, and in-hospital mortality.

RESULTS

A total of 93,692 patients (68.4 years, 40.1% women) with acute ischemic stroke were finally enrolled. Women had a higher age at stroke onset, a higher prevalence of atrial fibrillation, and more severe strokes than men. Women had lower proportion of favorable functional outcomes at discharge and higher proportion of in-hospital mortality compared to men each year. The proportion of patients who received intravenous thrombolysis was lower or similar in women compared to men in most years, and the proportion of patients who received endovascular thrombectomy did not significantly differ between sexes annually. Sex differences in acute reperfusion therapy remained unchanged over 10 years.

CONCLUSION

Women have received acute reperfusion therapy at similar or lower rates than men and experienced poorer outcomes, despite having more stroke risk factors and often more severe strokes.

Primordial and Primary Prevention of Ischemic Stroke in Saudi Arabia: A Combination Approach and Evolving Concepts

Ischemic stroke is a considerable public health hazard and a significant cause of disability and mortality in Saudi Arabia. Primary prevention strategies in the country are currently limited. With the health sector transformation program that depends on the principles of value-based care and applying the new model of care in disease prevention, aggressive and serious steps for primary stroke prevention are expected to be implemented. This article reviews primordial and primary prevention of ischemic stroke in Saudi Arabia and suggests a combination approach and framework for implementation. We provide a pragmatic solution to implement primordial and primary stroke prevention in Saudi Arabia and specify the roles of the government, health professionals, policymakers, and the entire population. Currently, there are several key priorities for primordial and primary stroke prevention in Saudi Arabia that should target people at different levels of risk. These include an emphasis on a comprehensive approach that includes both individual and population-based strategies and establishing partnerships across health-care providers to share responsibility for developing and implementing both strategies. This is an urgent call for action to initiate different strategies suggested by experts for primary stroke prevention in Saudi Arabia.

Impact of prior use of antiplatelet agents and non-vitamin K antagonist oral anticoagulants on stroke outcomes among endovascular-treated patients with high pre-stroke CHA2DS2-VASc score

BACKGROUND

We assessed the influence of prior non-vitamin K antagonist (NOAC) use on stroke outcomes after endovascular treatment (EVT) in patients at a high risk of stroke based on their pre-stroke CHA2DS2-VASc score, and compared them with those who did not use any antithrombotic (NAU) or antiplatelet (APT) agents.

METHODS

Data were collected from a multicenter database comprising consecutive acute ischemic stroke patients who underwent EVT during a span of 103 months. We evaluated pre-stroke CHA2DS2-VASc scores in enrolled patients and measured instances of successful reperfusion and symptomatic hemorrhagic transformation (SHT) following EVT as the main outcome measures.

RESULTS

Among 12 807 patients with acute ischemic stroke, 3765 (29.4%) had a history of atrial fibrillation. Of these, 418 patients with CHA2DS2-VASc scores ≥2 received EVT alone. The prior NOAC group showed higher successful reperfusion rates compared with the prior NAU and APT groups (p=0.04). Multivariate analysis revealed that prior NOAC use increased the likelihood of successful reperfusion after EVT (OR [95% CI] 2.54 [1.34 to 4.83], p=0.004) and improved stroke outcomes, while the prior APT group did not. Furthermore, the prior NOAC use group was not associated with SHT after EVT. Propensity score matching confirmed these findings.

CONCLUSION

Prior use of NOAC is associated with improved outcomes in high-risk stroke patients (pre-stroke CHA2DS2-VASc score ≥2) undergoing EVT.

Integrative identification of hub genes in development of atrial fibrillation related stroke

BACKGROUND

As the most common arrhythmia, atrial fibrillation (AF) is associated with a significantly increased risk of stroke, which causes high disability and mortality. To date, the underlying mechanism of stroke occurring after AF remains unclear. Herein, we studied hub genes and regulatory pathways involved in AF and secondary stroke and aimed to reveal biomarkers and therapeutic targets of AF-related stroke.

