Rivaroxaban for Prevention of Covert Brain Infarcts and Cognitive Decline

Toward Individual Treatment in Cervical Artery Dissection: Subgroup Analysis of the TREAT-CAD Randomized Trial

OBJECTIVE

Uncertainty remains regarding antithrombotic treatment in cervical artery dissection. This analysis aimed to explore whether certain patient profiles influence the effects of different types of antithrombotic treatment.

METHODS

This was a post hoc exploratory analysis based on the per-protocol dataset from TREAT-CAD (NCT02046460), a randomized controlled trial comparing aspirin to anticoagulation in patients with cervical artery dissection. We explored the potential effects of distinct patient profiles on outcomes in participants treated with either aspirin or anticoagulation. Profiles included (1) presenting with ischemia (no/yes), (2) occlusion of the dissected artery (no/yes), (3) early versus delayed treatment start (median), and (4) intracranial extension of the dissection (no/yes). Outcomes included clinical (stroke, major hemorrhage, death) and magnetic resonance imaging outcomes (new ischemic or hemorrhagic brain lesions) and were assessed for each subgroup in separate logistic models without adjustment for multiple testing.

RESULTS

All 173 (100%) per-protocol participants were eligible for the analyses. Participants without occlusion had decreased odds of events when treated with anticoagulation (odds ratio [OR] = 0.28, 95% confidence interval [CI] = 0.07-0.86). This effect was more pronounced in participants presenting with cerebral ischemia (n = 118; OR = 0.16, 95% CI = 0.04-0.55). In the latter, those with early treatment (OR = 0.26, 95% CI = 0.07-0.85) or without intracranial extension of the dissection (OR = 0.34, 95% CI = 0.11-0.97) had decreased odds of events when treated with anticoagulation.

INTERPRETATION

Anticoagulation might be preferable in patients with cervical artery dissection presenting with ischemia and no occlusion or no intracranial extension of the dissection. These findings need confirmation. ANN NEUROL 2024;95:886-897.

Advances in Cerebral Small Vessel Disease: Sandra E. Black Lecture to the Canadian Neurological Sciences Federation

Cerebral small vessel diseases (CSVDs) are among the most common age-related pathologies of the brain. Arteriolosclerosis and cerebral amyloid angiopathy (CAA) are the most common CSVDs. In addition to causing stroke and dementia, CSVDs can have diverse covert radiological manifestations on computed tomography and magnetic resonance imaging including lacunes, T2-weighted white matter hyperintensities, increased density of visible perivascular spaces, microbleeds and cortical superficial siderosis. Because they cannot be visualized directly, research on the pathophysiology of CSVD has been difficult. However, advances in quantitative imaging methods, including physiological imaging such as measurement of cerebrovascular reactivity and increased vascular permeability, are beginning to allow investigation of the early effects of CSVD in living people. Furthermore, genomics, metabolomics and proteomics have the potential to illuminate previously unrecognized pathways to CSVD that could be important targets for new clinical trials.

Safety and efficacy of factor XIa inhibition with milvexian for secondary stroke prevention (AXIOMATIC-SSP): a phase 2, international, randomised, double-blind, placebo-controlled, dose-finding trial

BACKGROUND

People with factor XI deficiency have lower rates of ischaemic stroke than the general population and infrequent spontaneous bleeding, suggesting that factor XI has a more important role in thrombosis than in haemostasis. Milvexian, an oral small-molecule inhibitor of activated factor XI, added to standard antiplatelet therapy, might reduce the risk of non-cardioembolic ischaemic stroke without increasing the risk of bleeding. We aimed to estimate the dose-response of milvexian for recurrent ischaemic cerebral events and major bleeding in patients with recent ischaemic stroke or transient ischaemic attack (TIA).

METHODS

AXIOMATIC-SSP was a phase 2, randomised, double-blind, placebo-controlled, dose-finding trial done at 367 hospitals in 27 countries. Eligible participants aged 40 years or older, with acute (<48 h) ischaemic stroke or high-risk TIA, were randomly assigned by a web-based interactive response system in a 1:1:1:1:1:2 ratio to receive one of five doses of milvexian (25 mg once daily, 25 mg twice daily, 50 mg twice daily, 100 mg twice daily, or 200 mg twice daily) or matching placebo twice daily for 90 days. All participants received clopidogrel 75 mg daily for the first 21 days and aspirin 100 mg daily for the first 90 days. Investigators, site staff, and participants were masked to treatment assignment. The primary efficacy endpoint was the composite of ischaemic stroke or incident covert brain infarct on MRI at 90 days, assessed in all participants allocated to treatment who completed a follow-up MRI brain scan, and the primary analysis assessed the dose-response relationship with Multiple Comparison Procedure-Modelling (MCP-MOD). The main safety outcome was major bleeding at 90 days, assessed in all participants who received at least one dose of the study drug. This trial is registered with ClinicalTrials.gov (NCT03766581) and the EU Clinical Trials Register (2017-005029-19).

