Microbleeds and the Effect of Anticoagulation in Patients With Embolic Stroke of Undetermined Source: An Exploratory Analysis of the NAVIGATE ESUS Randomized Clinical Trial

Cerebrovascular Involvement in Transthyretin Amyloid Cardiomyopathy

Background: Intracardiac thrombosis is common in transthyretin amyloid cardiomyopathy (ATTR-CM), and patients are at risk for thromboembolic events. However, silent cerebral infarcts and the extent of cerebral small vessel disease in patients with cardiac amyloidosis are unknown. Methods: Thirty-two consecutively selected ATTR-CM patients were prospectively studied by cerebral magnetic resonance imaging (cMRI) and compared with 43 CHA2DS2-VASc-matched controls (Co). Structural clinical standard cMRI sequences and features of cerebral vessel involvement were included and quantified by two board certified neuroradiologists in consensus blinded to clinical status. Group differences were estimated using generalized (logistic) linear regression models adjusting for vascular risk factors based on the CHA2DS2-VASc score. Results: The median CHA2DS2-VASc score was 4 for ATTR-CM and Co (p = 0.905). There were no differences between groups in the frequency of current or former smokers (p = 0.755), body-mass-index > 30 (p = 0.106), and hyperlipidemia (p = 0.869). The number of territorial infarcts (4 vs. 0, p = 0.018) was higher in ATTR-CM compared to Co, as was the mean number of cerebral microbleeds (1.4 vs. 0.3, p ≤ 0.001) and the number of Virchow-Robin spaces (43.8 vs. 20.6, p ≤ 0.001). Lacunar lesion presence was higher in ATTR-CM (6 vs. 2, p = 0.054). CHA2DS2-VASc score, atrial fibrillation, anticoagulation, and the interaction term of CHA2DS2-VASc score and atrial fibrillation did not affect the probability of a territorial ischemic lesion or lacunar lesion in logistic regression modeling. Conclusions: In patients with ATTR-CM free from clinically apparent neurological symptoms, cMRI revealed unreported significant small cerebral vessel disease and territorial ischemia. Our findings may support low thresholds for anticoagulation and cMRI in patients with ATTR-CM.

Cerebral microbleeds and asundexian in non-cardioembolic ischemic stroke: Secondary analyses of the PACIFIC-STROKE randomized trial

BACKGROUND AND AIMS

Cerebral microbleeds are magnetic imaging resonance (MRI) markers of hemorrhage-prone cerebral small vessel disease that predict future risk of ischemic stroke and intracranial hemorrhage (ICrH). There exist concerns about the net benefit of antithrombotic therapy in patients with microbleeds. We aimed to investigate the effects of an oral factor-XIa inhibitor (asundexian), that is hypothesized to inhibit thrombosis without compromising hemostasis, on the development of new microbleeds over time and interactions between microbleeds and asundexian treatment on clinical outcomes. We additionally assessed associations between baseline microbleeds and the risks of clinical and neuroimaging outcomes in patients with non-cardioembolic ischemic stroke.

METHODS

This is a secondary analysis of the PACIFIC-STROKE, international, multi-center Phase 2b double-blind, randomized clinical trial. PACIFIC-STROKE enrolled patients aged ⩾ 45 years with mild-to-moderate non-cardioembolic ischemic stroke who presented within 48 h of symptom onset for whom antiplatelet therapy was intended. Microbleeds were centrally adjudicated, and participants with an interpretable T2*-weighted sequence at their baseline MRI were included in this analysis. Patients were randomized to asundexian (10/20/50 mg daily) versus placebo plus standard antiplatelet treatment. Regression models were used to estimate the effects of (1) all pooled asundexian doses and (2) asundexian 50 mg daily on new microbleed formation on 26-week MRIs. Cox proportional hazards or regression models were additionally used to estimate interactions between treatment assignment and microbleeds for ischemic stroke/transient ischemic attack (TIA) (primary outcome), and ICrH, all-cause mortality, hemorrhagic transformation (HT), and new microbleeds (secondary outcomes).

RESULTS

Of 1746 participants (mean age, 67.0 ± 10.0; 34% female) with baseline MRIs, 604 (35%) had microbleeds. During a median follow-up of 10.6 months, 7.0% (n = 122) had ischemic stroke/TIA, 0.5% (n = 8) ICrH, and 2.1% (n = 37) died. New microbleeds developed in 10.3% (n = 155) of participants with adequate follow-up MRIs and HT in 31.4% (n = 345). In the total sample of patients with adequate baseline and 26-week follow-up MRIs (n = 1507), new microbleeds occurred in 10.2% of patients assigned to any asundexian dose and 10.5% of patients assigned to placebo (OR, 0.96; 95% CI, 0.66-1.41). There were no interactions between microbleeds and treatment assignment for any of the outcomes (p for interaction > 0.05). The rates of new microbleeds, HT, and ICrH were numerically less in patients with microbleeds assigned to asundexian relative to placebo. The presence of microbleeds was associated with a higher risk of HT (aOR, 1.6; 95% CI, 1.2-2.1) and new microbleeds (aOR, 4.4; 95% CI, 3.0-6.3).