METHODS

The GSE79768 and GSE58294 datasets were used to analyze AF- and stroke-related differentially expressed genes (DEGs) to obtain a DEG1 dataset. Weighted correlation network analysis (WGCNA) was used to identify modules associated with AF-related stroke in GSE66724 (DEG2). DEG1 and DEG2 were merged, and hub genes were identified based on protein-protein interaction networks. Gene Ontology terms were used to analyze the enriched pathways. The GSE129409 and GSE70887 were applied to construct a circRNA-miRNA-mRNA network in AF-related stroke. Hub genes were verified in patients using quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

We identified 3,132 DEGs in blood samples and 253 DEGs in left atrial specimens. Co-expressed hub genes of EIF4E3, ZNF595, ZNF700, MATR3, ACKR4, ANXA3, SEPSECS-AS1, and RNF166 were significantly associated with AF-related stroke. The hsa_circ_0018657/hsa-miR-198/EIF4E3 pathway was explored as the regulating axis in AF-related stroke. The qRT-PCR results were consistent with the bioinformatic analysis.

CONCLUSIONS

Hub genes EIF4E3, ZNF595, ZNF700, MATR3, ACKR4, ANXA3, SEPSECS-AS1, and RNF166 have potential as novel biomarkers and therapeutic targets in AF-related stroke. The hsa_circ_0018657/hsa-miR-198/EIF4E3 axis could play an important role regulating the development of AF-related stroke.

Mild and moderate cardioembolic stroke patients may benefit more from direct mechanical thrombectomy than bridging therapy: A subgroup analysis of a randomized clinical trial (DIRECT-MT)

Background

The benefit of intravenous alteplase before endovascular thrombectomy is unclear in patients with acute cardioembolic stroke.

Methods

We collected cardioembolic (CE) stroke patient data from the multicentre randomized clinical trial of Direct Intra-arterial Thrombectomy to Revascularize Acute Ischaemic Stroke Patients with Large Vessel Occlusion Efficiently in Chinese Tertiary Hospitals (DIRECT-MT). The primary outcome was the 90-day modified Rankin Scale (mRS) score. Five subgroups of cardioembolic stroke patients were analyzed. A multivariable ordinal logistic regression analysis analyzed the difference in the primary outcome between the direct mechanical thrombectomy (MT) and bridging therapy groups. An interaction term was entered into the model to test for subgroup interaction. The DIRECT-MT trial is registered with clinicaltrials.gov Identifier: NCT03469206.

Results

A total of 290 CE stroke patients from the DIRECT-MT trial were enrolled in this study: 146 patients in the direct MT group and 144 patients in the bridging therapy group. No difference between the two treatment groups in the primary outcome was found (adjusted common odds ratio, 1.218; 95% confidence interval, 0.806 to 1.841; P = 0.34). In the subgroup analysis, CE stroke patients with an NIHSS ≤ 15 in the direct MT group were associated with better outcomes (47 vs. 53, acOR, 3.14 [1.497, 6.585]) and lower mortality (47 vs. 53, aOR, 0.16 [0.026, 0.986]) than those in the bridging therapy group, while there were no significant differences between the two treatment groups in the outcome and mortality of CE stroke patients with an NIHSS >15.

Conclusion

Mild and moderate cardioembolic stroke patients may benefit more from direct mechanical thrombectomy than bridging therapy. This need to be confirmed by further prospective studies in a larger number of patients.

Acute Stroke and Atrial Fibrillation: Risk of Incorrect NOAC Dosage When Estimating Renal Function From Plasma Creatinine Only

Background

Cardioembolic stroke (CS) due to atrial fibrillation (AF) bears a high risk of unfavorable outcome. Treatment with a non-vitamin K antagonist oral anticoagulant (NOAC) reduces this risk. NOAC dosage occurs on a thin line during the acute phase of the stroke unit when the patient is threatened by both recurrent CS and a hemorrhagic stroke. It is often adapted to renal function—usually glomerular filtration rate (GFR)—to prevent both under- and overdosing. This study investigates the hypothetical risk of incorrect NOAC dosage after acute stroke when relying on plasma creatinine alone in comparison to a more exact renal function assessment including urine collection.