FINDINGS

Between Jan 27, 2019, and Dec 24, 2021, 2366 participants were randomly allocated to placebo (n=691); milvexian 25 mg once daily (n=328); or twice-daily doses of milvexian 25 mg (n=318), 50 mg (n=328), 100 mg (n=310), or 200 mg (n=351). The median age of participants was 71 (IQR 62-77) years and 859 (36%) were female. At 90 days, the estimates of the percentage of participants with either symptomatic ischaemic stroke or covert brain infarcts were 16·8 (90·2% CI 14·5-19·1) for placebo, 16·7 (14·8-18·6) for 25 mg milvexian once daily, 16·6 (14·8-18·3) for 25 mg twice daily, 15·6 (13·9-17·5) for 50 mg twice daily, 15·4 (13·4-17·6) for 100 mg twice daily, and 15·3 (12·8-19·7) for 200 mg twice daily. No significant dose-response was observed among the five milvexian doses for the primary composite efficacy outcome. Model-based estimates of the relative risk with milvexian compared with placebo were 0·99 (90·2% CI 0·91-1·05) for 25 mg once daily, 0·99 (0·87-1·11) for 25 mg twice daily, 0·93 (0·78-1·11) for 50 mg twice daily, 0·92 (0·75-1·13) for 100 mg twice daily, and 0·91 (0·72-1·26) for 200 mg twice daily. No apparent dose-response was observed for major bleeding (four [1%] of 682 participants with placebo, two [1%] of 325 with milvexian 25 mg once daily, two [1%] of 313 with 25 mg twice daily, five [2%] of 325 with 50 mg twice daily, five [2%] of 306 with 100 mg twice daily, and five [1%] of 344 with 200 mg twice daily). Five treatment-emergent deaths occurred, four of which were considered unrelated to the study drug by the investigator.

INTERPRETATION

Factor XIa inhibition with milvexian, added to dual antiplatelet therapy, did not substantially reduce the composite outcome of symptomatic ischaemic stroke or covert brain infarction and did not meaningfully increase the risk of major bleeding. Findings from our study have informed the design of a phase 3 trial of milvexian for the prevention of ischaemic stroke in patients with acute ischaemic stroke or TIA.

FUNDING

Bristol Myers Squibb and Janssen Research & Development.

Consensus statement for the management of incidentally found brain white matter hyperintensities in general medical practice

INTRODUCTION

There is a paradigm shift in our understanding of white matter hyperintensities (WMH) found on brain imaging. They were once thought to be a normal phenomenon of ageing and, therefore, warranted no further investigation. However, evidence now suggests these lesions are markers of poor brain and cardiovascular health, portending an increased risk of stroke, cognitive decline, depression and death. Nevertheless, no specific guidelines exist for the management of incidentally found WMH for general medical practitioners and other clinicians ordering brain magnetic resonance imaging scans for diverse clinical indications. Informed by a literature review and expert opinion gleaned from stroke neurologists, medical and imaging specialists, and general practitioners, we present our consensus statement to guide the management of incidentally found WMH in adults.

MAIN RECOMMENDATIONS

When incidental WMH are found on brain imaging: Perform a detailed history and examination to screen for neurological events. Investigate for potential undiagnosed or undertreated cardiovascular risk factors, especially hypertension and diabetes mellitus. Commence intensive and individualised cardiovascular risk management when risk factors are uncovered. Treat underlying risk factors via accepted guidelines but note that antiplatelet and anticoagulant medications should not be prescribed for incidental WMH in the absence of an alternative indication.

CHANGES TO MANAGEMENT AS A RESULT OF THIS CONSENSUS STATEMENT

A brain health opportunity. We consider the discovery of incidental WMH on brain imaging to represent an opportunity to investigate for common cardiovascular risk factors and to optimise brain health. This can be commenced and monitored by the general practitioner or physician without delay in waiting for an outpatient neurology review.

