Left Ventricular Dysfunction Among Patients With Embolic Stroke of Undetermined Source and the Effect of Rivaroxaban vs Aspirin: A Subgroup Analysis of the NAVIGATE ESUS Randomized Clinical Trial

Andexanet alfa therapy showed No increased rate of thromboembolic events in spontaneous intracranial hemorrhage patients: A multicenter electronic health record study

•Intracranial hemorrhage accounts for two out of every three major intracranial hemorrhages.•Systemic anticoagulation is routinely prescribed for prevention of cerebrovascular accidents.•The FDA approved Andexanet alfa to treat life-threatening bleeding.•Andexanet alfa relationship to outcomes requires further investigation.

Ischemic Stroke and Reduced Left Ventricular Ejection Fraction: A Multidisciplinary Approach to Optimize Brain and Cardiac Health

Reduced left ventricular ejection fraction ≤40%, a known risk factor for adverse cardiac outcomes and recurrent acute ischemic stroke, may be detected during an acute ischemic stroke hospitalization. A multidisciplinary care paradigm informed by neurology and cardiology expertise may facilitate the timely implementation of an array of proven heart failure-specific therapies and procedures in a nuanced manner to optimize brain and cardiac health.

Enhanced diagnostic workup increases pathological findings in patients with acute ischaemic stroke: results of the prospective HEBRAS study

BACKGROUND

Stroke aetiology remains cryptogenic in a relevant proportion of patients with acute ischaemic stroke (AIS). We assessed whether enhanced diagnostic workup after AIS yields a higher rate of prespecified pathological findings compared with routine diagnostic care in-hospital.

METHODS

Hospitalised patients with AIS were prospectively enrolled in the investigator-initiated observational HEart and BRain Interfaces in Acute Ischaemic Stroke (HEBRAS) study at the Charité, Berlin, Germany. Patients with AIS without known atrial fibrillation (AF) underwent cardiovascular MR imaging (CMR), MR-angiography of the aortic arch and prolonged Holter-ECG monitoring on top of routine diagnostic care.

RESULTS

Among 356 patients with AIS (mean age 66 years, 37.6% female), enhanced workup yielded a higher rate of prespecified pathological findings compared with routine care (17.7% vs 5.3%; p<0.001). Consequently, fewer patients were classified as cryptogenic after enhanced diagnostic workup (38.5% vs 45.5%, p<0.001). Routine care included echocardiography in 228 (64.0%) patients. CMR was successfully performed in 292 (82.0%) patients and revealed more often a prespecified pathological finding compared with routine echocardiography (16.1% vs 5.3%). Furthermore, study-related ECG monitoring (median duration 162 hours (IQR 98-210)) detected AF in 16 (4.5%) patients, while routine monitoring (median duration 51 hours (IQR 34-74)) detected AF in seven (2.0%) patients.

CONCLUSIONS

Enhanced diagnostic workup revealed a higher rate of prespecified pathological findings in patients with AIS compared with routine diagnostic care and significantly reduced the proportion of patients with cryptogenic stroke.

TRIAL REGISTRATION NUMBER

NCT02142413.

Left atrial strain, embolic stroke of undetermined source, and atrial fibrillation detection

BACKGROUND

Atrial cardiopathy is a proposed mechanism of embolic stroke of undetermined source (ESUS). Left atrial (LA) strain may identify early atrial cardiopathy prior to structural changes. We aim to study the associations between LA strain, ESUS, and atrial fibrillation (AF) detection in ESUS.

METHODS

The study population included patients with ESUS and noncardioembolic (NCE) stroke presenting to the Rhode Island Hospital Stroke Center between January 2016 and June 2017 who underwent transthoracic echocardiography. Speckle tracking echocardiography (STE) was used to measure the three phases of LA strain (reservoir, conduit, and contractile). Binary logistic regression analysis was performed to determine the associations between LA strain and stroke subtype (ESUS vs. NCE) as well as follow-up detection of AF in ESUS patients.