Methods

In a cohort study on consecutive 481 patients treated in a stroke unit with acute stroke and AF, the GFR estimated from plasma creatinine (eGFR) was compared to concurrent creatinine clearance measurement (CrCl) from urine collection regarding the hypothetically derived NOAC dosage.

Results

The risk of incorrect dosage (mean, 95% confidence interval) was 6.9% (4.8–9.5), 26% (23–31), 38% (33–42), and 20% (16–23) for apixaban, dabigatran, edoxaban, and rivaroxaban, respectively. The overall risk for incorrect dosage of any NOAC was 23% (21–25). Thresholds for age and admission eGFR were optimized to achieve an overall risk below 5% by additional CrCl measurements in selected patients (apixaban <36 ml/min and any age, dabigatran <75 ml/min and >70 y, edoxaban >36 ml/min and >58 y, rivaroxaban <76 ml/min and >75 y, any NOAC <81 ml/min and >54 y). The resulting portion of patients requiring an additional CrCl measurement was 10, 60, 80, 55, and 65% for apixaban, dabigatran, edoxaban, rivaroxaban, and any NOAC, respectively.

Conclusions

There is a considerable risk of incorrect NOAC dosage in patients with acute CS treated in a stroke unit that can be lowered by targeted CrCl measurements in selected patients.

Endovascular thrombectomy for acute ischemic stroke in elderly patients with atrial fibrillation

Background

To assess the clinical outcomes after endovascular thrombectomy (EVT) in elderly large vessel occlusion (LVO)-related acute ischemic stroke (AIS) patients with atrial fibrillation (AF).

Methods

Between January 2019 and December 2020, consecutive AF patients who received EVT due to anterior-circulation stroke were enrolled. The primary outcome was modified Rankin scale (mRS) score at 90 days. Secondary outcomes included all-cause mortality, the recanalization status after EVT (assessed using modified thrombolysis in cerebral infarction scale, mTICI) and any intracranial hemorrhage (ICH). A multivariate logistic regression model was performed to identify predictors of the functional outcome.

Results

A total of 148 eligible patients were finally enrolled. Among them, 42 were ≥ 80 years old. Compared to their younger counterparts, patients aged ≥80 years had lower likelihood of good functional outcome (mRS score 0–2) at 90 days (26.2% vs. 48.1%, P = 0.015), less satisfied recanalization (mTICI, 2b-3) (78.6% vs. 94.3%, P = 0.004) and higher all-cause mortality rate (35.7% vs. 14.2%, P = 0.003). A multivariable logistic regression analysis showed that age ≥ 80 years at baseline were the significant predictors for a poor functional outcome (OR: 3.72, 95% CI: 1.17–11.89, p = 0.027). Intravenous thrombolysis (IVT) prior to EVT and longer time intervals from onset of symptoms to EVT tended to be associated with poor functional outcome in patients ≥80 years old.

Conclusions

Age ≥ 80 years was a significant predictor of unfavorable outcomes after EVT for AIS patients with AF. An increased risk of adverse events must be balanced against the benefit from EVT in elderly patients with AF.

Mendelian randomization study on atrial fibrillation and cardiovascular disease subtypes

Atrial fibrillation (AF) has been associated with numerous diseases. However, whether AF is a cause or consequence of these diseases is uncertain. To clarify, we assessed the causal role of AF on ischemic heart disease (IHD), stroke, other cardiovascular disease (CVD) subtypes, type 2 diabetes mellitus (T2DM), and late-onset AD using bi-directional two-sample Mendelian randomization (MR) among people primarily of European descent. Genetically predicted log odds of AF was associated with any stroke (odds ratio (OR) 1.22, 95% CI 1.18 to 1.27), particularly cardioembolic stroke and possibly subdural hemorrhage, with sensitivity analyses showing similar positive findings. Genetically predicted AF was also associated with arterial thromboembolism (1.32, 1.13 to 1.53), and heart failure (1.26, 1.21 to 1.30). No association of genetically predicted AF with IHD, T2DM, cognitive function, or late-onset AD was found. Conversely, genetically predicted IHD, heart failure and possibly ischemic stroke, particularly cardioembolic stroke, were positively associated with AF. Atrial fibrillation plays a role in any stroke, arterial thromboembolism, and heart failure, corroborating current clinical guidelines on the importance of preventing these complications by effective AF management. In addition, patients with IHD, heart failure or possibly ischemic stroke might be predisposed to developing AF, with implications for management.