ECG Smart Monitoring versus Implantable Loop Recorders for Atrial Fibrillation Detection after Cryptogenic Stroke-An Overview for Decision Making

Up to 20% of patients with ischemic stroke or transient ischemic attack have a prior history of known atrial fibrillation (AF). Additionally, unknown AF can be detected by different monitoring strategies in up to 23% of patients with cryptogenic or non-cardioembolic stroke. However, most studies had substantial gaps in monitoring time, especially early after the index event. Following this, AF rates would be higher if patients underwent continuous monitoring early after stroke, avoiding any gaps in monitoring. The few existing randomized studies focused on patients with cryptogenic stroke but did not focus otherwise specifically on prevention strategies in patients at high risk for AF (patients at higher age or with high CHA2DS2-VASC scores). Besides invasive implantable loop recorders (ILRs), external loop recorders (ELRs) and mobile cardiac outpatient telemetry (MCOT) are non-invasive tools that are commonly used for long-term ECG monitoring in cryptogenic-stroke patients in the ambulatory setting. The role of MCOT and hand-held devices within ECG smart monitoring in the detection of AF for the prevention of and after cryptogenic stroke is currently unclear. This intense review provides an overview of current evidence, techniques, and gaps in knowledge and aims to advise which patients benefit most from the current available devices.

Are Factor Xa Inhibitors Efficacious for Ischemic Stroke Prevention in Patients Without Atrial Fibrillation? Evidence From Randomized Clinical Trials

BACKGROUND

Clinical trials provide conflicting evidence regarding oral factor Xa inhibitors for prevention of ischemic stroke in patients without a history of atrial fibrillation (AF).

METHODS

We performed a critical appraisal of randomized clinical trials that tested oral factor Xa inhibitors in patients without AF that reported ischemic stroke.

RESULTS

Considering the 11 trials that reported > 10 ischemic strokes during follow-up (97,578 participants, 1195 ischemic strokes), 1 tested apixaban (57 strokes), 1 betrixaban (52 strokes), and 9 rivaroxaban (1086 strokes). In 7 trials with placebo comparisons, numerically fewer ischemic strokes occurred among those assigned factor Xa inhibitors in 7 of 8 randomized comparisons (range of hazard ratios [HRs], 0.89-0.51), including statistically significant reductions in 2 trials that compared rivaroxaban 2.5 mg twice daily vs placebo on a background of aspirin in patients with cardiovascular disease, COMPASS (HR, 0.51; 95% confidence interval [CI], 0.38-0.68) and COMMANDER-HF (HR, 0.64; 95% CI, 0.43-0.95). Compared with aspirin in 4 trials, oral factor Xa inhibitors were associated with fewer ischemic strokes in 2, with statistically significant reduction in 1 (rivaroxaban 5 mg twice daily in COMPASS; HR, 0.69; 95% CI, 0.53-0.90). Major bleeding was increased by oral factor Xa inhibitors in all 7 placebo-controlled trials (HR range, 1.42-4.08), with statistically significant increases reported in 5 trials, and in all 4 aspirin-controlled trials (all statistically significant increases; HR range, 1.52-2.72).

CONCLUSIONS

Aggregate evidence on the basis of placebo comparisons from randomized trials supports the potential for oral factor Xa inhibitors to reduce ischemic stroke in patients without AF, but major bleeding is increased.

Factor XIa inhibition with asundexian after acute non-cardioembolic ischaemic stroke (PACIFIC-Stroke): an international, randomised, double-blind, placebo-controlled, phase 2b trial

BACKGROUND

Asundexian (Bayer AG, Leverkusen, Germany), an oral small molecule factor XIa (FXIa) inhibitor, might prevent thrombosis without increasing bleeding. Asundexian's effect for secondary prevention of recurrent stroke is unknown.