CONCLUSION

Factor XIa inhibition with asundexian appears safe in patients with non-cardioembolic ischemic stroke and hemorrhage-prone cerebral small vessel disease marked by microbleeds on MRI. These preliminary findings will be confirmed in the ongoing OCEANIC-STROKE randomized trial.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04304508.

Brain MRI microbleeds and risk of intracranial hemorrhage in atrial fibrillation patients: A Swedish case-control study

OBJECTIVES

Our goal was to quantify the independent association of brain microbleeds with future intracranial hemorrhage (ICrH). Microbleed findings on brain magnetic resonance imaging (MRI) may identify distinctive risk factors for ICrH which could inform the anticoagulant therapy decision for atrial fibrillation (AF) patients. Our study design includes patients with MRIs for numerous reasons, not limited to evaluation of stroke.

MATERIALS AND METHODS

The source population was all patients with AF from a nationwide Swedish health care register. Case patients had an ICrH between 2006 and 2013 and ≥1 brain MRI for an unrelated condition before the ICrH. Each case was matched to four controls who had a brain MRI without a subsequent ICrH. The MRIs were re-reviewed by neuroradiologists. Associations between MRI findings and subsequent ICrH were assessed using logistic regression, adjusting for comorbidities and antithrombotic medications.

RESULTS

A total of 78 cases and 312 matched controls were identified; 29 cases and 79 controls had MRI sequences suitable for analysis of microbleeds. Patients with ≥10 microbleeds had a markedly increased risk of ICrH (adjusted odds ratio 14.56; 95 % confidence interval: 2.86-74.16, p < 0.001). All patients with ≥10 microbleeds had microbleeds in the lobar region and ≥10 lobar microbleeds was associated with intracerebral hemorrhages, univariable OR 8.54 (2.01-36.33), p = 0.004.

CONCLUSIONS

Leveraging a nationwide database with brain imaging obtained prior to ICrH, we identified a strong association between ≥10 microbleeds on brain MRI and subsequent ICrH among AF patients. Lobar brain regions were involved whenever there were ≥10 microbleeds. Brain MRIs may help optimize the anticoagulation decision in selected AF patients.

Risk of intracranial hemorrhage in patients using anticoagulant therapy for atrial fibrillation after cerebral microbleeds combined with acute ischemic stroke: a meta-analysis

Objective

To evaluate intracerebral hemorrhage (ICH) risk in patients with ischemic stroke (IS) and cerebral microbleeds (CMBs) undergoing anticoagulation therapy for non-valvular atrial fibrillation (AF).

Methods

We conducted a comprehensive search across multiple databases, including Embase, PubMed, Cochrane, UpToDate, Scopus, WOS, and SinoMed. The search covered observational literature published from each database inception until February 1, 2023. We analyzed the prevalence of CMBs during the follow-up period, compared future ICH risk between patients with and without baseline CMBs (CMBs presence/absence, ≧5 CMBs), and examined factors influencing ICH occurrence in patients with CMBs. Also studied recurrent stroke during anticoagulation therapy, the risk of future ICH when white matter hyperintensity (WMH) and CMBs coexist, and the effects of anticoagulants vitamin K antagonists (VKAs) and direct oral anticoagulants (DOACs) on future ICH.

Results

We included 7 articles involving 5,134 participants. The incidence of CMBs was 24%; baseline CMBs were associated with an increased ICH risk compared to patients without CMBs. ICH-risk was more significant in patients with baseline ≥5 CMBs. After anticoagulant therapy, ICH risk was higher than that of recurrent IS. The risk of future ICH was significantly increased with anticoagulant VKAs compared with NOAC.

Conclusion

Anticoagulant therapy for ischemic stroke patients with non-valvular AF and CMBs increases future ICH risk. Discontinuing anticoagulation due to ICH risk should be avoided. NOACs are safe and effective for patients with CMBs and IS.

Acute cerebral microbleeds detected on high resolution head CT presenting with transient neurologic events

Introduction

Cerebral microbleeds (CMBs) are deposits of hemosiderin-laden macrophages that can be visualized on T2-weighted MRI sequences as small, ovoid areas of signal void. These markers represent hemorrhagic cerebral small vessel disease and are usually subclinical and asymptomatic. In these cases, we present two patients who presented with symptomatic, acute CMBs.

Case description

Case 1 involves a 70-year-old male with history of diabetes, hypertension, hyperlipidemia, and obstructive sleep apnea. Five days prior to presentation, this patient reported a transient period of left upper extremity weakness. CT was performed and demonstrated a lesion on CT imaging consistent with an acute CMB in the R centrum semiovale.Case 2 describes an 82-year-old female with history of hypertension, remote large ischemic stroke, and post-stroke epilepsy. Patient described an episode of prolonged left sided shaking consistent with prior seizures despite her consistently taking anti-epileptic drugs. On CT, a small hyperdensity was seen in the R thalamus/internal capsule region consistent with acute CMB.

Discussion

These two examples demonstrate acute CMBs causing patients to demonstrate symptoms mirroring those of a TIA and experience breakthrough seizures. A TIA would normally be an indication for antiplatelet therapy. Though prior reasoning warns against anticoagulation in patients with CMBs, recent works including the SPS3 (Shoamanesh et al., 2017) and WAKE-UP (Schlemm et al., 2022) trials both showed that the presence of CMB did not significantly affect outcomes after initiating antiplatelet therapy. One should adopt a more personalized approach when deciding the therapeutic intervention of choice in patients with prior CMB.