Significance of CHA2DS2-VASC on the severity and hemorrhagic transformation in patients with non-valvular atrial fibrillation-induced acute ischemic stroke

Atrial fibrillation causes a fivefold increase of stroke risk. CHA₂DS₂-VAS_C is widely used to evaluate the risk of cardiac embolism in patients with non-valvular atrial fibrillation (NVAF) and identify the patients eligible for anticoagulation therapy. This study aimed to identify the significance of CHA₂DS₂-VAS_C score on the severity and hemorrhagic transformation (HT) in patients with NVAF-induced acute ischemic stroke (NVAF-AIS). Total 113 patients diagnosed as NVAF-AIS were included in this study. Patients were categorized into severe stroke group (NIHSS > 10) and non-severe group (NIHSS ≤ 10), and the risk factors for severe stroke were investigated. Based on the results of repeated brain CT/MRI examination performed within 14 days from stroke onset or immediately in case of clinical worsening, patients were divided into HT group and non-HT group, and the predictors for HT were then analyzed. CHA₂DS₂-VAS_C score [median (interquartile range) 5 (3-5) vs. 3 (2-4); p = 0.002] in severe stroke group was significantly higher than that in non-severe group. The severe stroke group showed significantly increased prevalence of heart failure (20% vs. 48.5%, p = 0.002) and decreased hemoglobin (136.4 ± 18.0 vs.143.6 ± 15.6 g/L, p = 0.031) compared with non-severe group. Multivariate regression analysis revealed that CHA₂DS₂-VASc score was a powerful predictor for the severity of NVAF-AIS. Forty-seven of total recruited patients (43.2%) developed HT within 14 days after the onset of NVAF-AIS. CHA₂DS₂-VASc score as well as elevated glycated hemoglobin and intravenous rt-PA were the independent risk factors of HT. CHA₂DS₂-VAS_C score was closely associated with the severity of NVAF-AIS. Patients with higher CHA₂DS₂-VAS_C score were more likely to develop HT after NVAF-AIS.

N-Terminal Pro B-Type Natriuretic Peptide's Usefulness for Paroxysmal Atrial Fibrillation Detection Among Populations Carrying Cardiovascular Risk Factors

Background: Atrial fibrillation (AF) systematic screening studies have not shown a clear usefulness in stroke prevention, as AF might present as paroxysmal and asymptomatic. This study aims to determine the usefulness of some blood-biomarkers to identify paroxysmal atrial fibrillation in the context of a screening programme. Methods: A total of 100 subjects aged 65-75 years with hypertension and diabetes were randomly selected. AF was assessed by conventional electrocardiogram (ECG) and 4 weeks monitoring with a wearable Holter device (Nuubo™). N-terminal pro B-type natriuretic peptide (NT-proBNP), apolipoprotein CIII (ApoC-III), von Willebrand factor (vWF), ADAMTS13, urokinase plasminogen activator surface receptor (uPAR), and urokinase plasminogen activator (uPA) were determined in serum/plasma samples and the levels were compared depending on AF presence and mode of detection. Results: The AF prevalence in the studied population was found to be 20%. In seven subjects, AF was only detected after 1 month of Holter monitoring (hAF group). NT-proBNP levels were higher in subjects with AF compared with subjects with no AF (p < 0.0001), even when only taking into account the hAF group (p = 0.031). No significant differences were found in the other biomarkers. The NT-proBNP >95 pg/ml cut-off showed high sensitivity and specificity to detect AF (95%, 66.2%) or hAF (85.72%, 66.2%) and was found to be an independent predictor of AF and hAF in a logistic regression analysis. NT-proBNP correlated with AF burden (r = 0.597, p = 0.024). Conclusion: NT-proBNP was elevated in AF cases not identified by ECG; thus, it may be used as a screening biomarker in asymptomatic high-risk populations, with a promising cut-off point of 95 pg/ml that requires further validation.