METHODS

In this randomised, double-blind, placebo-controlled, phase 2b dose-finding trial (PACIFIC-Stroke), patients with acute (within 48 h) non-cardioembolic ischaemic stroke were recruited from 196 hospitals in 23 countries. Patients were eligible if they were aged 45 years or older, to be treated with antiplatelet therapy, and able to have a baseline MRI (either before or within 72 h of randomisation). Eligible participants were randomly assigned (1:1:1:1), using an interactive web-based response system and stratified according to anticipated antiplatelet therapy (single vs dual), to once daily oral asundexian (BAY 2433334) 10 mg, 20 mg, or 50 mg, or placebo in addition to usual antiplatelet therapy, and were followed up during treatment for 26-52 weeks. Brain MRIs were obtained at study entry and at 26 weeks or as soon as possible after treatment discontinuation. The primary efficacy outcome was the dose-response effect on the composite of incident MRI-detected covert brain infarcts and recurrent symptomatic ischaemic stroke at or before 26 weeks after randomisation. The primary safety outcome was major or clinically relevant non-major bleeding as defined by International Society on Thrombosis and Haemostasis criteria. The efficacy outcome was assessed in all participants assigned to treatment, and the safety outcome was assessed in all participants who received at least one dose of study treatment. This study is registered with ClinicalTrials.gov, NCT04304508, and is now complete.

FINDINGS

Between June 15, 2020, and July 22, 2021, 1880 patients were screened and 1808 participants were randomly assigned to asundexian 10 mg (n=455), 20 mg (n=450), or 50 mg (n=447), or placebo (n=456). Mean age was 67 years (SD 10) and 615 (34%) participants were women, 1193 (66%) were men, 1505 (83%) were White, and 268 (15%) were Asian. The mean time from index stroke to randomisation was 36 h (SD 10) and median baseline National Institutes of Health Stroke Scale score was 2·0 (IQR 1·0-4·0). 783 (43%) participants received dual antiplatelet treatment for a mean duration of 70·1 days (SD 113·4) after randomisation. At 26 weeks, the primary efficacy outcome was observed in 87 (19%) of 456 participants in the placebo group versus 86 (19%) of 455 in the asundexian 10 mg group (crude incidence ratio 0·99 [90% CI 0·79-1·24]), 99 (22%) of 450 in the asundexian 20 mg group (1·15 [0·93-1·43]), and 90 (20%) of 447 in the asundexian 50 mg group (1·06 [0·85-1·32]; t statistic -0·68; p=0·80). The primary safety outcome was observed in 11 (2%) of 452 participants in the placebo group versus 19 (4%) of 445 in the asundexian 10 mg group, 14 (3%) of 446 in the asundexian 20 mg group, and 19 (4%) of 443 in the asundexian 50 mg group (all asundexian doses pooled vs placebo hazard ratio 1·57 [90% CI 0·91-2·71]).

INTERPRETATION

In this phase 2b trial, FXIa inhibition with asundexian did not reduce the composite of covert brain infarction or ischaemic stroke and did not increase the composite of major or clinically relevant non-major bleeding compared with placebo in patients with acute, non-cardioembolic ischaemic stroke.

FUNDING

Bayer AG.

Cognitive Dysfunction in Heart Failure: Pathophysiology and Implications for Patient Management

PURPOSE OF REVIEW

There is increasing recognition of the prevalence and impact of cognitive dysfunction (CD) in heart failure (HF) patients. This contemporary review appraises the evidence for epidemiological association, direct pathophysiological links and emerging pharmacological and non-pharmacological interventions. Furthermore, we present evidence for care models that aim to mitigate the morbidity and poor quality of life associated with these dual processes and propose future work to improve outcomes.

RECENT FINDINGS

CD disproportionately affects heart failure patients, even accounting for known comorbid risk factors, and this may extend to subclinical left ventricular dysfunction. Neuroimaging studies now provide evidence of anatomical and functional differences which support previously postulated mechanisms of reduced cerebral blood flow, micro-embolism and systemic inflammation. Interventions such as multidisciplinary ambulatory HF care, education and memory training improve HF outcomes perhaps to a greater degree in those with comorbid CD. Additionally, optimisation of standard heart failure care (cardiac rehabilitation, pharmacological and device therapy) may lead to additional cognitive benefits. Epidemiological, neuroimaging and intervention studies provide evidence for the causal association between HF and CD, although evidence for Alzheimer's dementia is less certain. Specific reporting of cognitive outcomes in HF trials and evaluation of targeted interventions is required to further guide care provision.

Antithrombotic therapy to prevent cognitive decline in people with small vessel disease on neuroimaging but without dementia

BACKGROUND

Cerebral small vessel disease is a progressive disease of the brain's deep perforating blood vessels. It is usually diagnosed based on lesions seen on brain imaging. Cerebral small vessel disease is a common cause of stroke but can also cause a progressive cognitive decline. As antithrombotic therapy is an established treatment for stroke prevention, we sought to determine whether antithrombotic therapy might also be effective in preventing cognitive decline in people with small vessel disease.