Histopathological Correlates of Lobar Microbleeds in False-Positive Cerebral Amyloid Angiopathy Cases

OBJECTIVE

A definite diagnosis of cerebral amyloid angiopathy (CAA), characterized by the accumulation of amyloid β in walls of cerebral small vessels, can only be obtained through pathological examination. A diagnosis of probable CAA during life relies on the presence of hemorrhagic markers, including lobar cerebral microbleeds (CMBs). The aim of this project was to study the histopathological correlates of lobar CMBs in false-positive CAA cases.

METHODS

In 3 patients who met criteria for probable CAA during life, but showed no CAA upon neuropathological examination, lobar CMBs were counted on ex vivo 3T magnetic resonance imaging (MRI) and on ex vivo 7T MRI. Areas with lobar CMBs were next sampled and cut into serial sections, on which the CMBs were then identified.

RESULTS

Collectively, there were 25 lobar CMBs on in vivo MRI and 22 on ex vivo 3T MRI of the analyzed hemispheres. On ex vivo MRI, we targeted 12 CMBs for sampling, and definite histopathological correlates were retrieved for 9 of them, of which 7 were true CMBs. No CAA was found on any of the serial sections. The "culprit vessels" associated with the true CMBs instead showed moderate to severe arteriolosclerosis. Furthermore, CMBs in false-positive CAA cases tended to be located more often in the juxtacortical or subcortical white matter than in the cortical ribbon.

INTERPRETATION

These findings suggest that arteriolosclerosis can generate lobar CMBs and that more detailed investigations into the exact localization of CMBs with respect to the cortical ribbon could potentially aid the diagnosis of CAA during life. ANN NEUROL 2023;94:856-870.

Interatrial Block Association With Adverse Cardiovascular Outcomes in Patients Without a History of Atrial Fibrillation

BACKGROUND

Interatrial block (IAB) is associated with thromboembolism and atrial arrhythmias. However, prior studies included small patient cohorts so it remains unclear whether IAB predicts adverse outcomes particularly in context of atrial fibrillation (AF)/atrial flutter (AFL).

OBJECTIVES

This study sought to determine whether IAB portends increased stroke risk in a large cohort in the presence or absence of AFAF/AFL.

METHODS

We performed a 5-center retrospective analysis of 4,837,989 electrocardiograms (ECGs) from 1,228,291 patients. IAB was defined as P-wave duration ≥120 ms in leads II, III, or aVF. Measurements were extracted as .XML files. After excluding patients with prior AF/AFL, 1,825,958 ECGs from 458,994 patients remained. Outcomes were analyzed using restricted mean survival time analysis and restricted mean time lost.

RESULTS

There were 86,317 patients with IAB and 355,032 patients without IAB. IAB prevalence in the cohort was 19.6% and was most common in Black (26.1%), White (20.9%), and Hispanic (18.5%) patients and least prevalent in Native Americans (9.2%). IAB was independently associated with increased stroke probability (restricted mean time lost ratio coefficient [RMTLRC]: 1.43; 95% CI: 1.35-1.51; tau = 1,895), mortality (RMTLRC: 1.14; 95% CI: 1.07-1.21; tau = 1,924), heart failure (RMTLRC: 1.94; 95% CI: 1.83-2.04; tau = 1,921), systemic thromboembolism (RMTLRC: 1.62; 95% CI: 1.53-1.71; tau = 1,897), and incident AF/AFL (RMTLRC: 1.16; 95% CI: 1.10-1.22; tau = 1,888). IAB was not associated with stroke in patients with pre-existing AF/AFL.

CONCLUSIONS

IAB is independently associated with stroke in patients with no history of AF/AFL even after adjustment for incident AF/AFL and CHA2DS2-VASc score. Patients are at increased risk of stroke even when AF/AFL is not identified.

Impact of Cerebral Microbleeds in Stroke Patients with Atrial Fibrillation

OBJECTIVES

Cerebral microbleeds are associated with the risks of ischemic stroke and intracranial hemorrhage, causing clinical dilemmas for antithrombotic treatment decisions. We aimed to evaluate the risks of intracranial hemorrhage and ischemic stroke associated with microbleeds in patients with atrial fibrillation treated with vitamin K antagonists, direct oral anticoagulants, antiplatelets, and combination therapy (i.e. concurrent oral anticoagulant and antiplatelet).

METHODS

We included patients with documented atrial fibrillation from the pooled individual patient data analysis by the Microbleeds International Collaborative Network. Risks of subsequent intracranial hemorrhage and ischemic stroke were compared between patients with and without microbleeds, stratified by antithrombotic use.

RESULTS

A total of 7,839 patients were included. The presence of microbleeds was associated with an increased relative risk of intracranial hemorrhage (adjusted hazard ratio [aHR] = 2.74, 95% confidence interval = 1.76-4.26) and ischemic stroke (aHR = 1.29, 95% confidence interval = 1.04-1.59). For the entire cohort, the absolute incidence of ischemic stroke was higher than intracranial hemorrhage regardless of microbleed burden. However, for the subgroup of patients taking combination of anticoagulant and antiplatelet therapy, the absolute risk of intracranial hemorrhage exceeded that of ischemic stroke in those with 2 to 4 microbleeds (25 vs 12 per 1,000 patient-years) and ≥ 11 microbleeds (94 vs 48 per 1,000 patient-years).