Cardioembolic Ischemic Stroke Gene Expression Fingerprint in Blood: a Systematic Review and Verification Analysis

An accurate etiological classification is key to optimize secondary prevention after ischemic stroke, but the cause remains undetermined in one third of patients. Several studies pointed out the usefulness of circulating gene expression markers to discriminate cardioembolic (CE) strokes, mainly due to atrial fibrillation (AF), while only exploring them in small cohorts. A systematic review of studies analyzing high-throughput gene expression in blood samples to discriminate CE strokes was performed. Significantly dysregulated genes were considered as candidates, and a selection of them was validated by RT-qPCR in 100 patients with defined CE or atherothrombotic (LAA) stroke etiology. Longitudinal performance was evaluated in 12 patients at three time points. Their usefulness as biomarkers for AF was tested in 120 cryptogenic strokes and 100 individuals at high-risk for stroke. Three published studies plus three unpublished datasets were considered for candidate selection. Sixty-seven genes were found dysregulated in CE strokes. CREM, PELI1, and ZAK were verified to be up-regulated in CE vs LAA (p = 0.010, p = 0.003, p < 0.001, respectively), without changes in their expression within the first 24 h after stroke onset. The combined up-regulation of these three biomarkers increased the probability of suffering from CE stroke by 23-fold. In cryptogenic strokes with subsequent AF detection, PELI1 and CREM showed overexpression (p = 0.017, p = 0.059, respectively), whereas in high-risk asymptomatic populations, all three genes showed potential to detect AF (p = 0.007, p = 0.007, p = 0.015). The proved discriminatory capacity of these gene expression markers to detect cardioembolism even in cryptogenic strokes and asymptomatic high-risk populations might bring up their use as biomarkers.

Treatment With Intravenous Alteplase for Acute Ischemic Stroke After Reversal of Dabigatran With Idarucizumab: A Case Study

Treatment options for anticoagulated patients presenting with ischemic stroke are limited. Off-label use of idarucizumab to rapidly reverse the anticoagulant effect of dabigatran may ensure eligibility for thrombolytic therapy with alteplase. This case describes a 77-year-old white male who presented to the hospital 89 minutes after sudden onset of right-sided hemiparesis, dysarthria, and facial palsy. Significant history included atrial fibrillation and previous right-sided cortical stroke. Medication reconciliation revealed he was taking dabigatran 150 mg twice a day, with the last dose being 179 minutes before presentation. Neuroimaging revealed no new infarct or hemorrhage, and 60 minutes after arrival, a decision was made to give idarucizumab to reverse the anticoagulant effect of dabigatran. In the absence of any contraindication, he was then treated with intravenous alteplase and idarucizumab. No adverse outcomes were noted, and at discharge, his new stroke symptoms were completely resolved.

Cardioembolic Stroke: A Case Study

Cardioembolic stroke is a critical health condition that requires immediate intervention. Cardiac emboli are the most common type of embolism and account for 14% to 30% of all ischemic strokes. Atrial fibrillation is the most common cause of cardioembolic strokes, and its prevalence increases substantially with age. Other factors that increase the risk for cardioembolic stroke include hypertension, diabetes mellitus, hyperlipidemia, cardiac disease, and lifestyle choices. General supportive care and treatment of the acute phase and subsequent complications should be started immediately. Nurses must play an active role in screening patients for stroke subtypes, using appropriate diagnostic tools, and providing medical and nursing interventions. Nurses also play a crucial role in prevention by providing education to patients and patients' families on how to recognize stroke signs and symptoms. This case study discusses the course of illness, treatment, and prevention strategies for patients who have suffered cardioembolic stroke due to atrial fibrillation.

Clinical outcome of cardioembolic stroke treated by intravenous thrombolysis

INTRODUCTION

Cardioembolic stroke (CS) in patients without thrombolytic treatment is associated with a worse clinical outcome and higher mortality compared to other types of stroke. The aim of this study was to determine the clinical outcome of CS in patients treated by intravenous thrombolysis (IVT).