RESULTS

We identified 656 patients, 307 with ESUS and 349 with NCE. In binary logistic regression, the lowest tertiles of LA reservoir (adjusted OR 1.944, 95% CI 1.266-2.986, p = .002), contractile (aOR 1.568, 95% CI 1.035-2.374, p = .034), and conduit strain (aOR 2.288, 95% CI 1.448-3.613, p = .001) were more likely to be significantly associated with ESUS compared to NCE stroke. Among all ESUS patients, the lowest tertiles of LA reservoir strain (OR 2.534, 95% CI 1.029-6.236, p = .043), contractile strain (OR 2.828, 95% CI 1.158-6.903, p = .022), and conduit strain (OR 2.614, 95% CI 1.003-6.815, p = .049) were significantly associated with subsequent detection of AF.

CONCLUSION

Reduced LA strain is associated with ESUS occurrence and AF detection in ESUS patients. Therefore, quantification of LA strain in ESUS patients may improve risk stratification and guide secondary prevention strategies.

Independent external validation of a stroke recurrence score in patients with embolic stroke of undetermined source

BACKGROUND

Embolic stroke of undetermined source (ESUS) accounts for a substantial proportion of ischaemic strokes. A stroke recurrence score has been shown to predict the risk of recurrent stroke in patients with ESUS based on a combination of clinical and imaging features. This study aimed to externally validate the performance of the ESUS recurrence score using data from a randomized controlled trial.

METHODS

The validation dataset consisted of eligible stroke patients with available magnetic resonance imaging (MRI) data enrolled in the PreDAFIS sub-study of the MonDAFIS study. The score was calculated using three variables: age (1 point per decade after 35 years), presence of white matter hyperintensities (2 points), and multiterritorial ischaemic stroke (3 points). Patients were assigned to risk groups as described in the original publication. The model was evaluated using standard discrimination and calibration methods.

RESULTS

Of the 1054 patients, 241 (22.9%) were classified as ESUS. Owing to insufficient MRI quality, three patients were excluded, leaving 238 patients (median age 65.5 years [IQR 20.75], 39% female) for analysis. Of these, 30 (13%) patients experienced recurrent ischaemic stroke or transient ischemic attack (TIA) during a follow-up period of 383 patient-years, corresponding to an incidence rate of 7.8 per 100 patient-years (95% CI 5.3-11.2). Patients with an ESUS recurrence score value of ≥ 7 had a 2.46 (hazard ratio (HR), 95% CI 1.02-5.93) times higher risk of stroke recurrence than patients with a score of 0-4. The cumulative probability of stroke recurrence in the low-(0-4), intermediate-(5-6), and high-risk group (≥ 7) was 9%, 13%, and 23%, respectively (log-rank test, χ2 = 4.2, p = 0.1).

CONCLUSIONS

This external validation of a published scoring system supports a threshold of ≥ 7 for identifying ESUS patients at high-risk of stroke recurrence. However, further adjustments may be required to improve the model's performance in independent cohorts. The use of risk scores may be helpful in guiding extended diagnostics and further trials on secondary prevention in patients with ESUS.

TRIAL REGISTRATION

Clinical Trials, NCT02204267. Registered 30 July 2014, https://clinicaltrials.gov/ct2/show/NCT02204267 .

Predicting risk of AF in ischaemic stroke using sinus rhythm ECG abnormalities: A meta-analysis

OBJECTIVE

To identify ECG changes in sinus rhythm that may be used to predict subsequent development of new AF.

METHOD

We identified prospective and retrospective cohort or case control studies evaluating ECG patterns from a 12-lead ECG in sinus rhythm taken in hospital or community predicting subsequent development of new AF. For each identified ECG predictor, we then identify absolute event rates and pooled risk ratios (RR) using an aggregate level random effects meta-analysis.

RESULTS

We identified 609,496 patients from 22 studies. ECG patterns included P wave terminal force V1 (PTFV1), interatrial block (IAB) and advanced interatrial block (aIAB), abnormal P wave axis (aPWA), PR prolongation and atrial premature complexes (APCs). Pooled risk ratios reached significance for each of these; PTFV1 RR 1.48 (95% CI 1.04-2.10), IAB 2.54 (95% CI 1.64-3.93), aIAB 4.05 (95% CI 2.64-6.22), aPWA 1.89 (95% CI 1.25-2.85), PR prolongation 2.22 (95% CI 1.27-3.87) and APCs 3.71 (95% CI 2.23-6.16). Diabetes reduced the predictive value of PR prolongation.