INTERPRETATION

Patients with atrial fibrillation and high burden of microbleeds receiving combination therapy have a tendency of higher rate of intracranial hemorrhage than ischemic stroke, with potential for net harm. Further studies are needed to help optimize stroke preventive strategies in this high-risk group. ANN NEUROL 2023;94:61-74.

Effect of antiplatelet therapy on the incidence, prognosis, and rebleeding of intracerebral hemorrhage

OBJECTIVE

Antiplatelet medications are increasingly being used for primary and secondary prevention of ischemic attacks owing to the increasing prevalence of ischemic stroke occurrences. Currently, many patients receive antiplatelet therapy (APT) to prevent thromboembolic events. However, long-term use of APT might also lead to an increased occurrence of intracerebral hemorrhage (ICH) and affect the prognosis of patients with ICH. Furthermore, some research suggest that restarting APT for patients who have previously experienced ICH may result in rebleeding events. The precise relationship between APT and ICH remains unknown.

METHODS

We searched PubMed for the most recent related literature and summarized the findings from various studies. The search terms included "antiplatelet," "intracerebral hemorrhage," "cerebral microbleeds," "hematoma expansion," "recurrent," and "reinitiate." Clinical studies involving human subjects were ultimately included and interpreted in this review, and animal studies were not discussed.

RESULTS

When individuals are administered APT, the risk of thrombotic events should be weighted against the risk of bleeding. In general, for some patients' concomitant with risk factors of thrombotic events, the advantages of antiplatelet medication may outweigh the inherent risk of rebleeding. However, the use of antiplatelet medications for other patients with a higher risk of bleeding should be carefully evaluated and closely monitored. In the future, a quantifiable system for assessing thrombotic risk and bleeding risk will be necessary. After evaluation, the appropriate time to restart APT for ICH patients should be determined to prevent underlying ischemic stroke events. According to the present study results and expert experience, most patients now restart APT at around 1 week following the onset of ICH. Nevertheless, the precise time to restart APT should be chosen on a case-by-case basis as per the patient's risk of embolic events and recurrent bleeding. More compelling evidence-based medicine evidence is needed in the future.

CONCLUSION

This review thoroughly discusses the relationship between APT and the development of ICH, the impact of APT on the course and prognosis of ICH patients, and the factors influencing the decision to restart APT after ICH. However, different studies' conclusions are inconsistent due to the differences in quality control. To support future clinical decisions, more large-scale randomized controlled trials are required.

A multicenter, prospective, randomized controlled trial of intracranial hemorrhage risk of intensive statin therapy in patients with acute ischemic stroke combined with cerebral microbleeds (CHRISTMAS): Study protocol

Background

Low serum levels of major lipid markers have been proved to be significantly associated with increased risks of hemorrhagic stroke (HS) and cerebral microbleeds (CMBs). However, there is no lipid modification guideline telling us how to maintain a balance between the prevention of ischemic stroke recurrence and the prevention of hemorrhagic events, especially in patients with acute ischemic stroke (AIS) and CMBs.

Aim

The Intracranial Hemorrhage Risk of Intensive Statin Therapy in Patients with Acute Ischemic Stroke combined with Cerebral Microbleeds (CHRISTMAS) trial evaluates the risk of intracranial hemorrhage (i.e., HS and CMBs) of high-dose statin therapy in patients with AIS combined with CMBs.

Methods and design

This is an investigator-initiated, multicenter, prospective, randomized controlled clinical trial design. Up to 344 eligible patients will be consecutively randomized to receive high-dose or low-dose atorvastatin in 1:1 ratio in 5 stroke centers in China.

Outcomes

CHRISTMAS trial has co-primary outcomes, namely, hemorrhage risk: the incidence of HS and the changes in degree of CMBs until the end of 36-month follow-up.

Discussion

The primary hypothesis of this study is that an excessive reduction in serum lipid levels by an intensive statin therapy in AIS patients with CMBs can increase the risk of intracranial hemorrhage. This study will shed light on new clinical decisions regarding the long-term serum lipid management in these patients with dilemma in clinical practice.

Clinical trial registration

Clinicaltrials.gov, identifier: NCT05589454.

Mechanisms and Clinical Manifestations of Cognitive Decline in Atrial Fibrillation Patients: Potential Implications for Preventing Dementia

Atrial fibrillation (AF) patients face an approximate 1.5-fold increased risk of cognitive decline compared with the general population. Among poststroke AF patients, the risk of cognitive decline is even higher with an estimated threefold increase. This article provides a narrative review on the current evidence and highlights gaps in knowledge and areas for future research. Although earlier studies hypothesized that the association between AF and cognitive decline is mainly a consequence of previous ischemic strokes, more recent evidence also suggests such an association in AF patients without a history of clinical stroke. Because AF and cognitive decline mainly occur among elderly individuals, it is not surprising that both entities share multiple risk factors. In addition to clinically overt ischemic strokes, silent brain infarcts and other brain injury are likely mechanisms for the increased risk of cognitive decline among AF patients. Oral anticoagulation for stroke prevention in AF patients with additional stroke risk factors is one of the only proven therapies to prevent brain injury. Whether a broader use of oral anticoagulation, or more intense anticoagulation in some patients are beneficial in this context needs to be addressed in future studies. Although direct studies are lacking, it is reasonable to recommend optimal treatment of comorbidities and risk factors for the prevention of cognitive decline and dementia.