OBJECTIVES

To assess the effects of antithrombotic therapy for prevention of cognitive decline in people with small vessel disease on neuroimaging but without dementia.

SEARCH METHODS

We searched ALOIS, the Cochrane Dementia and Cognitive Improvement Review Group's Specialised Register, and the Cochrane Stroke Group's Specialised Register; the most recent search was on 21 July 2021. We also searched MEDLINE, Embase, four other databases and two trials registries. We searched the reference lists of the articles retrieved from these searches. As trials with a stroke focus may include relevant subgroup data, we complemented these searches with a focussed search of all antithrombotic titles in the Cochrane Stroke Group database.  SELECTION CRITERIA: We included randomised controlled trials (RCT) of people with neuroimaging evidence of at least mild cerebral small vessel disease (defined here as white matter hyperintensities, lacunes of presumed vascular origin and subcortical infarcts) but with no evidence of dementia. The trials had to compare antithrombotic therapy of minimum 24 weeks' duration to no antithrombotic therapy (either placebo or treatment as usual), or compare different antithrombotic treatment regimens. Antithrombotic therapy could include antiplatelet agents (as monotherapy or combination therapy), anticoagulants or a combination.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened all the titles identified by the searches. We assessed full texts for eligibility for inclusion according to our prespecified selection criteria, extracted data to a proforma and assessed risk of bias using the Cochrane tool for RCTs. We evaluated the certainty of evidence using GRADE. Due to heterogeneity across included participants, interventions and outcomes of eligible trials, it was not possible to perform meta-analyses.

MAIN RESULTS

We included three RCTs (3384 participants). One study investigated the effect of antithrombotic therapy in participants not yet on antithrombotic therapy; two studies investigated the effect of additional antithrombotic therapy, one in a population already taking a single antithrombotic agent and one in a mixed population (participants on an antithrombotic drug and antithrombotic-naive participants). Intervention and follow-up durations varied from 24 weeks to four years. Jia 2016 was a placebo-controlled trial assessing 24 weeks of treatment with DL-3-n-butylphthalide (a compound with multimodal actions, including a putative antiplatelet effect) in 280 Chinese participants with vascular cognitive impairment caused by subcortical ischaemic small vessel disease, but without dementia. There was very low-certainty evidence for a small difference in cognitive test scores favouring treatment with DL-3-n-butylphthalide, as measured by the 12-item Alzheimer's Disease Assessment Scale-Cognitive subscale (adjusted mean difference -1.07, 95% confidence interval (CI) -2.02 to -0.12), but this difference may not be clinically relevant. There was also very low-certainty evidence for greater proportional improvement measured with the Clinician Interview-Based Impression of Change-Plus Caregiver Input (57% with DL-3-n-butylphthalide versus 42% with placebo; P = 0.01), but there was no difference in other measures of cognition (Mini-Mental State Examination and Clinical Dementia Rating) or function. There was no evidence of a difference in adverse events between treatment groups. The SILENCE RCT compared antithrombotic therapy (aspirin) and placebo during four years of treatment in 83 participants with 'silent brain infarcts' who were on no prior antithrombotic therapy. There was very low-certainty evidence for no difference between groups across various measures of cognition and function, rates of stroke or adverse events. The Secondary Prevention of Subcortical Stroke Study (SPS3) compared dual antiplatelet therapy (clopidogrel plus aspirin) to aspirin alone in 3020 participants with recent lacunar stroke. There was low-certainty evidence of no effect on cognitive outcomes as measured by the Cognitive Abilities Screening Instruments (CASI) assessed annually over five years. There was also low-certainty evidence of no difference in the annual incidence of mild cognitive decline between the two treatment groups (9.7% with dual antiplatelet therapy versus 9.9% with aspirin), or the annual stroke recurrence rate (2.5% with dual antiplatelet therapy versus 2.7% with aspirin). Bleeding risk may be higher with dual antiplatelet therapy (hazard ratio (HR) 2.15, 95% CI 1.49 to 3.11; low certainty evidence), but there may be no significant increase in intracerebral bleeding risk (HR 1.52, 95% CI 0.79 to 2.93; low-certainty evidence). None of the included trials assessed the incidence of new dementia.