CONCLUSION

APC and aIAB were most predictive of AF, while IAB, PR prolongation, PTFV1 and aPWA were also significantly associated with development of AF. These support their use in a screening tool to identify at risk cohorts who may benefit from further investigation, or following stroke, with empirical anticoagulation.

Stroke in patients with heart failure and reduced or preserved ejection fraction

AIMS

Stroke is an important problem in patients with heart failure (HF), but the intersection between the two conditions is poorly studied across the range of ejection fraction. The prevalence of history of stroke and related outcomes were investigated in patients with HF.

METHODS AND RESULTS

Individual patient meta-analysis of seven clinical trials enrolling patients with HF with reduced (HFrEF) and preserved ejection fraction (HFpEF). Of the 20 159 patients with HFrEF, 1683 (8.3%) had a history of stroke, and of the 13 252 patients with HFpEF, 1287 (9.7%) had a history of stroke. Regardless of ejection fraction, patients with a history of stroke had more vascular comorbidity and worse HF. Among those with HFrEF, the incidence of the composite of cardiovascular death, HF hospitalization, stroke, or myocardial infarction was 18.23 (16.81-19.77) per 100 person-years in those with prior stroke vs. 13.12 (12.77-13.48) in those without [hazard ratio 1.37 (1.26-1.49), P < 0.001]. The corresponding rates in patients with HFpEF were 14.16 (12.96-15.48) and 9.37 (9.06-9.70) [hazard ratio 1.49 (1.36-1.64), P < 0.001]. Each component of the composite was more frequent in patients with stroke history, and the risk of future stroke was doubled in patients with prior stroke. Among patients with prior stroke, 30% with concomitant atrial fibrillation were not anticoagulated, and 29% with arterial disease were not taking statins; 17% with HFrEF and 38% with HFpEF had uncontrolled systolic blood pressure (≥140 mmHg).

CONCLUSION

Heart failure patients with a history of stroke are at high risk of subsequent cardiovascular events, and targeting underutilization of guideline-recommended treatments might be a way to improve outcomes in this high-risk population.

Diagnosis and Management of Cardioembolic Stroke

OBJECTIVE

Cardioembolic stroke accounts for nearly 30% of ischemic strokes. Prompt diagnosis of the underlying mechanism may improve secondary prevention strategies. This article reviews recent randomized trials, observational studies, case reports, and guidelines on the diagnosis and treatment of cardioembolic stroke.

LATEST DEVELOPMENTS

Several pathologies can lead to cardioembolic stroke, including atrial fibrillation, aortic arch atheroma, patent foramen ovale, left ventricular dysfunction, and many others. Secondary stroke prevention strategies differ across these heterogeneous mechanisms. In addition to medical treatment advances such as the use of direct oral anticoagulants in patients with atrial fibrillation, surgical treatments such as closure of patent foramen ovale have been shown to reduce the risk of recurrent stroke in select patients. Furthermore, left atrial appendage occlusion is a promising strategy for patients with atrial fibrillation who are candidates for short-term oral anticoagulation therapy but not long-term oral anticoagulation therapy.

ESSENTIAL POINTS

A thorough diagnostic evaluation is essential to determine cardioembolic causes of stroke. In addition to risk factor management and lifestyle modifications, identification and targeting of the underlying cardioembolic stroke mechanisms will lead to improved stroke prevention strategies in patients with cardioembolic stroke.

Efficacy and safety of vitamin-K antagonists and direct oral anticoagulants for stroke prevention in patients with heart failure and sinus rhythm: An updated systematic review and meta-analysis of randomized clinical trials

INTRODUCTION

Heart failure (HF) is a major public health issue associated with significantly increased risk of stroke. It remains uncertain whether oral anticoagulation (OAC) in patients with heart failure and sinus rhythm (HF-SR) could improve prognosis.