MATERIAL AND METHODOLOGY

Data of patients from the SITS-EAST register (Safe Implementation of Treatments in Stroke) were analyzed in patients who received IVT treatment from 2000 to April 2014. The effect of the stroke etiology according to ICD-10 classification on outcome was analyzed using a univariate and multivariate analysis. The outcomes were assessed as follows: excellent clinical outcome (modified Rankin scale (mRS) 0-1) at 3 months, the rate of symptomatic intracranial hemorrhage (sICH), mortality, and improvement at 24 hours after IVT.

RESULTS

Data of 13 772 patients were analyzed. CS represented 30% of all strokes. The mean age of patients with CS, atherothrombotic stroke, lacunar stroke, and other stroke was 70.8, 66.7, 66.2, and 63.3 years, respectively (P < .001). Severity of stroke on admission by median NIHSS score was 13 points in patients with CS, 12 points - in atherothrombotic stroke, 7 points - in lacunar stroke, and 10 points-in other stroke types (P < .001). No difference in mortality was detected among atherothrombotic and CS; however, atherothrombotic strokes had higher odds of sICH [OR = 1.63 (95% CI: 1.07-2.47), P = .023], lower odds of early improvement [OR = 0.79 (95% CI: 0.72-0.86), P < .001], and excellent clinical outcome [OR = 0.77 (95% CI: 0.67-0.87), P < .001] compared with CS.

CONCLUSIONS

Cardioembolic strokes are not associated with increased mortality. Patients with CS are less likely to have sICH and have better outcome after IVT.

A new algorithm for suspected stroke patient management with NT-proBNP POCT platform in the emergency department: A new algorithm for suspected stroke patient

Introduction:

Stroke is a leading cause of mortality and morbidity in China. Of the different subtypes of ischemic stroke, cardioembolic stroke is of particular importance because it is potentially preventable. This study aimed to evaluate the usefulness of measuring N-terminal pro-brain natriuretic peptide in the emergency department in early recognition of patients with cardioembolic stroke.

Methods:

This was a multicenter prospective cohort study conducted from 1 June 2015 to 30 June 2016 in four emergency departments. Adult patients with acute ischemic stroke were recruited. Plasma N-terminal pro-brain natriuretic peptide was measured in the emergency department. Discharge diagnosis was determined by neurologists according to the Trial of ORG 10172 in Acute Stroke Treatment criteria. The diagnostic performance of N-terminal pro-brain natriuretic peptide was assessed by measuring the sensitivity, specificity, receiver operating characteristic curve, and the area under curve.

Results:

In all, 258 patients were analyzed. Of them, 17.9% were diagnosed with cardioembolic stroke. The optimal cut-off concentration, sensitivity, specificity, and the area under the curve of the plasma N-terminal pro-brain natriuretic peptide concentration suitable to distinguish cardioembolic stroke from other subtypes of stroke were 501.2 pg/mL, 82.6%, 80.2%, and 0.87 (95% confidence interval: 0.83–0.92), respectively.

Conclusion:

Emergency physicians should strongly consider cardioembolic stroke in patients presented with acute ischemic stroke with an N-terminal pro-brain natriuretic peptide level over 501.2 pg/mL. However, it must be considered in context with clinical assessment and judgment before making treatment decisions.

Cardioembolic Stroke

PURPOSE OF REVIEW

Cardioembolic stroke is common and disproportionately more disabling than nonembolic mechanisms of stroke. Its incidence is expected to rise because of the age-related incidence of atrial fibrillation and an aging population. This article summarizes the different causes of cardioembolism and outlines current management guidelines.