Cerebral small vessel disease and intracranial bleeding risk: Prognostic and practical significance

Balancing the risks of recurrent ischemia and antithrombotic-associated bleeding, particularly intracranial hemorrhage (ICH), is a key challenge in the secondary prevention of ischemic stroke and transient ischemic attack. In hyperacute ischemic stroke, the use of acute reperfusion therapies is determined by the balance of anticipated benefit and the risk of ICH. Cerebral small vessel disease (CSVD) causes most spontaneous ICH. Here, we review the evidence linking neuroimaging markers of CSVD to antithrombotic and thrombolytic-associated ICH, with emphasis on cerebral microbleeds (CMB). We discuss their role in the prediction of ICH, and practical implications for clinical decision making. Although current observational data suggest CMB presence should not preclude antithrombotic therapy in patients with ischemic stroke or TIA, they are useful for improving ICH risk prediction with potential relevance for determining the optimal secondary prevention strategy, including the use of left atrial appendage occlusion. Following ICH, recommencing antiplatelets is probably safe in most patients, while the inconclusive results of recent randomized controlled trials of anticoagulant use makes recruitment to ongoing trials (including those testing left atrial appendage occlusion) in this area a high priority. Concern regarding CSVD and ICH risk after hyperacute stroke treatment appears to be unjustified in most patients, though some uncertainty remains regarding patients with very high CMB burden and other risk factors for ICH. We encourage careful phenotyping for underlying CSVD in future trials, with the potential to enhance precision medicine in stroke.

Managing antithrombotic treatment in a patient with atrial fibrillation and coronary stent with transient neurological symptoms in cerebral amyloid angiopathy

We present the antithrombotic dilemma in a case with atrial fibrillation and a coronary stent and suspected transient ischemic attacks after diagnosed as a probable cerebral amyloid angiopathy and discuss plausible treatment options for the patient based on the available evidence.

Impact of type of oral anticoagulants in patients with cerebral microbleeds after atrial fibrillation-related ischemic stroke or TIA: Results of the NOACISP-LONGTERM registry

Background

Cerebral microbleeds (CMBs) may have a differential impact on clinical outcome in stroke patients with atrial fibrillation (AF) treated with different types of oral anticoagulation (OAC).

Methods

Observational single-center study on AF-stroke-patients treated with OAC. Magnetic-resonance-imaging was performed to assess CMBs. Outcome measures consisted of recurrent ischemic stroke (IS), intracranial hemorrhage (ICH), death, and their combined analysis. Functional disability was assessed by mRS. Using adjusted logistic regression and Cox proportional-hazards models, we assessed the association of the presence of CMBs and OAC type (vitamin K antagonists [VKAs] vs. direct oral anticoagulants [DOACs]) with clinical outcome.

Results

Of 310 AF-stroke patients treated with OAC [DOACs: n = 234 (75%); VKAs: n = 76 (25%)], CMBs were present in 86 (28%) patients; of these, 66 (77%) received DOACs. In both groups, CMBs were associated with an increased risk for the composite outcome: VKAs: HR 3.654 [1.614; 8.277]; p = 0.002; DOACs: HR 2.230 [1.233; 4.034]; p = 0.008. Patients with CMBs had ~50% higher absolute rates of the composite outcome compared to the overall cohort, with a comparable ratio between treatment groups [VKAs 13/20(65%) vs. DOACs 19/66(29%); p &lt; 0.01]. The VKA-group had a 2-fold higher IS [VKAs:4 (20%) vs. DOACs:6 (9%); p = 0.35] and a 10-fold higher ICH rate [VKAs: 3 (15%) vs. DOACs: 1 (1.5%); p = 0.038]. No significant interaction was observed between type of OAC and presence of CMBs. DOAC-patients showed a significantly better functional outcome (OR 0.40 [0.17; 0.94]; p = 0.04).

Conclusions

In AF-stroke patients treated with OAC, the presence of CMBs was associated with an unfavorable composite outcome for both VKAs and DOACs, with a higher risk for recurrent IS than for ICH. Strokes were numerically higher under VKAs and increased in the presence of CMBs.

Clinical trial registration

http://www.clinicaltrials.gov, Unique identifier: NCT03826927.

Embolic infarct topology differs between atrial fibrillation subtypes and embolic stroke of undetermined source

BACKGROUND

The lack of superiority of anticoagulation over antiplatelet therapy in embolic stroke of undetermined source (ESUS) may be in part due to the misclassification of radiographic ESUS patterns as cardioembolic. In this imaging analysis, we sought to differentiate clinical and radiographic patterns of ESUS patients from patterns in patients with a highly probable cardioembolic source.