METHODS

We performed a systematic search of PubMed and Embase databases for randomized controlled clinical trials assessing oral anticoagulants versus antiplatelets or placebo in patients with HF or ventricular dysfunction/cardiomyopathy without clinical HF and SR. The outcomes assessed were stroke/systemic embolism, major bleeding, myocardial infarction, all-cause mortality, and HF hospitalization.

RESULTS

Seven trials of 15,794 patients were eligible for our analyses. The overall follow-up duration was 32,367 patient-years corresponding to a mean follow-up of 2.05 years per patient. Four trials included patients treated with warfarin and three included patients treated with rivaroxaban. OAC was associated with reduced rate of stroke or systemic embolism compared to control (odds ratio (OR): 0.57, 95% confidence interval (CI): 0.44, 0.73, number needed to treat (NNT): 71.9) but higher rate of major bleeding (OR: 1.92, 95% CI: 1.47, 2.50, number needed to harm (NNH): 57.1). In the subgroup analysis according to the type of OAC, rivaroxaban was associated with significantly reduced rate of stroke or systemic embolism (1.24 vs 1.97 events per 100 patient-years, respectively, OR: 0.63, 95% CI: 0.45, 0.88, NNT: 82) and higher risk of major bleeding (OR: 1.66, 95% CI: 1.26, 2.20) compared to antiplatelets or placebo. There was no significant differences between groups for the outcomes of myocardial infarction, all-cause mortality, and HF hospitalization.

CONCLUSION

This analysis shows that any benefit of OAC for stroke prevention may be offset by an increased risk of major bleeding in HF-SR patients. A well-designed randomized controlled trial of newer safer OACs is needed in this population.

Atrial Fibrillation Risk Assessment after Embolic Stroke of Undetermined Source

OBJECTIVE

Approximately 20% of strokes are embolic strokes of undetermined source (ESUS). Undetected atrial fibrillation (AF) remains an important cause. Yet, oral anticoagulation in unselected ESUS patients failed in secondary stroke prevention. Guidance on effective AF detection is lacking. Here, we introduce a novel, non-invasive AF risk assessment after ESUS.

METHODS

Catch-Up ESUS is an investigator-initiated, observational cohort study conducted between 2018 and 2019 at the Munich University Hospital. Besides clinical characteristics, patients received ≥72 h digital electrocardiogram recordings to generate the rhythm irregularity burden. Uni- and multivariable regression models predicted the primary endpoint of incident AF, ascertained by standardized follow-up including implantable cardiac monitors. Predictors included the novel rhythm irregularity burden constructed from digital electrocardiogram recordings. We independently validated our model in ESUS patients from the University Hospital Tübingen, Germany.

RESULTS

A total of 297 ESUS patients were followed for 15.6 ± 7.6 months. Incident AF (46 patients, 15.4%) occurred after a median of 105 days (25th to 75th percentile 31-33 days). Secondary outcomes were recurrent stroke in 7.7% and death in 6.1%. Multivariable-adjusted analyses identified the rhythm irregularity burden as the strongest AF-predictor (hazard ratio 3.12, 95% confidence interval 1.62-5.80, p < 0001) while accounting for the known risk factors age, CHA₂ DS₂ -VASc-Score, and NT-proBNP. Independent validation confirmed the rhythm irregularity burden as the most significant AF-predictor (hazard ratio 2.20, 95% confidence interval 1.45-3.33, p < 0001).

INTERPRETATION

The novel, non-invasive, electrocardiogram-based rhythm irregularity burden may help adjudicating AF risk after ESUS, and subsequently guide AF-detection after ESUS. Clinical trials need to clarify if high-AF risk patients benefit from tailored secondary stroke prevention. ANN NEUROL 2023;93:479-488.

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.

Outcomes associated with antithrombotic strategies in heart failure with reduced ejection fraction and sinus rhythm following acute ischemic stroke

Purpose

Insufficient data exist regarding the benefit of long-term antiplatelet vs. anticoagulant therapy in the prevention of recurrent ischemic stroke in patients with ischemic stroke and heart failure with reduced ejection fraction (HFrEF). Therefore, this study aimed to compare longitudinal outcomes associated with antiplatelet vs. anticoagulant use in a cohort of patients with stroke and with an ejection fraction of ≤40%.