RECENT FINDINGS

Since cardioembolic stroke is not a single disease entity, its diagnosis requires initial clinical suspicion and a comprehensive evaluation, including ECG, echocardiography, brain imaging, and cardiac monitoring. Atrial fibrillation is the most common cause of cardioembolic stroke, and anticoagulation is usually recommended. This article reviews risk stratification models to assist in the decision-making process and highlights the increased use of novel oral anticoagulants for stroke prevention in atrial fibrillation. New data support the importance of prolonged cardiac monitoring for diagnosing occult atrial fibrillation. Current data on other mechanisms of cardioembolic stroke, such as prosthetic heart valves and aortic arch atherosclerosis, are also presented, and the available evidence regarding patent foramen ovale closure in cryptogenic stroke is summarized.

SUMMARY

Cardioembolism is an important cause of ischemic stroke, with diverse underlying mechanisms requiring a tailored approach to diagnosis, management, and prevention.

Personalized Analysis by Validation of Monte Carlo for Application of Pathways in Cardioembolic Stroke

BACKGROUND Cardioembolic stroke (CES), which causes 20% cause of all ischemic strokes, is associated with high mortality. Previous studies suggest that pathways play a critical role in the identification and pathogenesis of diseases. We aimed to develop an integrated approach that is able to construct individual networks of pathway cross-talk to quantify differences between patients with CES and controls. MATERIAL AND METHODS One biological data set E-GEOD-58294 was used, including 23 normal controls and 59 CES samples. We used individualized pathway aberrance score (iPAS) to assess pathway statistics of 589 Ingenuity Pathways Analysis (IPA) pathways. Random Forest (RF) classification was implemented to calculate the AUC of every network. These procedures were tested by Monte Carlo Cross-Validation for 50 bootstraps. RESULTS A total of 28 networks with AUC >0.9 were found between CES and controls. Among them, 3 networks with AUC=1.0 had the best performance for classification in 50 bootstraps. The 3 pathway networks were able to significantly identify CES versus controls, which showed as biomarkers in the regulation and development of CES. CONCLUSIONS This novel approach could identify 3 networks able to accurately classify CES and normal samples in individuals. This integrated application needs to be validated in other diseases.

Secondary prevention of cardiogenic arterial thromboembolism in the cat: The double-blind, randomized, positive-controlled feline arterial thromboembolism; clopidogrel vs. aspirin trial (FAT CAT)

OBJECTIVES

To determine if clopidogrel administration is associated with a reduced likelihood of recurrent cardiogenic arterial thromboembolism (CATE) in cats compared to aspirin administration. Secondary aims were to determine if clopidogrel administration had an effect on the composite endpoint of recurrent CATE and cardiac death and to identify adverse effects of chronic clopidogrel or aspirin therapy.

ANIMALS

Seventy-five cats that survived a CATE event.

METHODS

Multicenter, double-blind, randomized, positive-controlled study. Cats were assigned to clopidogrel (18.75 mg/cat PO q 24 h) or aspirin (81 mg/cat PO q 72 h). Kaplan-Meier survival curves were created for each endpoint and the log rank test performed to compare treatment groups with respect to time to event and the likelihood of the event occurring.

RESULTS

The mean age of all cats was 8.0 ± 3.5 yr and 57/75 (76%) were male (p < 0.001); 62/75 (83%) were mixed breed with the remainder including Persian, Abyssinian, American Shorthair, Bengal, Birman, Himalayan, Maine Coon, Ragdoll, Snowshoe, and Sphynx breeds. Only 15% (11/75) of cats had a history of heart disease recorded prior to the CATE event. Clopidogrel administration was associated with significantly reduced likelihood of recurrent CATE compared to aspirin (p = 0.024) and had a longer median time to recurrence [443 (95% CI 185-990) days vs. 192 (95% CI 62-364) days, respectively]. Clopidogrel was also associated with a significantly reduced likelihood of the composite endpoint of recurrent CATE or cardiac death (p = 0.033) with a longer median time to event [346 (95% CI 146-495) days vs. 128 (95% CI 58-243) days].

CONCLUSIONS

Clopidogrel administration significantly reduces the likelihood of recurrent CATE compared with aspirin in cats; both drugs were well tolerated.