MATERIALS & METHODS

A prospective registry of consecutive adults with acute infarction on diffusion-weighted magnetic resonance imaging was queried. Patients with infarctions due to small vessel disease, large vessel disease, and other causes were excluded. Multivariable logistic regression was used to identify independent predictors of two potentially embolic patterns: (1) multifocal and (2) cortical lesions, comparing patients with ESUS against those with atrial fibrillation (AF).

RESULTS

Among 1243 screened patients, 343 (27.6%) experienced strokes due to ESUS or AF. Prior to the index stroke, patients with AF as compared to ESUS were older (median 75 vs. 65, p<0.01) and had more heart failure (25.9% vs. 8.4%, p<0.01). The odds of multifocal infarction were the same between patients with ESUS and both AF subtypes (p>0.05), however, cortical involvement was more associated with both AF versus ESUS (77.7% vs. 65.7%, P=0.02). A higher Fazekas grade of white matter disease was inversely associated with cortical infarction among included patients (aOR 0.77, 95% CI 0.62-0.96).

CONCLUSION

Cortical infarctions were twice as common among patients with AF versus ESUS. Subcortical infarct topography was strongly associated with chronic microvascular ischemic changes and therefore may not represent embolic phenomena. Larger-scale investigations are warranted to discern whether large or multifocal subcortical infarcts ought to be excluded from the ESUS designation.

Symptomatic intracerebral hemorrhage after non-emergency percutaneous coronary intervention: Incidence, risk factors, and association with cardiovascular outcomes

Objective

To investigate the incidence, risk factors, and association with cardiovascular outcomes of patients who developed symptomatic intracerebral hemorrhage (ICH) after non-emergency percutaneous coronary intervention (PCI).

Methods

We conducted a single-institution retrospective study of patients who developed symptomatic ICH after non-emergency PCI. To identify associations between clinical variables and outcomes, Cox-proportional hazards regression models were constructed. Outcomes analyzed include (1) all-cause mortality, (2) acute ischemic stroke (AIS) or transient ischemic attack (TIA), and (3) major adverse cardiovascular events (MACE).

Results

A total of 1,732 patients were included in the analysis. The mean (±SD) age was 61.1 (±11.3) years, and 1,396 patients (80.6%) were male. The cumulative incidence of symptomatic ICH after non-emergency PCI was 1.3% (22 patients). Age, chronic kidney disease, and prior coronary artery bypass graft surgery were independently associated with a higher risk of ICH after PCI, while hyperlipidemia was independently associated with a lower risk of ICH after PCI. ICH after PCI was independently associated with a higher risk of all-cause mortality and AIS or TIA after PCI.

Conclusion

Patients who are older, who have chronic kidney disease, and who have had prior coronary artery bypass graft surgery should be monitored for symptomatic ICH after non-emergency PCI.

Atrial cardiopathy is associated with cerebral microbleeds in ischemic stroke patients

Objective

Cerebral microbleeds (CMB) are small accumulations of hemosiderin associated with cerebrovascular risk factors, but whether they are associated with atrial cardiopathy is not known. The goal of this study is to determine, among ischemic stroke patients, the association between study-defined atrial cardiopathy and CMB presence, location, and number.

Methods

Ischemic stroke patients admitted to Johns Hopkins (2015–2019) with transthoracic echocardiography and electrocardiography were included. Cerebral microbleeds were defined as small, round hypo-intensities on T2* susceptibility weighted imaging or gradient recalled echo magnetic resonance imaging sequences. Atrial cardiopathy was defined as the presence of ≥1: left atrium diameter &gt;4.0 cm (males) or &gt;3.8 cm (females), PR interval &gt;200 ms, or N-terminal pro-B-type natriuretic peptide &gt;250 pg/ml. Binary/Ordinal logistic regression models were used to determine the association between atrial cardiopathy, and cerebral microbleed presence, location (lobar/deep), or number, each, adjusted for potential confounders.

Results

Patients (N = 120) were mean age 60 years (range 22–98), 46% female, 62% black, and 39% were on anti-thrombotic medication at time of admission. 39 (32%) participants had ≥1 cerebral microbleeds. Forty-six (38%) patients had atrial cardiopathy. Atrial cardiopathy was associated with higher odds of having cerebral microbleeds (OR 2.50, 95% CI 1.02–6.15). Atrial cardiopathy was associated with lobar cerebral microbleeds (OR 2.33, 95% CI 1.01–5.37) in univariate analysis but not with deep cerebral microbleeds (OR 0.45, 95% CI 0.13–1.54), with neither association significant after adjustment. There was no difference in risk of having 1 vs. no cerebral microbleeds (RRR 2.51, 95% CI 0.75–8.37) and &gt;1 cerebral microbleed vs none (RRR 2.57, 95% CI 0.87–7.60) among those with atrial cardiopathy.

Conclusions

Atrial cardiopathy is associated with the presence, but not burden, of cerebral microbleeds in ischemic stroke patients. We cautiously suggest that atrial cardiopathy, either directly or through shared vascular risk, may contribute to the presence of CMB.