AUTHORS' CONCLUSIONS

We found no convincing evidence to suggest any clinically relevant cognitive benefit of using antithrombotic therapy in addition to standard treatment in people with cerebral small vessel disease but without dementia, but there may be an increased bleeding risk with this approach. There was marked heterogeneity across the trials and the certainty of the evidence was generally poor.

Rivaroxaban versus aspirin for prevention of covert brain infarcts in patients with embolic stroke of undetermined source: NAVIGATE ESUS MRI substudy

Background

Covert brain infarcts are associated with important neurological morbidity. Their incidence in patients with embolic stroke of undetermined source (ESUS) is unknown.

Aims

To assess the incidence of covert brain infarcts and cerebral microbleeds using MRI in a prospective substudy of the NAVIGATE ESUS randomized trial and to evaluate the effects of antithrombotic therapies.

Methods

At 87 sites in 15 countries, substudy participants were randomly assigned to receive rivaroxaban 15 mg daily or aspirin 100 mg daily and underwent brain MRI near randomization and after study termination. The primary outcome was incident brain infarct (clinical ischemic stroke or covert brain infarct). Brain infarcts and microbleeds were ascertained centrally by readers unaware of treatment. Treatment effects were estimated using logistic regression.

Results

Among the 718 substudy participants with interpretable, paired MRIs, the mean age was 67 years and 61% were men with a median of 52 days between the qualifying ischemic stroke and randomization and a median of seven days between randomization and baseline MRI. During the median (IQR) 11 (12) month interval between scans, clinical ischemic strokes occurred in 27 (4%) participants, while 60 (9%) of the remaining participants had an incident covert brain infarct detected by MRI. Assignment to rivaroxaban was not associated with reduction in the incidence of brain infarct (OR 0.77, 95% CI 0.49, 1.2) or of covert brain infarct among those without clinical stroke (OR 0.85, 95% CI 0.50, 1.4). New microbleeds were observed in 7% and did not differ among those assigned rivaroxaban vs. aspirin (HR 0.95, 95% CI 0.52–1.7).

Conclusions

Incident covert brain infarcts occurred in twice as many ESUS patients as a clinical ischemic stroke. Treatment with rivaroxaban compared with aspirin did not significantly reduce the incidence of covert brain infarcts or increase the incidence of microbleeds, but the confidence intervals for treatment effects were wide.

Registration:https://www.clinicaltrials.gov. Unique identifier: NCT 02313909

Emerging agents for the treatment and prevention of stroke: progress in clinical trials

INTRODUCTION

Recent years have witnessed unprecedented progress in stroke care, but unmet needs persist regarding the efficacy of acute treatment and secondary prevention. Novel approaches are being tested to enhance the efficacy of thrombolysis or provide neuroprotection in non-thrombolized patients.

AREAS COVERED

The current review highlights pharmaceutical agents under evaluation in clinical trials concerning the acute, subacute, and chronic phase post-stroke. We examine the evidence in favor of tenecteplase as an alternative thrombolytic drug to alteplase, nerinetide as a promising neuroprotective agent, and glibenclamide for reducing edema in malignant hemispheric infarction. We discuss the use of ticagrelor and the promising novel category of factor XI inhibitors in the subacute phase after stroke. We offer our insights on combined rivaroxaban and antiplatelet therapy, PCSK-9 inhibitors, and other non-statin hypolipidemic agents, as well as novel antidiabetic agents that have been shown to reduce cardiovascular events in the long-term.

EXPERT OPINION

Current approaches in stroke treatment and stroke prevention have already transformed stroke care from a linear one-for-all treatment paradigm to a more individualized approach that targets specific patient subgroups with novel pharmaceutical agents. This tendency enriches the therapeutic armamentarium with novel agents developed for specific stroke subgroups.