Methods

We retrospectively analyzed single-center registry data (2015-2021) of patients with ischemic stroke, HFrEF, and sinus rhythm. Time to the primary outcome of recurrent ischemic stroke, major bleeding, or death was assessed using the adjusted Cox proportional hazards model and was compared between patients treated using anticoagulation (±antiplatelet) vs. antiplatelet therapy alone after propensity score matching using an intention-to-treat (ITT) approach, with adjustment for residual measurable confounders. Sensitivity analyses included the multivariable Cox proportional hazards model using ITT and as-treated approaches without propensity score matching.

Results

Of 2,974 screened patients, 217 were included in the secondary analyses, with 130 patients matched according to the propensity score for receiving anticoagulation treatment for the primary analysis, spanning 143 patient-years of follow-up. After propensity score matching, there was no significant association between anticoagulation and the primary outcome [hazard ratio (HR) 1.10, 95% confidence interval (CI): 0.56-2.17]. Non-White race (HR 2.26, 95% CI: 1.16-4.41) and the presence of intracranial occlusion (HR 2.86, 95% CI: 1.40-5.83) were independently associated with the primary outcome, while hypertension was inversely associated (HR 0.42, 95% CI: 0.21-0.84). There remained no significant association between anticoagulation and the primary outcome in sensitivity analyses.

Conclusion

In HFrEF patients with an acute stroke, there was no difference in outcomes of antithrombotic strategies. While this study was limited by non-randomized treatment allocation, the results support future trials of stroke patients with HFrEF which may randomize patients to anticoagulation or antiplatelet.

Clinical and radiographic phenotypes of patients with multifocal subcortical versus cortical cerebral infarcts

BACKGROUND AND PURPOSE

Infarct topology is a key determinant in classification of a stroke as potentially embolic, with cortical and multifocal lesions being presumed embolic. Whether isolated subcortical multifocal infarcts are likely embolic has not been well studied.

METHODS

A prospective, single-center cohort study of consecutive patients with acute multifocal strokes confirmed on diffusion-weighting imaging (DWI) was queried, and patients compared according to the presence of isolated subcortical infarct topology versus cortical ± subcortical topology. Descriptive statistics and multivariable logistic regression were used to determine independent predictors of cryptogenic, subcortical infarcts.

RESULTS

Of 1739 patients screened, 743 had complete diagnostic testing with DWI evidence of acute infarction, 183 (24.6%) of whom had a multifocal stroke pattern. Isolated subcortical involvement was disproportionate among patients with ESUS (64.9%) when compared to patients with cardioembolic (24.3%) or large vessel disease (10.8%, p<0.01). Following multivariable adjustment, independent predictors of isolated subcortical multifocal infarction were milder strokes (OR 0.94, 95%CI 0.89-0.98) and higher grade Fazekas score (OR 2.32, 95%CI 1.02-5.29), while cardioembolism (OR 0.30, 95%CI 0.08-1.13) and large vessel disease (OR 0.27, 95%CI 0.08-0.91) remained inversely associated (as compared to ESUS).

CONCLUSIONS

These data suggest that multifocal subcortical infarctions are less likely to have an associated proximal embolic source than multifocal infarctions with cortical involvement. The strong association with chronic microvascular disease suggests this topology is more consistent with acute-on-chronic microvascular injury rather than an occult embolic source.

Cardiac CT for intra-cardiac thrombus detection in embolic stroke of undetermined source (ESUS)

INTRODUCTION

Embolic stroke of undetermined source (ESUS) is a common medical challenge regarding secondary prevention strategy. Cardiac imaging is the cornerstone of embolic stroke workup, in an effort to diagnose high risk cardio-embolic sources. Cardiac computed tomography angiography (CCTA) is an emerging imaging modality with high diagnostic performance for intra-cardiac thrombus detection. The yield of CCTA implementation in addition to standard care in ESUS workup is unknown. Thus, the aim of this study was to assess the utility of CCTA in detecting intra-cardiac thrombi in the routine ESUS workup.