Antithrombotic dilemmas in stroke medicine: new data, unsolved challenges

Antithrombotic therapy is a key element of secondary prevention in patients who have had an ischaemic stroke or transient ischaemic attack. However, its use in clinical practice is not always straightforward. This review provides an update on certain difficult scenarios in antithrombotic management, with a focus on recent clinical trials and large observational studies. We discuss the approach to patients with an indication for antithrombotic treatment who also have clinical or radiological evidence of previous intracranial bleeding, patients with indications for both anticoagulant and antiplatelet treatment, and patients in whom antithrombotic treatment fails to prevent stroke. We also review the timing of anticoagulation initiation after cardioembolic stroke, and the use of antithrombotics in patients with asymptomatic cerebrovascular disease. Despite a wealth of new evidence, numerous uncertainties remain and we highlight ongoing trials addressing these.

Evaluating the Potential Pathology and Short-Term Outcomes of Cryptogenic Stroke Using the Etiological Classification System

AIM

Various embolic sources and pathogenetic mechanisms underlie cryptogenic stroke (CS). We investigated the association of etiological diversity with short-term outcomes in patients with CS using a modified atherosclerosis (A), small-vessel disease (S), cardiac pathology (C), other causes (O), and dissection (D) (ASCOD) system.

METHODS

Patients with CS who underwent transesophageal echocardiography were registered in this multicenter, observational study. In the modified classification system, O and D were inapplicable and thus excluded. Instead, atherosclerosis, small-vessel disease, cardiac pathology-CS classification was specifically constructed for the etiological diagnosis of CS. We utilized this system to explore the mechanism of CS by grading each pathology and evaluated its association with poorer modified Rankin Scale scores of 3-6 at hospital discharge.

RESULTS

A total of 672 patients (68.7±12.8 years, 220 females) were analyzed. In the multiple logistic regression model, female sex (odds ratio [OR], 1.87 [1.15-3.04]; P=0.012), body mass index (OR, 0.93 [0.88-0.99]; P=0.025), National Institute of Health Stroke Scale score (OR, 1.16 [1.12-1.21]; P＜0.001), CHADS2 score (OR, 1.56 [1.30-1.86]; P＜0.001), D-dimer (OR, 1.04 [1.01-1.08]; P=0.015), diffusion-weighted image (DWI) lesion size (OR, 1.44 [1.10-1.89]; P=0.009), and S＋C score (OR, 1.26 [1.03-1.56]; P=0.029) were associated with poor functional outcome at discharge whereas the S＋C score was marginally associated with poor functional outcome after excluding 137 patients with a premorbid modified Rankin Scale score of ≥ 3.

CONCLUSIONS

The coexistence of small-vessel disease and cardiac pathology might be associated with poor in-hospital functional outcome in CS.

A critical assessment of the current pharmacotherapy for the treatment of embolic strokes of undetermined source

INTRODUCTION

"Embolic stroke of undetermined source" (ESUS) is a term coined to identify non-lacunar stroke whose mechanism is likely to be embolic, and the source remains unidentified. The best antithrombotic treatment for preventing stroke recurrence in this population has not been delineated.

AREAS COVERED

The authors summarize and critically appraise the currently available evidence about the antithrombotic treatment for preventing stroke recurrence in patients with ESUS. Randomized trials addressing this topic were identified through MEDLINE (accessed by PubMed, as of November 2021, week 4).

EXPERT OPINION

Recent randomized trials have failed to demonstrate a significant benefit of direct oral anticoagulants over aspirin in reducing the recurrence of cerebral infarctions in unselected cohorts of patients with ESUS. The heterogeneity and often overlap of embolic sources may be possible explanations for the overall absence of a benefit of oral anticoagulants in ESUS as a single homogeneous entity. The results of these trials and their subgroup analyses have provided important cues to understand the pathophysiology of ESUS. They have, furthermore, increased in the interest in researchers in identifying distinct etiological phenotypes within this stroke population. There is a good rationale for ongoing and future investigations in order to tailor antithrombotic treatment according to individual features of patients with ESUS.

Advances in Recurrent Stroke Prevention: Focus on Antithrombotic Therapies

The past decade has seen significant advances in stroke prevention. These advances include new antithrombotic agents, new options for dyslipidemia treatment, and novel techniques for surgical stroke prevention. In addition, there is greater recognition of the benefits of multifaceted interventions, including the role of physical activity and dietary modification. Despite these advances, the aging of the population and the high prevalence of key vascular risk factors pose challenges to reducing the burden of stroke. Using a cause-based framework, current approaches to prevention of cardioembolic, cryptogenic, atherosclerotic, and small vessel disease stroke are outlined in this paper. Special emphasis is given to recent trials of antithrombotic agents, including studies that have tested combination treatments and responses according to genetic factors.

Cerebral Amyloid Angiopathy and Atrial Fibrillation: An up to Date Case Report

Concurrent Cerebral Amyloid Angiopathy (CAA) and Atrial Fibrillation are becoming an increasingly common dilemma in clinical practice due to the aging population and the comorbidities associated with it. In such patients, the physician must appreciate and strike the difficult balance between the risk of ischemic strokes from atrial fibrillation on one hand, and that of intracerebral hemorrhage from coexisting CAA on the other. Anticoagulation is necessary for the former but potentially deleterious for the latter. In this case report, we present the case of a 67-year-old woman with a long history of atrial fibrillation on rivaroxaban who recently began to experience recurrent transient neurological deficits that were later diagnosed as amyloid spells related to concomitant CAA. While there is no clear-cut consensus in published literature on how to best manage these patients regarding the use of anticoagulation, it is recommended to involve a multidisciplinary team for optimal management of these patients.