ABBREVIATIONS

IVT: intravenous thrombolysis; RCTs: randomized-controlled clinical trials; TNK: Tenecteplase; COVID-19: Coronavirus 2019 Disease; EXTEND-IA TNK: The Tenecteplase versus Alteplase Before Endovascular Therapy for Ischemic Stroke trial; AIS: acute ischemic stroke; NNT: number needed to treat; MT: mechanical thrombectomy; sICH: symptomatic intracranial hemorrhage; mRS: modified Rankin Scale; AHA/ASA: American Heart Association/American Stroke Association; ESO: European Stroke Organization; NA-1: Nerinetide; ENACT: Evaluating Neuroprotection in Aneurysm Coiling Therapy; CTA: CT angiography; TIA: transient ischemic attack; CHANCE: Clopidogrel in High-risk patients with Acute Non-disabling Cerebrovascular Events; LOF: loss-of-function; PRINCE: Platelet Reactivity in Acute Nondisabling Cerebrovascular Events; THALES: Acute Stroke or Transient Ischemic Attack Treated with Ticagrelor and ASA [acetylsalicylic acid] for Prevention of Stroke and Death; CHANCE-2: Clopidogrel With Aspirin in High-risk Patients With Acute Non-disabling Cerebrovascular Events II; FXI: Factor XI; PACIFIC-STROKE: Program of Anticoagulation via Inhibition of FXIa by the Oral Compound BAY 2433334-NonCardioembolic Stroke study; COMPASS: Cardiovascular Outcomes for People Using Anticoagulation Strategies; CANTOS-ICAD: Combination Antithrombotic Treatment for Prevention of Recurrent Ischemic Stroke in Intracranial Atherosclerotic Disease; SAMMPRIS: Stenting and Aggressive Medical Therapy for Preventing Recurrent Stroke in Intracranial Stenosis; WASID: Warfarin-Aspirin Symptomatic Intracranial Disease; SPARCL: Stroke Prevention by Aggressive Reduction in Cholesterol Levels; LDL-C: low-density lipoprotein cholesterol; TST: Treat Stroke to Target; IMPROVE-IT: Improved Reduction of Outcomes: Vytorin Efficacy International Trial; PCSK9: proprotein convertase subtilisin-kexin type 9; FOURIER: Further Cardiovascular Outcomes Research with PCSK9 Inhibition in Subjects with Elevated Risk; CLEAR: Cholesterol Lowering via Bempedoic acid, an ACL-inhibiting Regimen; REDUCE-IT: Reduction of Cardiovascular Events With EPA Intervention Trial; STRENGTH: Outcomes Study to Assess STatin Residual Risk Reduction With EpaNova in HiGh CV Risk PatienTs With Hypertriglyceridemia; ACCORD: Action to Control Cardiovascular Risk in Diabetes; ADVANCE: Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation; VADT: Veterans Affairs Diabetes Trial; GLP-1R: Glucagon-like peptide-1 receptor; SGLT2: sodium-glucose cotransporter 2; CONVINCE: COlchicine for preventioN of Vascular Inflammation in Non-CardioEmbolic stroke; PROBE: Prospective Randomized Open-label Blinded Endpoint assessment.

Cervical and intracranial artery dissections

This review summarizes recent therapeutic advances in cervical (CeAD) and intracranial artery dissection (IAD) research. Despite unproven benefits, but in the absence of any signal of harm, in patients, with acute ischemic stroke attributable to CeAD, intravenous thrombolysis and, in case of large-vessel occlusion, endovascular revascularization should be considered. Future research will clarify which patients benefit most from either treatment modality. For stroke prevention, the recently published randomized controlled TREAT-CAD study showed that, against the initial hypothesis, aspirin was not shown non-inferior to anticoagulation with vitamin K antagonists (VKAs). With the results of two randomized controlled trials (CADISS and TREAT-CAD) available now, the evidence to consider aspirin as the standard therapy of CeAD is weak. Further analyses might clarify whether the assumption supports, in particular, that patients presenting with cerebral ischemia, clinical or subclinical with magnetic resonance imaging surrogates, might benefit most from VKA treatment. In turn, it remains to be shown, whether in CeAD patients presenting with pure local symptoms and without hemodynamic compromise, antiplatelets are sufficient, and whether a dual antiplatelet therapy during the first weeks of treatment is recommendable. The observation that ischemic strokes occurred (or recurred) very early after CeAD diagnosis, consistently across randomized and observational studies, supports the recommendation to start antithrombotic treatment immediately, whatever antithrombotic agent is chosen in each individual case. The lack of a license for the use in CeAD patients and the paucity of data are still arguments against the use of direct oral anticoagulants in CeAD. Nevertheless, due to their beneficial safety and efficacy profile proven in atrial fibrillation, these agents are a worthwhile treatment option to be tested in further CeAD treatment trials. In IAD, the experience with the use of antithrombotic agents is limited. As the risk of suffering intracranial hemorrhage is higher in IAD than in CeAD, the use of antithrombotic therapy in IAD remains controversial.