PATIENTS AND METHODS

This is a retrospective observational analysis of ESUS cases managed in vascular neurology unit between 2019 and 2021. Within this ESUS registry, consecutive patients undergoing CCTA were included and carefully analyzed.

RESULTS

During the study period 1066 Ischemic stroke (IS) cases were treated and evaluated. 266/1066 (25%) met ESUS criteria and 129/266 (48%) underwent CCTA. Intra-cardiac thrombus was detected by CCTA in 22/129 (17%; 95% CI, 11.5%-23.5%) patients: left ventricular thrombus (LVT) in 13 (10.1%) patients, left atrial appendage (LAA) thrombus in 8 (6.2%) patients, and left atrial (LA) thrombus in 1 (0.8%) patient. Only 5/22 (23%) of these thrombi were suspected, but could not be confirmed, in trans-thoracic echocardiogram (TTE). Among CCTA-undergoing patients, 27/129 (21%; 95% CI, 14%-28%) were found to have an indication (including pulmonary embolism) for commencing anticoagulation (AC) treatment, rather than anti-platelets. In favor of CCTA implementation, 22/266 (8.2%; 95% CI, 4.9%-11.5%) patients within the entire ESUS cohort were diagnosed with intra-cardiac thrombus, otherwise missed.

CONCLUSION

CCTA improves the detection of intra-cardiac thrombi in addition to standard care in ESUS patients. The implementation of CCTA in routine ESUS workup can change secondary prevention strategy in a considerable proportion of patients.

A score to predict the stroke recurrence of patients with embolic stroke of undetermined source

AIM

We aimed to develop a score and validate it in a prospective cohort to identify the patients with ESUS at high risk for stroke recurrence.

METHODS

We assessed the stroke recurrence in ESUS patients of the Third China National Stroke Registry. We performed multivariable logistic regression analysis to identify predictors of stroke recurrence in the derivation cohort. Based on the coefficient of each covariate of the fitted multivariable model, we generated an integer-based point scoring system. We validated the score in the validation cohort assessing its discrimination and calibration.

RESULTS

2415 patients were included: 1611 in the derivation and 804 in the validation sample. We developed a scoring system (0-15 points) by assigning 2 points for hypertension, 3 points for diabetes mellitus, 4 points for multiple stage infarction, 2 points for watershed involved infarction, 1 points for left atrial diameter index (per increasing 2.5 mm/m2) and 3 points for without statin at discharge. The rate of stroke recurrence was 5.9% per year (95% CI 4.2-7.6%) in patients with low risk(a score of 0-5), 9.4% (7.3-11.5%) in patients with intermediate risk (6-10), and 26.8% (16.5-37.1%) in patients with high risk (11-15). The AUC (area under curve of receiver operator characteristic curve) of the score in the derivation cohort and validation cohort was, respectively, 0.60 (0.55-0.65) and 0.63 (0.56-0.70). The score was well calibrated both in the derivation cohort (p = 0.36) and validation cohort (p = 0.26) with the Hosmer-Lemeshow test.

CONCLUSION

The developed score can improve risk stratification after ESUS in secondary care settings.

Association between implantable loop recorder use and secondary stroke prevention: a meta-analysis

OBJECTIVE

To conduct a meta-analysis of randomised controlled trials (RCTs) to evaluate the impact of ILR use on occurrence of recurrent stroke.

METHODS

PubMed, EMBASE, CENTRAL and ClinicalTrials.gov were searched from 1966 to November 2021 to identify RCTs comparing ILR versus non-ILR in patients with ischaemic stroke. Relative risk (RR) with 95% CI was used as a measure of the effect of ILR versus non-ILR on recurrent stroke, recurrent ischaemic stroke, AF detection and oral anticoagulant (OAC) initiation. A fixed-effect estimate based on the Mantel-Haenszel method was computed.