Cerebral Microbleeds and Treatment Effect of Intravenous Thrombolysis in Acute Stroke: An Analysis of the WAKE-UP Randomized Clinical Trial

Background and Objectives

Cerebral microbleeds (CMBs) are common in patients with acute ischemic stroke and are associated with increased risk of intracerebral hemorrhage (ICH) after intravenous thrombolysis. Whether CMBs modify the treatment effect of thrombolysis is unknown.

Methods

We performed a prespecified analysis of the prospective randomized controlled multicenter Efficacy and Safety of MRI-Based Thrombolysis in Wake-Up Stroke (WAKE-UP) trial including patients with acute ischemic stroke with unknown time of symptom onset and diffusion-weighted imaging–fluid-attenuated inversion recovery mismatch on MRI receiving alteplase or placebo. Patients were screened and enrolled between September 2012 and June 2017 (with final follow-up in September 2017). Patients were randomized to treatment with IV thrombolysis with alteplase at 0.9 mg/kg body weight or placebo. CMB status (presence, number, and distribution) was assessed after study completion by 3 raters blinded to clinical information following a standardized protocol. Outcome measures were excellent functional outcome at 90 days, defined by modified Rankin Scale (mRS) score ≤1, and symptomatic ICH according to National Institutes of Neurological Disease and Stroke trial criteria 22 to 36 hours after treatment.

Results

Of 503 patients enrolled in the WAKE-UP trial, 459 (91.3%; 288 [63%] men) were available for analysis. Ninety-eight (21.4%) had at least 1 CMB on baseline imaging; 45 (9.8%) had exactly 1 CMB; 37 (8.1%) had 2 to 4 CMBs; and 16 (3.5%) had ≥5 CMBs. Presence of CMBs was associated with a nonsignificant increased risk of symptomatic ICH (11.2% vs 4.2%; adjusted odds ratio [OR] 2.32, 95% confidence interval [CI] 0.99–5.43, p = 0.052) but had no effect on functional outcome at 90 days (mRS score ≤1: 45.8% vs 50.7%; adjusted OR 0.99, 95% CI 0.59–1.64, p = 0.955). Patients receiving alteplase had better functional outcome (mRS score ≤1: 54.6% vs 44.6%, adjusted OR 1.61, 95% CI 1.07–2.43, p = 0.022) without evidence of heterogeneity in relation to CMB presence (p of the interactive term = 0.546). Results were similar for subpopulations with strictly lobar (presumed cerebral amyloid angiopathy related) or not strictly lobar CMB distribution.

Discussion

In the randomized-controlled WAKE-UP trial, we saw no evidence of reduced treatment effect of alteplase in patients with acute ischemic stroke with ≥1 CMBs. Additional studies are needed to determine the treatment effect of alteplase and its benefit-harm ratio in patients with a larger number of CMBs.

Trial Registration Information

ClinicalTrials.gov identifier NCT01525290; ClinicalTrialsRegister.EU identifier 2011-005906-32.

Classification of Evidence

This study provides Class II evidence that for patients with acute ischemic stroke with unknown time of onset and diffusion-weighted imaging–fluid-attenuated inversion recovery mismatch who received IV alteplase, CMBs are not significantly associated with functional outcome at 90 days.

Anticoagulation Therapy Reduces Recurrent Stroke in Embolic Stroke of Undetermined Source Patients With Elevated Coagulation Markers or Severe Left Atrial Enlargement

Background: The objective of this study was to evaluate if anticoagulation therapy reduces recurrent stroke in embolic stroke of undetermined source (ESUS) patients with left atrial enlargement (LAE) or abnormal markers of coagulation and hemostatic activity (MOCHA) compared to antiplatelet therapy.

Methods: ESUS patients from January 1, 2017, to June 30, 2019, underwent outpatient cardiac monitoring and the MOCHA profile (serum d-dimer, prothrombin fragment 1.2, thrombin–antithrombin complex, and fibrin monomer). Anticoagulation was offered to patients with abnormal MOCHA (≥2 elevated markers) or left atrial volume index 40 mL/m². Patients were evaluated for recurrent stroke or major hemorrhage at routine clinical follow-up. We compared this patient cohort (cohort 2) to a historical cohort (cohort 1) who underwent the same protocol but remained on antiplatelet therapy.

Results: Baseline characteristics in cohort 2 (n = 196; mean age = 63 ± 16 years, 59% female, 49% non-White) were similar to cohort 1 (n = 42) except that cohort 2 had less diabetes (43 vs. 24%, p = 0.01) and more tobacco use (26 vs. 43%, p = 0.04). Overall, 45 patients (23%) in cohort 2 initiated anticoagulation based on abnormal MOCHA or LAE. During mean follow-up of 13 ± 10 months, cohort 2 had significantly lower recurrent stroke rates than cohort 1 (14 vs. 3%, p = 0.009) with no major hemorrhages.

Conclusions: Anticoagulation therapy in a subgroup of ESUS patients with abnormal MOCHA or severe LAE may be associated with a reduced rate of recurrent stroke compared to antiplatelet therapy. A prospective, randomized study is warranted to validate these results.