Resuming anticoagulant therapy after intracerebral bleeding

The clinical benefit of resuming anticoagulant treatment after an anticoagulants-associated intracranial hemorrhage (ICH) is debated. No randomized trial has been conducted on this particular clinical issue. The risk of ICH recurrence from resuming anticoagulant therapy is expected to be higher after index lobar than deep ICH and in patients with not amendable risk factors for ICH. Retrospective studies have recently shown improved survival with resumption of treatment after index anticoagulants-associated ICH. Based on these evidences and on the risk for thromboembolic events without anticoagulant treatment, resumption of anticoagulation should be considered in all patients with mechanical heart valve prosthesis and in those with amendable risk factors for anticoagulants-associated ICH. Resumption with direct oral anticoagulants appears a reasonable option for non-valvular atrial fibrillation (NVAF) patients at moderate to high thromboembolic risk after deep ICH and for selected NVAF patients at high thromboembolic risk after lobar ICH. For VTE patients at high risk for recurrence, resumption of anticoagulation or insertion of vena cava filter should be tailored on the estimated risk for ICH recurrence.

Physician's fear of anticoagulant therapy in nonvalvular atrial fibrillation

Despite the availability of predictive tools and treatment guidelines, anticoagulant therapies are underprescribed and many patients are undertreated for conditions that predispose to thromboembolic complications, including stroke. This review explores reasons for which physicians fear that the risks of anticoagulation may be greater than the potential benefit. The results of numerous clinical trials confirm that patients benefit from judiciously managed anticoagulation and that physicians can take various approaches to minimize risk. Use of stratification scores for patient selection and accurate estimation of stroke risk may improve outcomes; bleeding risk is less important than stroke risk. Adoption of newer anticoagulants with simpler regimens may help physicians allay their fears of anticoagulant use in patients with atrial fibrillation. These fears, although not groundless, should not overtake caution and hinder the delivery of appropriate evidence-based care.

Intra-aortic balloon pump (IABP) counterpulsation improves cerebral perfusion in patients with decreased left ventricular function

Background:

The current goal of treatment after acute ischemic stroke is the increase of cerebral blood flow (CBF) in ischemic brain tissue. Intra-aortic balloon pump (IABP) counterpulsation in the setting of cardiogenic shock is able to reduce left ventricular afterload and increase coronary blood flow. The effects of an IABP on CBF have not been sufficiently examined. We hypothesize that the use of an IABP especially enhances cerebral blood flow in patients with pre-existing heart failure.

Methods:

In this pilot study, 36 subjects were examined to investigate the effect of an IABP on middle cerebral artery (MCA) transcranial Doppler (TCD) flow velocity change and relative CBF augmentation by determining velocity time integral changes (ΔVTI) in a constant caliber of the MCA compared to a baseline measurement without an IABP. Subjects were divided into two groups according to their left ventricular ejection fraction (LVEF): Group 1 LVEF >30% and Group 2 LVEF ≤30%.

Results:

Both groups showed an increase in CBF using an IABP. Patients with a LVEF ≤30% showed a significantly higher increase of ΔVTI in the MCA under IABP augmentation compared to patients with a LVEF >30% (20.9% ± 3.9% Group 2 vs.10.5% ± 2.2% Group 1, p<0,05). The mean arterial pressure (MAP) increased only marginally in both groups under IABP augmentation.

Conclusions:

IABP improves cerebral blood flow, particularly in patients with pre-existing heart failure and highly impaired LVEF. Hence, an IABP might be a treatment option to improve cerebral perfusion in selected patients with cerebral misperfusion and simultaneously existing severe heart failure.

A cardiac cause for deafness

We describe a case of a 49-year-old diabetic man with a history of myocardial infarction, presenting with deafness for 2 weeks. Initial assessment by otorhinolaryngologists was suggestive of sensorineural hearing loss. Subsequently, the cardiac evaluation showed an apical clot in the left ventricle. Careful neurological reassessment and a cranial MRI yielded a diagnosis of cortical deafness with auditory agnosia secondary to bilateral temporal infarcts. Doppler and MRI ruled out carotid artery thrombosis. The temporal infarcts were therefore considered to be cardioembolic in origin. Cardioembolic stroke is an important differential diagnosis for patients presenting with neurological symptoms on a background of cardiac disease.