RESULTS

We identified three RCTs with 1233 patients with ischaemic stroke. Among three included RCTs, 54 recurrent stroke events were reported in two RCTs and 84 recurrent ischaemic stroke events were reported in three RCTs. Pooled results showed that patients who received ILR versus no ILR was not associated with a significantly reduced risk of recurrent stroke (5.6% vs 8.0%; RR 0.70; 95% CI 0.42 to 1.19) or recurrent ischaemic stroke (5.7% vs 7.9%; RR 0.72; 95% CI 0.48 to 1.10). Compared to non-ILR patients, ILR patients had higher rates of AF detection (12.9% vs 2.4%; RR 5.31; 95% CI, 3.10 to 9.11) and OAC initiation (15.2% vs 5.5%; RR 2.77; 95% CI 1.90 to 4.03).

CONCLUSIONS

Patients assigned to ILR vs non-ILR did not have a significantly reduced risk of recurrent stroke or recurrent ischaemic stroke despite higher rates of AF detection and OAC initiation. Sufficiently powered RCTs of ILR to assess the risk of recurrent stroke are warranted.

Review and update of the concept of embolic stroke of undetermined source

Ischaemic strokes have traditionally been classified according to the TOAST criteria, in which strokes with unclear aetiology are classified as cryptogenic strokes. However, the definition of cryptogenic stroke did not meet the operational criteria necessary to define patient populations for randomized treatment trials. To address this problem, the concept of embolic stroke of undetermined source (ESUS) was developed and published in 2014. A hypothesis that underpinned this concept was that most strokes in patients with ESUS are caused by embolic events, perhaps many cardioembolic, and that anticoagulation would prevent secondary ischaemic events. On this basis, two large randomized trials were conducted to compare the non-vitamin K antagonist oral anticoagulants (NOACs) dabigatran and rivaroxaban with aspirin. Neither NOAC was superior to aspirin in these trials, although subgroups of patients with ESUS seemed to benefit specifically from anticoagulation or antiplatelet therapy. The neutral results of the trials of anticoagulation and insights into ESUS from research conducted since the concept was introduced warrant reassessment of the ESUS construct as a research concept and a treatment target. In this Review, we discuss the evidence produced since the concept of ESUS was introduced, and propose updates to the criteria and diagnostic algorithm in light of the latest knowledge.

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.

Age Alters Prevalence of Left Atrial Enlargement and Nonstenotic Carotid Plaque in Embolic Stroke of Undetermined Source

BACKGROUND

Nonstenotic carotid plaque and undetected atrial fibrillation are potential mechanisms of embolic stroke of undetermined source (ESUS), but it is unclear which is more likely to be the contributing stroke mechanism. We explored the relationship between left atrial enlargement (LAE) and nonstenotic carotid plaque across age ranges in an ESUS population.

METHODS

A retrospective multicenter cohort of consecutive patients with unilateral, anterior circulation ESUS was queried (2015 to 2021). LAE and plaque thickness were determined by transthoracic echocardiography and computed tomography angiography, respectively. Descriptive statistics were used to compare plaque features in relation to age and left atrial dimensions.

RESULTS

Among the 4155 patients screened, 273 (7%) met the inclusion criteria. The median age was 65 years (interquartile range [IQR] 54-74), 133 (48.7%) were female, and the median left atrial diameter was 3.5 cm (IQR 3.1-4.1). Patients with any LAE more frequently had hypertension (85.9% versus 67.2%, P<0.01), diabetes (41.0% versus 25.6%, P=0.01), dyslipidemia (56.4% versus 40.0%, P=0.01), and coronary artery disease (22.8% versus 11.3%, P=0.02). Carotid plaque thickness was greater ipsilateral versus contralateral to the stroke hemisphere in the overall cohort (median 1.9 mm [IQR 0-3] versus 1.5 mm [IQR 0-2.6], P<0.01); however, this was largely driven by the subgroup of patients without any LAE (median 1.8 mm [IQR 0-2.9] versus 1.5 mm [IQR 0-2.5], P<0.01). Compared with patients ≥70 years, younger patients had more carotid plaque ipsilateral versus contralateral (mean difference 0.42 mm±1.24 versus 0.08 mm±1.54, P=0.047) and less moderate-to-severe LAE (6.3% versus 15.3%, P=0.02).

CONCLUSIONS

Younger patients with ESUS had greater prevalence of ipsilateral nonstenotic plaque, while the elderly had more LAE. The differential effect of age on the probability of specific mechanisms underlying ESUS should be considered in future studies.