Aspirin versus anticoagulation in cervical artery dissection (TREAT-CAD): an open-label, randomised, non-inferiority trial

BACKGROUND

Cervical artery dissection is a major cause of stroke in young people (aged <50 years). Historically, clinicians have preferred using oral anticoagulation with vitamin K antagonists for patients with cervical artery dissection, although some current guidelines-based on available evidence from mostly observational studies-suggest using aspirin. If proven to be non-inferior to vitamin K antagonists, aspirin might be preferable, due to its ease of use and lower cost. We aimed to test the non-inferiority of aspirin to vitamin K antagonists in patients with cervical artery dissection.

METHODS

We did a multicentre, randomised, open-label, non-inferiority trial in ten stroke centres across Switzerland, Germany, and Denmark. We randomly assigned (1:1) patients aged older than 18 years who had symptomatic, MRI-verified, cervical artery dissection within 2 weeks before enrolment, to receive either aspirin 300 mg once daily or a vitamin K antagonist (phenprocoumon, acenocoumarol, or warfarin; target international normalised ratio [INR] 2·0-3·0) for 90 days. Randomisation was computer-generated using an interactive web response system, with stratification according to participating site. Independent imaging core laboratory adjudicators were masked to treatment allocation, but investigators, patients, and clinical event adjudicators were aware of treatment allocation. The primary endpoint was a composite of clinical outcomes (stroke, major haemorrhage, or death) and MRI outcomes (new ischaemic or haemorrhagic brain lesions) in the per-protocol population, assessed at 14 days (clinical and MRI outcomes) and 90 days (clinical outcomes only) after commencing treatment. Non-inferiority of aspirin would be shown if the upper limit of the two-sided 95% CI of the absolute risk difference between groups was less than 12% (non-inferiority margin). This trial is registered with ClinicalTrials.gov, NCT02046460.

FINDINGS

Between Sept 11, 2013, and Dec 21, 2018, we enrolled 194 patients; 100 (52%) were assigned to the aspirin group and 94 (48%) were assigned to the vitamin K antagonist group. The per-protocol population included 173 patients; 91 (53%) in the aspirin group and 82 (47%) in the vitamin K antagonist group. The primary endpoint occurred in 21 (23%) of 91 patients in the aspirin group and in 12 (15%) of 82 patients in the vitamin K antagonist group (absolute difference 8% [95% CI -4 to 21], non-inferiority p=0·55). Thus, non-inferiority of aspirin was not shown. Seven patients (8%) in the aspirin group and none in the vitamin K antagonist group had ischaemic strokes. One patient (1%) in the vitamin K antagonist group and none in the aspirin group had major extracranial haemorrhage. There were no deaths. Subclinical MRI outcomes were recorded in 14 patients (15%) in the aspirin group and in 11 patients (13%) in the vitamin K antagonist group. There were 19 adverse events in the aspirin group, and 26 in the vitamin K antagonist group.

INTERPRETATION

Our findings did not show that aspirin was non-inferior to vitamin K antagonists in the treatment of cervical artery dissection.

FUNDING

Swiss National Science Foundation, Swiss Heart Foundation, Stroke Funds Basel, University Hospital Basel, University of Basel, Academic Society Basel.

Cerebral microbleeds: from depiction to interpretation

Cerebral microbleeds (CMBs) are defined as hypointense foci visible on T2*-weighted and susceptible-weighted MRI sequences. CMBs are increasingly recognised with the widespread use of MRI in healthy individuals as well as in the context of cerebrovascular disease or dementia. They can also be encountered in major critical medical conditions such as in patients requiring extracorporeal mechanical oxygenation. The advent of MRI-guided postmortem neuropathological examinations confirmed that, in the context of cerebrovascular disease, the vast majority of CMBs correspond to recent or old microhaemorrhages. Detection of CMBs is highly influenced by MRI parameters, in particular field strength, postprocessing methods used to enhance T2* contrast and three dimensional sequences. Despite recent progress, harmonising imaging parameters across research studies remains necessary to improve cross-study comparisons. CMBs are helpful markers to identify the nature and the severity of the underlying chronic small vessel disease. In daily clinical practice, presence and numbers of CMBs often trigger uncertainty for clinicians especially when antithrombotic treatments and acute reperfusion therapies are discussed. In the present review, we discuss those clinical dilemmas and address the value of CMBs as diagnostic and prognostic markers for future vascular events.